Research released today in New England Journal of Medicine (link below) stated that milk, if not pasteurized, can be potentially infectious. The study also looked at reduction of virus at pasteurization temperatures ( 181 degrees Fahrenheit, for 15 or 20 seconds) and determined that there was log reduction, but not complete elimination.
New tests confirm milk from flu-infected cows can make other animals sick — and raise questions about flash pasteurization
By Brenda Goodman, CNN
5 minute read
Published 10:02 AM EDT, Fri May 24, 2024
New lab experiments with milk from cows infected by H5N1 influenza, known as bird flu, confirm that it is infectious, especially when left raw, or untreated, and potentially even when flash pasteurized.
Because H5N1 virus is considered a select agent, it was handled in a high-security Biosafety Level 3 lab at the University of Wisconsin, using strict safety protocols.
First, they confirmed the raw milk was chock-full of H5N1 virus. Then, they stored some of the raw milk at refrigerator temperature to see if levels of the virus in milk would drop off over time. Over 5 weeks, viral levels in raw milk dropped a bit, but not much.
“That it wasn’t decaying over time is concerning,” said Dr. Seema Lakdawala, an associate professor of immunology and microbiology at Emory University who is also part of the CEIRR network but was not involved in the study.
Early test results show pasteurized milk with traces of H5N1 virus isn’t infectious, FDA says
In another series of tests, the researchers checked to see what types of pasteurization might work best for inactivating the virus.
They heated small samples of the milk at times and temperatures used in two types of pasteurization: low-temperature, long-time, or vat pasteurization; and high-temperature short-time, or flash pasteurization, which is the most common method used in the US today, according to the International Dairy Foods Association.
Heating the milk to 63 degrees Celsius, or 145 degrees Fahrenheit, for intervals between 5 and 30 minutes — the vat pasteurization method — reduced the virus to undetectable levels.
Heating the milk to 72 degrees Celsius, or 181 degrees Fahrenheit, for 15 or 20 seconds — conditions that approximated flash pasteurization — greatly reduced levels of the virus in the milk, but it didn’t inactivate it completely.
Milk samples heated for 15 or 20 seconds were still able to infect incubated chicken eggs, a test the US Food and Drug Administration has called the gold-standard for determining whether viruses remain infectious in milk.
The researchers, from the University of Wisconsin School of Veterinary Medicine, are part of a federally funded program called the Centers of Excellence for Influenza Research and Response, or CEIRR. This network has been conducting rapid research to answer pressing questions in the H5N1 outbreak in dairy cattle.
In a research letter posted online on Friday in the New England Journal of Medicine, the researchers describe the results of experiments using milk from four infected cows — two from New Mexico and two from Kansas.
Because H5N1 virus is considered a select agent, it was handled in a high-security Biosafety Level 3 lab at the University of Wisconsin, using strict safety protocols.
First, they confirmed the raw milk was chock-full of H5N1 virus. Then, they stored some of the raw milk at refrigerator temperature to see if levels of the virus in milk would drop off over time. Over 5 weeks, viral levels in raw milk dropped a bit, but not much.
“That it wasn’t decaying over time is concerning,” said Dr. Seema Lakdawala, an associate professor of immunology and microbiology at Emory University who is also part of the CEIRR network but was not involved in the study.
Studies involving foot-and-mouth disease virus revealed that heat inactivation of virus-positive milk samples required higher temperature or longer incubation times (or both) than heat inactivation of virus spiked into milk,2,3 presumably because fat globules and casein micelles may partly protect viruses in virus-positive milk samples. Accordingly, we tested heat inactivation of four HPAI A(H5N1) virus–positive milk samples (NM#93, NM#115, KS#3, and KS#6). Undiluted milk samples were incubated in a polymerase-chain-reaction (PCR) thermocycler at 63°C for 5, 10, 20, or 30 minutes or at 72°C for 5, 10, 15, 20, or 30 seconds (Table 1; see also the Supplementary Appendix). Control samples were left untreated. Heat treatment at 63°C reduced the virus titers below the detection limit of the TCID50 (50% tissue-culture infectious dose) assay (1.5 log10/ml). Heat treatment at 72°C was performed, with the default settings of the PCR thermocycler (i.e., preheated lid at 105°C) or with a metal lid (heated to 72°C) covering the PCR block (see the Supplementary Appendix for details). After heat treatment, samples were inoculated into embryonated chicken eggs or Madin–Darby canine kidney (MDCK) cells for virus detection. Under these conditions, heat treatment for 15 or 20 seconds reduced virus titers by more than 4.5 log units but did not completely inactivate the virus (Table 1). We emphasize that the conditions used in our laboratory study are not identical to the large-scale industrial treatment of raw milk.
Virus Positivity of Heat-Treated Milk Samples.
The stability of HPAI A(H5N1) virus in cow’s milk stored at 4°C is another important question. For milk sample NM#93, we detected a decline of only two log units over 5 weeks. HPAI A(H5N1) virus may therefore remain infectious for several weeks in raw milk kept at 4°C.
To further assess the risk that HPAI A(H5N1)–positive milk poses to animals and humans, we orally inoculated BALB/cJ mice with 50 μl (3×106 pfu) of sample NM#93. The animals showed signs of illness starting on day 1, including ruffled fur and lethargy. All the animals survived until day 4, when they were euthanized to determine virus titers in multiple organs (Figure S3 in the Supplementary Appendix). We detected high virus titers in the respiratory organs (which suggests that infection may have occurred through the pharynx) and moderate virus titers in several other organs, findings consistent with the systemic infections typically caused by HPAI H5 viruses in mammals. Detection of virus in the mammary glands of two mice was consistent with the high virus load in the milk of lactating cows, even though these mice were not lactating. Collectively, our data indicate that HPAI A(H5N1) virus in untreated milk can infect susceptible animals that consume it. In summary, HPAI H5–positive milk poses a risk when consumed untreated, but heat inactivation under the laboratory conditions used here reduces HPAI H5 virus titers by more than 4.5 log units. However, bench-top experiments do not recapitulate commercial pasteurization processes.
Reuters
https://www.reuters.com/world/us/us-fda-tested-retail-milk-samples-bird-flu-17-states-2024-05-20/
US FDA tested retail milk samples for bird flu in 17 states
By Reuters
May 20, 20242:22 PM EDTUpdated 4 days ago
May 20 (Reuters) - The U.S. Food and Drug Administration said on Monday that it tested retail samples of milk and other dairy products in 17 states for viable bird flu virus, providing further details about the locations of the previously disclosed tests.
The regulator said it collected 297 samples at retail locations in 17 states between April 18-22, but the retail samples represented products made at 132 processing locations in 38 states.
"Even if a sample was collected in one particular state, the milk in a consumer package could have come from cows on several farms located in several states, pasteurized in a different state from where the milk was produced, and available for purchase in yet another state," the agency said in its statement.
The U.S. has confirmed bird flu in dairy cattle in nine states since late March.
The FDA had said on May 10 that no live virus was found in retail milk samples. It has also said that pasteurized milk is safe to drink but has cautioned against consuming raw milk.
Scientists, however, have said they believe the outbreak is more widespread based on the FDA's findings that showed about 20% of retail milk samples contained remnants of the H5N1 virus.
The samples included cottage cheese, cream, and half and half, which is equal parts milk and cream, sour cream and yoghurt, in addition to milk.
FDA
Researchers summarized, "HPAI H5–positive milk poses a risk when consumed untreated, but heat inactivation under the laboratory conditions used here reduces HPAI H5 virus titers by more than 4.5 log units. However, bench-top experiments do not recapitulate commercial pasteurization processes."
“But, we emphasize that the conditions used in our laboratory study are not identical to the large-scale industrial treatment of raw milk,” senior study author Dr. Yoshihiro Kawaoka, a virologist who specializes in the study of flu and Ebola, said in an email."
Added to this is that milk from cows found to be infected is diverted. The question is whether all infected cows are detected.
FDA released results of their market survey of milk samples tested for the virus. FDA "collected 297 samples at retail locations in 17 states between April 18-22, but the retail samples represented products made at 132 processing locations in 38 states." "The FDA had said on May 10 that no live virus was found in retail milk samples. It has also said that pasteurized milk is safe to drink but has cautioned against consuming raw milk."
What about eggs? Are eggs in the retail market safe to eat?From the FDA
Yes. The likelihood that eggs from infected poultry are found in the retail market is low and proper storage and preparation further reduce the risk. In 2010, the U.S. Food and Drug Administration (FDA) participated in a joint risk assessment with the USDA Food Safety and Inspection Service (FSIS) to examine the human health impact of HPAI in poultry, shell eggs, and egg products. The risk assessment determined that the risk of humans becoming infected with HPAI through the consumption of contaminated shell eggs is low. For instance, when a case of HPAI is detected in the US, the chance of infected poultry or eggs entering the food chain is low because of the rapid onset of symptoms in poultry as well as the safeguards in place, which include testing of flocks and federal inspection programs.
Additionally, when food is properly prepared and stored, the risk of consumers becoming infected with HPAI is reduced even further. For more information of HPAI and human health visit the Centers for Disease Control and Prevention (CDC) website.
What about infecting humans?
From the CDC
- Although avian (bird) influenza (flu) A viruses usually do not infect people, there have been some rare cases of human infection with these viruses.
- In late March 2024, a human case of influenza A(H5N1) virus infection was identified after exposure to dairy cows presumably infected with bird flu. On May 22, CDC reported a second human case in a person who had exposure to infected dairy cows in Michigan. Some bird flu infections of people have been identified in which the source of infection was unknown.
- The spread of bird flu viruses from one infected person to a close contact is very rare, and when it has happened, it has only spread to a few people. However, because of the possibility that bird flu viruses could change and gain the ability to spread easily between people, monitoring for human infection and person-to-person spread is extremely important for public health.
CNN
https://www.cnn.com/2024/05/24/health/new-experiments-milk-h5n1-infected-cows-raise-questions-flash-pasteurization/index.htmlNew tests confirm milk from flu-infected cows can make other animals sick — and raise questions about flash pasteurization
By Brenda Goodman, CNN
5 minute read
Published 10:02 AM EDT, Fri May 24, 2024
New lab experiments with milk from cows infected by H5N1 influenza, known as bird flu, confirm that it is infectious, especially when left raw, or untreated, and potentially even when flash pasteurized.
Because H5N1 virus is considered a select agent, it was handled in a high-security Biosafety Level 3 lab at the University of Wisconsin, using strict safety protocols.
First, they confirmed the raw milk was chock-full of H5N1 virus. Then, they stored some of the raw milk at refrigerator temperature to see if levels of the virus in milk would drop off over time. Over 5 weeks, viral levels in raw milk dropped a bit, but not much.
“That it wasn’t decaying over time is concerning,” said Dr. Seema Lakdawala, an associate professor of immunology and microbiology at Emory University who is also part of the CEIRR network but was not involved in the study.
Early test results show pasteurized milk with traces of H5N1 virus isn’t infectious, FDA says
In another series of tests, the researchers checked to see what types of pasteurization might work best for inactivating the virus.
They heated small samples of the milk at times and temperatures used in two types of pasteurization: low-temperature, long-time, or vat pasteurization; and high-temperature short-time, or flash pasteurization, which is the most common method used in the US today, according to the International Dairy Foods Association.
Heating the milk to 63 degrees Celsius, or 145 degrees Fahrenheit, for intervals between 5 and 30 minutes — the vat pasteurization method — reduced the virus to undetectable levels.
Heating the milk to 72 degrees Celsius, or 181 degrees Fahrenheit, for 15 or 20 seconds — conditions that approximated flash pasteurization — greatly reduced levels of the virus in the milk, but it didn’t inactivate it completely.
Milk samples heated for 15 or 20 seconds were still able to infect incubated chicken eggs, a test the US Food and Drug Administration has called the gold-standard for determining whether viruses remain infectious in milk.
The researchers, from the University of Wisconsin School of Veterinary Medicine, are part of a federally funded program called the Centers of Excellence for Influenza Research and Response, or CEIRR. This network has been conducting rapid research to answer pressing questions in the H5N1 outbreak in dairy cattle.
In a research letter posted online on Friday in the New England Journal of Medicine, the researchers describe the results of experiments using milk from four infected cows — two from New Mexico and two from Kansas.
Because H5N1 virus is considered a select agent, it was handled in a high-security Biosafety Level 3 lab at the University of Wisconsin, using strict safety protocols.
First, they confirmed the raw milk was chock-full of H5N1 virus. Then, they stored some of the raw milk at refrigerator temperature to see if levels of the virus in milk would drop off over time. Over 5 weeks, viral levels in raw milk dropped a bit, but not much.
“That it wasn’t decaying over time is concerning,” said Dr. Seema Lakdawala, an associate professor of immunology and microbiology at Emory University who is also part of the CEIRR network but was not involved in the study.
Early test results show pasteurized milk with traces of H5N1 virus isn’t infectious, FDA says
In another series of tests, the researchers checked to see what types of pasteurization might work best for inactivating the virus.
They heated small samples of the milk at times and temperatures used in two types of pasteurization: low-temperature, long-time, or vat pasteurization; and high-temperature short-time, or flash pasteurization, which is the most common method used in the US today, according to the International Dairy Foods Association.
Heating the milk to 63 degrees Celsius, or 145 degrees Fahrenheit, for intervals between 5 and 30 minutes — the vat pasteurization method — reduced the virus to undetectable levels.
Heating the milk to 72 degrees Celsius, or 181 degrees Fahrenheit, for 15 or 20 seconds — conditions that approximated flash pasteurization — greatly reduced levels of the virus in the milk, but it didn’t inactivate it completely.
Milk samples heated for 15 or 20 seconds were still able to infect incubated chicken eggs, a test the US Food and Drug Administration has called the gold-standard for determining whether viruses remain infectious in milk.
“But, we emphasize that the conditions used in our laboratory study are not identical to the large-scale industrial treatment of raw milk,” senior study author Dr. Yoshihiro Kawaoka, a virologist who specializes in the study of flu and Ebola, said in an email.
In another series of tests, the researchers checked to see what types of pasteurization might work best for inactivating the virus.
They heated small samples of the milk at times and temperatures used in two types of pasteurization: low-temperature, long-time, or vat pasteurization; and high-temperature short-time, or flash pasteurization, which is the most common method used in the US today, according to the International Dairy Foods Association.
Heating the milk to 63 degrees Celsius, or 145 degrees Fahrenheit, for intervals between 5 and 30 minutes — the vat pasteurization method — reduced the virus to undetectable levels.
Heating the milk to 72 degrees Celsius, or 181 degrees Fahrenheit, for 15 or 20 seconds — conditions that approximated flash pasteurization — greatly reduced levels of the virus in the milk, but it didn’t inactivate it completely.
Milk samples heated for 15 or 20 seconds were still able to infect incubated chicken eggs, a test the US Food and Drug Administration has called the gold-standard for determining whether viruses remain infectious in milk.
“But, we emphasize that the conditions used in our laboratory study are not identical to the large-scale industrial treatment of raw milk,” senior study author Dr. Yoshihiro Kawaoka, a virologist who specializes in the study of flu and Ebola, said in an email.
That’s a good reason not to panic over the study findings, said Lakdawala.
Lakdawala said that commercial flash pasteurization involves a preheating step, which wasn’t done here. It also involves homogenization, a process that emulsifies the fat globules in milk so the cream won’t separate. Both of those steps would probably make it harder for the virus to survive, but she adds that the results of this study suggest full process of commercial flash pasteurization should be done “with all the steps in place.”
Cows have human flu receptors, study shows, raising stakes on bird flu outbreak in dairy cattle
Recent tests of 297 dairy products purchased at retail stores by the FDA found traces of genetic material from the H5N1 virus in about 1 of 5 milk samples, and further testing confirmed the viral fragments were inert and couldn’t make anyone sick.
The US Centers for Disease Control and Prevention says the risk to the general public is low, but people should not eat or drink raw milk or products made from it.
To date, H5N1 influenza has been found in 58 dairy herds in nine states. Michigan has now surpassed Texas as the state with the greatest number of infected herds.
To test whether the raw milk could infect other animals, researchers also squirted some of the milk into the mouths of mice. The animals showed signs of illness the next day.
Lakdawala said that commercial flash pasteurization involves a preheating step, which wasn’t done here. It also involves homogenization, a process that emulsifies the fat globules in milk so the cream won’t separate. Both of those steps would probably make it harder for the virus to survive, but she adds that the results of this study suggest full process of commercial flash pasteurization should be done “with all the steps in place.”
Cows have human flu receptors, study shows, raising stakes on bird flu outbreak in dairy cattle
Recent tests of 297 dairy products purchased at retail stores by the FDA found traces of genetic material from the H5N1 virus in about 1 of 5 milk samples, and further testing confirmed the viral fragments were inert and couldn’t make anyone sick.
The US Centers for Disease Control and Prevention says the risk to the general public is low, but people should not eat or drink raw milk or products made from it.
To date, H5N1 influenza has been found in 58 dairy herds in nine states. Michigan has now surpassed Texas as the state with the greatest number of infected herds.
To test whether the raw milk could infect other animals, researchers also squirted some of the milk into the mouths of mice. The animals showed signs of illness the next day.
On day four, the mice hadn’t died of their infections, but they were euthanized so that researchers could see what parts of their bodies had become infected. Scientists found the virus all over their bodies, with high viral loads in the lungs and respiratory tract. They also found virus in the mammary glands of the mice, even though they weren’t producing milk at the time.
Taken together, their findings confirm that raw milk can infect susceptible animals, the researchers said — and that could also indicate a risk to humans.
In a recent news briefing, officials with the US Department of Agriculture said that to their knowledge, none of the raw milk from farms known to have H5N1 infections was being sold to consumers.
Not all dairy farms are testing their cows, however, and some of the infected cows in the current outbreak have not shown any symptoms.
“Raw milk is unsafe at any speed, and the notion that you could protect yourself against H5 infection by consuming it is erroneous. There are there are much safer ways to protect oneself namely avoiding raw milk,” CDC Principal Deputy Director Dr. Nirav Shah said in a briefing.
Asked if the raw milk in the new experiments looked different than normal, Kawaoka said the researchers only got a small number of samples but some had more debris than milk from healthy cows. That would get filtered out prior to sale, he said. Some of the milk looked yellow-ish, but he points out that milk from healthy and infected cows would likely be mixed together in a big vat, making it look normal — and impossible to tell whether milk is safe to drink just by looking at it.New England Journal of Medicine
New England Journal of Medicine
Taken together, their findings confirm that raw milk can infect susceptible animals, the researchers said — and that could also indicate a risk to humans.
In a recent news briefing, officials with the US Department of Agriculture said that to their knowledge, none of the raw milk from farms known to have H5N1 infections was being sold to consumers.
Not all dairy farms are testing their cows, however, and some of the infected cows in the current outbreak have not shown any symptoms.
“Raw milk is unsafe at any speed, and the notion that you could protect yourself against H5 infection by consuming it is erroneous. There are there are much safer ways to protect oneself namely avoiding raw milk,” CDC Principal Deputy Director Dr. Nirav Shah said in a briefing.
Asked if the raw milk in the new experiments looked different than normal, Kawaoka said the researchers only got a small number of samples but some had more debris than milk from healthy cows. That would get filtered out prior to sale, he said. Some of the milk looked yellow-ish, but he points out that milk from healthy and infected cows would likely be mixed together in a big vat, making it look normal — and impossible to tell whether milk is safe to drink just by looking at it.New England Journal of Medicine
New England Journal of Medicine
https://www.nejm.org/doi/full/10.1056/NEJMc2405495
Cow’s Milk Containing Avian Influenza A(H5N1) Virus — Heat Inactivation and Infectivity in Mice
Published May 24, 2024
DOI: 10.1056/NEJMc2405495
TO THE EDITOR:
In late March 2024, highly pathogenic avian influenza virus (HPAI) of the H5N1 subtype was for the first time detected in nasal swabs and milk of dairy cows, increasing concern that HPAI A(H5N1) viruses may enter the human food chain. The Texas A&M Veterinary Medical Diagnostic Laboratory obtained cow’s milk samples from an affected herd in New Mexico, from which eight HPAI A(H5N1) viruses were isolated (Table S1; for details, see the Supplementary Appendix, available with the full text of this letter at NEJM.org).
We compared the genetic origin of these HPAI A(H5N1) milk virus isolates with the sequences publicly available at the time of our analysis (Fig. S1 in the Supplementary Appendix). The cow viruses form a single clade encompassing many smaller clades of viruses isolated from cats, raccoons, chickens, and wild birds. The phylogeny is consistent with a single introduction into cows. The viruses isolated in our study (labeled in Fig. S1) fall within the clade of publicly available cow virus sequences, including that from a human isolate, A/Texas/37/2024 (Fig. S1). Further assessment of the cow virus sequences and all avian influenza A virus sequences collected in the Americas since the start of 2020 identified a reassortment event for NP and PB2 segments that occurred immediately before the introduction of HPAI A(H5N1) viruses into cows (Fig. S2), consistent with findings reported by Anderson and colleagues.1
Cow’s Milk Containing Avian Influenza A(H5N1) Virus — Heat Inactivation and Infectivity in Mice
Published May 24, 2024
DOI: 10.1056/NEJMc2405495
TO THE EDITOR:
In late March 2024, highly pathogenic avian influenza virus (HPAI) of the H5N1 subtype was for the first time detected in nasal swabs and milk of dairy cows, increasing concern that HPAI A(H5N1) viruses may enter the human food chain. The Texas A&M Veterinary Medical Diagnostic Laboratory obtained cow’s milk samples from an affected herd in New Mexico, from which eight HPAI A(H5N1) viruses were isolated (Table S1; for details, see the Supplementary Appendix, available with the full text of this letter at NEJM.org).
We compared the genetic origin of these HPAI A(H5N1) milk virus isolates with the sequences publicly available at the time of our analysis (Fig. S1 in the Supplementary Appendix). The cow viruses form a single clade encompassing many smaller clades of viruses isolated from cats, raccoons, chickens, and wild birds. The phylogeny is consistent with a single introduction into cows. The viruses isolated in our study (labeled in Fig. S1) fall within the clade of publicly available cow virus sequences, including that from a human isolate, A/Texas/37/2024 (Fig. S1). Further assessment of the cow virus sequences and all avian influenza A virus sequences collected in the Americas since the start of 2020 identified a reassortment event for NP and PB2 segments that occurred immediately before the introduction of HPAI A(H5N1) viruses into cows (Fig. S2), consistent with findings reported by Anderson and colleagues.1
Studies involving foot-and-mouth disease virus revealed that heat inactivation of virus-positive milk samples required higher temperature or longer incubation times (or both) than heat inactivation of virus spiked into milk,2,3 presumably because fat globules and casein micelles may partly protect viruses in virus-positive milk samples. Accordingly, we tested heat inactivation of four HPAI A(H5N1) virus–positive milk samples (NM#93, NM#115, KS#3, and KS#6). Undiluted milk samples were incubated in a polymerase-chain-reaction (PCR) thermocycler at 63°C for 5, 10, 20, or 30 minutes or at 72°C for 5, 10, 15, 20, or 30 seconds (Table 1; see also the Supplementary Appendix). Control samples were left untreated. Heat treatment at 63°C reduced the virus titers below the detection limit of the TCID50 (50% tissue-culture infectious dose) assay (1.5 log10/ml). Heat treatment at 72°C was performed, with the default settings of the PCR thermocycler (i.e., preheated lid at 105°C) or with a metal lid (heated to 72°C) covering the PCR block (see the Supplementary Appendix for details). After heat treatment, samples were inoculated into embryonated chicken eggs or Madin–Darby canine kidney (MDCK) cells for virus detection. Under these conditions, heat treatment for 15 or 20 seconds reduced virus titers by more than 4.5 log units but did not completely inactivate the virus (Table 1). We emphasize that the conditions used in our laboratory study are not identical to the large-scale industrial treatment of raw milk.
Virus Positivity of Heat-Treated Milk Samples.
The stability of HPAI A(H5N1) virus in cow’s milk stored at 4°C is another important question. For milk sample NM#93, we detected a decline of only two log units over 5 weeks. HPAI A(H5N1) virus may therefore remain infectious for several weeks in raw milk kept at 4°C.
To further assess the risk that HPAI A(H5N1)–positive milk poses to animals and humans, we orally inoculated BALB/cJ mice with 50 μl (3×106 pfu) of sample NM#93. The animals showed signs of illness starting on day 1, including ruffled fur and lethargy. All the animals survived until day 4, when they were euthanized to determine virus titers in multiple organs (Figure S3 in the Supplementary Appendix). We detected high virus titers in the respiratory organs (which suggests that infection may have occurred through the pharynx) and moderate virus titers in several other organs, findings consistent with the systemic infections typically caused by HPAI H5 viruses in mammals. Detection of virus in the mammary glands of two mice was consistent with the high virus load in the milk of lactating cows, even though these mice were not lactating. Collectively, our data indicate that HPAI A(H5N1) virus in untreated milk can infect susceptible animals that consume it. In summary, HPAI H5–positive milk poses a risk when consumed untreated, but heat inactivation under the laboratory conditions used here reduces HPAI H5 virus titers by more than 4.5 log units. However, bench-top experiments do not recapitulate commercial pasteurization processes.
Reuters
https://www.reuters.com/world/us/us-fda-tested-retail-milk-samples-bird-flu-17-states-2024-05-20/
US FDA tested retail milk samples for bird flu in 17 states
By Reuters
May 20, 20242:22 PM EDTUpdated 4 days ago
May 20 (Reuters) - The U.S. Food and Drug Administration said on Monday that it tested retail samples of milk and other dairy products in 17 states for viable bird flu virus, providing further details about the locations of the previously disclosed tests.
The regulator said it collected 297 samples at retail locations in 17 states between April 18-22, but the retail samples represented products made at 132 processing locations in 38 states.
"Even if a sample was collected in one particular state, the milk in a consumer package could have come from cows on several farms located in several states, pasteurized in a different state from where the milk was produced, and available for purchase in yet another state," the agency said in its statement.
The U.S. has confirmed bird flu in dairy cattle in nine states since late March.
The FDA had said on May 10 that no live virus was found in retail milk samples. It has also said that pasteurized milk is safe to drink but has cautioned against consuming raw milk.
Scientists, however, have said they believe the outbreak is more widespread based on the FDA's findings that showed about 20% of retail milk samples contained remnants of the H5N1 virus.
The samples included cottage cheese, cream, and half and half, which is equal parts milk and cream, sour cream and yoghurt, in addition to milk.
FDA
https://www.fda.gov/food/alerts-advisories-safety-information/updates-highly-pathogenic-avian-influenza-hpai
Updates on Highly Pathogenic Avian Influenza (HPAI)
Highly Pathogenic Avian Influenza (HPAI) is a disease that is highly contagious and often deadly in poultry, caused by highly pathogenic avian influenza A (H5) and A (H7) viruses; it is also known as bird or avian flu. HPAI viruses can be transmitted by wild birds to domestic poultry and other bird and animal species. Although bird flu viruses do not normally infect humans, sporadic human infections have occurred. It is important to note that “highly pathogenic” refers to severe impact in birds, not necessarily in humans.
Updates on Highly Pathogenic Avian Influenza (HPAI)
May 20, 2024
In our May 10 update, we announced that all 297 samples from the FDA’s initial survey of retail dairy products were found to be negative for viable Highly Pathogenic H5N1 Avian Influenza (H5N1 HPAI) virus. Today, for continued transparency, the FDA is providing additional information on our retail sample survey (see Testing Results).
Background
The U.S. Department of Agriculture (USDA), the U.S. Food and Drug Administration (FDA), and the Centers for Disease Control and Prevention (CDC), along with state partners, continue to investigate an outbreak of highly pathogenic avian influenza (HPAI) virus impacting dairy cows in multiple states. Infection with the virus is causing decreased lactation, low appetite, and other symptoms in affected cattle.
The FDA and USDA have indicated that based on the information currently available, our commercial milk supply is safe because of these two reasons:
1) the pasteurization process and
2) the diversion or destruction of milk from sick cows.
The pasteurization process has served public health well for more than 100 years. Pasteurization is a process that kills harmful bacteria and viruses by heating milk to a specific temperature for a set period of time to make milk safer. Even if virus is detected in raw milk, pasteurization is generally expected to eliminate pathogens to a level that does not pose a risk to consumer health. However, pasteurization is different than complete sterilization; sterilization extends shelf life but is not required to ensure milk safety. While milk is pasteurized, not sterilized, this process has helped ensure the health of the American public for more than 100 years by inactivating infectious agents.
Nearly all (99%) of the commercial milk supply that is produced on dairy farms in the U.S. comes from farms that participate in the Grade “A” milk program and follow the Pasteurized Milk Ordinance (PMO), which includes controls that help ensure the safety of dairy products. Pasteurization and diversion or destruction of milk from sick cows are two important measures that are part of the federal-state milk safety system.
Testing Results
In our May 10 update, we announced that all 297 samples from the FDA’s initial survey of retail dairy products were found to be negative for viable Highly Pathogenic H5N1 Avian Influenza (H5N1 HPAI) virus. Today, for continued transparency, the FDA is providing additional information on our retail sample survey.
The samples taken as part of this survey were collected at retail locations in 17 states by milk specialists in the FDA’s Office of Regulatory Affairs. USDA Agricultural Research Service’s U.S. National Poultry Research Center (ARS) analyzed these samples using stepwise, scientific methods. This testing included first conducting quantitative real time polymerase chain reaction (qRT-PCR) screening to determine if any of the retail samples contained H5N1 viral nucleic acid. The samples that were found to contain viral nucleic acid during qRT-PCR screening were followed with gold-standard egg inoculation testing conducted by ARS to determine if they contained live virus. None of the samples were positive for live virus. ARS scientists are currently obtaining peer review of their analysis as a first step to publishing these results. The prepublication is available at https://www.medrxiv.org/content/10.1101/2024.05.21.24307706v1External Link Disclaimer.
While the FDA collected the 297 samples at retail locations in 17 states, these retail samples represent products produced at 132 processing locations in 38 states. The information in the first chart below shows the state in which the product was processed. Because the intent of our study was to assess a variety of products, samples were selected to be representative of processors in states that have been reported to have impacted dairy cattle and those that have not. Of note, the location of where milk was processed does not indicate where the milk was produced. This is because milk could be produced from cows on a farm or farms a few states away, processed (pasteurized) in a different state, and then be available for purchase in yet another state.
The charts below provide additional details on the samples taken as part of our survey of retail dairy products.
As noted previously, qRT-PCR-positive results do not necessarily represent live virus that may be a risk to consumers. Therefore, viability testing by egg inoculation was performed on the qPCR samples that were positive for viral nucleic acid. All of these samples did not detect any viable virus. If samples tested by qRT-PCR were negative, no further testing was performed since those samples did not contain HPAI viral nucleic acid. These findings further support our assessment that the milk safety system including pasteurization is effective against this virus and that the commercial milk supply remains safe.
Retail samples were collected between April 18-22 and represent a snapshot in time. This testing did not detect any live, infectious virus.
Table 1: Breakdown of Retail Sample Results by State Where Milk Was Processed
State Where Milk Was Processed (May Not Relate to Where Milk Was Produced) Detection of Live Virus in Retail Product(s) Number of Retail Product Samples Tested Retail Product Samples Negative for Viral RNA
This retail sampling study was designed to assess the effectiveness of the PMO milk safety system; it was not designed to assess the prevalence of H5N1 in dairy herds. It is important to underscore that milk purchased for the retail study in a particular state does not mean that it was produced or processed in that state. Commercial milk is typically pooled from many dairy farms, pasteurized in bulk and distributed to a variety of states. Even if a sample was collected in one particular state, the milk in a consumer package could have come from cows on several farms located in several states, pasteurized in a different state from the states where the milk was produced, and available for purchase in yet another state.
To further validate pasteurization effectiveness against the recently identified H5N1 virus, we are undertaking a pasteurization study designed to better replicate real-world conditions. Preliminary results from this work are expected in the near future.
Data Considerations
Multiple tests are used to assess the safety of food items. Understanding how and why different methodologies are used and work, as well as how results fit into the larger picture, is critical to interpret any findings.
Quantitative polymerase chain reaction (qRT-PCR) is a screening tool used to determine the presence or absence of an organism’s genetic material in a sample. A positive qRT-PCR means that the genetic material from the targeted pathogen was detected in the sample, but that does not mean that the sample contains an intact, infectious pathogen. That’s because qRT-PCR tests will also detect the residual genetic material from pathogens killed by heat, like pasteurization, or other food safety treatments. Importantly, additional testing is required to determine whether intact pathogen is still present and if it remains infectious, which determines whether there is any risk of illness associated with consuming the product.
Embryonated Egg Viability Studies are considered the “gold standard” for sensitive detection of active, infectious virus. These studies are one of the types of additional tests necessary following PCR testing. These studies are done by injecting an embryonated chicken egg with a sample and then evaluating to see whether any active virus replicates. While this provides the most sensitive results, it takes a longer time to complete than other methods.
Madin-Darby Canine Kidney (MDCK) Cell Culture is different type of additional test used following PCR testing to detect live, infectious virus. This is done by injecting a sample into specific tissue cells to determine whether any live virus is present and replicates. This method can usually be done more quickly than embryonated egg viability studies, but it is not as sensitive and may provide false negative results when the amount of virus in the sample is very low.
FDA
Updates on Highly Pathogenic Avian Influenza (HPAI)
Highly Pathogenic Avian Influenza (HPAI) is a disease that is highly contagious and often deadly in poultry, caused by highly pathogenic avian influenza A (H5) and A (H7) viruses; it is also known as bird or avian flu. HPAI viruses can be transmitted by wild birds to domestic poultry and other bird and animal species. Although bird flu viruses do not normally infect humans, sporadic human infections have occurred. It is important to note that “highly pathogenic” refers to severe impact in birds, not necessarily in humans.
Updates on Highly Pathogenic Avian Influenza (HPAI)
May 20, 2024
In our May 10 update, we announced that all 297 samples from the FDA’s initial survey of retail dairy products were found to be negative for viable Highly Pathogenic H5N1 Avian Influenza (H5N1 HPAI) virus. Today, for continued transparency, the FDA is providing additional information on our retail sample survey (see Testing Results).
Background
The U.S. Department of Agriculture (USDA), the U.S. Food and Drug Administration (FDA), and the Centers for Disease Control and Prevention (CDC), along with state partners, continue to investigate an outbreak of highly pathogenic avian influenza (HPAI) virus impacting dairy cows in multiple states. Infection with the virus is causing decreased lactation, low appetite, and other symptoms in affected cattle.
The FDA and USDA have indicated that based on the information currently available, our commercial milk supply is safe because of these two reasons:
1) the pasteurization process and
2) the diversion or destruction of milk from sick cows.
The pasteurization process has served public health well for more than 100 years. Pasteurization is a process that kills harmful bacteria and viruses by heating milk to a specific temperature for a set period of time to make milk safer. Even if virus is detected in raw milk, pasteurization is generally expected to eliminate pathogens to a level that does not pose a risk to consumer health. However, pasteurization is different than complete sterilization; sterilization extends shelf life but is not required to ensure milk safety. While milk is pasteurized, not sterilized, this process has helped ensure the health of the American public for more than 100 years by inactivating infectious agents.
Nearly all (99%) of the commercial milk supply that is produced on dairy farms in the U.S. comes from farms that participate in the Grade “A” milk program and follow the Pasteurized Milk Ordinance (PMO), which includes controls that help ensure the safety of dairy products. Pasteurization and diversion or destruction of milk from sick cows are two important measures that are part of the federal-state milk safety system.
Testing Results
In our May 10 update, we announced that all 297 samples from the FDA’s initial survey of retail dairy products were found to be negative for viable Highly Pathogenic H5N1 Avian Influenza (H5N1 HPAI) virus. Today, for continued transparency, the FDA is providing additional information on our retail sample survey.
The samples taken as part of this survey were collected at retail locations in 17 states by milk specialists in the FDA’s Office of Regulatory Affairs. USDA Agricultural Research Service’s U.S. National Poultry Research Center (ARS) analyzed these samples using stepwise, scientific methods. This testing included first conducting quantitative real time polymerase chain reaction (qRT-PCR) screening to determine if any of the retail samples contained H5N1 viral nucleic acid. The samples that were found to contain viral nucleic acid during qRT-PCR screening were followed with gold-standard egg inoculation testing conducted by ARS to determine if they contained live virus. None of the samples were positive for live virus. ARS scientists are currently obtaining peer review of their analysis as a first step to publishing these results. The prepublication is available at https://www.medrxiv.org/content/10.1101/2024.05.21.24307706v1External Link Disclaimer.
While the FDA collected the 297 samples at retail locations in 17 states, these retail samples represent products produced at 132 processing locations in 38 states. The information in the first chart below shows the state in which the product was processed. Because the intent of our study was to assess a variety of products, samples were selected to be representative of processors in states that have been reported to have impacted dairy cattle and those that have not. Of note, the location of where milk was processed does not indicate where the milk was produced. This is because milk could be produced from cows on a farm or farms a few states away, processed (pasteurized) in a different state, and then be available for purchase in yet another state.
The charts below provide additional details on the samples taken as part of our survey of retail dairy products.
As noted previously, qRT-PCR-positive results do not necessarily represent live virus that may be a risk to consumers. Therefore, viability testing by egg inoculation was performed on the qPCR samples that were positive for viral nucleic acid. All of these samples did not detect any viable virus. If samples tested by qRT-PCR were negative, no further testing was performed since those samples did not contain HPAI viral nucleic acid. These findings further support our assessment that the milk safety system including pasteurization is effective against this virus and that the commercial milk supply remains safe.
Retail samples were collected between April 18-22 and represent a snapshot in time. This testing did not detect any live, infectious virus.
Table 1: Breakdown of Retail Sample Results by State Where Milk Was Processed
State Where Milk Was Processed (May Not Relate to Where Milk Was Produced) Detection of Live Virus in Retail Product(s) Number of Retail Product Samples Tested Retail Product Samples Negative for Viral RNA
This retail sampling study was designed to assess the effectiveness of the PMO milk safety system; it was not designed to assess the prevalence of H5N1 in dairy herds. It is important to underscore that milk purchased for the retail study in a particular state does not mean that it was produced or processed in that state. Commercial milk is typically pooled from many dairy farms, pasteurized in bulk and distributed to a variety of states. Even if a sample was collected in one particular state, the milk in a consumer package could have come from cows on several farms located in several states, pasteurized in a different state from the states where the milk was produced, and available for purchase in yet another state.
To further validate pasteurization effectiveness against the recently identified H5N1 virus, we are undertaking a pasteurization study designed to better replicate real-world conditions. Preliminary results from this work are expected in the near future.
Data Considerations
Multiple tests are used to assess the safety of food items. Understanding how and why different methodologies are used and work, as well as how results fit into the larger picture, is critical to interpret any findings.
Quantitative polymerase chain reaction (qRT-PCR) is a screening tool used to determine the presence or absence of an organism’s genetic material in a sample. A positive qRT-PCR means that the genetic material from the targeted pathogen was detected in the sample, but that does not mean that the sample contains an intact, infectious pathogen. That’s because qRT-PCR tests will also detect the residual genetic material from pathogens killed by heat, like pasteurization, or other food safety treatments. Importantly, additional testing is required to determine whether intact pathogen is still present and if it remains infectious, which determines whether there is any risk of illness associated with consuming the product.
Embryonated Egg Viability Studies are considered the “gold standard” for sensitive detection of active, infectious virus. These studies are one of the types of additional tests necessary following PCR testing. These studies are done by injecting an embryonated chicken egg with a sample and then evaluating to see whether any active virus replicates. While this provides the most sensitive results, it takes a longer time to complete than other methods.
Madin-Darby Canine Kidney (MDCK) Cell Culture is different type of additional test used following PCR testing to detect live, infectious virus. This is done by injecting a sample into specific tissue cells to determine whether any live virus is present and replicates. This method can usually be done more quickly than embryonated egg viability studies, but it is not as sensitive and may provide false negative results when the amount of virus in the sample is very low.
FDA
https://www.fda.gov/food/egg-guidance-regulation-and-other-information/questions-and-answers-regarding-safety-eggs-during-highly-pathogenic-avian-influenza-outbreaks
What is HPAI and why is it a problem?
Highly Pathogenic Avian Influenza (HPAI) is a disease that is highly contagious and often deadly in poultry, caused by highly pathogenic avian influenza A (H5) and A (H7) viruses; it is also known as bird or avian flu. HPAI viruses can be transmitted by wild birds to domestic poultry and other bird and animal species. Although bird flu viruses do not normally infect humans, sporadic human infections have occurred. It is important to note that “highly pathogenic” refers to severe impact in birds, not necessarily in humans.
In April 2024, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) confirmed the detection of HPAI in commercial table egg layer flocks in Michigan and Texas.
Are eggs in the retail market safe to eat?
Yes. The likelihood that eggs from infected poultry are found in the retail market is low and proper storage and preparation further reduce the risk. In 2010, the U.S. Food and Drug Administration (FDA) participated in a joint risk assessment with the USDA Food Safety and Inspection Service (FSIS) to examine the human health impact of HPAI in poultry, shell eggs, and egg products. The risk assessment determined that the risk of humans becoming infected with HPAI through the consumption of contaminated shell eggs is low. For instance, when a case of HPAI is detected in the US, the chance of infected poultry or eggs entering the food chain is low because of the rapid onset of symptoms in poultry as well as the safeguards in place, which include testing of flocks and federal inspection programs.
Additionally, when food is properly prepared and stored, the risk of consumers becoming infected with HPAI is reduced even further. For more information of HPAI and human health visit the Centers for Disease Control and Prevention (CDC) website.
What is HPAI and why is it a problem?
Highly Pathogenic Avian Influenza (HPAI) is a disease that is highly contagious and often deadly in poultry, caused by highly pathogenic avian influenza A (H5) and A (H7) viruses; it is also known as bird or avian flu. HPAI viruses can be transmitted by wild birds to domestic poultry and other bird and animal species. Although bird flu viruses do not normally infect humans, sporadic human infections have occurred. It is important to note that “highly pathogenic” refers to severe impact in birds, not necessarily in humans.
In April 2024, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) confirmed the detection of HPAI in commercial table egg layer flocks in Michigan and Texas.
Are eggs in the retail market safe to eat?
Yes. The likelihood that eggs from infected poultry are found in the retail market is low and proper storage and preparation further reduce the risk. In 2010, the U.S. Food and Drug Administration (FDA) participated in a joint risk assessment with the USDA Food Safety and Inspection Service (FSIS) to examine the human health impact of HPAI in poultry, shell eggs, and egg products. The risk assessment determined that the risk of humans becoming infected with HPAI through the consumption of contaminated shell eggs is low. For instance, when a case of HPAI is detected in the US, the chance of infected poultry or eggs entering the food chain is low because of the rapid onset of symptoms in poultry as well as the safeguards in place, which include testing of flocks and federal inspection programs.
Additionally, when food is properly prepared and stored, the risk of consumers becoming infected with HPAI is reduced even further. For more information of HPAI and human health visit the Centers for Disease Control and Prevention (CDC) website.
Do I need to make changes to my food preparation?
There is no evidence that the virus can be transmitted to humans through properly prepared food. Safe food handling and preparation is always important. Cooking poultry, eggs, and other animal products to the proper temperature and preventing cross-contamination between raw and cooked food are the keys to prevent any food safety hazard. To this end, the FDA’s Food Code provides guidelines on proper preparation of foods to retail establishments; moreover, the FDA has published several fact sheets, pamphlets, flyers, and videos on proper preparation of foods for both consumers and retail food establishments. For more information on proper egg handling and cooking: What You Need to Know About Egg Safety.
What federal agencies are responsible for ensuring the safety of eggs?
The FDA and USDA-FSIS share regulatory authority over egg safety. In addition, the USDA-APHIS conducts a control program that certifies poultry breeding stock and hatcheries as Salmonella Enteritidis (SE) - free and the USDA’s Agricultural Marketing Service (AMS) conducts a surveillance program to ensure proper disposition of restricted shell eggs (i.e., eggs that cannot be marketed as table eggs).
Under the Federal Food, Drug, and Cosmetic Act, (FFDCA) the FDA protects consumers against impure, unsafe, and fraudulently labeled food, which includes shell eggs. The FDA has regulations in place that govern proper production, transportation, and storage of shell eggs.
The USDA has primary responsibility for implementing the Egg Products Inspection Act (EPIA). Under the EPIA, FSIS has primary responsibility for the inspection of processed egg products to prevent the distribution of adulterated or misbranded liquid, frozen and dried egg products.
Is the FDA taking steps to prevent the spread of HPAI on farm visits during egg inspections?
Following the 2014-2015 avian flu outbreak, the FDA updated its biosecurity protocols for on-farm visits to prevent the spread of HPAI during egg farm inspections. Before initiating an egg farm inspection, the FDA:
Uses a HPAI risk-based classification system to determine the order in which egg farms are inspected,
Contacts the State Veterinarian/State Animal Health Official before initiating inspections to ensure there are no quarantines or other reasons investigators should not visit a specific farm,
Conducts a check of the most up-to-date information on USDA’s HPAI reporting website for any detection in close proximity to the intended inspection,
Follows the mandatory waiting periods between inspections and uses multiple inspection teams,
Thoroughly washes the vehicles used during inspection before and after every inspection and at the end of every day on multiday inspections. This is followed by sanitation of the floor mats, the wheel wells and undercarriage of the vehicle with appropriate disinfectants.
When outbreaks like this occur, the FDA evaluates its other inspection programs that may contain an on-farm component and considers adjustments to those programs. We do retain the ability to respond to emergencies or other events as necessary, however, while following appropriate biosecurity practices.
Should farmers who have biosecurity plans in place be concerned about HPAI?
Farmers who continuously follow the biosecurity requirements in 21 CFR 118.4(b) will reduce the potential risk of HPAI infection in birds on the farm. The biosecurity requirements of this regulation, which are aimed at preventing the introduction or transfer of Salmonella Enteritidis onto a farm, also serve to reduce the risk of HPAI contaminating the farm. Since wild birds and migratory waterfowl can be carriers of HPAI, the requirement to prevent wild birds, cats, stray poultry, and other animals from entering poultry houses also serves to protect against HPAI.
Are there additional biosecurity measures farmers can implement to further protect their farms from HPAI?
The USDA’s APHIS works to defend America’s animal and plant resources from agricultural pests and diseases. APHIS has developed biosecurity measures for poultry which are available at their website: Defend the Flock - Biosecurity 101.
CDC
https://www.cdc.gov/flu/avianflu/avian-in-humans.htm
Bird Flu Virus Infections in Humans
Español | Other Languages Print
Information about the latest developments around avian influenza A(H5N1) is available at Bird Flu Current Situation Summary.
Although avian (bird) influenza (flu) A viruses usually do not infect people, there have been some rare cases of human infection with these viruses. Illness in humans from avian influenza virus infections have ranged in severity from no symptoms or mild illness to severe disease that resulted in death. Avian influenza A(H7N9) virus and highly pathogenic avian influenza (HPAI) A(H5N1) and A(H5N6) viruses have been responsible for most human illness from avian influenza viruses reported worldwide to date, including the most serious illnesses with high mortality.
Infected birds shed avian influenza viruses through their saliva, mucous and feces. Other animals infected with avian influenza viruses may have virus present in respiratory secretions, different organs, blood, or in other body fluids, including animal milk. Human infections with avian influenza viruses can happen when virus gets into a person’s eyes, nose or mouth, or is inhaled. This can happen when virus is in the air (in droplets, small aerosol particles, or possibly dust) and deposits on the mucus membranes of the eyes or a person breathes it in, or possibly when a person touches something contaminated by viruses and then touches their mouth, eyes or nose.
Avian influenza viruses have been detected in many other species. Avoid contact with surfaces that appear to be contaminated with animal feces, raw milk, litter, or materials contaminated by birds or other animals with suspected or confirmed avian influenza virus infection. CDC has information about precautions to take with wild birds, poultry and other animals.
CDC has guidance for specific groups of people with exposure to poultry and other potentially infected animals, including poultry or dairy workers, for example, and people responding to bird flu outbreaks. Additional information is available at Information for People Exposed to Birds Infected with Avian Influenza Viruses of Public Health Concern.
In late March 2024, a human case of influenza A(H5N1) virus infection was identified after exposure to dairy cows presumably infected with bird flu. On May 22, CDC reported a second human case in a person who had exposure to infected dairy cows in Michigan. Some bird flu infections of people have been identified in which the source of infection was unknown.
The spread of bird flu viruses from one infected person to a close contact is very rare, and when it has happened, it has only spread to a few people. However, because of the possibility that bird flu viruses could change and gain the ability to spread easily between people, monitoring for human infection and person-to-person spread is extremely important for public health.
There is no evidence that the virus can be transmitted to humans through properly prepared food. Safe food handling and preparation is always important. Cooking poultry, eggs, and other animal products to the proper temperature and preventing cross-contamination between raw and cooked food are the keys to prevent any food safety hazard. To this end, the FDA’s Food Code provides guidelines on proper preparation of foods to retail establishments; moreover, the FDA has published several fact sheets, pamphlets, flyers, and videos on proper preparation of foods for both consumers and retail food establishments. For more information on proper egg handling and cooking: What You Need to Know About Egg Safety.
What federal agencies are responsible for ensuring the safety of eggs?
The FDA and USDA-FSIS share regulatory authority over egg safety. In addition, the USDA-APHIS conducts a control program that certifies poultry breeding stock and hatcheries as Salmonella Enteritidis (SE) - free and the USDA’s Agricultural Marketing Service (AMS) conducts a surveillance program to ensure proper disposition of restricted shell eggs (i.e., eggs that cannot be marketed as table eggs).
Under the Federal Food, Drug, and Cosmetic Act, (FFDCA) the FDA protects consumers against impure, unsafe, and fraudulently labeled food, which includes shell eggs. The FDA has regulations in place that govern proper production, transportation, and storage of shell eggs.
The USDA has primary responsibility for implementing the Egg Products Inspection Act (EPIA). Under the EPIA, FSIS has primary responsibility for the inspection of processed egg products to prevent the distribution of adulterated or misbranded liquid, frozen and dried egg products.
Is the FDA taking steps to prevent the spread of HPAI on farm visits during egg inspections?
Following the 2014-2015 avian flu outbreak, the FDA updated its biosecurity protocols for on-farm visits to prevent the spread of HPAI during egg farm inspections. Before initiating an egg farm inspection, the FDA:
Uses a HPAI risk-based classification system to determine the order in which egg farms are inspected,
Contacts the State Veterinarian/State Animal Health Official before initiating inspections to ensure there are no quarantines or other reasons investigators should not visit a specific farm,
Conducts a check of the most up-to-date information on USDA’s HPAI reporting website for any detection in close proximity to the intended inspection,
Follows the mandatory waiting periods between inspections and uses multiple inspection teams,
Thoroughly washes the vehicles used during inspection before and after every inspection and at the end of every day on multiday inspections. This is followed by sanitation of the floor mats, the wheel wells and undercarriage of the vehicle with appropriate disinfectants.
When outbreaks like this occur, the FDA evaluates its other inspection programs that may contain an on-farm component and considers adjustments to those programs. We do retain the ability to respond to emergencies or other events as necessary, however, while following appropriate biosecurity practices.
Should farmers who have biosecurity plans in place be concerned about HPAI?
Farmers who continuously follow the biosecurity requirements in 21 CFR 118.4(b) will reduce the potential risk of HPAI infection in birds on the farm. The biosecurity requirements of this regulation, which are aimed at preventing the introduction or transfer of Salmonella Enteritidis onto a farm, also serve to reduce the risk of HPAI contaminating the farm. Since wild birds and migratory waterfowl can be carriers of HPAI, the requirement to prevent wild birds, cats, stray poultry, and other animals from entering poultry houses also serves to protect against HPAI.
Are there additional biosecurity measures farmers can implement to further protect their farms from HPAI?
The USDA’s APHIS works to defend America’s animal and plant resources from agricultural pests and diseases. APHIS has developed biosecurity measures for poultry which are available at their website: Defend the Flock - Biosecurity 101.
CDC
https://www.cdc.gov/flu/avianflu/avian-in-humans.htm
Bird Flu Virus Infections in Humans
Español | Other Languages Print
Information about the latest developments around avian influenza A(H5N1) is available at Bird Flu Current Situation Summary.
Although avian (bird) influenza (flu) A viruses usually do not infect people, there have been some rare cases of human infection with these viruses. Illness in humans from avian influenza virus infections have ranged in severity from no symptoms or mild illness to severe disease that resulted in death. Avian influenza A(H7N9) virus and highly pathogenic avian influenza (HPAI) A(H5N1) and A(H5N6) viruses have been responsible for most human illness from avian influenza viruses reported worldwide to date, including the most serious illnesses with high mortality.
Infected birds shed avian influenza viruses through their saliva, mucous and feces. Other animals infected with avian influenza viruses may have virus present in respiratory secretions, different organs, blood, or in other body fluids, including animal milk. Human infections with avian influenza viruses can happen when virus gets into a person’s eyes, nose or mouth, or is inhaled. This can happen when virus is in the air (in droplets, small aerosol particles, or possibly dust) and deposits on the mucus membranes of the eyes or a person breathes it in, or possibly when a person touches something contaminated by viruses and then touches their mouth, eyes or nose.
Avian influenza viruses have been detected in many other species. Avoid contact with surfaces that appear to be contaminated with animal feces, raw milk, litter, or materials contaminated by birds or other animals with suspected or confirmed avian influenza virus infection. CDC has information about precautions to take with wild birds, poultry and other animals.
CDC has guidance for specific groups of people with exposure to poultry and other potentially infected animals, including poultry or dairy workers, for example, and people responding to bird flu outbreaks. Additional information is available at Information for People Exposed to Birds Infected with Avian Influenza Viruses of Public Health Concern.
In late March 2024, a human case of influenza A(H5N1) virus infection was identified after exposure to dairy cows presumably infected with bird flu. On May 22, CDC reported a second human case in a person who had exposure to infected dairy cows in Michigan. Some bird flu infections of people have been identified in which the source of infection was unknown.
The spread of bird flu viruses from one infected person to a close contact is very rare, and when it has happened, it has only spread to a few people. However, because of the possibility that bird flu viruses could change and gain the ability to spread easily between people, monitoring for human infection and person-to-person spread is extremely important for public health.
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