According to CDC's MMWR weekly report, there has been an increase in the number of cases of Strongyloidiasis in LA County, California. While there were none in 2012, there were 14 cases in 2013 and 29 cases in 2014.
So what the heck is strongyloidiasis? Just because you wanted to know.......
So, there you are out tending your garden (or whatever they do in LA where one has their hands in the soil), and this little parasitic worm burrows into your skin and then finds its way to your intestines where it creates a never-ending maternity ward for more parasitic worms. Isn't that a pleasant thought.
Strongyloidiasis is a disease caused by a nematode, or a roundworm, in the genus Strongyloides. While there are a number of species of this roundworm that can infect birds, reptiles and such, Strongyloides stercoralis is the primary species that infects humans. The larvae are only about 1.5mm in length and are found in the soil. "When the larvae come in contact with skin, they are able to penetrate it and migrate through the body, eventually finding their way to the small intestine where they burrow and lay their eggs and these eggs hatch into larvae in the intestine. Most of these larvae will be excreted in the stool, but some of the larvae may molt and immediately re-infect the host either by burrowing into the intestinal wall, or by penetrating the perianal skin. This characteristic of Strongyloides is termed auto-infection. The significance of auto-infection is that unless treated for Strongyloides, persons may remain infected throughout their lifetime."
"The majority of people infected with Strongyloides are without symptoms. Those who do develop symptoms tend to have non-specific, or generalized complaints. Some people develop abdominal pain, bloating, heartburn, intermittent episodes of diarrhea and constipation, a dry cough, and rashes. Rarely people will develop arthritis, kidney problems, and heart conditions."
"In the United States, Strongyloides has classically been associated with uniformed-service veterans who returned from tropical regions such as Southeast Asia and the South Pacific during World War II. Small domestic studies have shown locations of infection in rural Appalachia. The highest rates in the United States have been documented in immigrant populations."
CDC - MMWR
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6433a8.htm?s_cid=mm6433a8_e
Increase in Reports of Strongyloides Infection — Los Angeles County, 2013–2014
Weekly
August 28, 2015 / 64(33);922-923
Curtis Croker, MPH1; Rosemary She, MD2
During the 1990s, reports of infection with the nematode (roundworm) Strongyloides stercoralis submitted to the Los Angeles County Department of Public Health (LACDPH) ranged from 40 to 50 per year, but by 2000, reports had decreased to five per year; in 2006, Strongyloides infection was removed from the LACDPH reportable disease list. Currently, it is only reported at the discretion of Los Angeles County clinicians and laboratories as an unusual disease occurrence. LACDPH currently only monitors case counts and does not investigate reported Strongyloides cases. During 2013–2014, an increase in Strongyloides cases occurred, with 43 cases reported.
Although Strongyloides infects humans worldwide, typically through skin contact with contaminated soil (1), infection is rare in the United States. Persons at risk for infection include immigrants, refugees, military veterans who have lived in areas where Strongyloides is endemic, (1) and persons who have lived in rural areas of the southeastern United States (2). Most infections are asymptomatic and might remain latent for decades. Persons with latent infection who receive immunosuppressive treatments or are otherwise immunosuppressed are at risk for a severe hyperinfection syndrome and disseminated disease, which is associated with a high mortality rate (3). During 1991–2006, the number of Strongyloides-associated deaths in the United States listed on death certificates ranged from 14 to 29 annually (4). Eosinophilia is the most common indicator of infection, but it is not specific to this disease and is not always present (5).
Beginning in 2013, Strongyloides case reports in Los Angeles County increased; no cases were reported in 2012, but 14 were reported in 2013 and 29 in 2014. Twenty-five (58%) of these reports were submitted by CDC's parasitic serology reference laboratory, for patients examined at Los Angeles County–University of Southern California Medical Center (LAC-USC). Sixteen reports were submitted by refugee health clinics, and two by other health care providers. The increase in case reports prompted a review of the 25 patients with Strongyloides examined at LAC-USC, a facility that accounts for 3% of all hospitalizations in a county of nearly 10 million residents.
The patients with Strongyloides examined at LAC-USC were mostly male (76%), Hispanic (80%), or Asian (16%). Most were foreign born (75%), primarily from a Latin American country (60%). The average patient age was 50 years (median = 55 years; range = 25–73 years). All patients tested positive for Strongyloides-specific antibody by enzyme immunoassay (EIA) testing performed by the CDC reference laboratory, indicating current or recent infection (6). The average test reaction value was 25.76 units/µl (range = 2.37–75.58 units/µl; reference 1.7 units/µl). Four were immunocompromised. Three patients were hospitalized at the time of testing; no patient had a diagnosis of disseminated disease or hyperinfection.
Of the 25 patients, 21 (88%) had peripheral eosinophilia (>450 eosinophils/µl) at the time of Strongyloides testing; the average eosinophil count was 1,297/µl (range = 201–3,472/µl). Nearly all patients (96%) had documentation of eosinophilia at some point during the 6 months preceding Strongyloides testing. Most were tested in an outpatient facility (88%), and many were being followed for other chronic health conditions such as hypertension (52%) or diabetes (48%), where eosinophilia appeared to be an incidental finding. Treatment was documented for 17 patients (68%), consisting of ivermectin alone for 15 patients, albendazole alone for one patient, and both drugs for one patient.
The recent increase in reports of Strongyloides in Los Angeles County is likely the result of screening guidelines published in 2012, which recommend screening all persons with a potential Strongyloides exposure history who are at risk for disseminated disease, including persons requiring immunosuppressive therapy (7), and changes in existing screening protocols, rather than an actual increase in disease prevalence. The high prevalence of eosinophilia among persons with latent Strongyloides infection in Los Angeles County highlights the importance of screening persons with eosinophilia for whom more common causes have been ruled out. Diagnosis of latent infection is important so that treatment can be initiated and the risk for more severe disease eliminated, and is crucial for persons with unexplained eosinophilia who will be placed on immunosuppressive drug regimens (7).
The burden of disseminated disease and hyperinfection in Los Angeles County remains unknown. Further research is needed to better characterize the at-risk group in Los Angeles County and enhance screening policies.
1Acute Communicable Disease Control Program, Los Angeles County Department of Public Health, California; 2Keck School of Medicine of the University of Southern California, Los Angeles, California.
Corresponding author: Curtis Croker, ccroker@ph.lacounty.gov, 213-240-7941.
References
CDC. Traveler's health. Chapter 3: infectious disease related to travel. Atlanta, GA: US Department of Health and Human Services, CDC; 2015. Available at http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-3-infectious-diseases-related-to-travel/strongyloidiasis.
CDC. Notes from the field: strongyloidiasis in a rural setting—southeastern Kentucky, 2013. Morb Mortal Wkly Rep 2013;62:843.
CDC. Parasites. Strongyloides: resources for health professionals. Atlanta, GA: US Department of Health and Human Services, CDC; 2015. Available at http://www.cdc.gov/parasites/strongyloides/health_professionals/.
Croker C, Reporter R, Redelings M. Strongyloidiasis-related deaths in the United States, 1991–2006. Am J Trop Med Hyg 2010;83:422–6.
Naidu P, Yanow SK, Kowalewska-Grochowska KT. Eosinophilia: a poor predictor of Strongyloides infection in refugees. Can J Infect Dis Med Microbiol 2013;24:93–6.
Loutfy MR, Wilson M, Keystone JS, Kain KC. Serology and eosinophil count in the diagnosis and management of strongyloidiasis in a non-endemic area. Am J Trop Med Hyg 2002;66:749–52.
Mejia R, Nutman TB. Screening, prevention, and treatment for hyperinfection syndrome and disseminated infections caused by Strongyloides stercoralis. Curr Opin Infect Dis 2012;25:458–63.
CDC Website
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6433a8.htm?s_cid=mm6433a8_e
Strongyloidiasis Infection FAQs
On this Page
What is strongyloidiasis?
How do people get infected with strongyloides?
Where do most cases of strongyloidiasis occur in the United States?
What are the signs and symptoms of strongyloidiasis?
How soon after the exposure do symptoms develop?
What should I do if I think I might have strongyloidiasis?
How is infection with Strongyloides diagnosed?
How is strongyloidiasis treated?
How can strongyloidiasis be prevented?
What is strongyloidiasis?
Strongyloidiasis is a disease caused by a nematode, or a roundworm, in the genus Strongyloides. Though there are over 40 species within this genus that can infect birds, reptiles, amphibians, livestock and other primates, Strongyloides stercoralis is the primary species that accounts for human disease. The larvae are small; the longest reach about 1.5mm in length -- the size of a mustard seed or a large grain of sand.
How do people get infected with strongyloides?
Strongyloides is classified as a soil-transmitted helminth. This means that the primary mode of infection is through contact with soil that is contaminated with free-living larvae. When the larvae come in contact with skin, they are able to penetrate it and migrate through the body, eventually finding their way to the small intestine where they burrow and lay their eggs. Unlike other soil-transmitted helminths such as hookworm and whipworm whose eggs do not hatch until they are in the environment, the eggs of Strongyloides hatch into larvae in the intestine. Most of these larvae will be excreted in the stool, but some of the larvae may molt and immediately re-infect the host either by burrowing into the intestinal wall, or by penetrating the perianal skin. This characteristic of Strongyloides is termed auto-infection. The significance of auto-infection is that unless treated for Strongyloides, persons may remain infected throughout their lifetime.
In addition to contact with soil and auto-infection, there have been rare cases of person-to-person transmission in:
organ transplantation
institutions for the developmentally disabled
long-term care facilities
daycare centers.
Where do most cases of strongyloidiasis occur in the United States?
In the United States, Strongyloides has classically been associated with uniformed-service veterans who returned from tropical regions such as Southeast Asia and the South Pacific during World War II. Small domestic studies have shown locations of infection in rural Appalachia. The highest rates in the United States have been documented in immigrant populations.
Strongyloides is more commonly found in areas that are relatively warm and moist, in rural areas, and areas associated with agricultural activity, but it can occur anywhere. It is found more frequently in socio-economically disadvantaged persons and in institutionalized populations.
What are the signs and symptoms of strongyloidiasis?
The majority of people infected with Strongyloides are without symptoms. Those who do develop symptoms tend to have non-specific, or generalized complaints. Some people develop abdominal pain, bloating, heartburn, intermittent episodes of diarrhea and constipation, a dry cough, and rashes. Rarely people will develop arthritis, kidney problems, and heart conditions.
Strongyloidiasis can be severe and life-threatening in persons who:
are on oral or intravenous steroids -- such as those with asthma or chronic obstructive pulmonary disease (COPD) exacerbations, lupus, gout, or in persons using steroids for immunosuppression or symptomatic relief
are infected with the virus HTLV-1
have hematologic malignancies such as leukemia or lymphoma
are transplant recipients.
How soon after the exposure do symptoms develop?
Most people do not know when their exposure occurred. For those who do, a local rash can occur immediately. The cough usually occurs several days later. Abdominal symptoms typically occur approximately 2 weeks later, and larvae can be found in the stool about 3 to 4 weeks later.
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What should I do if I think I might have strongyloidiasis?
See your health care provider.
How is infection with Strongyloides diagnosed?
Strongyloides is classically diagnosed by visualization of larvae on microscopic stool examination. This may require that you provide multiple stool samples to your doctor or the laboratory. Some laboratories are capable of diagnosing Strongyloides with blood tests.
How is strongyloidiasis treated?
Safe and effective drugs are available to treat infection with Strongyloides.
How can strongyloidiasis be prevented?
The best way to prevent Strongyloides infection is to wear shoes when you are walking on soil, and to avoid contact with fecal matter or sewage. Proper sewage disposal and fecal management are keys to prevention.
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