COVID-19 - 40% of Cases Asymptomatic May Point to Pre-existing Partial Immunity and Mask-related Lower Infecting Dose

An article in the Washington Post discusses the level of asymptomatic people within the population and the role of partial immunity and potential impact of infecting dose. Clearly here has been uneven transmission, especially with far less children being infected, but when we look at those who test positive, there are a high percentage who are asymptomatic, a number which CDC estimates to be about 40%. One thought is that these people have partial immunity, perhaps acquired from a past infection from the normal cold virus, or from some childhood vaccination. In fact, in samples of blood from people who had not had the disease, there was some immune reactivity to the virus by T-cells. .

Another interesting factor may be the impact of masks on how much virus a person encounters during an infection event. We had discussed infecting dose a few weeks back and now it does seem that this plays a factor. The evidence they provide is when looking at outbreaks among large groups where mask wearing was and was not used. In cases where the level of masking was high, the levels of asymptomatic infection was higher.

Washington Post - Health
https://www.washingtonpost.com/health/2020/08/08/asymptomatic-coronavirus-covid/
Forty percent of people with coronavirus infections have no symptoms. Might they be the key to ending the pandemic?
New research suggests that some of us may be partially protected due to past encounters with common cold coronaviruses.

Firms Recall Citrus and Potatoes After Finding Listeria monocytogenes on Food Contact Surface

Freshouse II LLC of Salisbury, NC, and Wegmans is recalling Valencia oranges, lemons, limes, organic limes, and red B potatoes after the company’s routine internal testing identified Listeria monocytogenes on a piece of equipment in one of the packing facilities.

This would be considered a low risk in that the items 1) will not support the growth of Listeria, although organisms may survive 2) items are likely to be washed (cirtus) or cooked (potatoes) before use and 3) the Listeria was found on equipment and not the products.  To find Listeria on fresh produce is not uncommon (Heisick etal 1989), but once you find it on a food contact surface, you have to follow your corrective action.  For this facility, it will be important to understand whether this is a transient organism or is it an established strain.

The Produce News
https://www.theproducenews.com/news-dep-menu/29719-listeria-risk-prompts-citrus-potato-recall
Listeria risk prompts citrus, potato recall 

This Week in Mislabeled Product for Week Ending August 7, 2020

Wheat Missing from Label - H-E-B is voluntarily issuing an all-store recall for Blue Cheese Salmon Burgers due to an undeclared allergen - wheat.  The package types would indicate that this was a print-and-apply label.

Almond Milk Contains Cashew - SmithFoods Inc. announced that it is voluntarily recalling 16-oz pint packages of Earth Grown Vegan Non-Dairy Almond Based Frozen Desserts because it may contain an undeclared cashew allergen. The recall was initiated following a consumer complaint. The company continues to go through root cause analysis and is conducting a detailed review of allergen controls within all aspects of operations and supply chain processes.   There has been one reported incident of an allergic reaction to date.

Companies Issue Recalls for Products Containing Recalled Thomson Onions

FDA and FSIS issued notices for companies that had manufactured and distributed products using onions that had been included in onions recalled by Thomson International as part of the Salmonella outbreak.  Taylor Farms, Amana Meat Shop and Smokehouse and Giant Eagle issued recalls of product containing the onions.

https://www.fsis.usda.gov/wps/portal/fsis/home/!ut/p/a1/04_Sj9CPykssy0xPLMnMz0vMAfGjzOINAg3MDC2dDbwsfDxdDDz9AtyMgnyMDf3dDIAKIkEKcABHA0L6w_WjUJX4Wxq6AZWEBfp7OzsbWPgZwxTgtqIgN8Ig01FREQBCfym8/?
FSIS Issues Public Health Alert For Ready-to-Eat Meat and Poultry Products Containing FDA-Regulated Onions that have been Recalled due to Possible Salmonella Newport Contamination 

CDC Report - Characteristics of Meat Processing Facility Workers with Confirmed SARS-CoV-2 Infection — Nebraska, April–May 2020

In CDC MMWR, an article was posted on the investigation of an COVID-19 outbreak in a meat processing facility. There were 1,216 facility workers tested with 375 (31%) having positive results. They were able to question 241 of those who were infected.

• Approximately one third (78; 32%) of respondents reported no symptoms. Among the 163 symptomatic respondents, two were hospitalized, and no deaths were identified.  Only 24% had a cough and 34% had a measured fever.
• Close contact† with a visibly ill person (or person with diagnosed COVID-19) at work was reported by 70 (29%) workers; the most frequently reported close contact locations were production areas (74%) and cafeteria/break areas (51%).
• Most (87%) reported always having their temperature checked upon entry to work, fewer (41%) reported always being asked about symptoms.
• Thirty of 235 (13%) workers reported close contact with a visibly ill person (or a person with diagnosed COVID-19) outside of work.

What is striking in the report is the difficulty in preventing through just watching for cough and fever.   There will be many who are asymptomatic or just have minor symptoms.  In the end, screening is important (checking temperature and asking about the minor symptoms and potential exposure), but distancing and mask wearing are also very important.

FDA Warning Letters - Three Importers Issued Warning Letters for Not Having FSVP

In the weekly listing of Warning Letters, FDA had issued Warning Letters to three food importers for not having FSVP (Foreign Supplier Verification Programs in place for items that were being imported into the US.  "The FSVP regulation requires that importers perform certain risk-based activities to verify that human and/or animal food they import into the United States has been produced in a manner that meets applicable U.S. food safety standards."   This includes conducting a hazard analysis on each imported item from a supplier, determining if there are any significant risks, and then implementing controls for risks that are being controlled by the supplier.

1. Pasha Food Distribution USA, Inc.,of Chatsworth, California did not have a FSVP for roasted eggplant product, dried sumac and tahini products.  The company also did not register the facility as required.
2. Kaymile Trading, Inc.of South El Monte, California did not develop, maintain, and follow an FSVP fir the following items - Roasted onion granules and coarse black pepper
3. Ventura Terra Garden Inc., of  Ventura, CA was not in compliance for fresh packaged enoki mushrooms.

Pillsbury Releases Raw Cookie and Brownie Dough Products that Can Safely Be Eaten Raw

General Mills and their Pillsbury division announced they their refrigerated raw cookie dough and brownie dough are now safe to eat raw (on those packages marked as such). This comes due to the "move to use heat-treated flour and pasteurized eggs, creating a unique product that families can enjoy baked or straight from the package."

Cookie and brownie dough traditionally contain flour and eggs, two raw materials that can contain microbial pathogens such as Salmonella and E. coli. These pathogens have led to cases of foodborne illness when that product was eaten raw. But by using pretreated eggs and flour, the product is designed to be safe when eaten raw, that is, before cooking by the consumer.

One of the difficulties has been creating a product where the pretreatment does not affect the functionality of the ingredients so that the product comes out the same as it did with the untreated ingredients.

General Mills
https://www.generalmills.com/en/News/NewsReleases/Library/2020/July/Pillsbury-brings-childhood-dreams-to-life
News Releases
Jul 27, 2020
Pillsbury brings childhood dreams to life: Cookie and brownie dough now ‘safe to eat raw’

CDC Issues Alert on Red Onions for Salmonella, Company Issues Recall for Onions Distributed Nationwide

CDC is reporting that there is close to 400 reported cases of Salmonella infection linked to red onions. The outbreak covers 34 states. There are also cases reported in Canada. The reporting dates range from June 19, 2020, to July 12, 2020.

The onions likely originated from California by Thomson International Inc, so consumers should not eat onions from this company or products made with these onions. Onion types include red, white, yellow, and sweet varieties.  A recall for red, white and sweet yellow onions was issued by Thomson International on August 1, 2020.  The recall states that onions were distributed to wholesalers, restaurants, and retail stores in all 50 states, the District of Columbia and Canada.

Posted pictures from the release included the following label brands.

• Thomson  International Premium
• TLC Thomson International
• Majestic
• Kroger
• Utah Onions
• Hartley’s Best
• Onions 52
• Tender Loving Care
• Imperial Fresh
• El Competitor
• Food Lion.

It may be difficult for consumers to know which onions are from Thomson, whether that is when buying fresh onions or products processed using fresh onions, so it is important to ask the grocer or foodservice operator.

CDC Food Safety Alert
https://www.cdc.gov/salmonella/newport-07-20/index.html
Outbreak of Salmonella Newport Infections Linked to Red Onions
Posted July 31, 2020 at 8:00 PM ET

At A Glance
Reported Cases: 396
States: 34
Hospitalizations: 59
Deaths: 0
Recall: Yes

This Week in Mislabeled Products for Week Ending July 31, 2020

Whole Foods issued two allergen-related recalls this week, both with print-on-demand labels going onto product in plastic clamshell packaging.

• Whole Foods Market is voluntarily recalling Kouign-amann pastries in 35 stores across Colorado, Kansas, Missouri, Nebraska, New Mexico, Texas and Utah due to undeclared eggs. 
• Whole Foods Market is voluntarily recalling Chantilly Key Lime Tartlets from stores in Connecticut, Maine, Massachusetts, New Hampshire and Rhode Island due to an undeclared tree nut (almond) allergen.

While no reason was listed, one would guess that the ingredient statement had not been properly added into the database from which the label machine pulls the data.

https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/allergy-alert-undeclared-egg-kouign-amann-pastries-issued-select-whole-foods-market-stores-seven
Allergy Alert for Undeclared Egg In Kouign-Amann Pastries Issued By Select Whole Foods Market Stores In Seven States
Summary