By: Heather Williams

Concern is growing as the numbers keep increasing in the Papaya Salmonella outbreak.  With 109 cases from at least 16 states, this is a serious situation.  Authorities have begun to identify the source of the outbreak, but still investigating if any other farms could be affected.  Until this is resolved, the CDC (Center for Disease Control and Prevention) is asking that consumers do not consume and throw away or return Maradol papayas imported from Mexico.  Retailers should remove them from the shelves and restaurants should not buy or serve Maradol papayas imported from Mexico.  Any place that the papayas have touched such as counters, refrigerator shelves, or refrigerator drawers should be disinfected.

Update

As of the last CDC update August 4, 2017, 109 cases have been reported, 35 have been hospitalized, and 1 death has occurred in the State of New York.  States affected include: Connecticut, Delaware, Iowa, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, North Carolina, New Jersey, New York, Oklahoma, Pennsylvania, Virginia, and Wisconsin.

At first it seemed that Salmonella Kiambu traced back to Maradol papayas was the only bacteria involved in the outbreak.  However testing has proved that another Salmonella strain, Salmonella Thompson has also been found on these papayas and has infected people.  The FDA has identified several types of bacteria in papaya sources.  More investigation is underway to determine what has contributed to this outbreak.

Currently the Caribeña brand of papayas imported from Mexico have been identified as one brand linked to the outbreak.  Additionally, the farm Carica de Campeche has also been identified as a likely source of Salmonella infected papayas.  Investigators are looking into other brands that may have used the farm Carica de Campeche as a papaya source.The agency is working with the farm and the distributer to test and identify any additional sources of the Salmonella infection.  On July 26, 2017 Grande Produce recalled Maradol papayas under the brand Caribeña that were distributed between July 10 and July 19, 2017. Recently, the Cavi brand of papayas were also recalled, as they too come from the same farm.

How Does Salmonella Get Inside Produce?

Many instances of outbreaks trace back to produce.  In fact, 13% of all outbreaks between 1990 and 2005 were linked to fresh produce.  One of the driving factors is that produce is one of the main food products that are often consumed raw and many times handled the least.  The question becomes, how did the bacteria get inside the fruit or vegetable?  While the bacteria is Salmonella and the fruit or vegetable in this case is papaya, this is a question many have pondered.  The answer to this important question would allow farmers and distributers better ways of preventing contamination, which would lower opportunities for outbreaks.

Could the irrigation water be contaminated with feces from livestock or wild animals such as deer or geese?  Could animals wandering through the crops contaminate the fruits and vegetables with infectious feces?  Is uncomposted animal manure being applied to a field?  Is the water table contaminated with an infectious bacteria?  If so, can the plant pull the bacteria through the root structure into the plant?

One of the main questions researchers are interested in finding out, is how the bacteria contaminate produce.  In fact, many companies sponsor research to get to the bottom of this question for their particular product in order to prevent future contaminations.  As each plant has unique properties and mechanisms for bringing in nutrients and how the water and nutrients travel through itself, investigations can only focus on one type of produce at a time.

Baby Spinach E. coli Investigation

In 2006, baby spinach was the source of an E. coli outbreak.  Fresh Express, a produce company, funded research to determine if the roots of the plant could pull pathogens from the soil and transport them to other parts of the plant, such as the stems and leaves.  This research would be beneficial to spinach farmers and could carry over to other salad greens with similar mechanisms.  By placing a fluorescence gene in an experimental E. coli bacteria, researchers could spy on the bacteria and watch how it moves through the plant.  They found that E. coli can survive for a surprising 28 days and could move from the soil into the roots of the spinach plants.  It turns out that the E. coli did not move past the roots to the plants interior structures, leaning toward E. coli contamination originating from the external parts of the plant.

Cantaloupes and Salmonella Investigation

Researchers from University of California, Davis investigated how cantaloupes may get contaminated with Salmonella.  This is a major concern for California, as 70% of the cantaloupes sold in the United States comes from this state.  Researchers concluded that uptake from contaminated soil was unlikely to travel beyond root structures, urging scientist to identify another route of entry.  They considered that external contact with pathogens could provide potential for contamination.  Irrigation water or contamination from the ground’s surface could transfer pathogens to the melons during normal growing and transporting methods.  Researchers concluded that an opening in the surface of the fruit such as a nick or cut, could allow a route of entry for the pathogen.  In these cases, the pathogen makes its way inside and no amount of washing it could remove the bacteria.

How to Protect Yourself

Prevention and helming keep ourselves safe is something we can always do, despite issues in the food system.  While we expect that the food we purchase from reputable vendors is safe and healthy, we can take small extra steps to keep ourselves and our family safe.

The best way to protect yourself from contaminated produce is to inspect it thoroughly prior to purchasing.  Do not buy any fruit or vegetable with nicks, cuts, or bruises.  These are avenues for harmful bacteria to make its way inside, potentially causing illness.

Once you get the produce home, store it properly.  If it is a product meant to store at room temperature, set aside a place for it on your counter in a basket or contained location.  If it is a product meant to store in the refrigerator, use the produce drawers in your refrigerator if possible.  This contains it until you are ready to use it.  Wash these areas regularly so bacteria cannot grow out of control and begin to contaminate other things in your kitchen and home.

Wash produce thoroughly.  There are different techniques depending on the type of produce you are working with.  Wash and dry thoroughly to remove any residual contamination from the farm or even the store you purchased it from.  This also applies to any produce grown in your own garden.  You may have bacteria lurking in your own back yard.  Always be safe and remember to wash.

 

Sources:

https://www.cdc.gov/salmonella/kiambu-07-17/index.html

https://www.cdc.gov/salmonella/kiambu-07-17/map.html