Although it is a relatively minor holiday in Mexico, in the United States Cinco de Mayo has become increasingly popular, partly because it provides those with ties to Mexico to celebrate its customs and culture and partly because of the marketing efforts of the fresh produce industry.

Cinco de Mayo mealThe annual remembrance of the Mexican army’s 1862 victory over France at the Battle of Puebla during the Franco-Mexican War has become a sales tool for growers and shippers of avocados, tomatoes, onions and limes. Retailers also use Cinco de Mayo as a marketing opportunity for everything from tortilla chips to margarita mix.

What the holiday promotions don’t generally include is information about how dangerous Cinco de Mayo can be if food safety practices are not front and center in homes, restaurants and at civic activities.

Salsa, guacamole, ceviche and shredded meat and poultry are all potential vectors for foodborne pathogens such as E. coli, Salmonella, Listeria monocytogenes, Vibrio parahaemolyticus, cholera and Clostridium perfringens.

Salsa and guacamole
“The reason that salsa and guacamole are so susceptible to contamination is that they are made with multiple raw, uncooked vegetables and are often stored at room temperature,” according to the Food and Drug Administration.

“Tomatoes, cilantro, avocados and peppers have all been linked to separate outbreaks… These ingredients should be properly washed before preparation.”

Popular in South and Central America, the raw seafood dish ceviche has become a favorite in Mexican cuisine also. Traditional recipes call for raw seafood to be “cooked” in a marinade of citrus juice, vinegar, or other acidic liquid.

ceviche with chipsWhile the marinade denatures the raw seafood, it does not actually cook it. Consequently, bacteria, viruses and parasites are often served up as an unintended garnish on ceviche.

The FDA reports that specific microbial hazards in ceviche include: Anisakis simplex, Diphyllobothrium spp., Pseudoterranova decipiens and Pseudoterranova cattani, and Vibrio parahaemolyticus. Anisakiasis is a zoonotic disease caused by the ingestion of larval nematodes.

Cholera outbreaks in Latin America in the 1990s were linked to contaminated seafood that was eaten as ceviche.

Pregnant women are particularly at risk if they eat ceviche, with the American Dietetic Association urging all women to avoid ceviche during pregnancy. The increased risk for pregnant women extends to virtually all foodborne illnesses.

“Everyone is susceptible to contracting a foodborne illness. However, because your immune system changes during pregnancy, and your unborn child has an underdeveloped immune system, you and your unborn child are at risk from foodborne illnesses,” according to the FDA.

Shredded meat and poultry
Some of the most popular Mexican foods served in the United States at Cinco de Mayo celebrations are chimichangas, fajitas and tacos, which usually contain shredded beef, chicken and/or pork. Many people use slow cookers to prepare the meat and poultry, but the FDA warns that special precautions need to be taken to avoid food safety problems.

  • Before you begin — Check your slow cooker manual to find out how much meat it can hold. Some smaller cookers can only hold three pounds of meat, while others may fit up to 10 pounds;
  • Buy the meat of your choice, place it in a plastic bag and take it home within two hours; or one hour when the temperature is above 90 degrees F. Use chicken within two days and cuts of beef and pork within three to five days;
  • Always start with a clean cooker, clean utensils and a clean work area;
  • Wash hands for 20 seconds with warm water and soap before food preparation;
  • Add thawed meat and desired amount of liquid and spices suggested in your recipe;
  • Keep the lid in place, removing it only to stir the food; and
  • When you’re ready to shred the meat, use either a clean large, shallow bowl or platter and two clean forks to pull the meat apart.

Clostridium perfringens
Clostridium perfringens, often abbreviated to C. perfringens, is one of the most common causes of food poisoning in the United States. The Centers for Disease Control and Prevention estimate it causes nearly 1 million cases of foodborne illness each year.

The bacteria can be found on raw meat and poultry, in the intestines of animals and humans, and in the environment. C. perfringens infections can result when foods are not held at the proper temperatures before serving.

Hot foods must be kept at 140 degrees or higher and cold foods must be kept at 40 degrees or lower to minimize pathogen growth.

“Germs can grow in many foods within two hours unless you refrigerate them,” according to the FDA. When the temperature is above 90 degrees F, that time should be cut to one hour.

Public health officials recommend using a food thermometer to make sure foods are cooked to a high enough temperature to kill pathogens and bacteria. Those temperatures are:

  • 145 degrees F for whole beef, veal, fish, lamb, fresh pork and ham — allowing the meat to cool for 3 minutes before carving or consuming;
  • 160°F for ground beef, veal, pork and lamb, and for egg dishes.
  • 165°F for all poultry, including ground chicken and ground turkey, and stuffing, leftovers and casseroles.

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