A quick primer for nurses
You’re not alone if you are wondering about the safety of the country’s food supply after the recent outbreaks of salmonella. Foodborne illness is a major cause of concern, with an estimated 76 million cases causing 325,000 hospitalizations and 5,000 deaths annually. Because healthy people with a competent immune system are usually able to successfully fight these bacterial and viral diseases, it is suspected that much foodborne illness goes unreported. The Centers for Disease Control and Prevention (CDC) estimate that for each one of the 35,000 known cases of salmonella, another 38 cases go undiagnosed and unreported each year. In other words, there are over 1.3 million cases of salmonella annually, and this is only one cause of foodborne disease.
Outbreaks of foodborne illness are discovered when a group of people eating the same contaminated food come down with the same illness. The food they shared may have become contaminated in a number of ways: poor hygiene practices on the part of the food preparers, food left unrefrigerated for too long a period, or contamination at the source with fertilizers, pesticides or unclean water. Raw or undercooked foods are always suspect, and although the benefit of fresh produce is recognized for health reasons, these foods should always be washed and carefully inspected before eating.
Managing an Outbreak
Disease surveillance is conducted across the country and relies on doctors or laboratories to report positive cases from the list of “reportable diseases” to their state health department. This list includes many diseases that are dangerously contagious and often easily preventable. When the reportable disease is spread over a wide geographic area, an outbreak is more difficult to detect, but regional reports can be examined by a central agency, which may coordinate a timely response.
Food safety is managed not just by local, county and state health officials, but also by the nation’s primary public health agency, the CDC. FoodNet is the principle arm of the CDC’s Emerging Infectious Disease Program and conducts surveillance as a collaborative project with the U.S. Food and Drug Agency, the Department of Health and Senior Services, and the U.S. Department of Agriculture.
Once an outbreak is detected, an army of investigators contacts the sick individuals as well as their healthcare providers to determine the offending agent and then control the spread as quickly as possible. Stool and blood tests may be ordered on the patient, and food samples examined microscopically. Because many foodborne illnesses have an incubation period of several days, it can become a lengthy and difficult process to determine exactly what was eaten over the last few days and find the common elements.
Once the agent and cause is identified, public health officials can take the necessary steps to limit further spread and offer education to the public and to healthcare providers. Restaurants or packers may be closed, supermarkets ordered to remove food, and consumers directed to return merchandise. Communication to the media that is clear and accurate is vital in order to gain additional case reports and to prevent panic.
Bacteria and Viruses Are to Blame
Both bacteria and viral microbes can be responsible for foodborne disease. Some of the more common bacterial infections found in our food are campylobacter, which lives in the intestines of healthy birds, and salmonella, which also lives in birds but can be found in reptiles and mammals. Infected birds may produce contaminated eggs with intact shells. Because poultry is raised in crowded conditions, much of the poultry stock may be affected with either disease without showing symptoms. For this reason thorough cooking is always demanded.
E. coli is another bacterial pathogen, which may cause severe bloody diarrhea and painful abdominal cramping. In a small number of patients, intense infection may get into the bloodstream and can proceed to kidney failure. This pathogen lives in cattle and gets into the food supply during slaughter or when farm water run-off contaminates crop areas.
Viruses can also cause foodborne illness; calicivirus, or norwalk-like virus, is very common and extremely contagious. It causes vomiting and diarrhea that may resolve with only supportive treatment in about two days. This virus doesn’t have an animal reservoir but seems to spread readily from person to person. It may enter the food chain through lack of hand hygiene.
Also included as a cause of foodborne disease are parasites like cyclospora, recently found in Guatamalan raspberries, and giardia, which can be found in contaminated water. Toxins, like those produced by staphylococcus aureus, can also become a source of intense vomiting. This particular toxin can cause illness even after the microbe that produces it is gone.
Because many of these illnesses are self-limiting, no medication may be warranted. Occasionally, an anti-diarrhea agent may be indicated to prevent dehydration, and an increase in fluids, including Pedialyte and Gatorade, will promote electrolyte balance. A physician should be consulted for:
– Oral fever of over 101.5
– Blood in the stool
– Illness lasting longer than three days
– Dehydration despite an increase in fluids. Symptoms of dehydration include thirst, decrease in urination and dizziness upon standing.
Christine Contillo, RN, BSN, has worked as a nurse since 1979 and has written extensively for various nursing publications, as well as The New York Times.
This article is from workingnurse.com.