It begins almost innocuously. A slight queasy feeling around dinnertime. Stomach cramps by morning. By afternoon, you have a fever and are unable to leave the bathroom. Most people wait it out, drink some water, and dismiss it as a rough stomach bug. They get better and move on in a few days. However, salmonella poisoning is not always the controllable annoyance that people believe it to be. Each year, it sends over a million Americans to their sick beds and recently claimed a life in the United Kingdom.
The recent outbreak in the UK provides a helpful, if sobering, case study. 207 cases of a closely related strain of Salmonella Enteritidis were confirmed by the UK Health Security Agency, with the majority of cases occurring in England. Over one-third of those infected needed medical attention. Two became infected with bloodstream infections. One person passed away. Eggs imported from outside the UK are the suspected source, which is still the subject of an ongoing investigation. This information has sparked unsettling concerns about food supply chains and the regulations governing imported produce.
Both human and animal intestines are ideal habitats for salmonella bacteria. Contaminated water, improperly handled meat and poultry, raw eggs, and even seemingly insignificant things like not washing your hands after handling an animal or cracking an egg can all introduce them into food. Although some people become ill within six hours of exposure, symptoms usually appear eight to seventy-two hours later. The typical constellation consists of nausea, vomiting, fever, cramping in the stomach, and diarrhea. It usually goes away on its own in three to seven days.
However, what occurs in the small percentage of cases where something goes wrong makes Salmonella more difficult to rule out. The bacteria do not remain in the gut in certain patients. They penetrate the intestinal lining, enter the bloodstream, and cause what medical professionals refer to as an invasive infection, which can develop into sepsis, a disease in which the body’s own organs are attacked by the immune system. Age is a factor.
The infected person’s underlying health also changes. The risk of the infection spreading beyond the digestive tract is significantly higher in infants, adults over 65, and those with compromised immune systems. In many cases, the body the bacteria is in—rather than the bacteria itself—is what makes the difference between a bad few days and a potentially fatal hospital admission.
Less than a hundred of the more than 2,600 different types of Salmonella that scientists have discovered are responsible for the majority of human illnesses. Certain strains are more likely than others to enter the bloodstream; for example, Salmonella Dublin appears in blood samples far more frequently than Salmonella Enteritidis, the strain responsible for the current outbreak in the UK.
This distinction is important. Public health officials advise against interpreting the 38% hospitalization rate from this outbreak too broadly because individuals with severe symptoms are just more likely to be tested and counted, which distorts the picture of how dangerous a particular strain is.
For what it’s worth, prevention is actually quite easy in theory, even though it can be more difficult in reality. The bacteria are eliminated by thoroughly cooking eggs and poultry. It is very beneficial to wash your hands both before and after cooking.
The possibility of the bacteria spreading from person to person—which is frequently underestimated—can be avoided by not preparing food for others while ill. The UK’s Food Standards Agency has been especially forthright in recommending that vulnerable populations, such as young children, elderly people, and expectant mothers, stick to eggs bearing the British Lion mark or the Laid in Britain program, which requires hen vaccination and additional testing.
The specifics of imported eggs are worth considering. Salmonella vaccinations are required for hens in the United Kingdom. The conditions under which eggs are produced may differ when they arrive from overseas. This tension has long been noted by the industry. Although the current outbreak hasn’t proven that imported eggs are the source—investigators are still figuring out the food chain—it has raised the question once again.
Because salmonella poisoning is so common, it rarely causes much concern. That might be the appropriate reaction; for the majority of healthy adults, it is actually transient and self-limiting. However, it’s important to understand the distinction between waiting too long and waiting it out. Call a doctor instead of just reaching for more water if you have a high fever, blood in the stool, severe dehydration, or symptoms that don’t start to go away after a few days. It’s not overly dramatic advice. When the boundary between uncomfortable and dangerous turns out to be thinner than anticipated, it’s the kind of thing that matters.
