After person eats a foodborne pathogen, such as Salmonella, E. coli O157:H7 or Norovirus, what is now going to happen? First, there is a period where the individual experiences a delay between ingestion and illness onset, this is called an incubation period. Incubation periods vary from pathogen to pathogen. Some can be quick like Norovirus which can onset in a matter of hours. Others, like Hepatitis A, can have an onset time that lasts for over a month.
During the incubation period, the food pathogens pass through the stomach and into the intestines. Under perfect circumstances, the foodborne illness would get killed by stomach acids, but that is not always the case with food poisoning and if just a few microbes survive (only 10 E. coli O157:H7 bacteria are believed to be enough to cause illness), they can take hold in the intestines.
Upon entering the intestines, the food pathogens typically attach to the intestinal lining and start to multiply. Some of these foodborne illness microbes stay in the intestine, others pathogens can produce toxins that get absorbed into the blood stream and some spread into other body tissues.
When a pathogen, let’s say Campylobacter, stays in the gut, it can cause bloody diarrhea, intense nausea, vomiting, abdominal cramping and dehydration. These symptoms can be so severe they may require hospitalization.
When a bacteria like E. coli O157:H7 produces shiga-toxins that get into the blood, we encounter the dangerous and potentially fatal condition hemolytic uremic syndrome (HUS). When hemolytic uremic syndrome (HUS) occurs, the E. coli toxins cause damage to red blood cells eventually cutting of circulation to important organ systems, typically the kidneys. A battle with hemolytic uremic syndrome (HUS) typically results in long term kidney damage and in about 10% of hemolytic uremic syndrome (HUS) cases, the condition is fatal.
When a bacterium, such as Salmonella, gets into the blood stream we can see a complication called septicemia or sepsis. The body’s autoimmune response to the bacteria in blood and body tissue causes a severe reaction where the body essential tries to reject the blood or tissue. This condition is referred to by some as “blood poisoning”. Sepsis can turn very bad very quickly and has very high mortality rates associated with the condition.
For most people, the realities of a foodborne illness will be experienced at least once in their lives. The majority of these individuals will recover with no long term impact, other than memories of what many describe as the most intense sickness ever experienced. For an unfortunate few, foodborne illness will lead to complications like hospitalizations, hemolytic uremic syndrome (HUS) and septicemia. For as many as 5000 of those unfortunate ones will not win the battle with their foodborne illness and a “simple” food poisoning will prove to be fatal.
Richard J. Arsenault, 2010
