Changes during pregnancy alter the mother’s immune system, making pregnant women more susceptible to foodborne illness. Harmful bacteria can also cross the placenta and infect an unborn baby whose immune system is under-developed and not able to fight infection. Foodborne illness during pregnancy is serious and can lead to miscarriage, premature delivery, stillbirth, sickness or the death of a newborn baby.
Young children are more at risk for foodborne illness because their immune systems are still developing.
As people age, their immune system and other organs become sluggish in recognizing and ridding the body of harmful bacteria and other pathogens that cause infections, such as foodborne illness. Many older adults have also been diagnosed with one or more chronic conditions, such as diabetes, arthritis, cancer, or cardiovascular disease, and are taking at least one medication. The chronic disease process and/or the side effects of some medications may also weaken the immune system. In addition, stomach acid decreases as people get older, and stomach acid plays an important role in reducing the number of bacteria in the intestinal tract – and the risk of illness.
The immune system is the body’s natural reaction or response to “foreign invasion.” In healthy people, a properly functioning immune system readily fights off harmful bacteria and other pathogens that cause infection. However, the immune systems of transplant patients and people with certain illnesses, such as HIV/AIDS, cancer, and diabetes, are often weakened from the disease process and/or the side effects of some treatments, making them susceptible to many types of infections — like those that can be brought on by harmful bacteria that cause foodborne illness. In addition, diabetes may lead to a slowing of the rate at which food passes through the stomach and intestines, allowing harmful foodborne pathogens an opportunity to multiply.