In other threads at these boards I’ve covered my own theories that too clean of an environment can lead to a compromised immune system. The link that I wanted to post will not work so here are some excerpts from the study and its report in the famous British medical journal Lancet:
Dust bacteria may help stop asthma By David Derbyshire
“A BACTERIAL by-product found in household dust and dirt may protect babies from asthma later in life, a new study suggests. Researchers at the National Jewish Medical and Research Centre in Denver say that exposure to endotoxin, a substance produced by micro-organisms in soil and waste, may help prime the immune system.”
“The finding backs up the “hygiene theory” of asthma and allergies - that the preoccupation with cleanliness is partly to blame for the growing incidence of the disease. Allergies were rare 150 years ago. Today, one in seven British children is being treated for asthma.”
“High standards of cleanliness mean that infants are not being exposed to the microbacteria and toxins that could help the immune system develop.”
Search for the Science News cover article, “Germs of Endearment” for more information. I remain adamant that too many people are sterilizing their environments with all of the new antibacterial cleaners. Such a reduction in challenges to the immune system do not bode well for human disease resistance.
As to the people in the third world and their illnesses, I would venture that more of them are related to parasites and virulent pathogens. I doubt that salmonella is a major killer for the populations in question. Cholera, influenza, tuberculosis and river fevers are much bigger factors than low level food poisoning. You are mixing apples and oranges.