From the New York Times:
Aflatoxins — poisons produced by fungi that grow on moldy peanuts and corn — may be worsening Africa’s AIDS epidemic by helping suppress the immune systems of newly infected people, a new study has found.
The study, by researchers at the University of Alabama at Birmingham and published recently in the World Mycotoxin Journal, measured blood levels of aflatoxins and H.I.V. in 314 Ghanaians who had never taken antiviral drugs.
The more aflatoxins they had, the more likely they were to have high blood levels of H.I.V. — even those with higher levels of CD4 blood cells, meaning they had not been infected long and were not yet eligible for triple-therapy cocktails under the latest World Health Organization guidelines.
The toxins, produced by aspergillus fungi that grow on damp grains, nuts and beans, are so common as to be almost unavoidable in humid climates, but so dangerous that federal law limits concentrations in food to 20 parts per billion. American peanut-butter makers are always on the watch for them. Ground peanuts are a staple food of West Africa.
In high doses, aflatoxins can be deadly. A 2004 outbreak in Kenya killed 125 people; samples of moldy corn had up to 8,000 parts per billion. Regular exposure to low doses can cause liver cancer.
The authors suggested that aflatoxins either contribute proteins that help H.I.V. reproduce or somehow lessen the numbers of the white blood cells that the virus targets, making its attack on the immune system more potent.