Many food stores in countries near the equator are contaminated by Aspergillus flavus
and A. parasiticus
, fungi that produce a toxic substance called aflatoxin. Aflatoxins
are toxic and among the most carcinogenic substances known, although in most cases the liver can render the toxins relatively harmless.
In many parts of the world grain is tested and protective measures are in place. For example, the United States Food and Drug Administration (FDA) has established action levels for aflatoxin
present in food or feed to protect human and animal health. However, such measures are not in place in most parts of Africa.
In a study led by Pauline, Jolly, Ph.D., professor in the Department of Epidemiology within the School of Public Health at the University of Alabama at Birmingham (UAB), people infected with HIV who consume foods containing aflatoxins are at risk from an accelerated onset of AIDS.
For the experiment
, 314 HIV-positive people who were not yet on antiretroviral therapy and who lived in Kumasi, Ghana, were recruited. The researchers divided patients into four groups based on their level of aflatoxin exposure and found that those in the highest exposure group were around three times more likely to have a high HIV viral load than those in the lowest exposure group. Higher viral load translates into higher rates of HIV transmission and the potential for earlier progression to the opportunistic infections of AIDS.
The theory runs that fungal toxin may suppress the immune system by reducing the production of certain immune cells or the proteins that activate them.
The findings have been published
in the World Mycotoxin Journa
l. The study is called "Association between high aflatoxin B1 levels and high viral load in HIV-positive people."