There is more uncertainty in the total number of Chagas’ cases than there are total cases of HIV infection in Latin America.
I picked up the just-off-the-(virutal)press issue of the American Journal of Tropical Medicine and Hygiene, the publication of the American Society of Tropical Medicine and Hygiene. There were three new articles on Chagas’ Disease. So in the same issue I read that 18 million or 9.8-11 million or 9-13 million individuals are infected with Trypanosoma cruzi. One paper–the World Health Organization’s 2002 report, Control of Chagas’ Disease: Second Report of the WHO Expert Committee–claims that Chagas’ Disease is the main cause of death in endemic areas.
So what is the point here? Certainly not to compare one disease to another. Not all of those infected with Trypanosoma cruzi will go on to develop the debilitating and fatal chronic form of the disease, but presumably every case of HIV will infection will progress to AIDS, or require years, if not decades, of treatment. Interestingly, there are more and better drugs for the treatment of HIV infection than there are for chronic Chagas’ Disease. To complicate matters, immune suppression, like that caused by HIV infection, is a factor in the activation of chronic Chagas’ Disease, and there are an unknown number of cases of co-infection with Chagas’ Disease and HIV. Chagas’ Disease runs a more severe course in those who are immune-suppressed.
So what is the point here?
It is that Chagas’ is so widespread that just the level of error in our estimates is even greater than our best estimates for the total prevalence of HIV in the same geographic area.