Thursday, March 30, 2023

Part II

We previously mentioned how the HIV and AIDS epidemic had its most florid manifestation in sub-Saharan Africa. More than two-thirds of the world’s AIDS cases have occurred in that region. As noted in our last episode, it seems that the initial appearance of HIV came about from the cross-species transmission of HIV from a primate carrier to a human in the early 1950s, probably in Cameroon.

But what other factors contributed to this terrible epidemic in Africa? It is difficult to say exactly what caused it, but certain things can be hypothesized as contributory. Most of the virus’s transmission appears to be from heterosexual male-female contact. It is relatively common in cultures that engage in intercourse with multiple partners and this casual practice obviously enhances the rate of HIV transmission. In some of the countries as well, there are a large number of women engaged in prostitution, further enhancing these problems. Local cultural customs and attitudes may exacerbate these problems. For example, there was a widespread resistance to the use of condoms despite numerous educational programs regarding its utility in disease prevention. Furthermore, while stigma and discrimination have been serious issues even in the U.S., it is a significantly larger problem in the towns and villages of Africa, leading to an aversion to being tested for HIV and thereby interrupting the cycle of spread.

Male-to-male transmission was and is likewise a major problem. Aside from its prevalence as a natural part of African society, its prevalence is enhanced by circumstances that lead to male isolation. Thus, large numbers of workers brought from their homes to mines in South Africa or elsewhere for two or three months at a time may engage in this sort of sexual activity, which is known to engender a high rate of HIV transmission. When they return to their homes, they then transmit the virus to their spouses.

Widespread poverty has also played a role. Even for those who did choose or were willing to use condoms, they may not have had the financial resources to purchase them. When antiretroviral therapy first became available, its cost was prohibitive for the average African. Subsequent programs by local governments and NGOs have made great efforts to provide these public health programs either at low cost or for free, so the situation has recently improved dramatically.

The impact of these factors has led to HIV infection rates that are staggering. In some countries, such as eSwatini (the former Swaziland), one of the landlocked countries of South Africa, or Botswana, the HIV prevalence rate has risen to 25-27%. This is a figure that is difficult to comprehend. South Africa, the largest and most prosperous country in sub-Saharan Africa, has the most HIV-infected individuals of any country (because of its large population) with an overall prevalence rate that exceeds 20%.

In the pre-treatment era, HIV had a profound impact on life expectancy in these countries. For the most part, HIV kept life expectancy below 50 years. For example, Botswana’s life expectancy of about 58 years prior to 1980 declined to about 38 years in 2008. Similarly, life expectancy for South African Blacks, the high-HIV prevalence population, was in the 45 years range. The consequence for these sub-Saharan countries was that the diseases of middle and older ages—cancer, heart disease, stroke, diabetes—were relatively uncommon.

Antiretroviral therapy became truly effective around 1997. Making it widely available in Africa has been a challenge. Its cost has been one problem. In addition, the regimen itself is complex, and thus maintaining adherence to it has been a problem as well. By this point, it is estimated that over 80% of HIV-infected individuals in most of the high-prevalence countries have had the treatment made available to them. The results have been truly remarkable. HIV for those treated is becoming, in essence, a chronic disease with a survival that approaches that of the uninfected population. The result is that life expectancy has now climbed back up to 55-60 years. With that has come the “blessing” of the chronic diseases of middle and older ages that we suffer from in the West—cancer, coronary heart disease, stroke, diabetes. Cancer rates are soaring in countries where the infrastructure for coping with this is nonexistent—some countries have one or few oncologists, no (or only one) linear accelerator for radiation therapy, one pathologist, one chemotherapy infusion center with only limited chemotherapy drugs available. Ministries of health are struggling to remedy this and bring themselves into the modern era.

Increased affluence in Africa in recent years has also increased the cancer burden—an increase in dietary meat with a concomitant reduction in raw fruits and vegetables; increased obesity; a more sedentary lifestyle; increased tobacco use. We are consequently in the midst of a powerful ongoing epidemic of cancer (as well as the other chronic diseases) in Africa, and should stay tuned to see how the various governments, philanthropic organizations (like the Gates Foundation) and other NGOs provide resources and support to this continent.

Alfred I. Neugut, MD, PhD, is a medical oncologist and cancer epidemiologist at Columbia University Irving Medical Center/New York Presbyterian and Mailman School of Public Health in New York.

This article is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment, and does not constitute medical or other professional advice. Always seek the advice of your qualified health provider with any questions you may have regarding a medical condition or treatment.

Sign up now!