AIDS

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Definition of epidemiology:
The branch of medicine that deals with the study of the causes, distribution, and control of disease in populations.
Causes and pathogenesis of AIDS in Africa:In Africa, AIDS is caused by severe starvation. An individual suffering from severe starvation usually loses up to 90% of his or her thymus size along with the capacity of the functions of their immune system. The release of endogenous cortisol plays a major role in the pathogenesis of AIDS in people suffering from malnutrition. In starvation, cortisol, a hormone released from the adrenal glands, is required for the conversion of fat and protein to glucose in the liver. Glucose is used as energy by the heart, brain, and other organs and without the endogenous cortisol, human beings are unable to survive very long without food. Any person who suffers from severe starvation has AIDS regardless if the person is HIV-positive or HIV-negative. Fortunately, AIDS in people who are suffering from severe starvation is reversible with proper nutrition and supportive medical care as shown by the following studies.

In a study involving 110 malnourished children, the thymic area was found to be 20% of the size in healthy children. The size of the thymus in these children was increased from 20% of normal to 107% of normal following 9 weeks of proper feeding ( 12).
The reversal of the reduction in CD4+T cell count in HIV+ pregnant women following proper feeding was also reported by Fawzi et al. ( 13). Briefly, the influence of diet on T cells counts in peripheral blood of 1,075 HIV-infected pregnant women who had poor nutritional status was studied. The CD4+ T cell counts of the women who received multivitamins increased from 424/µL to 596/µL during six months of proper feeding.
The prevalence of KS, lymphoma, lymphadenitis, and tuberculosis in Africa is similar or even higher than those observed in homosexual men, drug users, and AIDS patients in the United States and Europe ( 1). However, AIDS in Africa occurs almost equally in males and females because starvation affects both sexes equally. For example, Sibanda and Stanczuk reviewed all histopathology reports of lymph node biopsy submitted to the Histopathology unit in Harare, Zimbabwe in the period of January 1988 to June 1990. The most common diseases in the 2,194 lymph node specimens were: non-specific hyperplasia (33%), tuberculous lymphadenitis (27%); metastases (12%), Kaposi's sarcoma (9%); and lymphomas (7%). Kaposi's sarcoma (KS) involving the lymph nodes was reported in 176 (9%). In children, the prevalence of KS was higher in children under 5 years than in 6-15 year bracket. Approximately two thirds (65%) of all patients with KS were aged between 20 and 40 years ( 14).


orating centers, including CDC in the United States, the WHO Collaborating Centre in Paris, and WHO regional offices and ministries of health. Accuracy and completeness of AIDS reporting vary in different areas of the world.
Epidemiologic studies indicate three broad yet distinct geographic patterns of transmission.Pattern I is typical of industrialized countries with large numbers of reported AIDS cases, such as North America, Western Europe, Australia, New Zealand, and parts of Latin America. In these areas, most cases occur among homosexual or bisexual males and urban IV drug users. Heterosexual transmission is responsible for only a small percentage of cases but is increasing.Pattern II is observed in areas of central, eastern, and southern Africa and in some Caribbean countries. In these areas, most cases occur among heterosexuals; the male to female ratio is approximately 1:1 and perinatal transmission is relatively more common than in other areas. IV drug use and homosexual transmission either do not occur or occur at a very low level.Pattern III is found in areas of Eastern Europe, the Middle East, Asia, and most of the Pacific. HIV appears to have been introduced into these areas in the early to mid-1980s, and only small numbers of cases have been reported. Homosexual and heterosexual transmission has only recently been documented. Generally, cases have occurred among persons who have traveled to endemic areas or who have had sexual contact with individuals from endemic areas, such as homosexual men and female prostitutes.