8 Dec 2003
Malaria, AIDS and The Population Question


Five-month-old AIDS sufferer Kgomotso Mahlangu, lays in a hospital bed in the Kalafong township near Pretoria, South Africa. 
-- AP Photo/Themba Hadebe
Problems vs Non-Problems in Africa
  • agric destructive? (note Guinea case)
  • agric backward? (note Nigerian cases)
  • trouble making nation-state work? (sure, but compare to many others)
  • barbaric traditions? (FGC controversy may teach us as much about our own obsessions)
  • but 2 medical problems, one big and one catastrophic

Malaria basics

  • protozoal disease, Plasmodium sp., deadly form is falciparum, spread by anopheles mosquitoes
  • was greatly reduced by DDT vector control in 1950s but DDT and other organochlorines banned (mostly due to agricultural overuse) and the disease developed resistance to drugs
  • today, ca. 2 million deaths/yr, mostly African kids
  • HIID-London School Hygiene study estimates SSA's gross domestic product would be 400 billion instead of 300 billion is malaria wiped out in 1965
  • prophylaxis controversy: mefloquine (Lariam), Malarone (see this discussion if you are heading for a malaria area)

AIDS stats, hard to believe

  • HIV-AIDS rates in recent years
  • 42 mill people w/HIV; 30 SSA
  • 70% in area w/10% global pop
  • 90% infant/child cases are in Afr
  • 12 mill died in SSA in decade, 1/4 children
  • these seroprevalence levels translate into lifetime chances of cying from AIDS of around 40% in Eastern and Southern Africa as a whole and 70% in Zimbabwe and Botswana...since 1997 the prevalence rate for the region has risen, especially rapidly in southern Africa. (Caldwell 2000)
  • not associated with homosexuality in Africa

Why high rates of AIDS?  (see J. Caldwell 2000 Rethinking the African AIDS epidemic. Population and Development Review 26:117-135)

  • claims relating to sexual practice -- highly unlikely
  • Africans more susceptible? Ironic, given prior claims (On the Populousness of Africa)
    • CCR5 allele in Euro pops protects against HIV infection, but this is very small effect
  • different virus?
    • different kinds of virus doesn't explain (HIV1 vs HIV2; clades A & B), but don't transmit differently
  • better explanation: common non-HIV STD's boost transmission of HIV
    • sexual transmission inefficient is otherwise healthy, 1/100 m->f; 1/300 f->m
    • but w/opening on skin, chances skyrocket; 1/3 or 50%
  • hi level sex outside marriage (inc prostitutes) in many segments of pop (note lack of wives (polygyny!), pop mobility
  • labor migration very important, associated with use of sex workers
  • low level of condom use
  • lack of circumcision in many areas; Caldwell earlier work shows HIV seroprevalence correlates somewhat w/male circum
    • "It has been suggested that following circumcision, the surface epithelium of the glans develops a protective keratin layer, a form of natural condom [8]. Thus, circumcision could reduce the HIV incidence by directly decreasing the susceptibility of uninfected men to HIV" (Male circumcision: a role in HIV prevention? I.Vincenzi and T. Mertens AIDS 1994, 8(2): 153-160)
    • STD like chancroid, herpes, ghonnorea etc. cause the spread; these may be reduced by circumcision
    • foreskin may hold virus
    • note, circumcision is not major cause, but is apparently an exacerbating factor.
    • some (like Ligonier, who found HIV) suggest FGC -> AIDS but no data

Why isn't transmission brought down?

  • persistence of ulcerated std's f/poverty & poor health care
  • and cover up AIDS deaths due to shame (Fela Kuti died of AIDS, brother announced to destigamtize, but his family denied)
  • and govn unwillingness to confront.
    Nowhere had there been riots or even demonstrations, and this is still the case even in countries where over one-quarter of adults are seropositive and where most of the deaths are from AIDS. This is one of the reasons why governments are not disposed to take effective action. They fear creating for themselves more trouble than the AIDS epidemic already causes them. Heads of state do not wish to be associated with the epidemic, and, in spite of much protest from the Lusaka conference, not a single president or prime minister attended it, even for the opening and closing ceremonies.

    There is a fear of alienating their followers by intruding into sexual matters and by speaking aloud on such subjects. There is a fear of failure. Above all there is a fear of confronting those who regard the only solution to be confining sexual activity within marriage...because it is the law of God... Three-quarters of Christian leaders in Nigeria believe that AIDS is a divine punishment...The Catholic Church holds that the use-and hence the distribution-of condoms is forbidden. Most adults regard it as immoral to provide adolescents with condoms and are reluctant to admit that the great majority are sexually active; either these views are held by the politicians themselves or else the leaders are daunted by those who do hold them. Even though AIDS has already killed well over 10 million Africans and at least 20 million more are moving toward death...there is little political gain to be had by helping to stop those numbers from multiplying.

  • Although there are some successes, e.g. Uganda
Interventions
  • Mwanza (Tanzania) study, in Lancet recently;
  • clinical intervention trial, 1 pop of several thousand got STD education, clinics, treatment for STD's
  • 40% reduction in HIV from control group
  • imp finding but could only have been got in Africa;
  • needed pop w/high enough HIV rate to allow reliable measurements, plus pop willing to be control;
  • informed consent basically impossible
  • data from I/Coast & Niger Delta where oil companies draw workers:
  • reduce rates by improving health services & providing condoms

The Population Question: Is AIDS a Result of, or Cure for, African Overpopulation?