Prevalence of depigmentation of the shins: a simple and cheap way to screen for severe endemic onchocerciasis in Africa.

The prevalence of skin depigmentation in the pretibial region is closely correlated in the adult Congolese population with conventional indices (microfilarial index, mean microfilarial density, cyst index) for the evaluation of endemic onchocerciasis. Individuals over 15 years of age in endemic villages who had a microfilarial index of 80-90%, had a cystic index of 60-70% and a pretibial depigmentation index about 20% (30-40% for individuals aged > 50 years). Thus, in Africa, this new evaluation index offers a simple, noninvasive, quick and cheap way to identify areas where the level of endemic onchocerciasis is probably high and which are likely to benefit from an anti-onchocerciasis campaign.

PIP: Skin depigmentation is a classic diagnostic sign of onchocerciasis and presents typically as an irregular, flat spot surrounded by slightly hyperpigmented zones. The depigmentation occurs mainly on the shins. The prevalence of skin depigmentation has been proposed as a marker for evaluating the endemicity of onchocerciasis in Nigeria, but has been contested for use in South America on the grounds of non-specificity. The microfilarial index currently used to assess the level of onchocerciasis endemicity is relatively time-consuming, costly, and harbors the risk of transmitting viral infections during mass screenings. 991 people over 15 years of age of mean age 55.4 years in five villages in the Congo endemic for onchocerciasis participated in this study. Individuals who had a microfilarial index of 80-90% had a cystic index of 60-70% and a pretibial depigmentation index of approximately 20%. The authors conclude that the existence of shin depigmentation as an evaluation index in Africa offers a simple, noninvasive, quick, and inexpensive way to identify areas where the level of endemic onchocerciasis is probably high and which are likely to benefit from an anti-onchocerciasis campaign. Although the new index does not allow total specificity, the incidence of shin depigmentation among patients with African onchocerciasis is such that there is probably little risk of confusing holo- or hyperendemic zones with an area where leprosy or treponema are endemic. In the absence of onchocerciasis, bites from Simulium spp. flies may also be responsible for skin depigmentation, as may be streptocerciasis. In this latter condition, however, the predominant site of depigmentation is not the shin. The authors have observed no notable prevalence of shin depigmentation in northern Congo, which is infested with S. albivirgulatum flies, but with no onchocerciasis transmission, and where there are also zones of streptocerciasis.

Ethical concerns about AIDS.

The HIV/ARC/AIDS story continues to unfold. It is both the old, sadly familiar experience of plague and disease, of lepers isolated as unclean, of smallpox decimating the American Indians, of a Black Death sweeping medieval Europe, of the 1918 influenza. It is also a new story, one in which medical scientists rather quickly identified the causative infectious agent but, as yet, have been unable to cure the infection, although some amelioration of the basic course of the illness appear possible if treatment with AZT is begun relatively early. The ethical problems are numerous and constantly change as the understanding of the disease and its potency evolves. The social answers have, after initial delay, received positive action on an official level. On the more personal level of the average American there remains animosity, prejudice, and a deeply rooted fear, the ancient fear of the leper, of the plague victim. The health professionals have also officially responded well to the challenge of AIDS. Personally, as in society generally, there has been a mixed response. We believe that the ethical concerns enumerated in this article will be resolved in favor of persons with AIDS. Nevertheless, the personal, spiritual, emotional, and economic isolation experienced by persons with AIDS and their families challenge us about what kind of society we wish to be. We will ultimately be measured as a civilization by the way in which we treated the least fortunate. America's track record in this regard has been mixed. AIDS presents us with a chance to change.