AIDS-related disseminated histoplasmosis in the greater Caribbean: how frequent is it?

HIV/AIDS in the Caribbean and the northern tip of south America is a major public health problem. This ‘greater Caribbean’ region is the second hardest hit after Africa. In French Guiana, the incidence of AIDS in 2004 was 38.6 per 100 000 inhabitants and the prevalence of HIV among pregnant women was 1.7%. With an incidence of 2.9 per 100 person-years among HIV-infected patients, disseminated histoplasmosis caused by Histoplasma capsulatum is the second most frequent opportunistic infection in HIV patients in French Guiana and the first cause of death [1]. However, we are struck by the rarity of such reports in countries that are part of the greater Caribbean region. Guyana, Suriname, and even Trinidad have a fauna that overlaps with that of French Guiana, notably bats. We would thus have expected that the above countries would have the same problem. This may simply be due to the fact that this infection is commonly diagnosed in the region but has not been reported in the literature. However, rare contacts with colleagues from the Caribbean seem to suggest that this treatable fungal infection is rarely diagnosed. Previous reports in the region have concerned Haiti [2], Cuba [3], Jamaica [4], Puerto Rico [5], Guadeloupe [6], Martinique [7], Barbados [8], Suriname [9], and Trinidad [8,10]. These scattered reports may simply reflect a genuinely rare disease. One could argue that the interface between humans and bats may be greater in French Guiana than elsewhere. However, skin testing showed that 29% of individuals in Guyana and 42% in Trinidad were reactive to histoplamin [8]. This suggested that disseminated histoplasmosis should be a relatively common presentation of AIDS, at least in certain countries in the region. The clinical presentation of histoplasmosis is polymorphic, diagnosis may not be straightforward. Early diagnosis often requires invasive diagnostic procedures, trained microscopists, and may sometimes require special facilities for culture or molecular biology [11]. Antigen detection is expensive and is only performed in the United States. With the help of the global fund for AIDS, tuberculosis and malaria, great efforts are underway to strengthen laboratory and treatment facilities, notably in order to tackle opportunistic infections. The first CHART (Caribbean HIV/AIDS Regional Training initiative; a remarkable initiative by the way) conference on the clinical management of HIV/AIDS in the Caribbean was recently conducted in Jamaica. It notably dealt with common opportunistic infections [12], but the respective importance of various pathologies was based on Centers for Disease Control and Prevention data from the USA, possibly because of the lack of such data in the Caribbean. However, the details of AIDS-defining events may not be extrapolated from data describing the situation in the USA. If the prevalence of the different AIDS-defining illnesses is not well described, training and investment may not prepare countries for the diagnosis and treatment of histoplasmosis. The epidemiology of HIV in the Caribbean is different from what is seen in the USA or in Europe. Although there is an impression of homogeneity because the epidemic is predominantly driven by heterosexual sex, there are notable geographical differences in the region that may have epidemiological consequences. In addition to the standard indicators used to monitor the epidemic throughout the region, the respective importance of different AIDS-defining events should be systematically collected to provide a better description of AIDS. In summary, the importance of histoplasmosis in French Guiana may be a south American situation (the problem is also endemic in Brazil) that does not represent the Caribbean. Politically, we are not part of the ‘greater Caribbean’; however, we are on the border of it, and we share biogeographical features with some of the ‘greater Caribbean’ countries. In addition, most of our patients come from there. We believe there are arguments to suggest that disseminated histoplasmosis may be a more widespread infection in some parts of the ‘greater Caribbean’ than previously thought. If so, laboratory and treatment capacity building should be modified also to encompass this infection.