The social epidemiology of HIV transmission among African American women who use drugs and their social network members.

Despite 15 years of prevention efforts, recent increases in HIV infection have been documented for Black women in the US. Little is known about the role played by HIV status disclosure in high HIV prevalence communities. 180 Black women who used drugs in the past 30 days were recruited between May 2002 and May 2004 in New York City. Women were administered a structured network questionnaire and HIV serotested. Risk practices, HIV status disclosure within networks and mixing patterns by known HIV status are examined. Most (85%) women had used crack in the past 30 days; 48 (27%) had injected drugs, 65 (36%) reported anal sex, and 99 (55%) reported sex work at some time. Forty (22%) women were HIV-seropositive; 29 (16%) knew their seropositive status. Of high risk individual behaviours, only a history of sex work was associated with an HIV-seropositive status [(aOR=3.0; 95%CI: 1.3-7.3), p=.01]. Few (7%) of 600 network members disclosed an HIV positive status, although 73% were sex or drug use partners. Women who knew themselves to be HIV-infected were more likely than other women to report HIV-infected network members [(OR=1.5; 95%CI: 1.1-6.4), p=.03]. However, only 51% of network members disclosed an HIV status and women disclosed to 50% of their network members. In a context of high background HIV prevalence and low levels of HIV status disclosure, serodiscordant mixing patterns likely facilitate transmission.

Plasmodium vivax polymorphs and Plasmodium falciparum circumsporozoite proteins in Anopheles (Diptera: Culicidae) from Belize, Central America.

Eight species of Anopheles mosquitoes from indoor/outdoor human landing collections in Belize, Central America, were examined for human Plasmodium circumsporozoite protein (CSP) using an enzyme-linked immunosorbent assay (ELISA). A total of 14 of 9,104 females tested were positive from general surveys throughout Belize and three of 11,966 were positive from a longitudinal study in Caledonia, northern Belize. ELISA results, using pooled head-thorax preparations and species-specific monoclonal antibodies directed against the circumsporozoite proteins of Plasmodium falciparum and two Plasmodium vivax polymorphs (210 and VK247), found four species reactive: Anopheles vestitipennis (3 pools), Anopheles darlingi (2 pools), Anopheles albimanus (10 pools), and Anopheles gabaldoni (2 pools). The minimum field infection rates (MFIR) for combined Plasmodium species from the general survey were 0.282% for An. vestitipennis, 0.271% for An. darlingi, 0.126% for An. albimanus, and 0.395% for An. gabaldoni. MFIRs for combined Plasmodium species from the longitudinal study in the village of Caledonia were 0.018% for both An. vestitipennis and An. albimanus and 1.66% for An. gabaldoni. Positive CSP pools were collected from the Cayo, Corozal, Orange Walk, Stann Creek, and Toledo political districts. No CSP positive pools were detected from collections in the Belize District. The study provides valuable information on the spatial distribution and species type of Plasmodium positive mosquitoes. This information, in combination with other vector data, suggest that An. vestitipennis and An. darlingi are commonly involved in malaria transmission. Additionally, these species appear to be much more efficient vectors than An. albimanus in Belize.

Description of a possible clonal expansion of Plasmodium vivax in Manaus-Amazonas-Brazil.

Atypical P. vivax cases reported in Manaus municipality led us to detect a genetic isolate of P. vivax. Variable regions of SSUrRNA were examined from the initial time of infection and in the two recrudescences/relapses from a patient exhibiting chloroquine and primaquine resistance. A unique isolate, found at all stages of infection, suggests the presence of a clonal expansion.