Prevalence and Genetic Diversity of Human Immunodeficiency Virus Type 1 (HIV-1) Among Blood Donors in the Service Area of the Santos/Sp Blood Center

Abstract

Rosane Rezende de Souza Giuliani, Marcos Montani Caseiro, Shirley Cavalcante Vasconcelos, Luiz Henrique Gagliani and Dercy Jose de Sa Filho

Introduction: The HIV-1 epidemic in the Baixada Santista region is complex due to the presence of different subtypes, recombinants, and mutations conferring resistance to antiretrovirals. Therefore, the study of samples from newly diagnosed individuals allows us to characterize the viruses currently circulating in the local transmission network.

Objectives: To determine the prevalence and genetic diversity of HIV-1 among blood donors in the Baixada Santista region, whose serological testing is performed at the Hemonúcleo de Santos.

Study Population and Methods: To calculate prevalence, we assessed the number of HIV-positive samples, confirmed by Western blot, relative to the number of donations during the period from January2009 a to May 2011. To analyze viral genetic diversity, we collected serum and/or plasma samples from the donors. Viral RNA was extracted, and reverse transcription was performed to generate cDNA. This material was used for PCR amplification of the HIV-1 pol gene to analyze subtypes, recombinants, and the presence of primary antiretroviral resistance mutations using bioinformatics tools.

Results: During the analyzed period, a total of 65,428 donations were recorded. Of these, 49 samples were identified as HIV-positive, with a prevalence of 0.07% during this period. Of the total 49 HIV-positive donors, it was only possible to characterize the viral genotype of 9 samples due to the inadequacy of the stored biological material for molecular biology techniques. Of these 9 sequenced samples, 7 belong to subtype B, 1 to subtype F, and 1 sample was identified as a B/F recombinant. Regarding primary resistance mutations, 6 samples exhibited isolated accessory mutations, such as: K20R, A71V, and M36I in the protease gene, and A62V, V118I, and T215I in the reverse transcriptase gene. With the exception of the T215I mutation, which causes a low level of resistance to zidovudine (AZT) and stavudine (D4T), these mutations alone do not cause complete resistance to any antiretroviral drug.

Final Considerations: The identified prevalence of HIV-positive donors was 0.07%. Despite the small number of sequenced samples, subtype B was found to predominate, and mutations associated with HIV-1 resistance to antiretrovirals were frequently detected. This indicates the need for more comprehensive studies to investigate primary HIV-1 resistance in the Baixada Santista region.

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