HIV-1 genetic diversity and transmitted drug resistance in health care settings in Maputo, Mozambique.

Objectives: To characterize HIV-1 diversity and transmitted drug resistance in persons with access to care and treatment in Maputo, Mozambique.

Methods: Samples were collected in 2002-2004 from 144 drug-naive patients attending public hospitals and private clinics. Plasma viremia, CD4, and CD8 cell counts were determined for each patient. The Stanford Algorithm was used for resistance genotyping on pol sequences. Subtyping was done by phylogenetic analysis.

Results: Most patients had high viral load (mean, 5.0 log copies/mL) and low CD4 cell counts (median, 260 CD4 cells/microL). Protease and/or reverse transcriptase sequences were obtained from 104 (72%) samples. Patients harbored subtypes C (80.8%), G (3.8%), CRF37_cpx (6.7%), untypable (U) (1.0%), and recombinant strains (7.7%) comprising the A, C, D, F, and U clades. There were no major protease inhibitor resistance mutations. Mutations conferring resistance to the nucleoside/nucleotide reverse transcriptase inhibitors and/or nonnucleoside reverse transcriptase inhibitors were found in 4 (4/68; 5.9%) patients. Phylogenetic analysis suggested an imported origin for 2 resistant variants.

Conclusions: The HIV-1 epidemic in Maputo is evolving rapidly in genetic complexity due to the recent introduction of all major subtypes and recombinant forms. Continued surveillance of drug resistance in treated and untreated populations is needed to prevent further transmission of HIV drug-resistant variants and maximize the efficacy of antiretroviral therapy in Maputo.