Introduction: The reported prevalence of primary resistance mutations differs between studies. An analysis was performed to determine the prevalence of primary resistance mutations and HIV subtypes in our area.
Methods: Prospective study performed in all patients diagnosed with HIV in the year 2005 in the province of Malaga (Spain). Plasma samples from these patients were tested for genotypic resistance (TruGene HIV-1 genotyping kit; Bayer Healthcare Diagnostics) and HIV subtype.
Results: A total of 172 cases were diagnosed, 6 of them recent seroconvertors. Genotype resistance testing disclosed resistance mutations in 7.8% (95% CI 3.5-12.0%) of 153 patients in which it was performed (6 to NNRTIs, 4 to NRTIs, and 3 to PIs). HIV subtype was B in 81.8% of patients, and non-B in 18.1% (51.8% of them of sub-Saharan origin, in whom the prevalence of this subtype was 73.6%). Among European patients, only those from Spain presented the non-B subtype (prevalence 7.4%). The only factor related with the presence of resistance mutations was seroconversion (OR 9.2; 95% CI 1.3-61.9; P < .02).
Conclusions: There was a considerable prevalence of primary resistance mutations in patients with newly diagnosed HIV infection in Malaga province, with seroconversion being the only related factor. The high prevalence of the non-B HIV subtype in the Spanish population is noteworthy. Genotype resistance testing is recommendable in all newly diagnosed HIV patients in our area.