Prevalence of drug resistance and importance of viral load measurements in Honduran HIV-infected patients failing antiretroviral treatment.

OBJECTIVE: The Honduran HIV/AIDS Program began to scale up access to HIV therapy in 2002. Up to May 2008, more than 6000 patients received combination antiretroviral therapy (cART). As HIV drug resistance is the major obstacle for effective treatment, the purpose of this study was to assess the prevalence of antiretroviral drug resistance in Honduran HIV-1-infected individuals. METHODS: We collected samples from 138 individuals (97 adults and 41 children) on cART with virological, immunological or clinical signs of treatment failure. HIV-1 pol sequences were obtained using an in-house method. Resistance mutations were identified according to the 2007 International AIDS Society (IAS)-USA list and predicted susceptibility to cART was scored using the ANRS algorithm. RESULTS: Resistance mutations were detected in 112 patients (81%), 74% in adults and 98% in children. Triple-, dual- and single-class drug resistance was documented in 27%, 43% and 11% of the study subjects, respectively. Multiple logistic regression showed that resistance was independently associated with type of treatment failure [virological failure (odds ratio (OR) = 1) vs. immunological failure (OR = 0.11; 95% confidence interval (CI) 0.030-0.43) vs. clinical failure (OR = 0.037; 95% CI 0.0063-0.22)], route of transmission (OR = 42.8; 95% CI 3.73-491), and years on therapy (OR = 1.81; 95% CI 1.11-2.93). CONCLUSION: The prevalence of antiretroviral resistance was high in Honduran HIV-infected patients with signs of treatment failure. A majority of study subjects showed dual- or triple-class resistance to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors and protease inhibitors. Virologically defined treatment failure was a strong predictor of resistance, indicating that viral load testing is needed to correctly identify patients with treatment failure attributable to resistance.

The Honduran human immunodeficiency virus type 1 (HIV-1) epidemic is dominated by HIV-1 subtype B as determined by V3 domain sero- and genotyping.

The distribution of subtypes A through F of human immunodeficiency virus type 1 (HIV-1) in Honduras was analyzed in 120 HIV-1 positive serum samples by V3 peptide serotyping and HIV-1 cDNA sequencing. In the Honduran HIV-1 epidemic, subtype B was detected in 98 of 99 subtyped samples.

PIP: The distribution of HIV-1 subtypes A through E in Honduras was analyzed in 120 HIV-1 positive serum samples by V3 peptide serotyping and HIV-1 cDNA sequencing. Serum samples from 100 HIV-1-seropositive Hondurans were obtained through the country's central AIDS reference laboratory as well as an additional 20 samples from HIV-1-seropositive cases from the Associacion Lucha Contra El SIDA of Tegucigalpa. These cases comprise 14% of all Honduran HIV-1 infection cases diagnosed in 1994. The samples from the country's central AIDS reference laboratory came from 46 males and 54 females aged 3.5-56 years of median age 30 years from all eight of the country's health districts. 49 patients were asymptomatic, 21 had AIDS-related complex, 25 had AIDS, and 5 were of unknown immunostatus. In the initial screening, it was possible to serotype 96 of the 120 samples, 95 of which were subtype B. An eventual 98 subtype B samples were detected among the 99 subtyped samples. One sample was identified as subtype A.

Geographical clustering of human T-cell lymphotropic virus type 1 infection in Honduras.

Geographical clustering of human T-cell lymphotropic virus type 1 (HTLV-1) infection has been identified in the nonmestizo communities in several cities along the Atlantic coast of Honduras. Of the 2,651 serum samples tested, 122 samples were repeatedly reactive for HTLV-1 antibodies in two different enzyme immunoassays and 3 were indeterminate. These sera did not react in the HTLV-2-specific antibody tests. The presence of HTLV-1 antibodies was confirmed by HTLV-1 immunoblots or Western blots (immunoblots), and the infection was verified by the detection of HTLV-1-specific genetic sequences in the cellular DNA by PCR. Genomic DNA from the peripheral blood mononuclear cells was first tested with generic primers and probes that identified both HTLV-1 and HTLV-2. Next, all DNA samples that showed HTLV reactivity were tested by PCR with specific primers and probes that distinguished HTLV-1 sequences from those of HTLV-2. Our results indicate that only HTLV-1 infection was present in the blood of both mestizo and nonmestizo residents of 15 cities in the Republic of Honduras. The overall prevalence of HTLV-1 infection in the nonmestizo population was 8.1% (95% confidence limit, 6.6 to 9.7%). The mestizo population residing in the same geographical vicinities showed a HTLV-1 antibodies in 0.5% of serum samples tested (95% confidence limit, 0.6 to 1.7%), indicating a significantly greater prevalence of HTLV-1 infection in the nonmestizo population than in the mestizo ethnic groups living in Honduras (P = 0.0001). Since no HTLV-2 antibody reactivity or HTLV-2-specific genetic sequences were detected by PCR with different primers and probes, it was concluded that HTLV-2 infection was not present in the Honduran population groups we tested. Our study also suggested an endemic nature for this virus because there was no difference in the prevalence rate of HTLV-1 antibodies in the nonmestizo community living in the coastal towns of Honduras between 1989 and 1993. This is the first report of HTLV-1 cluster identification in Honduras, Central America.