A single early introduction of HIV-1 subtype B into Central America accounts for most current cases.

Human immunodeficiency virus type 1 (HIV-1) variants show considerable geographical separation across the world, but there is limited information from Central America. We provide the first detailed investigation of the genetic diversity and molecular epidemiology of HIV-1 in six Central American countries. Phylogenetic analysis was performed on 625 HIV-1 pol gene sequences collected between 2002 and 2010 in Honduras, El Salvador, Nicaragua, Costa Rica, Panama, and Belize. Published sequences from neighboring countries (n = 57) and the rest of the world (n = 740) were included as controls. Maximum likelihood methods were used to explore phylogenetic relationships. Bayesian coalescence-based methods were used to time HIV-1 introductions. Nearly all (98.9%) Central American sequences were of subtype B. Phylogenetic analysis revealed that 437 (70%) sequences clustered within five significantly supported monophyletic clades formed essentially by Central American sequences. One clade contained 386 (62%) sequences from all six countries; the other four clades were smaller and more country specific, suggesting discrete subepidemics. The existence of one large well-supported Central American clade provides evidence that a single introduction of HIV-1 subtype B in Central America accounts for most current cases. An introduction during the early phase of the HIV-1 pandemic may explain its epidemiological success. Moreover, the smaller clades suggest a subsequent regional spread related to specific transmission networks within each country.

Honduras HIV cohort: HLA class I and CCR5-Δ32 profiles and their associations with HIV disease outcome.

IMPORTANCE: We identify both canonical and novel human leukocyte antigen (HLA)-HIV associations, providing a first step toward improved understanding of HIV immune control among the understudied Honduras Mestizo population. Our results are relevant to understanding the protective or detrimental effects of HLA subtypes in Latin America because their unique HLA diversity poses challenges for designing vaccines against HIV and interpreting results from such vaccine trials. Likewise, the description of the HLA profile in an understudied population that shows a unique HLA immunogenetic background is not only relevant for HIV immunology but also relevant in population genetics, molecular anthropology, susceptibility to other infections, autoimmune diseases, and allograft transplantation.

Prevalence of transmitted HIV-1 drug resistance among female sex workers and men who have sex with men in El Salvador, Central America.

Transmitted drug resistance has important implications for the successful use and management of therapy among persons infected with HIV. We estimated the prevalence of transmitted drug resistance in 145 samples from female sex workers (n = 47) and men who have sex with men (n = 98) in El Salvador. Samples were collected during March to September 2008, using a respondent driven sampling. The HIV-1 pol gene was sequenced to identify drug resistance mutations and transmitted drug resistance was scored as recommended by World Health Organization. Specimens were classified as recent or established infections using the Immunoglobulin G-Capture BED-Enzyme Immunoassay. The overall prevalence of transmitted drug resistance was 9.4% (95% CI: 4.7-16.1%), and was 5.9% for non-nucleoside reverse transcriptase inhibitors, 4.2% for nucleoside reverse transcriptase inhibitors, and 0.8% for protease inhibitors. Transmitted drug resistance prevalence was 10.3% (95% CI: 2.8-24.2%) among female sex workers, and 9.0% (95% CI: 3.6-17.6%) among men who have sex with men. Nineteen patients were classified as having recent infection (16.2%, 95% CI: 10.1-24.2%), while 98 patients (83.8%, 95% CI: 75.8-89.9%) were classified as having established infections. Transmitted drug resistance among recent and established infections was similar at 10.5% and 9.2%, respectively. This study shows that the prevalence of transmitted drug resistance is moderate among female sex workers and men who have sex with men in El Salvador. These results highlight the importance of transmitted drug resistance surveillance in a representative sample of recently infected patients following the World Health Organization guidelines.

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.

HIV Drug Resistance Surveillance in Honduras after a Decade of Widespread Antiretroviral Therapy.

INTRODUCTION: We assessed HIV drug resistance (DR) in individuals failing ART (acquired DR, ADR) and in ART-naïve individuals (pre-ART DR, PDR) in Honduras, after 10 years of widespread availability of ART. METHODS: 365 HIV-infected, ART-naïve, and 381 ART-experienced Honduran individuals were enrolled in 5 reference centres in Tegucigalpa, San Pedro Sula, La Ceiba, and Choluteca between April 2013 and April 2015. Plasma HIV protease-RT sequences were obtained. HIVDR was assessed using the WHO HIVDR mutation list and the Stanford algorithm. Recently infected (RI) individuals were identified using a multi-assay algorithm. RESULTS: PDR to any ARV drug was 11.5% (95% CI 8.4-15.2%). NNRTI PDR prevalence (8.2%) was higher than NRTI (2.2%) and PI (1.9%, p<0.0001). No significant trends in time were observed when comparing 2013 and 2014, when using a moving average approach along the study period or when comparing individuals with >500 vs. <350 CD4+ T cells/µL. PDR in recently infected individuals was 13.6%, showing no significant difference with PDR in individuals with longstanding infection (10.7%). The most prevalent PDR mutations were M46IL (1.4%), T215 revertants (0.5%), and K103NS (5.5%). The overall ADR prevalence in individuals with <48 months on ART was 87.8% and for the ≥48 months on ART group 81.3%. ADR to three drug families increased in individuals with longer time on ART (p = 0.0343). M184V and K103N were the most frequent ADR mutations. PDR mutation frequency correlated with ADR mutation frequency for PI and NNRTI (p<0.01), but not for NRTI. Clusters of viruses were observed suggesting transmission of HIVDR both from ART-experienced to ART-naïve individuals and between ART-naïve individuals. CONCLUSIONS: The global PDR prevalence in Honduras remains at the intermediate level, after 10 years of widespread availability of ART. Evidence of ADR influencing the presence of PDR was observed by phylogenetic analyses and ADR/PDR mutation frequency correlations.

Evaluation of a dried blood and plasma collection device, SampleTanker(®), for HIV type 1 drug resistance genotyping in patients receiving antiretroviral therapy.

Whatman 903 filter paper is the only filter paper that has been used for HIV drug resistance (HIVDR) genotyping in resource-limited settings. In this study, we evaluated another dried blood specimen collection device, termed SampleTanker(®) (ST), for HIVDR genotyping. Blood specimens from 123 antiretroviral therapy (ART)-experienced patients were used to prepare ST whole blood and ST plasma specimens; they were then stored at ambient temperature for 2 or 4 weeks. The remaining plasma specimens were stored at -80°C and used as frozen plasma controls. Frozen plasma viral load (VL) was determined using the Roche Amplicor HIV-1 Monitor test, v.1.5 and 50 specimens with VL ≥3.00 log10 copies/ml were genotyped using the broadly sensitive genotyping assay. The medium VL for the 50 frozen plasma specimens with VL ≥3.00 log10 was 3.58 log10 copies/ml (IQR: 3.32-4.11) and 96.0% (48/50) of them were genotyped. Comparing to frozen plasma specimens, significantly lower genotyping rates were obtained from ST whole blood (48.98% and 42.85%) and ST plasma specimens (36.0% and 36.0%) stored at ambient temperature for 2 and 4 weeks, respectively (p<0.001). Nucleotide sequence identity and resistance profile analyses between the matched frozen plasma and ST whole blood or ST plasma specimens revealed high nucleotide sequence identities and concordant resistance profiles (98.1% and 99.0%, and 96.6% and 98.9%, respectively). Our results indicate that with the current design, the ST may not be the ideal dried blood specimen collection device for HIVDR monitoring for ART patients in resource-limited settings.

Social network-based recruitment successfully reveals HIV-1 transmission networks among high-risk individuals in El Salvador.

OBJECTIVE: HIV in Central America is concentrated among certain groups such as men who have sex with men (MSM) and female sex workers (FSWs). We compared social recruitment chains and HIV transmission clusters from 699 MSM and 787 FSWs to better understand factors contributing to ongoing HIV transmission in El Salvador. METHODS: Phylogenies were reconstructed using pol sequences from 119 HIV-positive individuals recruited by respondent-driven sampling (RDS) and compared with RDS chains in 3 cities in El Salvador. Transmission clusters with a mean pairwise genetic distance ≤ 0.015 and Bayesian posterior probabilities =1 were identified. Factors associated with cluster membership were evaluated among MSM. RESULTS: Sequences from 34 (43%) MSM and 4 (10%) FSW grouped in 14 transmission clusters. Clusters were defined by risk group (12 MSM clusters) and geographic residence (only 1 spanned separate cities). In 4 MSM clusters (all n = 2), individuals were also members of the same RDS chain, but only 2 had members directly linked through recruitment. All large clusters (n ≥ 3) spanned >1 RDS chain. Among MSM, factors independently associated with cluster membership included recent infection by BED assay (P = 0.02), sex with stable male partners (P = 0.02), and sex with ≥ 3 male partners in the past year (P = 0.04). CONCLUSIONS: We found few HIV transmissions corresponding directly with the social recruitment. However, we identified clustering in nearly one-half of MSM suggesting that RDS recruitment was indirectly but successfully uncovering transmission networks, particularly among recent infections. Interrogating RDS chains with phylogenetic analyses may help refine methods for identifying transmission clusters.

Comparison of HIV-1 resistance profiles in plasma RNA versus PBMC DNA in heavily treated patients in Honduras, a resource-limited country.

The World Health Organization currently does not recommend the use of dried blood spot specimens for drug resistance testing in patients undergoing antiretroviral therapy (ART). Therefore, HIV-1 resistance testing using peripheral blood mononuclear cells (PBMCs) may be of value in resource-limited settings. We compared genotypic resistance profiles in plasma and PBMCs from patients failing ART in two cities of Honduras (Tegucigalpa and San Pedro Sula), a resource-limited country. One hundred patients failing ART were randomly selected from a longitudinal patient monitoring cohort. Plasma and PBMC samples without patient identifier were used for genotypic resistance testing. Sequence data were analyzed, resistance profiles were determined and compared using Stanford HIV Drug Resistance Database algorithm. Specimens with concordant resistance profiles between the two compartments were 88% (95% CI: 80.3% - 94.5 %). Nine specimens (12%, 95% CI: 6.5% - 21.3%) had discordant resistance profiles of clinical significance. Logistic regression analyses indicated that patients on triple therapy were 17.24 times more likely to have concordant drug resistance profile than those on non-triple therapies (OR=17.24, 95% CI: 3.48, 83.33), while patients with increasing number of regimens and years on ART have a decreased rate of concordance (OR = 0.59, 95% CI: 0.32, 1.09 and OR = 0.62, 95% CI: 0.43, 0.88), respectively, than those with less number of regimens and years on ART. Our results show high level of concordance between plasma and PBMC resistance profiles, indicating the possibility of using PBMCs for drug resistance testing in resources-limited settings.

Short communication: high prevalence of drug resistance in HIV type 1-infected children born in Honduras and Belize 2001 to 2004.

Antiretroviral therapy has had a great impact on the prevention of mother-to-child transmission (MTCT) of HIV-1. However, development of drug resistance, which could be subsequently transmitted to the child, is a major concern. In Honduras and Belize the prevalence of drug resistance among HIV-1-infected children remains unknown. A total of 95 dried blood spot samples was obtained from HIV-1-infected, untreated children in Honduras and Belize born during 2001 to 2004, when preventive antiretroviral therapy was often suboptimal and consisted of monotherapy with nevirapine or zidovudine. Partial HIV-1 pol gene sequences were successfully obtained from 66 children (Honduras n=55; Belize n=11). Mutations associated with drug resistance were detected in 13% of the Honduran and 27% of the Belizean children. Most of the mutations detected in Honduras (43%) and all mutations detected in Belize were associated with resistance to nonnucleoside reverse transcriptase inhibitors, which was expected from the wide use of nevirapine to prevent MTCT during the study period. In addition, although several mothers reported that they had not received antiretroviral therapy, mutations associated with resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors were found in Honduras. This suggests prior and unreported use of these drugs, or that these women had been infected with resistant virus. The present study demonstrates, for the first time, the presence of drug resistance-associated mutations in HIV-1-infected Honduran and Belizean children.

Transmitted drug resistance and type of infection in newly diagnosed HIV-1 individuals in Honduras.

BACKGROUND: Transmitted drug resistance (TDR) reduces the efficacy of antiretroviral treatment and is a public health concern. OBJECTIVES: To gain insight in the epidemiology of TDR in Honduras by evaluating the amount of TDR in a representative sample of newly diagnosed individuals and by determining whether these are recent or established infections. STUDY DESIGN: Two hundred treatment-naïve, newly diagnosed HIV-positive individuals representing different population groups (general population, Garifunas ethnic group, female sex workers and men who have sex with men) and different geographic regions were enrolled during April 2004-April 2007. The HIV-1 pol gene was sequenced to identify drug-resistant mutations and TDR was scored as recommended by the WHO. Specimens were classified as recent or established infections using the BED assay. RESULTS: Among 200 samples analyzed from Honduran patients the prevalence of TDR was 7% (95% CI: 3.9-11.5%), 5% for non-nucleoside reverse transcriptase inhibitors (NNRTIs), 3% for nucleoside reverse transcriptase inhibitors (NRTIs) and 0.5% for protease inhibitors (PIs). Testing of these samples with the BED assay revealed that 12% of the specimens were associated with recent infections. TDR was significantly more common in specimens with recent infection (21%) than established infection (5%) (p=0.016). CONCLUSIONS: The prevalence of TDR in Honduras was moderate (7%). The percentage of specimens who were recently infected was low (12%), suggesting that late HIV diagnosis is common. The TDR prevalence was higher in recent than in established infections, which may indicate that TDR is increasing over time. The higher prevalence of NNRTI and NRTI mutations as compared to PI mutations is probably due to a broader and longer use of these drugs in Honduras.

Humoral immune response of dengue hemorrhagic fever cases in children from Tegucigalpa, Honduras.

The humoral immune response in Honduran dengue hemorrhagic fever (DHF) hospitalized pediatric cases from the epidemics of 2004 and 2005 was studied in sera collected from 5 to 7 days of fever onset. A total of 145 cases were included in the study: 40 classified as primary with DHF Grade I or II and 86 classified as secondary; from them, 73 were DHF Grade I or II and 13 were dengue shock syndrome (DSS) Grade III or IV. The highest number of primary cases was found in children < 1 year of age. The highest number of secondary cases was observed in children between 5 and 10 years of age. The IgA values showed a statistically significant difference between primary and secondary groups. The relationship between antibody responses and severity grade is discussed. This is the first study related to the humoral immune response and severity grade in DHF cases in Honduran children.