Simultaneous Detection of Major Drug Resistance Mutations of HIV-1 Subtype B Viruses from Dried Blood Spot Specimens by Multiplex Allele-Specific Assay.

A multiplex allele-specific (MAS) assay has been developed for the detection of HIV-1 subtype C drug resistance mutations (DRMs). We have optimized the MAS assay to determine subtype B DRMs in dried blood spots (DBS) collected from patients on antiretroviral therapy. The new assay accurately detected DRMs, including low-abundance mutations that were often missed by Sanger sequencing.

Human rhinoviruses and enteroviruses in influenza-like illness in Latin America.

Background: Human rhinoviruses (HRVs) belong to the Picornaviridae family with high similarity to human enteroviruses (HEVs). Limited data is available from Latin America regarding the clinical presentation and strains of these viruses in respiratory disease.

Methods: We collected nasopharyngeal swabs at clinics located in eight Latin American countries from 3,375 subjects aged 25 years or younger who presented with influenza-like illness.

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.

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.

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.

Circulating strains of human respiratory syncytial virus in central and south America.

Human respiratory syncytial virus (HRSV) is a major cause of viral lower respiratory tract infections among infants and young children. HRSV strains vary genetically and antigenically and have been classified into two broad subgroups, A and B (HRSV-A and HRSV-B, respectively). To date, little is known about the circulating strains of HRSV in Latin America.

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.

Genetic analysis of influenza A/H1N1 of swine origin virus (SOIV) circulating in Central and South America.

Since the first detection of swine origin virus (SOIV) on March 28, 2009, the virus has spread worldwide and oseltamivir-resistant strains have already been identified in the past months. Here, we show the phylogenetic analysis of 63 SOIV isolates from eight countries in Central and South America, and their sensitivity to oseltamivir.

Molecular characterization of adenovirus circulating in Central and South America during the 2006-2008 period.

Background: Human Adenoviruses are recognized pathogens, causing a broad spectrum of diseases. Serotype identification is critical for epidemiological surveillance, detection of new strains and understanding of HAdvs pathogenesis. Little data is available about HAdvs subtypes in Latin America.

Antiviral resistance in influenza viruses circulating in Central and South America based on the detection of established genetic markers.

Background: Recent influenza antiviral resistance studies reveal an alarming increase in both adamantanes and neuraminidase inhibitors (NAIs) resistant viral strains worldwide, particularly in Asia, Europe and the United States.

Objectives: In this study, we have evaluated influenza virus resistance in Central and South America.

Methods: Influenza viruses, isolated from symptomatic patients throughout Central and South America in 2005-2008 were analyzed for inhibitor resistance.

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.

Optimization of the oligonucleotide ligation assay, a rapid and inexpensive test for detection of HIV-1 drug resistance mutations, for non-North American variants.

Objective: We evaluated the feasibility of the oligonucleotide ligation assay (OLA), a specific, sensitive, and economical ligase-based point mutation assay designed to detect HIV-1 drug-resistance mutations at 12 codons of HIV-1 subtype B pol, for potential use in resource-poor settings.

Methods: Specimens from HIV-1-infected individuals collected by 7 international laboratories, including subtypes A, B, C, D, F, G, J, and recombinants AE and AG, were tested by the OLA developed for HIV-1 subtype B. Common polymorphisms that interfered with reactivity of the OLA were identified and modified probes designed and evaluated.

Sampling designs for HIV molecular epidemiology with application to Honduras.

Proper sampling is essential to characterize the molecular epidemiology of human immunodeficiency virus (HIV). HIV sampling frames are difficult to identify, so most studies use convenience samples. We discuss statistically valid and feasible sampling techniques that overcome some of the potential for bias due to convenience sampling and ensure better representation of the study population.