Jorge Sanchez

Molecular Epidemiology of HIV Type 1 in Ecuador, Peru, Bolivia, Uruguay, and Argentina.

Surveillance for HIV infection among people at increased risk was conducted in five countries in South America. Seroprevalence studies were conducted in more than 36,000 people in Ecuador, Peru, Boliva, Uruguay, and Argentina, along with genetic analysis of the HIV-1 strains. In all countries, the prevalence of HIV-1 among men who have sex with men (MSM) was high (3-30%), whereas the prevalence among female commercial sex workers (FCSMs) was low (0.3-6%). By envelope heteroduplex mobility assay, subtype B predominated in MSM communities and in FCSWs in Ecuador, Bolivia, and Peru. A new genetic screening assay, the multiregion hybridization assay for subtypes B and F (MHA-bf), was developed to improve large-scale genetic screening in South America. MHA-bf can screen four regions of the genome for subtype B or subtype F, and thus can detect most recombinants. The sensitivity of MHA-bf when applied to a panel of pure subtypes and CRF12_BF was 100%, and 88% of unique recombinants were also detected as recombinant. Using MHA-bf, more than 80% of samples from Ecuador, Peru, and Bolivia were classified as pure subtype B, whereas in Uruguay and Argentina this proportion was only 30 to 40%. BF recombinants were the most prevalent form of HIV-1 in Uruguay and Argentina. Subtype B is the most common subtype in countries lacking injecting drug use (IDU) epidemics, whereas BF recombinants are more common in countries where extensive IDU epidemics have been documented, suggesting the ontogeny of recombinant strains in particular risk groups in South America.

Emerging genetic diversity of HIV-1 in South America

ObjectiveGenotype determination and risk group analysis of HIV-1 infected individuals in selected regions of South America. DesignCross-sectional convenience sampling of HIV-1-positive individuals in Peru, Ecuador, Uruguay and Paraguay from March, 1994 through September, 1998. MethodsHIV-1-positive subjects were identified through the national AIDS surveillance program in each country. A standardized questionnaire was used to obtain demographic, clinical and risk factor data on each study subject. Viral DNA was extracted from participants’ peripheral blood mononuclear cells either directly or after co-cultivation. A nested PCR was used to obtain selected fragments of the envelope genes for genotyping by the heteroduplex mobility assay (HMA). A 600 bp sequence encompassing the V3 loop was sequenced from a selection of 23 of these samples for phylogenetic analysis and confirmation of HMA genotype. ResultsAmong the 257 successfully genotyped HIV-1-positive samples, genotype B was found in 98.3% (228/232) of those obtained from subjects in Peru, Ecuador, and Paraguay. In contrast, 56% (14/25) of the samples from Uruguay were genotype F, and the remainder were genotype B. Genotype F was detected for the first time in Peru (2/224) and Paraguay (1/4), and genotype A for the first time in Peru (1/224). Phylogenetic analysis confirmed the genotype identified by HMA in the 23 samples sequenced. There was no detectable genetic clustering of HIV-1 within the different high-risk groups or geographic locations. ConclusionsThese findings verify and extend the presence of several different HIV-1 genotypes in South America.

Sexually transmitted infections in female sex workers: reduced by condom use but not by a limited periodic examination program.

Background and Objectives: The sexually transmitted diseases (STD) control program for female sex workers (FSW) in Lima, Peru, provided periodic serological tests for syphilis and cervical smears for gonococci, but not medication for STD or condoms. Goal of this Study: To assess program effectiveness. Study Design: We assessed prevalence of current STD and serum antibody to STD pathogens in FSW in relation to program participation and to condom use. Results: Program participation was not associated with significantly reduced rates of current gonococcal or chlamydial infections or Venereal Disease Research Laboratory (VDRL) titers ≥4 with reactive fluorescent treponemal antibody absorption (FTA‐ABS). However, regardless of control program participation, consistent condom use was associated with reduced prevalence of gonorrhea, and with significantly reduced seroreactivity for FTA‐ABS, C. trachomatis, anti‐hepatitis B core (HBc), and anti‐human T‐lymphotropic virus type I. Anti‐HBc was associated with years of receiving penicillin injections for syphilis prophylaxis. Conclusion: The scope, quality, and efficacy of STD control programs must be technically appropriate, well managed, and adequately financed. The safety of marginal programs warrants scrutiny.

Factors Associated with Oropharyngeal Human Immunodeficiency Virus Shedding

Orogenital transmission of human immunodeficiency virus (HIV) is considered to be inefficient, and infectious HIV is rarely detected in saliva. To evaluate the posterior oropharynx as a source of HIV shedding, we studied 64 HIV-infected men who have sex with men in Seattle, Washington, and Lima, Peru. In multivariate analysis, receipt of antiretroviral therapy, higher CD4 cell count, and history of tonsillectomy were predictors of lower pharyngeal HIV RNA levels.

Overview of recent tritium target filling, layering, and material testing at Los Alamos national laboratory in support of inertial fusion experiments

Abstract The Tritium Science and Engineering (AET-3) Group at Los Alamos National Laboratory (LANL) performs a variety of activities to support Inertial Fusion (IF) research - both to further fundamental fusion science and to develop technologies in support of Inertial Fusion Energy (IFE) power generation. Inertial fusion ignition target designs have a smooth spherical shell of cryogenic Deuterium-Tritium (DT) solid contained within a metal or plastic shell that is a few mm in diameter. Fusion is attained by imploding these shells under the symmetric application of energy beams. For IFE targets the DT solid must also survive the process of injecting it into the power plant reactor. Non-ignition IF targets often require a non-cryogenic DT gas fill of a glass or polymeric shell. In this paper an overview will be given of recent LANL activities to study cryogenic DT layering, observe tritium exposure effects on IF relevant materials, and fill targets in support of IF implosion experiments.

Body Parts Matter: Social, Behavioral, and Biological Considerations for Urethral, Pharyngeal, and Rectal Gonorrhea and Chlamydia Screening Among MSM in Lima, Peru

Background Gonorrhea (Neisseria gonorrhoeae [GC]) and chlamydia (Chlamydia trachomatis [CT]) disproportionately affect men who have sex with men (MSM), and public health implications vary by anatomic site and bacterial agent. Urethral and rectal GC and CT can increase risk of HIV transmission, whereas pharyngeal GC may be a reservoir for antimicrobial resistance. To define screening priorities in Latin America, we compare differences in the prevalence and correlates of urethral, pharyngeal, and rectal GC and CT among MSM in Peru. Methods A cross-sectional sample of 787 MSM from Lima was screened between 2012 and 2014. We described prevalence of urethral, pharyngeal, and rectal GC and CT infection and conducted bivariate analyses of associations with social, behavioral, and biological characteristics. Poisson regression analyses assessed the correlates of each infection at each anatomic site. Results The most commonly symptomatic infection (urethral GC; 42.1%) was the least prevalent (2.4%). The most prevalent infections were rectal CT (15.8%) and pharyngeal GC (9.9%). Rectal CT was the least commonly symptomatic (2.4%) infection, and was associated with younger age (adjusted prevalence ratio [95% confidence interval], 0.96 [0.94–0.98]), HIV infection (1.46 [1.06–2.02]), and pasivo (receptive; 3.59 [1.62–7.95]) and moderno (versatile; 2.63 [1.23–5.60]) sexual roles. Conclusions Results highlight limitations of current syndromic screening strategies for sexually transmitted diseases in Peru, wherein urethral CT and rectal GC and CT may be missed due to their frequently asymptomatic presentations. Successful management of GC and CT infections among MSM in low-resource settings requires differentiating between bacterial agent, symptomatic presentation, associated risk factors, and public health implications of untreated infection at different anatomic sites.