HIV-1 Polymerase Research Articles

False-negative HIV-1 polymerase chain reaction in a 15-month-old boy with HIV-1 subtype C infection.

Polymerase chain reaction (PCR) testing is the gold standard for determining the HIV status in children <18 months of age. However, when clinical manifestations are not consistent with laboratory results, additional investigation is required. We report a 15-month-old HIV-exposed boy referred to our hospital after he had been admitted several times for infectious diseases. A rapid antibody test on the child was positive, while routine diagnostic HIV PCRs using the Roche COBAS Ampliprep/COBAS TaqMan HIV Qual Test were negative at 6 weeks, 6 months, 7 months and 15 months. In addition, the same PCR test performed on the HIV-infected mother was also negative. Alternative PCR and viral load assays using different primer sets detected HIV RNA or proviral DNA in both child and mother. Gag sequences from the child and his mother classified both infections as HIV-1 subtype C, with very rare mutations that may have resulted in PCR assay primer/probe mismatch. Consequently, the child was commenced on antiretroviral therapy and made a remarkable recovery. These findings indicate that more reliable PCR assays capable of detecting a wide range of HIV subtypes are desirable to circumvent the clinical problems created by false-negative PCR results.

Time to implement 9-month infant HIV testing in South Africa.

South Africa (SA) is likely to meet the National Strategic Plan target of &lt;2% mother-to-child HIV transmission at 6 weeks of age in 2015. Children infected with HIV after 6 weeks often remain undiagnosed because of poor implementation of post-weaning and final outcome 18-month HIV testing. The World Health Organization recommends a screening HIV rapid test (HRT) in HIV-exposed infants at the 9-month immunisation visit to exclude postnatal infection, with a confirmatory HIV polymerase chain reaction (PCR) test if the HRT is positive. To evaluate the impact of substituting this recommendation for the post-weaning HIV testing recommended by SA guidelines. Rates of seroreversion and probability of infection at 9 months of age were applied to a theoretical population of 100 HIV-exposed infants, uninfected at birth and breastfed for 1 year with antiretroviral prophylaxis. Nine scenarios were developed and the number of HIV PCRs saved compared with current guidelines was calculated. Nine-month testing using the HRT reduced the number of follow-up PCR tests done in all scenarios by &gt;50%, with differences ranging from 51% to 59% and 81% to 89% for low and high seroreversion rates, respectively. Nine-month testing using HRT would increase identification and early treatment of HIV-infected infants, improve monitoring of postnatal transmission rates, and reduce the number of HIV PCR tests done with resultant cost saving. Training of healthcare workers implementing HRT would be required. Ongoing efforts to improve implementation and monitoring of testing at 9 and 18 months will be essential.

Transmitted Drug Resistance Among Recently Diagnosed Adults and Children in São Paulo, Brazil

Transmitted drug resistance mutations (TDRM) have been a constant threat to treatment efficacy. We evaluated TDRM in plasma RNA of 217 antiretroviral therapy-naive patients from sites in the São Paulo metropolitan area, collected from 2012 to 2014. The partial HIV-1 polymerase region was sequenced using Big Dye terminators at an ABI 3130 Genetic Analyzer. TDRM was defined according to the Stanford database calibrated population resistance (CPR v.6.0), but other drug resistance mutations (DRM) considered at the IAS list (IAS, 2014) and at the Stanford HIV Database Genotyping Resistance Interpretation (GRI-HIVdb) were also described. Out of 78% (170/217) of patients with information on the time of diagnosis, most (83%, 141/170) had been recently diagnosed, with the first positive HIV serology at a median of 58 days (IQR 18-184). Subtype B predominated (70%), followed by subtype F (10%), BF (7.5%), C (7.5%), and BC (5%). TDRMs were observed in 9.2% (20/217, CI 95% 5.9% to 13.6%), mostly (5.2%) to nonnucleoside reverse transcriptase inhibitor (NNRTI) antiretroviral class. Among children and adolescents, only a single patient showed TDRMs. Additional non-CPR mutations were observed: 11.5% (25/217) according to IAS or 4.6% (10/217) according to GRI-HIVdb. Overall, 23.5% (51/217) of the cases had one or more DRM identified. TDRM prevalence differed significantly among some sites. These trends deserve continuous and systematic surveillance, especially with the new policies of treatment as prevention being implemented in the country.

A mathematical model evaluating the timing of early diagnostic testing in HIV-exposed infants in South Africa.

Antiretroviral therapy is often initiated too late to impact early HIV-related infant mortality. Earlier treatment requires an earlier diagnosis, and the currently recommended 6-week HIV polymerase chain reaction (PCR) test needs reconsideration. This study aims to identify (1) optimal testing intervals to maximize the number of perinatal HIV infections diagnosed and (2) programmatic issues that impact diagnosis. A mathematical model was developed to simulate antiretroviral prophylaxis uptake and health outcomes in 240,000 HIV-exposed South African infants. The model considered routine early testing with 1 PCR (at birth, 6, 10, or 14 weeks of age) and with 2 PCR tests (at birth and at 6, 10, or 14 weeks of age). A single 6-week test would diagnose the same number of perinatal HIV infections as birth testing (P = 0.92) but fewer infections than a 10-week test (P < 0.01). Ten-week testing identifies the highest number of perinatally infected infants (P < 0.01 compared with a single test at all other ages) but does not save additional life years compared with birth testing (P = 0.27). Performing 2 PCR tests (at birth and 10 weeks) would identify the highest number of perinatal infections (P < 0.01 versus a second 6- or 14-week test). However, 25% of perinatal HIV infections would remain undiagnosed, largely because of failure to return PCR test results to caregivers. Six weeks may no longer be the optimal age to diagnose perinatal HIV infections. Two early PCR tests (at birth and 10 weeks) would likely be the ideal diagnostic algorithm, but must be coupled with improved program coverage.

Absence of Detectible HIV-1 Viremia After Treatment Cessation in an Infant.

Until very recently, the only patient “cured” of HIV was the “Berlin patient,” an adult male treated for HIV-associated acute myeloid leukemia with stem cell transplantation from a donor who was intrinsically resistant to HIV. The donor carried homozygous mutations (delta32) in the chemokine receptor 5 gene, which is an essential co-receptor for HIV entry into most target cells. The present study reports on an infant who also may be cured with early, highly active antiretroviral therapy (ART) after documented perinatal infection.A 35-week gestational age infant was born by normal vaginal delivery to an HIV-infected woman who received no prenatal care and who was not taking ART. ART was initiated in the infant at 30 hours of age with zidovudine, lamivudine, and nevirapine. At 1 week of age, this regimen was adjusted to zidovudine, lamivudine, and ritonavir-boosted lopinavir. The infant remained on ART for 18 months and was then lost to follow-up until 23 months of age. ART has been discontinued and, because of results from subsequent studies, has not been restarted.Standard HIV polymerase chain reaction (PCR) assays and HIV antibody testing were used to diagnose and monitor the HIV-exposed infant. Peripheral blood mononuclear cell cultures were analyzed with PCR for virus DNA and with co-culture techniques for replication-competent virus. Lymphocyte subset analysis was conducted with standard flow cytometry, and HIV-specific T-cell responses were evaluated with intracellular cytokine generation assays.During the first month of life and while receiving ART, the infant had elevated quantitative HIV RNA PCR measurements that declined to undetectable levels and remained there. Subsequently, although proviral DNA was detected at the limits of the assay at 26 months of age, plasma viral RNA was undetectable, and replication-competent virus could not be cultured at age 24 months. HIV antibody assays were not detected in the infant at or after 24 months of age, when maternal antibody would not confound the assays, and HIV-specific T-cell responses were not detected at age 28 months. CD4+ T-cell counts remain normal throughout the study.Very early ART therapy in infants born at risk may abort HIV infection.In patients with established HIV infection, effective ART drives the virus to “undetectable” levels, usually defined as <20/copies of viral RNA/mL of plasma. However, viremia persists in such patients at very low levels and as DNA pro-virus in peripheral blood mononuclear cells. Was this infant cured of HIV? According to the Centers for Disease Control and Prevention definition, the infant was “infected”: 2 positive PCR test results on at least 2 different blood specimens. The data presented demonstrated that after unintended discontinuation of therapy, the infant remained free of replication-competent HIV from at least 12 months of age. As the authors conclude, “very early ART in infants may alter the establishment and long term persistence of HIV-infection.” But why might this happen in a newborn when it has not been demonstrated in older patients except under the unique circumstances of the Berlin patient? HIV persistence depends on the establishment of a reservoir of infected cells. Recent studies suggest that this condition involves a specific population of “central memory T cells.” Perhaps very early therapy aborts or inhibits establishment of this reservoir or perhaps these cells have not fully matured to be infected in newborns. In any case, the present report suggests that very early therapy may prevent establishment of HIV in high-risk infants, and certainly this possibility is being studied intensively.

Infections in HIV-exposed uninfected children with focus on sub-Saharan Africa.

Infections in HIV-exposed uninfected children with focus on sub-Saharan Africa.

An Unusual Cause of Odynophagia in a Patient With Eosinophilic Esophagitis

Question: An 18-year-old white man presented with 3 days of epigastric pain, odynophagia, vomiting, and fevers. He also reported 4 months of dysphagia with solids. His history included heartburn, allergic rhinitis, and wheat allergy. There was no personal or family history of recent infection. On admission, he was febrile (101.8°F) and tachycardic (110 bpm). Physical examination revealed a 2-mm ulcer in the lower lip and epigastric tenderness. Blood counts, biochemistry, and liver function tests were normal. Esophagogastroduodenoscopy (EGD) revealed esophagitis with multiple discrete shallow round, 3- to 4-mm ulcers starting in upper esophagus and distributed throughout its circumference (Figure A, B). Histopathology revealed necroinflammatory tissue and squamous epithelium with intercellular edema, basal zone hyperplasia, and up to 56 eosinophils per high-power field (Figure C). Immunoperoxidase staining was negative for herpes simplex virus (HSV) and cytomegalovirus. Serum HSV antibodies, HIV, and cytomegalovirus polymerase chain reaction were negative. The histologic findings were interpreted as eosinophilic esophagitis (EoE) and treatment with pantoprazole was administered. Odynophagia persisted and repeated EGD at day 5 showed persistent coalescent esophageal ulcers along with white exudates and erythema (Figure D). Several specimens were obtained from the edge of the biopsy. A representative histopathology is shown (Figure E, F). What is the diagnosis? Look on page 38 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Histopathology revealed marked inflammation and viral cytopathic changes. Immunohistochemistry showed broad reactivity for HSV types I and II (Figure G). Further investigation of cell and humoral immunity was normal. The patient was treated with intravenous acyclovir with resolution of odynophagia within 3 days and then completed 14 days with valacyclovir. At 3 months on therapy with pantoprazol, dysphagia had improved and further endoscopy was normal but random biopsies revealed persistence of mucosal eosinophilia. A final diagnosis of herpetic esophagitis (HE) with concurrent EoE was made. Since its first description in 1940, close to 60 cases of HE have been well-documented in immunocompetent adults and adolescents.1Canalejo Castrillero E. Garcia Duran F. Cabello N. et al.Herpes esophagitis in healthy adults and adolescents: report of 3 cases and review of the literature.Medicine (Baltimore). 2010; 89: 204-210Crossref PubMed Scopus (77) Google Scholar HE usually affects young men. Prodromal symptoms of upper respiratory tract infection and concurrent orolabial lesions can be present. The most common clinical manifestations include acute onset of odynophagia, retrosternal pain, fever, and dysphagia. EGD reveals multiple, coalescent or discrete, small ulcers in most patients. The diagnosis can be confirmed by histopathology, viral culture, or polymerase chain reaction detection of biopsies taken from the edge of the ulcers or esophageal brush. Despite the initial negative histopathology in our patient, high clinical suspicion prompted further endoscopic evaluation, which led to the final diagnosis. Antiviral therapy on immunocompetent patients remains debatable. The pathogenesis of HE in the immunocompetent host is not entirely understood. EoE has been linked to the occurrence of HSV esophagitis in previous case reports.2Squires K.A. Cameron D.J. Oliver M. et al.Herpes simplex and eosinophilic oesophagitis: the chicken or the egg?.J Pediatr Gastroenterol Nutr. 2009; 49: 246-250Crossref PubMed Scopus (37) Google Scholar, 3Zaja Franulovic O. Lesar T. Busic N. et al.Herpes simplex primo-infection in an immunocompetent host with eosinophilic esophagitis.Pediatr Int. 2013; 55: e38-e41Crossref PubMed Scopus (20) Google Scholar In addition to local mucosal injury, dysregulation of T-helper 2 response in EoE may lead to a breakdown in barrier function and increase susceptibility to infection with swallowed virus. Future studies are needed to clarify the apparent link between these 2 entities.

Increased Diversity of the HLA-B40 Ligandome by the Presentation of Peptides Phosphorylated at Their Main Anchor Residue

Human leukocyte antigen (HLA) class I molecules bind peptides derived from the intracellular degradation of endogenous proteins and present them to cytotoxic T lymphocytes, allowing the immune system to detect transformed or virally infected cells. It is known that HLA class I-associated peptides may harbor posttranslational modifications. In particular, phosphorylated ligands have raised much interest as potential targets for cancer immunotherapy. By combining affinity purification with high-resolution mass spectrometry, we identified more than 2000 unique ligands bound to HLA-B40. Sequence analysis revealed two major anchor motifs: aspartic or glutamic acid at peptide position 2 (P2) and methionine, phenylalanine, or aliphatic residues at the C terminus. The use of immobilized metal ion and TiO2 affinity chromatography allowed the characterization of 85 phosphorylated ligands. We further confirmed every sequence belonging to this subset by comparing its experimental MS2 spectrum with that obtained upon fragmentation of the corresponding synthetic peptide. Remarkably, three phospholigands lacked a canonical anchor residue at P2, containing phosphoserine instead. Binding assays showed that these peptides bound to HLA-B40 with high affinity. Together, our data demonstrate that the peptidome of a given HLA allotype can be broadened by the presentation of peptides with posttranslational modifications at major anchor positions. We suggest that ligands with phosphorylated residues at P2 might be optimal targets for T-cell-based cancer immunotherapy.

Development of a cost-effective assay for genotyping of HIV-1 non-B subtype for drug resistance

Highly Active Antiretroviral Therapy (HAART) is the most effective way to control HIV-1 replication in infected patients. Prior to the start of therapy, genotyping of HIV-1 for mutations that confer resistance to potential drug candidates is crucial for it allows formulating an effective regimen. Ineffective drugs are excluded and potentially effective ones are included. A number of diagnostic kits are commercially available for this purpose but are tailored for HIV-1 subtype-B, a strain chiefly found in AIDS patients of Europe and America. However, AIDS patients of South-East Asia including Thailand are predominant infected with HIV-1 subtype non-B. In this study, an inexpensive assay was developed that genotypes HIV-1 non-B for drug resistance and tested it on 99 Thai AIDS patients. Results showed that 98 were infected with HIV-1 subtype non-B (or CRF01_AE) and one with subtype-B. Within the HIV-1 polymerase (pol), reverse transcriptase (RT) gene, the assay identified 18 codon mutations associated with resistance to Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs) and 17 Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs). Employing a commercially available kit, parallel genotyping of patient samples confirmed results providing validation of the assay. This method approximately costs 100 US dollars compared to $300 for a commercially available test. In Thailand, the burden of cost for treating HIV-infections is high not only for the average citizen but the country's health care systems. Therefore the low cost and yet effective genotyping test for HIV-1 subtype non-B is a practical and viable solution to expensive genotyping platforms.

Laboratory information system data demonstrate successful implementation of the prevention of mother-to-child transmission programme in South Africa.

Monitoring the prevention of mother-to-child transmission (PMTCT) programme to identify gaps for early intervention is essential as South Africa progresses from prevention to elimination of HIV infection in children. Early infant diagnosis (EID) by an HIV polymerase chain reaction (PCR) test is recommended at 6 weeks of age for all HIV-exposed infants. The National Health Laboratory Service (NHLS) performs the PCR tests for the public health sector and stores test data in a corporate data warehouse (CDW). To demonstrate the utility of laboratory data for monitoring trends in EID coverage and early vertical transmission rates and to describe the scale-up of the EID component of the PMTCT programme. HIV PCR test data from 2003 to 2012 inclusive were extracted from the NHLS CDW by year, province, age of infant tested and test result and used to calculate EID coverage and early vertical transmission rates to provincial level. Rapid scale-up of EID over the first decade of the PMTCT programme was evident from the 100-fold increase in PCR tests to 350 000 by 2012. In 2012, 73% of the estimated 270 000 HIV-exposed infants requiring an early PCR were tested and the early vertical transmission rate had fallen to 2.4% as a result of successful implementation of the PMTCT programme. Laboratory data can provide real time, affordable monitoring of aspects of the PMTCT programme and assist in achieving virtual elimination of paediatric HIV infection in South Africa.

The Global Transmission Network of HIV-1

Human immunodeficiency virus type 1 (HIV-1) is pandemic, but its contemporary global transmission network has not been characterized. A better understanding of the properties and dynamics of this network is essential for surveillance, prevention, and eventual eradication of HIV. Here, we apply a simple and computationally efficient network-based approach to all publicly available HIV polymerase sequences in the global database, revealing a contemporary picture of the spread of HIV-1 within and between countries. This approach automatically recovered well-characterized transmission clusters and extended other clusters thought to be contained within a single country across international borders. In addition, previously undescribed transmission clusters were discovered. Together, these clusters represent all known modes of HIV transmission. The extent of international linkage revealed by our comprehensive approach demonstrates the need to consider the global diversity of HIV, even when describing local epidemics. Finally, the speed of this method allows for near-real-time surveillance of the pandemic's progression.

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Aim Class I HLA reveal virus-derived peptide ligands to cytotoxic T lymphocytes (CTL) whose function is to eliminate infected cells. The Los Alamos National Laboratory (LANL) database reports numerous HIV-1 CTL epitopes characterized by various methods. To date, none have elicited protective immunity when tested in a vaccine. Our aim was to gather HLA-A*11:01 from HIV infected cells to identify viral ligands presented directly by HLA. An HLA-based view of HIV ligand presentation to CTL might enhance therapies directed against HIV. Methods Soluble class I HLA-A*11:01 (sHLA) was gathered from HIV-1 (NL4-3)-infected human CD4+ SUP-T1 cells. sHLA harvested from infected cells was immunoaffinity purified, then bound ligands were recovered, fractionated by RP-HPLC and mapped by tandem mass spectrometry. A*11:01 peptide maps from HIV-1 infected cells were compared to maps from uninfected as well as to maps of LANL’s 15 best characterized HLA-A11-restricted ligands. Results The HLA-A*11:01 of HIV-infected cells bound seven viral peptides. Three ligands (2 HIV Nef; 1 HIV polymerase) were previously reported in the LANL’s A*11:01 CTL target database. However, twelve LANL-reported HIV epitopes are definitively absent from the A*11:01 of infected SUP-T1 cells. Beyond what has been previously reported, we detect two Gag variants with partial homology to LANL sequences, a Nef 10mer variant, and a novel Nef-derived epitope not previously reported. Conclusions This is the first study to identify HIV/HLA peptides isolated from infected cells. An HLA-centric approach shows that class I HLA samples a handful of HIV ligands for presentation to CTL. New ligands found by our method provide a view of HIV infection not available using other approaches, and absence of most LANL ligands suggests that not all CTL targets are presented by infected cells. Identification of HIV ligands consistently displayed by HLA class I can improve vaccine strategies, and HLA-based methods are available to detect these promising targets.

Molecular Characterization of Ambiguous Mutations in HIV-1 Polymerase Gene: Implications for Monitoring HIV Infection Status and Drug Resistance

Detection of recent HIV infections is a prerequisite for reliable estimations of transmitted HIV drug resistance (t-HIVDR) and incidence. However, accurately identifying recent HIV infection is challenging due partially to the limitations of current serological tests. Ambiguous nucleotides are newly emerged mutations in quasispecies, and accumulate by time of viral infection. We utilized ambiguous mutations to establish a measurement for detecting recent HIV infection and monitoring early HIVDR development. Ambiguous nucleotides were extracted from HIV-1 pol-gene sequences in the datasets of recent (HIVDR threshold surveys [HIVDR-TS] in 7 countries; n=416) and established infections (1 HIVDR monitoring survey at baseline; n=271). An ambiguous mutation index of 2.04×10-3 nts/site was detected in HIV-1 recent infections which is equivalent to the HIV-1 substitution rate (2×10-3 nts/site/year) reported before. However, significantly higher index (14.41×10-3 nts/site) was revealed with established infections. Using this substitution rate, 75.2% subjects in HIVDR-TS with the exception of the Vietnam dataset and 3.3% those in HIVDR-baseline were classified as recent infection within one year. We also calculated mutation scores at amino acid level at HIVDR sites based on ambiguous or fitted mutations. The overall mutation scores caused by ambiguous mutations increased (0.54×10-23.48×10-2/DR-site) whereas those caused by fitted mutations remained stable (7.50-7.89×10-2/DR-site) in both recent and established infections, indicating that t-HIVDR exists in drug-naïve populations regardless of infection status in which new HIVDR continues to emerge. Our findings suggest that characterization of ambiguous mutations in HIV may serve as an additional tool to differentiate recent from established infections and to monitor HIVDR emergence.

HIV Type 1 Transmission Networks Among Men Having Sex with Men and Heterosexuals in Kenya

We performed a molecular phylogenetic study on HIV-1 polymerase sequences of men who have sex with men (MSM) and heterosexual patient samples in Kenya to characterize any observed HIV-1 transmission networks. HIV-1 polymerase sequences were obtained from samples in Nairobi and coastal Kenya from 84 MSM, 226 other men, and 364 women from 2005 to 2010. Using Bayesian phylogenetics, we tested whether sequences clustered by sexual orientation and geographic location. In addition, we used trait diffusion analyses to identify significant epidemiological links and to quantify the number of transmissions between risk groups. Finally, we compared 84 MSM sequences with all HIV-1 sequences available online at GenBank. Significant clustering of sequences from MSM at both coastal Kenya and Nairobi was found, with evidence of HIV-1 transmission between both locations. Although a transmission pair between a coastal MSM and woman was confirmed, no significant HIV-1 transmission was evident between MSM and the comparison population for the predominant subtype A (60%). However, a weak but significant link was evident when studying all subtypes together. GenBank comparison did not reveal other important transmission links. Our data suggest infrequent intermingling of MSM and heterosexual HIV-1 epidemics in Kenya.

Reduction in Perinatal HIV Infections in KwaZulu-Natal, South Africa, in the Era of More Effective Prevention of Mother to Child Transmission Interventions (2004–2012)

To describe a trend in perinatal HIV transmission associated with the implementation of rapidly changing prevention of mother to child transmission (PMTCT) interventions from 2004 to 2012. Retrospective analysis of infant HIV polymerase chain reaction results of infants from 2004 to 2012 archived from a Laboratory Information System. KwaZulu-Natal, South Africa. HIV infection in infants aged 4-8 weeks. The proportion of 4- to 8-week-old infants who tested HIV polymerase chain reaction positive decreased significantly (P < 0.0001) from 27.5% in 2004 to 2.9% in 2012. The reduction rates in perinatal HIV infections in 4- to 8-week-old HIV-exposed infants decreased significantly (P < 0.0001) by 48.7% following single-dose nevirapine (sdNVP) (2005 to April 2008), 68.4% with zidovudine from 28 weeks and sdNVP together with triple antiretroviral therapy for women with CD4 cell count < 200 cells/mm³ (May 2008-April 2010), and 89.5% with zidovudine from 14 weeks, sdNVP, and triple antiretroviral therapy for women with CD4⁺ cell count < 350 cells/mm³ (May 2010-December 2012). We show an almost 10-fold reduction in mother to child transmission from 2004 to 2012 in infants aged 4-8 weeks during a rapid implementation of more complex and robust PMTCT interventions. The significant reductions in mother to child transmission in the South African PMTCT program are encouraging for a middle-income country with the second highest antenatal HIV prevalence in the world.

HIV Transmission to Extremely Low Birth Weight Infants

Prematurity increases the perinatal HIV transmission rate compared with term infants. There is sparse literature documenting the risk of transmission of HIV to extremely low birth weight (ELBW) infants. To determine the risk of perinatal transmission of HIV to ELBW infants in a tertiary neonatal unit in South Africa. A prospective database was maintained on all inborn ELBW infants over a 1-year period from March 2010 to February 2011. Survival and DNA HIV polymerase chain reaction results at 6 weeks were recorded. Of the 180 ELBW infants, 51 (28%) of these babies were HIV exposed. Of these 51 infants, 37 survived until 6 weeks of age. Polymerase chain reaction testing revealed 1 HIV-positive infant for a rate of 2.7% (95% confidence interval: 0.7-14.1%). Twenty-six (72%) of the 36 mothers received antiretroviral drugs, but only 16 (44%) had been treated for more than 1 month. The rate of HIV transmission in this cohort of ELBW infants is very low despite only 44% of the mothers receiving adequate antiretroviral drugs. We postulate that this is due to our high (89%) cesarean section rate, universal (100%) infant prophylactic antiretroviral drugs and the use of pasteurized breast milk.

Kaposi's sarcoma in pregnancy after initiation of highly active antiretroviral therapy: a manifestation of immune reconstitution syndrome

A case of Kaposi's sarcoma (KS) presenting as an immune reconstitution inflammatory syndrome in pregnancy with conservative management is reported. Successful outcomes for mother and baby were achieved. HIV was diagnosed at antenatal booking and highly active antiretroviral therapy commenced at 20 weeks. Multiple lymphadenopathies developed two months later. Excision biopsy of a node confirmed KS. In the absence of advanced disease, she was managed conservatively until delivery. The placenta showed no evidence of KS or human herpes virus 8 (HHV-8). The baby had negative HIV and HHV-8 polymerase chain reaction tests at zero, six and 12 weeks of life. Six months postpartum, the KS had regressed and HHV-8 viral load was undetectable.

Screening for and Verification of Novel Mutations Associated with Drug Resistance in the HIV Type 1subtype B′ in China

ObjectiveMutations associated with HIV drug resistance have been extensively characterized at the HIV-1 polymerase domain, but more studies have verified that mutations outside of the polymerase domain also results in resistance to antiviral drugs. In this study, mutations were identified in 354 patients experiencing antiretroviral therapy (ART) failure and in 97 naïve-therapy patients. Mutations whose impact on antiviral drugs was unknown were verified by phenotypic testing.MethodsPol sequences of HIV subtype B′ obtained from patients experiencing ART failure and from naïve-therapy patients were analyzed for mutations distinct between two groups. Mutations that occurred at a significantly higher frequency in the ART failure than the naïve-therapy group were submitted to the Stanford HIV Drug Resistance Database (SHDB) to analyze the correlation between HIV mutations and drug resistance. For mutations whose impact on the antiviral drug response is unknown, the site-directed mutagenesis approach was applied to construct plasmids containing the screened mutations. 50% inhibitory concentration (IC50) to AZT, EFV and NVP was measured to determine the response of the genetically constructed viruses to antiviral drugs.Results7 mutations at 6 positions of the RT region, D123E, V292I, K366R, T369A, T369V, A371V and I375V, occurred more frequently in the ART failure group than the naïve-therapy group. Phenotypic characterization of these HIV mutants revealed that constructed viruses with mutations A371V and T369V exhibited dual resistance to AZT and EFV respectively, whereas the other 5 mutations showed weak resistance. Although the impact of the other six mutations on response to NVP was minimal, mutation T369V could enhance resistance to NVP.ConclusionsThis study demonstrated that mutations at the RT C-terminal in subtype B′ could result in resistance to RT inhibitors if the mutations occurred alone, but that some mutations could promote susceptibility to antiviral drugs.

Prevalence of HIV/STIs and Associated Factors Among Men Who Have Sex With Men in An Giang, Vietnam

The prevalence of HIV and sexually transmitted infections among men who have sex with men (MSM) has increased substantially in Vietnam. This study aimed to estimate the prevalence of HIV, syphilis, urethral gonorrhoea, and urethral chlamydia, and determined correlates of HIV infection among MSM in An Giang, Vietnam. A group of 381 MSM were recruited in a community-based cross-sectional survey between August and December 2009. Face-to-face interviews were conducted for collecting data on sociodemographics, behaviors, and access to HIV prevention programs. Serological tests for HIV and syphilis and polymerase chain reaction for gonorrhoea/chlamydia were performed. Multivariate regression analyses were used to investigate the correlates of HIV infection. The prevalence of HIV, syphilis, gonorrhoea, chlamydia, and gonorrhoea/chlamydia were 6.3%, 1.3%, 1.8%, 3.2%, and 4.7%, respectively. HIV prevalence among 63 injecting MSM was significantly higher than that of 318 noninjectors (20.6% vs. 3.5%, P < 0.001). Approximately 40.4% identified as heterosexual and 42.8% had ever had sex with females. The rate of unprotected anal intercourse with another male in the last month was substantially high (75.3%). Injecting drugs (adjusted prevalence ratio [aPR] = 2.88, 95% confidence interval [CI]: 1.12-7.42), being transgender (aPR = 4.27, 95% CI, 1.17-15.57), and unprotected sex with a female sex worker (aPR = 4.88, 95% CI: 1.91-12.50) were significantly associated with HIV infection. The infection risk increased with age to a peak of 25 years and then decreased. Although prevalence levels are lower in An Giang, Vietnam than in some other comparable locations, HIV/sexually transmitted infections prevention, and sexual health promotion targeting MSM are highly important in this location.

Evaluation of HIV-1 polymerase chain reaction (PCR) technique using dried blood spots (DBS) for diagnosis of perinatal transmission of HIV

Background Effective health care delivery to the majority of perinatally exposed infants is hampered by lack of access to accurate HIV diagnosis in infancy. Polymerase chain reaction is the most sensitive test to diagnose HIV-1 infection in children born to HIV seropositive mothers. The purpose of this study was to assess the feasibility and accuracy of using dried blood spot (DBS) technology in performing HIV-1 DNA PCR using Roche Amplicor HIV-1 DNA PCR version 1.5 for diagnosis in children less than 18 months of age.