Reducing vertical transmission of HIV in the UK.
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ABSTRACT:
SUBMITTER: Nicoll A
PROVIDER: S-EPMC1116998 | biostudies-literature | 1999 Nov
REPOSITORIES: biostudies-literature
Publications
Reducing vertical transmission of HIV in the UK.
BMJ (Clinical research ed.) 19991101 7219
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Project description: Not available
| S-EPMC1122131 | biostudies-literature
Project description:Perforin-1, a component of the immune system, is able to control Human Immunodeficiency Virus-1 (HIV-1) replication and could be involved in HIV-1 mother-to-child transmission (MTCT). This study aims at evaluating the role of the c.900C > T PRF1 gene (encoding for perforin-1) polymorphism (rs885822) in HIV-1 MTCT. The PRF1 c.900C > T polymorphism was genotyped in 331 children from Zambia using a Taqman probe on a Real Time PCR platform. The PRF1 c.900C > T C/T genotype was more frequent among HIV-1 exposed but non-infected children than in HIV-1 positive cases, and the results were confirmed among children infected during breastfeeding. PRF1 c.900C > T correlated with protection against HIV-1 MTCT, suggesting its role in HIV-1 vertical transmission.
| S-EPMC6905447 | biostudies-literature
Project description: Not available
| S-EPMC6434516 | biostudies-literature
Project description:BackgroundStrategies to reduce the risk of mother-to-child transmission of the human immunodeficiency virus (HIV) include lifelong antiretroviral therapy (ART) for HIV-positive women, exclusive breastfeeding from birth for six weeks plus nevirapine or replacement feeding plus nevirapine from birth for four to six weeks, elective Caesarean section delivery, and avoiding giving children chewed food. In some settings, these interventions may not be practical, feasible, or affordable. Simple, inexpensive, and effective interventions (that could potentially be implemented even in the absence of prenatal HIV testing programmes) would be valuable. Vitamin A, which plays a role in immune function, is one low-cost intervention that has been suggested in such settings.ObjectivesTo summarize the effects of giving vitamin A supplements to HIV-positive women during pregnancy and after delivery.Search methodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to 25 August 2017, and checked the reference lists of relevant articles for eligible studies.Selection criteriaWe included randomized controlled trials conducted in any setting that compared vitamin A supplements to placebo or no intervention among HIV-positive women during pregnancy or after delivery, or both.Data collection and analysisAt least two review authors independently assessed study eligibility and extracted data. We expressed study results as risk ratios (RR) or mean differences (MD) as appropriate, with their 95% confidence intervals (CI), and conducted random-effects meta-analyses. This is an update of a review last published in 2011.Main resultsFive trials met the inclusion criteria. These were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005 and none of the participants received ART. Women allocated to intervention arms received vitamin A supplements at a variety of doses (daily during pregnancy; a single dose immediately after delivery, or daily doses during pregnancy plus a single dose after delivery). Women allocated to comparison arms received identical placebo (6601 women, 4 trials) or no intervention (697 women, 1 trial). Four trials (with 6995 women) had low risk of bias and one trial (with 303 women) had high risk of attrition bias.The trials show that giving vitamin A supplements to HIV-positive women during pregnancy, the immediate postpartum period, or both, probably has little or no effect on mother-to-child transmission of HIV (RR 1.07, 95% CI 0.91 to 1.26; 4428 women, 5 trials, moderate certainty evidence) and may have little or no effect on child death by two years of age (RR 1.06, 95% CI 0.92 to 1.22; 3883 women, 3 trials, low certainty evidence). However, giving vitamin A supplements during pregnancy may increase the mean birthweight (MD 34.12 g, 95% CI -12.79 to 81.02; 2181 women, 3 trials, low certainty evidence) and probably reduces the incidence of low birthweight (RR 0.78, 95% CI 0.63 to 0.97; 1819 women, 3 trials, moderate certainty evidence); but we do not know whether vitamin A supplements affect the risk of preterm delivery (1577 women, 2 trials), stillbirth (2335 women, 3 trials), or maternal death (1267 women, 2 trials).Authors' conclusionsAntepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs. The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.
| S-EPMC5618453 | biostudies-literature
Project description:Symbiotic bacteria are commonly associated with cells and tissues of diverse animals and other organisms, which affect hosts' biology in a variety of ways. Most of these symbionts are present in the cytoplasm of host cells and maternally transmitted through host generations. The paucity of paternal symbiont transmission is likely relevant to the extremely streamlined sperm structure: the head consisting of condensed nucleus and the tail made of microtubule bundles, without the symbiont-harboring cytoplasm that is discarded in the process of spermatogenesis. Here, we report a previously unknown mechanism of paternal symbiont transmission via an intrasperm passage. In the leafhopper Nephotettix cincticeps, a facultative Rickettsia symbiont was found not only in the cytoplasm but also in the nucleus of host cells. In male insects, strikingly, most sperm heads contained multiple intranuclear Rickettsia cells. The Rickettsia infection scarcely affected the host fitness including normal sperm functioning. Mating experiments revealed both maternal and paternal transmission of the Rickettsia symbiont through host generations. When cultured with mosquito and silkworm cell lines, the Rickettsia symbiont was preferentially localized within the insect cell nuclei, indicating that the Rickettsia symbiont itself must have a mechanism for targeting nucleus. The mechanisms underlying the sperm head infection without disturbing sperm functioning are, although currently unknown, of both basic and applied interest.
| S-EPMC4034255 | biostudies-other
Project description:BackgroundThe human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) plays a pivotal role in the viral lifecycle: including encapsulating the viral genome, aiding in strand transfer during reverse transcription, and packaging two copies of the viral genome into progeny virions. Another gag gene product, p6, plays an integral role in successful viral budding from the plasma membrane and inclusion of the accessory protein Vpr within newly budding virions. In this study, we have characterized the gag NC and p6 genes from six mother-infant pairs following vertical transmission by performing phylogenetic analysis and by analyzing the degree of genetic diversity, evolutionary dynamics, and conservation of functional domains.ResultsPhylogenetic analysis of 168 gag NC and p6 genes sequences revealed six separate subtrees that corresponded to each mother-infant pair, suggesting that epidemiologically linked individuals were closer to each other than epidemiologically unlinked individuals. A high frequency (92.8%) of intact open reading frames of NC and p6 with patient and pair specific sequence motifs were conserved in mother-infant pairs' sequences. Nucleotide and amino acid distances showed a lower degree of viral heterogeneity, and a low degree of estimates of genetic diversity was also found in NC and p6 sequences. The NC and p6 sequences from both mothers and infants were found to be under positive selection pressure. The two important functional motifs within NC, the zinc-finger motifs, were highly conserved in most of the sequences, as were the gag p6 Vpr binding, AIP1 and late binding domains. Several CTL recognition epitopes identified within the NC and p6 genes were found to be mostly conserved in 6 mother-infant pairs' sequences.ConclusionThese data suggest that the gag NC and p6 open reading frames and functional domains were conserved in mother-infant pairs' sequences following vertical transmission, which confirms the critical role of these gene products in the viral lifecycle.
| S-EPMC1459197 | biostudies-literature
Project description:OBJECTIVE:To estimate and interpret time trends in vertical transmission rates for HIV using data from national obstetric and paediatric surveillance registers. DESIGN:Prospective study of HIV infected women reported through obstetric surveillance. HIV infection status of the child and onset of AIDS were reported through paediatric surveillance. Rates of vertical transmission and progression to AIDS rate were estimated by methods that take account of incomplete follow up of children with indeterminate infection status and delay in AIDS reporting. SETTING:British Isles. SUBJECTS:Pregnant women infected with HIV whose infection was diagnosed before delivery, and their babies. MAIN OUTCOME MEASURES:Mother to child transmission of infection and progression to AIDS in children. RESULTS:By January 1999, 800 children born to diagnosed HIV infected women who had not breast fed had been reported. Vertical transmission rates rose to 19.6% (95% confidence interval 8. 0% to 32.5%) in 1993 before falling to 2.2% (0% to 7.8%) in 1998. Between 1995 and 1998 use of antiretroviral treatment increased significantly each year, reaching 97% of live births in 1998. The rate of elective caesarean section remained constant, at around 40%, up to 1997 but increased to 62% in 1998. Caesarean section and antiretroviral treatment together were estimated to reduce risk of transmission from 31.6% (13.6% to 52.2%) to 4.2% (0.8% to 8.5%). The proportion of infected children developing AIDS in the first 6 months fell from 17.7% (6.8% to 30.8%) before 1994 to 7.2% (0% to 15. 7%) after, coinciding with increased use of prophylaxis against Pneumocystis carinii pneumonia. CONCLUSIONS:In the British Isles both HIV related morbidity and vertical transmission are being reduced through increased use of interventions.
| S-EPMC28270 | biostudies-literature
Project description:BackgroundThe burden of mother-to-child transmission rate of HIV is high and risk factors are common in Ethiopia. This systematic review and meta-analysis intended to provide the pooled estimation of mother-to-child transmission rate and its risk factors in Ethiopia.MethodsWe searched PubMed, Google Scholar, EMBASE and Web of Science electronic databases for all available references. We included observational studies including case-control, cohort, and cross-sectional studies. The search was further limited to studies conducted in Ethiopia and publish in English. Heterogeneity was checked using the I2 statistic. Egger's test and the funnel plot were used to assess publication bias. A meta-analysis using a weighted inverse variance random-effects model was performed.ResultsA total of 18 studies with 6253 individuals were included in this systematic review and meta-analysis. Of these, 14 studies with 4624 individuals were used to estimate the prevalence. The estimated pooled prevalence of mother-to-child transmission of HIV was 11.4% (95% CI = 9.1-13.7). The pooled adjusted odds ratio (AOR) of mother-to-child transmission of HIV for the infants from rural area was 3.8 (95% CI = 1.4 to 6.3), infants delivered at home was 3.2 (95% CI = 1.2 to 5.2), infant didn't take antiretroviral prophylaxis was 5.8 (95% CI = 1.5 to 10.3), mother didn't take antiretroviral prophylaxis was 6.1 (95% CI = 2.5 to 9.6), mothers didn't receive PMTCT intervention was 5.1 (95% CI = 1.6, 8.6), and on mixed feeding was 4.3 (95% CI = 1.8 to 6.7).ConclusionsThis systematic review and meta-analysis showed that mother-to-child transmission rate of HIV was high in Ethiopia. Being from the rural residence, home delivery, not taking antiretroviral prophylaxis, the absence of PMTCT intervention, and mixed infant feeding practices increased the risk of HIV transmission.Trial registrationIt is registered in the Prospero database: (PROSPERO 2017: CRD42017078232 ).
| S-EPMC6013937 | biostudies-literature
Project description:Despite the worldwide availability of antiretroviral therapy (ART), approximately 150,000 pediatric HIV infections continue to occur annually. ART can dramatically reduce HIV mother-to-child transmission (MTCT), but inconsistent drug access and adherence, as well as primary maternal HIV infection during pregnancy and lactation are major barriers to eliminating vertical HIV transmission. Thus, immunologic strategies to prevent MTCT, such as an HIV vaccine, will be required to attain an HIV-free generation. A primary goal of HIV vaccine research has been to elicit broadly neutralizing antibodies (bnAbs) given the ability of passive bnAb immunization to protect against sensitive strains, yet we previously observed that HIV-transmitting mothers have more plasma neutralization breadth than nontransmitting mothers. Additionally, we have identified infant transmitted/founder (T/F) viruses that escape maternal bnAb responses. In this study, we examine a cohort of postpartum HIV-transmitting women with neutralization breadth to determine if certain maternal bnAb specificities drive the selection of infant T/F viruses. Using HIV pseudoviruses that are resistant to neutralizing antibodies targeting common bnAb epitopes, we mapped the plasma bnAb specificities of this cohort. Significantly more transmitting women with plasma bnAb activity had a mappable plasma bnAb specificity (six of seven, or 85.7%) compared to that of nontransmitting women with plasma bnAb activity (7 of 21, or 33.3%, P = 0.029 by 2-sided Fisher exact test). Our study suggests that having multispecific broad activity and/or uncommon epitope-specific bnAbs in plasma may be associated with protection against the vertical HIV transmission in the setting of maternal bnAb responses. IMPORTANCE As mother to child transmission (MTCT) of HIV plays a major part in the persistence of the HIV/AIDS epidemic and bnAb-based passive and active vaccines are a primary strategy for HIV prevention, research in this field is of great importance. While previous MTCT research has investigated the neutralizing antibody activity of HIV-infected women, this is, to our knowledge, the largest study identifying differences in bnAb specificity of maternal plasma between transmitting and nontransmitting women. Here, we show that among HIV-infected women with broad and potent neutralization activity, more postpartum-transmitting women had a mappable plasma broadly neutralizing antibody (bnAb) specificity, compared to that of nontransmitting women, suggesting that the nontransmitting women more often have multispecific bnAb responses or bnAb responses that target uncommon epitopes. Such responses may be required for protection against vertical HIV transmission in the setting of maternal bnAb responses.
| S-EPMC9175633 | biostudies-literature
Project description:Purpose of reviewThe goal of this review is to highlight and interpret recent trends and developments in the diagnosis, treatment, and prevention of HIV vertical transmission from a clinical perspective.Recent findingsUniversal third-trimester retesting and partner testing may better identify incident HIV among pregnant patients and result in early initiation of antiretroviral therapy to prevent vertical transmission. The proven safety and efficacy of integrase inhibitors such as dolutegravir may be particularly useful in suppressing viremia in pregnant persons who present late for ART treatment. Pre-exposure prophylaxis (PrEP) during pregnancy may play a role in preventing HIV acquisition; however, its role in preventing vertical transmission is difficult to elucidate. Substantial progress has been made in recent years to eliminate HIV perinatal transmission. Future research hinges upon a multipronged approach to improving HIV detection, risk-stratified treatment strategies, and prevention of primary HIV infection among pregnant persons.
| S-EPMC10239317 | biostudies-literature