On a Shape-Invariant Hazard Regression Model with application to an HIV Prevention Study of Mother-to-Child Transmission.
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ABSTRACT:
SUBMITTER: Zheng C
PROVIDER: S-EPMC7730855 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThe reproductive health and Prevention of Mother-to-Child Transmission (PMTCT) of HIV programs in Iran were integrated as a pilot project in September 2014. This study aims to provide a comprehensive evaluation and analysis of the PMTCT of HIV program in Iran.MethodsThe pilot phase of PMTCT of HIV was launched in early September 2014 in selected centers including 170 health centers and 40 hospitals affiliated to medical universities of 16 provinces of Iran. In each medical university, a researcher-made checklist was administered to all newly-diagnosed HIV-positive pregnant women by an AIDS expert. Data was analyzed using SPSS 19.ResultsOverall, 69.4% of eligible pregnant women were enrolled in the pilot phase. From 134 reactive cases, 76 (56.7%) were confirmed as HIV positive. ARV consumption was irregular in 10 (13.2%) of HIV positive pregnant women. Also, 82.5% had CD4 count more than 350 after treatment, with an average of 55.5% increase in the number of CD4 in comparison to the baseline, and 84.8% had viral load suppression (< 200 copies/ml). Counseling and testing was done for the husbands of 75% of the women that resulted in the identification of 15 (39.5%) new HIV cases among husbands. Among the tested individuals, 23 (60.5%) males already knew their HIV status and were registered as HIV patients. HIV was diagnosed in one (1.5%) newborn.ConclusionImplementation of rapid HIV testing and PMTCT in Iran is one of the strengths of the national HIV control program. To eliminate MTCT, it is necessary to understand and overcome the barriers and challenges to the program in the pilot phase.
| S-EPMC7948351 | biostudies-literature
Project description:BackgroundIn trials designed to estimate rates of perinatal mother to child transmission of HIV, HIV assays are scheduled at multiple points in time. Still, infection status for some infants at some time points may be unknown, particularly when interim analyses are conducted.MethodsLogistic regression models are commonly used to estimate covariate-adjusted transmission rates, but their methods for handling missing data may be inadequate. Here we propose using coarsened multinomial regression models to estimate cumulative and conditional rates of HIV transmission. Through simulation, we compare the proposed models to standard logistic models in terms of bias, mean squared error, coverage probability, and power. We consider a range of treatment effect and visit process scenarios, while including imperfect sensitivity of the assay and contamination of the endpoint due to early breastfeeding transmission. We illustrate the approach through analysis of data from a clinical trial designed to prevent perinatal transmission.ResultsThe proposed cumulative and conditional models performed well when compared to their logistic counterparts. Performance of the proposed cumulative model was particularly strong under scenarios where treatment was assumed to increase the risk of in utero transmission but decrease the risk of intrapartum and overall perinatal transmission and under scenarios designed to represent interim analyses. Power to estimate intrapartum and perinatal transmission was consistently higher for the proposed models.ConclusionCoarsened multinomial regression models are preferred to standard logistic models for estimation of perinatal mother to child transmission of HIV, particularly when assays are missing or occur off-schedule for some infants.
| S-EPMC2515333 | biostudies-literature
Project description:Prevention of mother-to-child transmission (PMTCT) guidelines recommend that all HIV-infected pregnant women receive antiretroviral therapy (Option B) and HIV-infected infants should initiate therapy with a protease inhibitor-based regimen; however, implementation of these guidelines has lagged in many resource-limited settings. Tanzania only recently implemented these guidelines with little country-specific data to inform whether HIV non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance was present among infected infants under the Option A guidelines. This study aimed to identify primary resistance mutations in HIV-infected infants and to identify risk of nevirapine (NVP) resistance based on maternal and infant NVP exposure. Infant dried blood spots (DBSs) were sent to the zonal reference laboratory at Kilimanjaro Christian Medical Centre Clinical Laboratory and underwent DNA polymerase chain reaction testing for HIV as standard of care. Using the clinical laboratory registry, HIV-positive DBS cards, stored at ambient temperature, were identified and sent for further viral load testing, nucleotide sequencing, and analysis. Clinical information was obtained from the PMTCT clinical sites and the National PMTCT registry for information regarding maternal and infant demographics and PMTCT treatment regimen. Results demonstrated that infants exposed to NVP were more likely to have high level resistance mutations (HLRMs) to NVP than those infants not exposed to NVP (p?=?.002). The most common HLRMs to NVP were K103?N, Y181C, and Y188?L. HIV subtype A was most common, followed by subtype C. Approximately one-third of HIV-infected infants had documented referral to HIV care. This study demonstrated the ongoing need to scale up and strengthen points along the PMTCT continuum and supported the recommendation for all HIV-infected infants to initiate a lopinavir/ritonavir-based antiretroviral therapy regimen.
| S-EPMC5665493 | biostudies-literature
Project description:BackgroundWe performed a systematic review to assess the effect of integrated perinatal prevention of mother-to-child transmission of HIV interventions compared to non- or partially integrated services on the uptake in low- and middle-income countries.MethodsWe searched for experimental, quasi-experimental and controlled observational studies in any language from 21 databases and grey literature sources.ResultsOut of 28 654 citations retrieved, five studies met our inclusion criteria. A cluster randomized controlled trial reported higher probability of nevirapine uptake at the labor wards implementing HIV testing and structured nevirapine adherence assessment (RRR 1.37, bootstrapped 95% CI, 1.04-1.77). A stepped wedge design study showed marked improvement in antiretroviral therapy (ART) enrolment (44.4% versus 25.3%, p<0.001) and initiation (32.9% versus 14.4%, p<0.001) in integrated care, but the median gestational age of ART initiation (27.1 versus 27.7 weeks, p = 0.4), ART duration (10.8 versus 10.0 weeks, p = 0.3) or 90 days ART retention (87.8% versus 91.3%, p = 0.3) did not differ significantly. A cohort study reported no significant difference either in the ART coverage (55% versus 48% versus 47%, p = 0.29) or eight weeks of ART duration before the delivery (50% versus 42% versus 52%; p = 0.96) between integrated, proximal and distal partially integrated care. Two before and after studies assessed the impact of integration on HIV testing uptake in antenatal care. The first study reported that significantly more women received information on PMTCT (92% versus 77%, p<0.001), were tested (76% versus 62%, p<0.001) and learned their HIV status (66% versus 55%, p<0.001) after integration. The second study also reported significant increase in HIV testing uptake after integration (98.8% versus 52.6%, p<0.001).ConclusionLimited, non-generalizable evidence supports the effectiveness of integrated PMTCT programs. More research measuring coverage and other relevant outcomes is urgently needed to inform the design of services delivering PMTCT programs.
| S-EPMC3338706 | biostudies-literature
Project description:BackgroundPrevention of Mother-to-Child HIV Transmission (PMTCT) coverage has been low in Ethiopia and the service has been implemented in a fragmented manner. Solutions to this problem have mainly been sought on the supply-side in the form of improved management and allocation of limited resources. However, this approach largely ignores the demand-side factors associated with low PMTCT coverage in the country. The study assesses the factors associated with the utilization of PMTCT services taking into consideration counts of visits to antenatal care (ANC) services in urban high-HIV prevalence and rural low-HIV prevalence settings in Ethiopia.MethodsA multivariate regression model was employed to identify significant factors associated with PMTCT service utilization. Poisson and negative binomial regression models were applied, considering the number of ANC visits as a dependent variable. The explanatory variables were age; educational status; type of occupation; decision-making power in the household; living in proximity to educated people; a neighborhood with good welfare services; location (urban high-HIV prevalence and rural low-HIV prevalence); transportation accessibility; walking distance (in minutes); and household income status. The alpha dispersion test (a) was performed to measure the goodness-of-fit of the model. Significant results were reported at p-values of < 0.05 and < 0.001.ResultsHousehold income, socio-economic setting (urban high-HIV prevalence and rural low-HIV prevalence) and walking distance (in minutes) had a statistically significant relationship with the number of ANC visits by pregnant women (p < 0.05). A pregnant woman from an urban high-HIV prevalence setting would be expected to make 34% more ANC visits (counts) than her rural low-HIV prevalence counterparts (p < 0.05). Holding other variables constant, a unit increase in household income would increase the expected ANC visits by 0.004%. An increase in walking distance by a unit (a minute) would decrease the number of ANC visits by 0.001(p < 0.001).ConclusionLong walking distance, low household income and living in a rural setting are the significant factors associated with low PMTCT service utilization. The primary strategies for a holistic policy to improve ANC/PMTCT utilization should thus include improving the geographical accessibility of ANC/PMTCT services, expanding household welfare and paying more attention to remote rural areas.
| S-EPMC6245866 | biostudies-literature
Project description:To prevent mother-to-child-transmission of HIV-1, the 2010 WHO guidelines recommended prenatal zidovudine (ZDV) monotherapy (option A). To determine if ZDV monotherapy selects for HIV resistance in antiretroviral-naive women during pregnancy, specimens from 50 individuals were examined using pyrosequencing. ZDV-resistance mutations were detected at delivery in seven women (14%, 95% confidence interval 6.6-26.5%). These data raise the question whether women administered ZDV monotherapy for prevention of mother-to-child-transmission could have higher risk of virologic failure when later started on combination antiretroviral therapy, as has been demonstrated following single-dose nevirapine prophylaxis.
| S-EPMC4618483 | biostudies-literature
Project description:IntroductionThe Chinese government has invested US$140 million annually on prevention of mother-to-child transmission (PMTCT) of HIV. This study evaluates the programme by examining the improvements in programme coverage HIV testing and provision of antiviral drugs along the PMTCT cascade.MethodsData for PMTCT cascade indicators were collected through a comprehensive systematic review of published peer-reviewed English and Chinese literature during 2003-2011. Meta-analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.ResultsThis study included 113 publications. HIV prevalence among pregnant women in China who accessed antenatal care (ANC) remained below 0.1% during the past decade. HIV testing coverage in pregnant women attending ANC and in HIV-exposed infants at 18 months significantly increased from 62.4% (95% CI 4.7% to 98.2%) and 22.1% (16.3% to 32.3%) in 2003 to 90.3% (88.4% to 91.8%) and 82.8% (66.9% to 99.5%) in 2011 respectively, whereas antiretroviral (ARV) prophylaxis uptake increased from 35.2% (12.2% to 47.3%) and 26.9% (24.3% to 28.9%) to 86.2% (53.2% to 97.2%) and 90.3% (85.5% to 93.7%). HIV vertical transmission rate substantially decreased from 31.8% (25.7% to 38.6%) prior to the programme to 2.3% (1.4% to 3.8%) in 2011. During 2003-2011, among 25,312 (23,995-26,644) infants born to HIV-positive mothers who received ARV prophylaxis, 975 (564-1395) were diagnosed with HIV, corresponding to an average transmission rate of 3.9% (3.2% to 4.6%). However, while including transmissions among HIV-positive pregnant women who were lost along the cascade, the average transmission rate during 2003-2011 was 17.4% (15.8% to 19.0%).ConclusionsPMTCT programmes have reduced HIV mother-to-child transmission in China. Further improvements in the continuum of care remain essential in realising the full potential of the programme.
| S-EPMC4783331 | biostudies-literature
Project description:ObjectiveTo identify proportion of and factors for comprehensive knowledge on prevention of mother-to-child transmission of HIV in pregnant women attending antenatal care in Northern Ethiopia.MethodsA total of 416 pregnant women were interviewed between October 2012 and May 2013. Logistic regression analysis was used to identify factors for comprehensive knowledge on prevention of mother-to-child transmission of HIV.ResultsThe proportion of pregnant women, who have comprehensive knowledge on prevention of mother-to-child transmission of HIV, was 52%. The odds of having comprehensive knowledge on prevention of mother-to-child transmission of HIV were higher among pregnant women who were younger (16 to 24 years old) (Adjusted Odds Ratio (AOR) = 2.95; 95%CI: 1.20, 7.26), urban residents (AOR = 2.45; 95%CI: 1.39, 4.32), attending secondary education and above (AOR = 4.43; 95%CI: 2.40, 8.20), employed (AOR = 4.99;95%CI: 2.45, 10.16), have five children or more (AOR = 9.34; 95%CI:3.78, 23.07), have favored attitude towards HIV positive living (AOR = 2.53; 95%CI: 1.43, 4.44) and have perceived susceptibility to HIV (AOR = 10.72; 95%CI: 3.90, 29.39).ConclusionThe proportion of women who have comprehensive knowledge on prevention of mother-to-child transmission of HIV in this study setting was low. Measures which will escalate mother's knowledge on prevention of mother-to-child transmission of HIV should be emphasized. Efforts to improve mother's knowledge on prevention of mother-to-child transmission of HIV should target women who were older age (> = 35years), rural residents, unemployed, not attending formal education, primigravids, have no favored attitude towards HIV positive living and have not perceived susceptibility to HIV.
| S-EPMC6133350 | biostudies-literature
Project description:The prevention of mother-to-child transmission (PMTCT) of HIV is one of the great public health successes of the past 20 years. Much concerted research efforts and dedicated work have led to the achievement of very low rates of PMTCT of HIV in settings that can implement optimal prophylaxis. Though several implementation challenges remain, global elimination of pediatric HIV infection seems now more than ever to be an attainable goal. Often overlooked, the role of prophylaxis of the newborn is nevertheless a very important component of PMTCT. In this paper, we focus on the role of neonatal and infant prophylaxis, discuss mechanisms of protection, and present the clinical trial-generated evidence that led to the current recommendations for preventing infections in breastfed and non-breastfed infants. PMTCT of HIV should not end at birth; a continuum of care extending postpartum and postnatally is required to minimize the risk of new pediatric HIV infections.
| S-EPMC4470389 | biostudies-other
Project description: Not available
| S-EPMC1513047 | biostudies-literature