Perinatal HIV transmission and the cost-effectiveness of screening at 14 weeks gestation, at the onset of labour and the rapid testing of infants

HIV screening in pregnant women: A systematic review of cost-effectiveness studies

INTRODUCTION

Vertical transmission represents the major route of HIV infection for children. However, the preventive interventions available are extremely effective. This review summarizes evidence regarding the cost-effectiveness of mother-to-child-transmission preventive screenings, to help policy makers in choosing the optimal antenatal screening strategy.

METHODS

A systematic review following PRISMA guidelines was conducted, using 3 databases: PubMed, Scopus, and Cost-Effectiveness Analysis Registry. All articles regarding HIV screening to avoid vertical transmission were included.

RESULTS

The review included 21 papers. Seven studies assessed the cost-effectiveness of universal antenatal screening during early gestation. Two papers considered the integration of HIV screening with other medical interventions. Eight works estimated the cost-effectiveness of HIV screening in late pregnancy. Finally, 4 papers considered the combination of multiple strategies. The selected papers focused on both developed and developing countries, with a different HIV prevalence. The characteristics and methodology of the studies were heterogeneous. However, all studies agreed about the main findings, outlining the cost-effectiveness of both universal antenatal screening and HIV rescreening in late pregnancy. Cost-effectiveness improved when HIV burden increased. The major findings were proved to be robust across various scenarios when tested in sensitivity analysis.

CONCLUSIONS

The review confirmed the cost-effectiveness not only of HIV universal antenatal screening but also of rescreening in late gestation in both developed and developing countries. Universal screening is cost-effective even in case of extremely low HIV prevalence. Therefore, to maximize screening, coverage appears as a worldwide priority. In certain settings, a targeted screening towards high-risk groups could be a valuable option.

The prevalence and determinants of HIV seroconversion among booked ante natal clients in the University of Uyo teaching hospital, Uyo Akwa Ibom State, Nigeria

INTRODUCTION

The Prevention of Mother to Child transmission (PMTCT) of HIV, an important intervention in the fight against HIV/AIDS can only be of benefit if the HIV status of the mother is known. Unfortunately, some women receive HIV counseling and testing (HCT) during the window period or prior to new infection in pregnancy and therefore, miss-out on the gains of PMTCT. A repeat HIV test would identify this later seroconversion and ensure early intervention. This study aimed at determining the prevalence of HIV seroconversion during pregnancy and assessing the factors associated with HIV seroconversion in clients who attended ante-natal clinic (ANC) in University of Uyo Teaching Hospital, Uyo.

METHODS

A descriptive cross-sectional design was used to study 502 HIV negative clients who consecutively presented for ANC in the University of Uyo Teaching Hospital Uyo over a 3 months period (July -September 2013).

RESULTS

Fifteen (3%) of the 502 women who were HIV negative at booking visit tested positive (seroconverted) to HIV. Determinants of seroconversion at multivariate level were age bracket of 25-29 years (OR: 3.20; 95%CI: 2.39-4.29) clients' partners who had sexually transmitted infections, as evidenced by penile discharge (OR: 0.09; 95%CI: 0.01-0.45); Clients in polygamous setting (OR: 3.98; CI: 1.64-9.65); those taking alcohol (OR: 0.12; CI: 0.20-0.80) and those with partners taking recreational drugs (OR: 0.05, 95%CI: 0.002-0.995).

CONCLUSION

The study revealed a high seroconversion rate. Re-screening of pregnant women after the booking HCT is a very cost effective and beneficial strategy for the elimination of mother to child transmission of HIV.

Obstetrical, maternal characteristics and outcome of HIV-infected rapid progressor infants at Yaounde: a retrospective study

BACKGROUND

Rapid progressors are exposed to HIV infection at an early stage of life, and the prognosis is poor without treatment. Reducing the proportion of infants who are rapid progressors, require strengthening strategies to achieve the highest level of performance for the PMTCT program.

METHODS

This was a retrospective study carried out on HIV infected infants aged less than 12 months, clinically classified stage 4 (WHO) or having CD4 count <25%. We described maternal and obstetrical characteristics of HIV-infected rapid progressors using univariate and bivariate analysis. Patients' survival was monitored from the inclusion time to the end of the study. We then estimated their probability of survival with or without anti-retroviral (ARV) treatment from birth using the Kaplan-Meier method.

RESULTS

The characteristics of the mothers of the 150 rapid progressors infants we included were: low level of education (OR=3.87; P=0.016), CD4 count less than 200/mm(3) (OR=43.3; P=0.000), absence of ARV prophylaxis (OR=6.02; P=0.043), or treatment with HAART (OR=5.74; P=0.000) during pregnancy. In the children, the most important findings were lack of co-trimoxazole prophylaxis (OR=11.61; P=0.000) and antiretroviral prophylaxis (OR=2.70; P=0.0344). The survival rate was 84.3% in infants who were receiving HAART as opposed to 43.3% in those who were not (P<0.05).

CONCLUSIONS

HIV infected women who are eligible should start antiretroviral treatment prior to a pregnancy, in order to improve their immunological status. This measure associated to cotrimoxazole prophylaxis and ART could improve their survival.

Identifying HIV most-at-risk groups in Malawi for targeted interventions. A classification tree model

OBJECTIVES

To identify HIV-socioeconomic predictors as well as the most-at-risk groups of women in Malawi.

DESIGN

A cross-sectional survey.

SETTING

Malawi

PARTICIPANTS

The study used a sample of 6395 women aged 15-49 years from the 2010 Malawi Health and Demographic Surveys.

INTERVENTIONS N/A PRIMARY AND SECONDARY OUTCOME MEASURES

Individual HIV status: positive or not.

RESULTS

Findings from the Pearson χ(2) and χ(2) Automatic Interaction Detector analyses revealed that marital status is the most significant predictor of HIV. Women who are no longer in union and living in the highest wealth quintiles households constitute the most-at-risk group, whereas the less-at-risk group includes young women (15-24) never married or in union and living in rural areas.

CONCLUSIONS

In the light of these findings, this study recommends: (1) that the design and implementation of targeted interventions should consider the magnitude of HIV prevalence and demographic size of most-at-risk groups. Preventive interventions should prioritise couples and never married people aged 25-49 years and living in rural areas because this group accounts for 49% of the study population and 40% of women living with HIV in Malawi; (2) with reference to treatment and care, higher priority must be given to promoting HIV test, monitoring and evaluation of equity in access to treatment among women in union disruption and never married or women in union aged 30-49 years and living in urban areas; (3) community health workers, households-based campaign, reproductive-health services and reproductive-health courses at school could be used as canons to achieve universal prevention strategy, testing, counselling and treatment.

Utility of rapid antibody tests to exclude HIV-1 infection among infants and children aged <18 months in a low-resource setting

BACKGROUND

Excluding HIV infection among infants and young children in resource-poor settings where nucleic acid amplification tests (NAAT) are not routinely available remains a considerable challenge.

OBJECTIVES

To assess the performance of two rapid HIV antibody tests (RT) used alone and in parallel for excluding HIV infection among acutely ill infants and children <18 months in comparison to NAAT in a region where maternal HIV prevalence was approximately 7%.

STUDY DESIGN

Infants and children ≥2<18 months admitted to hospital with an acute febrile illness had two rapid antibody tests in parallel, with single and parallel results subsequently compared against NAAT.

RESULTS

HIV prevalence among 1602 enrolled infants was 3.4%. All 1526 infants with 2 negative RT were HIV negative by NAAT. All 46 infants with 2 positive RT were HIV positive by NAAT. The overall specificity of two rapid tests for excluding HIV infection was 99.5%. Sensitivity and specificity were ≥99% and >98%, respectively, across all age brackets ≥2<18 months. Overall sensitivity and specificity for a single RT was 98.2% and 99%, respectively, for Determine, and 85.5% and 99.6%, respectively, for Capillus.

CONCLUSIONS

In a setting with a maternal HIV prevalence rate of <10%, a single negative RT had excellent specificity and two negative RT performed in parallel had a perfect negative predictive value for HIV infection among acutely ill patients <18 months of age. In this and similar settings, RT could assist with excluding HIV infection with much lower complexity and cost than NAAT.

Number and timing of antenatal HIV testing: evidence from a community-based study in Northern Vietnam

BACKGROUND

HIV testing for pregnant women is an important component for the success of prevention of mother-to-child transmission of HIV (PMTCT). A lack of antenatal HIV testing results in loss of benefits for HIV-infected mothers and their children. However, the provision of unnecessary repeat tests at a very late stage of pregnancy will reduce the beneficial effects of PMTCT and impose unnecessary costs for the individual woman as well as the health system. This study aims to assess the number and timing of antenatal HIV testing in a low-income setting where PMTCT programmes have been scaled up to reach first level health facilities.

METHODS

A cross-sectional community-based study was conducted among 1108 recently delivered mothers through face-to-face interviews following a structured questionnaire that focused on socio-economic characteristics, experiences of antenatal care and HIV testing.

RESULTS

The prevalence of women who lacked HIV testing among the study group was 10% while more than half of the women tested had had more than two tests during pregnancy. The following factors were associated with the lack of antenatal HIV test: having two children (aOR 2.1, 95% CI 1.3-3.4), living in a remote rural area (aOR 7.8, 95% CI 3.4-17.8), late antenatal care attendance (aOR 3.6, 95% CI 1.3-10.1) and not being informed about PMTCT at their first antenatal care visits (aOR 7.4, 95% CI 2.6-21.1). Among women who had multiple tests, 80% had the second test after 36 weeks of gestation. Women who had first ANC and first HIV testing at health facilities at primary level were more likely to be tested multiple times (OR 2.9 95% CI 1.9-4.3 and OR = 4.7 95% CI 3.5-6.4), respectively.

CONCLUSIONS

Not having an HIV test during pregnancy was associated with poor socio-economic characteristics among the women and with not receiving information about PMTCT at the first ANC visit. Multiple testing during pregnancy prevailed; the second tests were often provided at a late stage of gestation.

Quantitative recovery of proviral HIV-1 DNA from leukocytes by the Dried Buffy Coat Spot method for real-time PCR determination

The current recommended method for diagnosing HIV-1 in newborns infected vertically and in adults, during the "window period", is the detection of proviral HIV-1 DNA within leukocytes (buffy coat). This study describes a new portable Dried Buffy Coat Spot (DBCS) assay able to provide a quantitative proviral HIV-1 DNA recovery from the buffy coat. Fifty blood samples were collected from HIV-positive children and processed for DBCSs. Total DNA and proviral DNA were normalised to β-globin and HIV-1 pol genes. Assay sensitivity and specificity were evaluated against the whole blood dried blood spot (DBS) method. Both procedures, using automatic DNA extraction, were compared to a standard whole blood DNA manual extraction. DNA recovery from whole blood was nearly equivalent to that of the DBCS-based extraction, while DBS-based extraction was 10-fold less sensitive. The detection rate of proviral HIV-1 DNA with DBCS assay was equivalent to whole blood manual extraction (100% concordance), but DBS-extracted samples showed limited concordance (44%). The DBCS assay may prove to be more feasible in resource-limited settings. It may represent a simple and robust point-of-care assay for HIV screening of children, for whom a reference test is still lacking.