Molecular assays can provide critical information for malaria diagnosis, speciation, and drug resistance, but their cost and resource requirements limit their application to clinical malaria studies. This study describes the application of a resource-conserving testing algorithm employing sample pooling for real-time PCR assays for malaria in a cohort of 182 pregnant women in Kinshasa. A total of 1,268 peripheral blood samples were collected during the study. Using a real-time PCR assay that detects all Plasmodium species, microscopypositive samples were amplified individually; the microscopy-negative samples were amplified after pooling the genomic DNA (gDNA) of four samples prior to testing. Of 176 microscopy-positive samples, 74 were positive by the real-time PCR assay; the 1,092 microscopy-negative samples were initially amplified in 293 pools, and subsequently, 35 samples were real-time PCR positive (3%). With the real-time PCR result as the referent standard, microscopy was 67.9% sensitive (95% confidence interval [CI], 58.3% to 76.5%) and 91.2% specific (95% CI, 89.4% to 92.8%) for malaria. In total, we detected 109 parasitemias by real-time PCR and, by pooling samples, obviated over 50% of reactions and halved the cost of testing. Our study highlights both substantial discordance between malaria diagnostics and the utility and parsimony of employing a sample pooling strategy for molecular diagnostics in clinical and epidemiologic malaria studies.
BackgroundDuring early pregnancy, the placenta develops to meet the metabolic demands of the foetus. The objective of this analysis was to examine the effect of malaria parasitaemia prior to 20 weeks’ gestation on subsequent changes in uterine and umbilical artery blood flow and intrauterine growth restriction.MethodsData were analysed from 548 antenatal visits after 20 weeks’ gestation of 128 women, which included foetal biometric measures and interrogation of uterine and umbilical artery blood flow. Linear mixed effect models estimated the effect of early pregnancy malaria parasitaemia on uterine and umbilical artery resistance indices. Log-binomial models with generalized estimating equations estimated the effect of early pregnancy malaria parasitaemia on the risk of intrauterine growth restriction.ResultsThere were differential effects of early pregnancy malaria parasitaemia on uterine artery resistance by nutritional status, with decreased uterine artery resistance among nourished women with early pregnancy malaria and increased uterine artery resistance among undernourished women with early pregnancy malaria. Among primigravidae, early pregnancy malaria parasitaemia decreased umbilical artery resistance in the late third trimester, likely reflecting adaptive villous angiogenesis. In fully adjusted models, primigravidae with early pregnancy malaria parasitaemia had 3.6 times the risk of subsequent intrauterine growth restriction (95% CI: 2.1, 6.2) compared to the referent group of multigravidae with no early pregnancy malaria parasitaemia.ConclusionsEarly pregnancy malaria parasitaemia affects uterine and umbilical artery blood flow, possibly due to alterations in placentation and angiogenesis, respectively. Among primigravidae, early pregnancy malaria parasitaemia increases the risk of intrauterine growth restriction. The findings support the initiation of malaria parasitaemia prevention and control efforts earlier in pregnancy.
In sub-Saharan Africa, our model suggests that increasing use of PE/E diagnostics, transfer to higher levels of care and increased hospitalization with cesarean section/induction of labor would substantially reduce maternal mortality from PE/E. Increasing use of MgSO4 would have a smaller impact on maternal mortality.
To evaluate the impact of neonatal resuscitation and basic obstetric care on intrapartum-related neonatal mortality in low and middle-income countries, using the mathematical model, Maternal and Neonatal Directed Assessment of Technology (MANDATE). Using MANDATE, we evaluated the impact of interventions for intrapartum-related events causing birth asphyxia (basic neonatal resuscitation, advanced neonatal care, increasing facility birth, and emergency obstetric care) when implemented in home, clinic, and hospital settings of sub-Saharan African and India for 2008. Total intrapartum-related neonatal mortality (IRNM) was acute neonatal deaths from intrapartum-related events plus late neonatal deaths from ongoing intrapartum-related injury. Introducing basic neonatal resuscitation in all settings had a large impact on decreasing IRNM. Increasing facility births and scaling up emergency obstetric care in clinics and hospitals also had a large impact on decreasing IRNM. Increasing prevalence and utilization of advanced neonatal care in hospital settings had limited impact on IRNM. The greatest improvement in IRNM was seen with widespread advanced neonatal care and basic neonatal resuscitation, scaled-up emergency obstetric care in clinics and hospitals, and increased facility deliveries, resulting in an estimated decrease in IRNM to 2.0 per 1,000 live births in India and 2.5 per 1,000 live births in sub-Saharan Africa. With more deliveries occurring in clinics and hospitals, the scale-up of obstetric care can have a greater effect than if modeled individually. Use of MANDATE enables health leaders to direct resources towards interventions that could prevent intrapartum-related deaths. A lack of widespread implementation of basic neonatal resuscitation, increased facility births, and emergency obstetric care are missed opportunities to save newborn lives.
The vaginal ring (VR) is a female-initiated drug-delivery platform used for different indications, including HIV pre-exposure prophylaxis (PrEP). We conducted a systematic review of VR acceptability, values and preferences among women in low- and middle-income countries (LMIC) to inform further investment and/or guidance on VR use for HIV prevention. Following PRISMA guidelines, we used structured methods to search, screen, and extract data from randomized controlled trials (RCTs) and observational studies reporting quantitative outcomes of acceptability of the VR for any indication published 1/1970-2/2019 (PROSPERO: CRD42019122220). Of 1,110 records identified, 68 met inclusion criteria. Studies included women 15–50+ years from 25 LMIC for indications including HIV prevention, contraception, abnormal bleeding, and menopause. Overall VR acceptability was high (71–98% across RCTs; 62–100% across observational studies), with 80–100% continuation rates in RCTs and favorable ease of insertion (greater than 85%) and removal 89–99%). Users reported concerns about the VR getting lost in the body (8–43%), although actual expulsions and adverse events were generally infrequent. Most women disclosed use to partners, with some worrying about partner anger/violence. The VR was not felt during intercourse by 70–92% of users and 48–97% of partners. Acceptability improved over time both within studies (as women gained VR experience and worries diminished), and over chronological time (as the device was popularized). Women expressed preferences for accessible, long-acting, partner-approved methods that prevent both HIV and pregnancy, can be used without partner knowledge, and have no impact on sex and few side effects. This review was limited by a lack of standardization of acceptability measures and study heterogeneity. This systematic review suggests that most LMIC women users have a positive view of the VR that increases with familiarity of use; and, that many would consider the VR an acceptable future delivery device for HIV prevention or other indications.
Objective To create a comprehensive model of the comparative impact of various interventions on maternal, fetal, and neonatal (MFN) mortality. Methods The major conditions and sub-conditions contributing to MFN mortality in low-resource areas were identified, and the prevalence and case fatality rates documented. Available interventions were mapped to these conditions, and intervention coverage and efficacy were identified. Finally, a computer model developed by the Maternal and Neonatal Directed Assessment of Technology (MANDATE) initiative estimated the potential of current and new interventions to reduce mortality. Results For PPH, the sub-causes, prevalence, and MFN case fatality rates were calculated. Available interventions were mapped to these sub-causes. Most available interventions did not prevent or treat the overall condition of PPH, but rather sub-conditions associated with hemorrhage and thus prevented only a fraction of the associated deaths. Conclusion The majority of current interventions address sub-conditions that cause death, rather than the overall condition; thus, the potential number of lives saved is likely to be overestimated. Additionally, the location at which mother and infant receive care affects intervention effectiveness and, therefore, the potential to save lives. A comprehensive view of MFN conditions is needed to understand the impact of any potential intervention.
Using the Maternal and Neonatal Directed Assessment of Technology (MANDATE) model, we estimate that WHO-recommended interventions could have saved nearly 300,000 lives in 2015. Combined interventions had the greatest impact. MANDATE can allow health officials to prioritize implementation strategies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.