Malaria control and elimination in sub-Saharan Africa: data from antenatal care centres.

Although the burden of malaria is progressively declining in most of sub-Saharan Africa, it remains a huge public health issue with complex challenges, such as the rise of drug and insecticide resistance, low coverage of existing preventive strategies, scarcity of safe and effective vaccines, and weakness of public health systems.1 Malaria prevalence surveillance is one of the key cornerstones for achieving malaria control and elimination. WHO’s Global Technical Strategy for malaria has highlighted the importance of malaria surveillance as the third pillar for moving closer to malaria elimination

Mapping routine measles vaccination in low- and middle-income countries.

The safe, highly effective measles vaccine has been recommended globally since 1974, yet in 2017 there were more than 17 million cases of measles and 83,400 deaths in children under 5 years old, and more than 99% of both occurred in low- and middle-income countries (LMICs)1-4. Globally comparable, annual, local estimates of routine first-dose measles-containing vaccine (MCV1) coverage are critical for understanding geographically precise immunity patterns, progress towards the targets of the Global Vaccine Action Plan (GVAP), and high-risk areas amid disruptions to vaccination programmes caused by coronavirus disease 2019 (COVID-19)5-8. Here we generated annual estimates of routine childhood MCV1 coverage at 5 × 5-km2 pixel and second administrative levels from 2000 to 2019 in 101 LMICs, quantified geographical inequality and assessed vaccination status by geographical remoteness. After widespread MCV1 gains from 2000 to 2010, coverage regressed in more than half of the districts between 2010 and 2019, leaving many LMICs far from the GVAP goal of 80% coverage in all districts by 2019. MCV1 coverage was lower in rural than in urban locations, although a larger proportion of unvaccinated children overall lived in urban locations; strategies to provide essential vaccination services should address both geographical contexts. These results provide a tool for decision-makers to strengthen routine MCV1 immunization programmes and provide equitable disease protection for all children

High Iron Levels Are Associated with Increased Malaria Risk in Infants during the First Year of Life in Benin.

The World Health Organization (WHO) estimates that 40% of children in low-income countries are anemic. Therefore, iron supplements are recommended by WHO in areas with high anemia rates. However, some studies have set into question the benefits of iron supplementation in malaria-endemic regions. In Benin, a west African country with high prevalence of anemia and malaria, no iron supplements are given systematically to infants so far despite the WHO recommendations. In this context, we wanted to investigate the effect of iron levels during the first year of life on malarial risk in Benin considering complementary risk factors. We followed 400 women and their offspring between January 2010 and June 2012 in Allada (Benin). Environmental, obstetric, and numerous clinical, maternal, and infant risk factors were considered. In multilevel models, high iron levels were significantly associated with the risk of a positive blood smear (adjusted odds ratio = 2.90, P < 0.001) and Plasmodium falciparum parasitemia (beta estimate = 0.38, P < 0.001). Infants with iron levels in the lowest quartile were less likely to have a positive blood smear (P < 0.001), and the risk increased with higher iron levels. Our results appeal for additional evaluation of the effect of different doses of iron supplements on the infant health status, including malaria incidence. Thus, the health status of infants should be compared between cohorts where iron is given either for prevention or anemia treatment, to better understand the effect of iron supplements on infant health

Placental impression smears is a good indicator of placental malaria in sub-Saharan Africa.

INTRODUCTION: Placental malaria (PM) is an important predictor of infant morbidity and mortality in sub-Saharan Africa. Although placental histology is the gold standard test to diagnose PM, the placenta impression smears remains widely used in epidemiological studies. This study is set to evaluate the performance of placental impression smears to detect PM in pregnant women in southern Benin. METHODS: A cross-sectional analysis was performed on data collected in the framework a multicenter randomized clinical trial (Malaria in Pregnancy Preventive and Alternative Drugs). Samples from 491 pregnant women were examined in the district of Allada, Southern Benin. Plasmodium falciparum infections have been assessed in placental blood and placental biopsy. RESULTS: Placental malaria detected by placenta impression smears and histology were prevalent in 11.4% and 10.8%, respectively. Sensitivity and specificity of placental impression smears were 90.6% and 98.4%. Among 55 pregnant women tested positive by placenta impression smears, 48 were positive by the histology, while 7 were negative (positive predictive value: 87.3%). Four hundred and twenty four (424) of the 429 tested negative by the placenta impression smears, were also negative according to histology whereas the rest (5 of 429) of the women were positive (negative predictive value: 98.8%). CONCLUSION: Placenta impression smear is an accurate and easy method for the diagnosis of placental malaria

Assessment of the anti-HBs antibody response in Beninese infants following 4 doses of HBV vaccine, including administration at birth, compared to the standard 3 doses regime; a cross-sectional survey.

Hepatitis B virus (HBV) infection remains one of the major neglected health issues worldwide. In sub-Saharan Africa (SSA), HBV endemicity is high, with more than 8% of the population being chronic HBV carriers. Recently, WHO recommended that all infants should receive their first dose of the HBV vaccine as soon as possible after birth. Unfortunately, the incorporation of a birth dose of HBV in the expanded programme immunization (EPI) has not occurred in the majority of countries in SSA. From April to September 2017, a cross-sectional survey was conducted in two vaccine units located in southern Benin. We assessed the sustained anti-HBs antibody response in infants induced by a standard scheme of 3 doses of HBV vaccination (6, 10, 14 weeks) in comparison to a scheme of 4 doses with a birth dose included (0, 6, 10, 14 weeks). Blood samples were systematically collected in the first 140 children aged 9 months and their mothers who had consented to participate for the detection of HBs antigen and the quantification of anti-HBs antibodies. The prevalence of HBV infection among infants and mothers was 2.2% and 7.1%, respectively. Infants who received 4 doses of HBV vaccine had a significantly higher level of anti-HBs antibody than those who received 3 doses of vaccine (557.9 UI/L vs. 386.9 UI/L, respectively, P = 0.03). We also showed that the scheme of 4 doses was associated with a significantly higher sustained protective response in comparison to the scheme of 3 doses (aOR 2.49, 95% CI 1.03-6.03, P = 0.04). This result provides further evidence of the importance of administering HBV vaccine at birth, but also highlights the importance for the prevention of vertical transmissions. Additional studies are needed to better establish the cost-effectiveness of such a 4 doses immunization strategy before implementing the HBV vaccination at birth in the EPI

Impact of the use and efficacy of long lasting insecticidal net on malaria infection during the first trimester of pregnancy - a pre-conceptional cohort study in southern Benin.

BACKGROUND: Malaria in pregnancy is prevalent in Sub-Saharan Africa. The first trimester of pregnancy is a critical period and the best preventive measure is Long Lasting Insecticidal Nets (LLIN). Unfortunately, few studies have been conducted which focuses on the usage and efficacy of LLIN on malaria prevention during the first trimester. METHODS: We assessed the use and effectiveness of LLIN in early pregnancy in Benin and its impact on malaria infection risk. We followed-up a cohort of 240 pregnant women from pre-conception to the end of the first trimester of pregnancy in Southern Benin. Parasitological, maternal and LLIN data were actively collected before, at the beginning and end of the first trimester of pregnancy. A Cox regression model was used to determine the relationship between the time to onset of the first malaria infection and the use, physical integrity, and bio-efficacy of the LLIN, adjusted for relevant covariables. RESULTS: The good use, good physical integrity and biological efficacy of LLIN were associated with a decreased risk of occurrence of the first malaria infection in early pregnancy (HRa = 0.38; (0.18-0.80); p < 0.001; HRa = 0.59; (0.29-1.19); p < 0.07; HRa = 0.97; (0.94-1.00); p < 0.04 respectively), after adjustment for other covariates. Primi/secundigravidity and malaria infection before pregnancy were associated with a risk of earlier onset of malaria infection. CONCLUSION: The classically used LLIN's indicators of possession and use may not be sufficient to characterize the true protection of pregnant women in the first trimester of pregnancy. Indicators of physical integrity and bio-efficacy should be integrated with those indicators in evaluation studies

Dynamics of Submicroscopic Plasmodium falciparum Infections Throughout Pregnancy: A Preconception Cohort Study in Benin.

BACKGROUND: In the context of global malaria elimination efforts, special attention is being paid to submicroscopic Plasmodium falciparum infections. In pregnant, sub-Saharan African women, such infections are more prevalent than microscopic infections, and are thought to have adverse effects on both mothers' and newborns' health. However, no study has studied the dynamics and determinants of these infections throughout pregnancy. Retard de Croissance Intra-uterin et Paludisme (RECIPAL), a preconception cohort study carried out in Benin between 2014 and 2017, represented a unique opportunity to assess this issue. METHODS: We used data from 273 pregnant Beninese women who were followed-up from preconception to delivery. We studied the dynamics of and factors influencing submicroscopic (and microscopic) P. falciparum infections during the 3 trimesters of pregnancy, using an ordinal logistic mixed model. RESULTS: The incidence rate of submicroscopic P. falciparum infections during pregnancy was 12.7 per 100 person-months (95% confidence interval [CI] 10.8-14.9), compared to 6.7 per 100 person-months (95% CI 5.5-8.1) for microscopic infections. The prevalences were highest in the first trimester for both submicroscopic and microscopic infections. After adjustment for potential confounding factors, we found that those of young age and those with a submicroscopic P. falciparum infection prior to pregnancy were at significantly higher risks of submicroscopic and microscopic infections throughout pregnancy, with a more pronounced effect in the first trimester of pregnancy. CONCLUSIONS: The first trimester of pregnancy is a particularly high-risk period for P. falciparum infection during pregnancy, especially for the youngest women. Malaria prevention tools covering the preconception period and early pregnancy are urgently needed to better protect pregnant women and their newborns

Impact of mobile phone intervention on intermittent preventive treatment of malaria during pregnancy in Burkina Faso : A pragmatic randomized trial.

PURPOSE: Intermittent preventive treatment of malaria with sulphadoxine-pyrimethamine for pregnant women (IPTp-SP) coverage remains far below the desirable goal of at least three doses before delivery. This study evaluates an innovative intervention using mobile phones as a means of increasing coverage for the third dose of IPTp-SP. METHODS: This study in Burkina Faso was designed as an open-label, pragmatic, two-arm, randomised trial. Pregnant women who attended antenatal clinic (ANC) visits were included at their first ANC visit and followed until delivery. The intervention was built around the use of mobile phones as means ensuring direct tracking of pregnant women. RESULTS: Two hundred and forty-eight (248) pregnant women were included in the study. The proportion of women who received at least three doses of IPTp-SP was 54.6 %. In the intervention group, 54.1 % of women received at least three doses of IPTp-SP versus 55.1 % in the control group, a non-significant difference (adjusted odds ratio "aOR", 0.86 ; 95 % confidence interval "95 % CI", 0.49-1.51). Women in the intervention group were more likely to carry out their ANC visits in a timely manner than those in the control group (aOR, 3.21 ; 95 % CI, 1.91-5.39). CONCLUSION: While mobile phone intervention did not increase the proportion of women receiving three doses of IPTp-SP, it did help to increase the proportion of timely ANC visits. TRIAL REGISTRATION: PACTR202106905150440

A Genotyping Study in Benin Comparing the Carriage of Plasmodium falciparum Infections Before Pregnancy and in Early Pregnancy: Story of a Persistent Infection

BACKGROUND: Malaria infections in the first trimester of pregnancy are frequent and deleterious for both mother and child health. To investigate if these early infections are newly acquired or already present in the host, we assessed whether parasites detected before pregnancy and those detected in early pregnancy are the same infection. METHODS: We used data from the preconceptional "RECIPAL" study (Benin, 2014-2017). Sixty-three pregnant women of 411 included who had a malaria infection detected by quantitative polymerase chain reaction both before pregnancy and at the first antenatal care (ANC) visit were selected for this study. Two highly polymorphic markers, msp-2 and glurp, and a fragment-analysis method were used to enumerate the Plasmodium falciparum genotypes and to quantify their proportions within isolates. An infection was considered as persistent when identical msp-2 and glurp genotypes were found in the corresponding prepregnancy and early-pregnancy samples. RESULTS: The median time between the 2 malaria screenings was 3 months. The median gestational age at the first ANC visit was 6.4 weeks. Most infections before pregnancy were submicroscopic infections. Based on both msp-2 and glurp genotyping, the infection was similar before and in early pregnancy in 46% (29/63) of cases. CONCLUSIONS: Almost half of P. falciparum infections detected in the first trimester originate before pregnancy. Protecting young women from malaria infection before pregnancy might reduce the prevalence of malaria in early pregnancy and its related poor maternal and birth outcomes.Impact du paludisme précoce au cours de la grossesse sur la croissance fœtale au Béni

Concordance of three alternative gestational age assessments for pregnant women from four African countries: A secondary analysis of the MIPPAD trial

Background: At times, ultrasound is not readily available in low resource countries in Africa for accurate determination of gestational age, so using alternative methods is pivotal during pregnancy. These assessments are used to aid the risk analysis for an infant and management strategies for premature delivery, if necessary. Currently, date of last menstrual period, fundal height measurements, and the New Ballard Score are commonly used in resource-limited settings. However, concordance of these measures is unknown for sub-Saharan Africa. We obtained data from an open-label randomized controlled trial, to assess the concordance of these alternative assessment methods. The purpose of our study was to determine the agreement between these alternative methods when used in sub-Saharan African populations. Methods: A total of 4,390 pregnant women from Benin, Gabon, Mozambique and Tanzania were included in our analysis. The assessment methods compared were: 1) reported last menstrual period, 2) symphysis-fundal height measurement, and 3) the New Ballard Score. The Bland-Altman method and intraclass correlation coefficient (ICC) were used to test the degree of agreement. Survival range gestational age, used as an inclusion criterion for further analysis, was from 22 to 44 weeks. Findings: Plots showed a lack of agreement between methods and the 95% limits of agreement too wide to be clinically useful. ICC = 0.25 indicated poor agreement. A post-hoc analysis, restricted from 32 to 42 weeks, was done to check for better agreement in this near-term population. The plots and ICC = 0.16 still confirmed poor agreement. Conclusion: The alternative assessments do not result in comparable outcomes and discrepancies are far beyond the clinically acceptable range. Last menstrual period should not be used as the only estimator of gestational age. In the absence of reliable early ultrasound, symphysis-fundal height measurements may be most useful during pregnancy for fetal risk assessment and the New Ballard Score after delivery as a confirmation of these estimations and for further neonatal management. However, promotion of portable ultrasound devices is required for accurate assessment of gestational age in sub-Sahara Africa