A systematic review and meta-analysis of asymptomatic malaria infection in pregnant women in Sub-Saharan Africa: A challenge for malaria elimination efforts

Malaria and anaemia prevalence and associated factors among pregnant women initiating antenatal care in two regions in Ghana: an analytical cross-sectional study

BACKGROUND

Malaria and anaemia in pregnancy remain public health problems because they increase the risk of adverse pregnancy outcomes. This study assessed malaria and anaemia prevalence and associated risk factors among pregnant women initiating antenatal care in selected districts of 2 regions of Ghana.

METHODS

An analytical cross-sectional study was conducted using data obtained from 5196 pregnant women at their booking antenatal care (ANC) visit. Women of any age, gestational age, parity and at any ANC visit, who consented were enrolled consecutively into the study. Data on socio-demographic and obstetric characteristics, bed net ownership and use were obtained using structured questionnaires. Haemoglobin concentration and malaria, Schistosoma and helminth infections were determined using an automated haematology analyser and microscopy, respectively. Summary statistics to describe study variables and chi-square test and logistic regression set at p < 0.05 to determine risk factors for anaemia and malaria were conducted using Stata SE14.

RESULTS

Overall malaria prevalence was 5.74% [95% CI: 5.1-6.4] and anaemia prevalence was 55.22% [ 95% CI: 53.85-56.58]. Living in Volta region (p < 0.001), being secondi- (p = 0.003) or multigravida (p < 0.001) and being of lower middle socio-economic status (p = 0.004) reduced the women's risk of malaria parasite infection. Being anaemic (p = 0.001) and reporting a symptom (p < 0.001) increased the odds of Plasmodium infection among the women. Residing in Volta region (p < 0.001), having malaria infection (p < 0.001), and booking ANC in the 2nd (p < 0.001) and 3rd trimesters (p < 0.001) increased the odds of anaemia among the women. Age 25-34 years (p < 0.001) and ≥ 35 years (p = 0.008) and belonging to middle (p = 0.009), upper middle (p = 0.006) or upper-level (p < 0.001) quintile of wealth index reduced the odds of anaemia among the women at their booking ANC visit.

CONCLUSIONS

More than half the women were anaemic signifying a severe public health problem. Malaria prevalence, though low, was a significant risk factor for anaemia. Existing malaria and anaemia control strategies through ANC need strengthening, especially among young, first-time pregnant women. This study further highlights socio-economic status as an important risk factor for anaemia in pregnancy.

TRIAL REGISTRATION

Not applicable.

Current update on malaria in pregnancy: a systematic review

BACKGROUND

Malaria during pregnancy poses significant risks to both the mother and the developing fetus. For pregnant women, the infection can result in severe illness and even death. Parasite sequestration in the placenta can cause maternal anemia and increase the risk of mortality both during and after childbirth. Malaria is also a major contributor to stillbirths and preterm births. Infected placental tissue can impede fetal growth, resulting in low birth weight, which is linked to delayed growth and cognitive development in the child. Furthermore, malaria during pregnancy remains a major contributor to perinatal, neonatal, and infant mortality.

OBJECTIVES

To review the epidemiological patterns of malaria in pregnancy and its impact on maternal and neonatal health, and to analyze the availability and effectiveness of drug treatment options.

METHODS

Relevant articles published only in English were searched using electronic databases such as PubMed, Web of Science, Scopus, and Pro-Quest. Keywords including "'malaria in pregnancy", "placental malaria", "congenital malaria", "treatment options", and "nutrition intervention and intermittent preventive treatment" were used in combination. Of the total of 4,486 articles identified, 139 articles were ultimately included. Whereas, others were excluded due to duplication, irrelevant abstract, title, and quality assessment.

RESULTS

From 139 included studies, 47 focused on epidemiology of malaria in pregnancy, 58 on its impact and 16 on treatment options and 18 on nutrition intervention and intermittent treatment. Plasmodium falciparum is the leading cause of complications in pregnant women and is primarily found in Africa, while P.vivax is recognized as an emerging global threat, and causing serious consequences. Other species, such as P.knowlesi, P.ovale, and P.malariae are less common. Malaria prevalence in pregnancy can reach 60% in sub-Saharan Africa and 36% globally, with placental malaria affecting up to 28% of cases. The disease causes serious complications such as maternal anemia, premature birth, and low birth weight, severe anemia and increased maternal and infant mortality. Prevention strategies like intermittent preventive treatment (IPTp), insecticide-treated nets (ITNs) and Indoor residual spray (IRS) are essential. Early diagnosis and treatment can reverse adverse effects on placental and congenital function. Artesunate is recommended for severe malaria in all trimesters. Even resistance to chloroquine reported in some areas, it is the drug of choice for uncomplicated P.vivax infections.

CONCLUSIONS

Malaria during pregnancy significantly impacts maternal and fetal health, leading to anemia, growth restriction, preterm birth, and neonatal death. Infants born to mothers with malaria are more likely to contract the disease. Further research and improved treatment strategies are needed to address this issue effectively.

Coverage and contextual factors associated with insecticide-treated net use among women of reproductive age in Nigeria: evidence from the 2021 malaria indicator survey data

Nigeria continues to face a serious public health problem due to malaria, which contributes around 27% of all cases worldwide. Although insecticide-treated nets (ITNs) are essential interventions for preventing malaria, their use in Nigeria is still sub-optimal. Understanding the factors influencing ITN use is essential to improve malaria control strategies. This study aimed to investigate the prevalence of and factors associated with ITN use among women of reproductive age in Nigeria. We conducted a secondary data analysis of the 2021 Malaria Indicator Survey (NMIS). The sample included 14,476 women of reproductive age (15-49 years) from 567 clusters across Nigeria's six geopolitical zones. Multilevel logistic regression was used to examine the contextual factors associated with ITN use, accounting for both fixed and random effects. Statistical significance was set at p<0.05, with 95% confidence intervals reported for all estimates. The weighted prevalence of ITN use was 41.5% (95% CI: 39.7, 43.3). The results showed Muslim women had 21% (aOR= 0.79; 95% CI: 0.67-0.94) lower odds of ITN use, when compared with the Christian women. Those who had living children were more likely to report ITN use, when compared with women with no child. The non-poor women had higher odds of ITN use, when compared with the poor women (aOR= 1.35; 95% CI: 1.19-1.52). In addition, women from multi-ethnic had 26% lower odds of ITN use, when compared with those from mono-ethnic community (aOR= 0.74; 95% CI: 0.57-0.94). The geographical region was significantly associated with ITN use among Nigerian women. Those from high-level community poverty had 53% reduction in the odds of ITN use, when compared with women from low-level community poverty (aOR= 0.47; 95% CI: 0.32-0.68). ITN use among women of reproductive age in Nigeria remained below the national target. Interventions to increase ITN use should consider the complex interplay of individual and community-level factors. Targeted strategies addressing socioeconomic disparities, leveraging cultural contexts, and implementing community-based approaches are crucial for improving ITN utilization and reducing the malarial burden in Nigeria.

The Burden of Asymptomatic Malaria Infection in Children in Sub-Saharan Africa: A Systematic Review and Meta-Analysis Exploring Barriers to Elimination and Prevention

BACKGROUND

Malaria remains a major public health problem that continues to cause death in under-five children nearly every minute. The purpose of this systematic review and meta-analysis was to determine the pooled prevalence and predictors of asymptomatic malaria in children in Sub-Saharan Africa.

METHODS

Relevant studies were retrieved from Web of Science, Cochrane Library, PubMed, Google Scholar, Gray Literature, Embase, and African Online Journal databases published between 2014 and 2024. Data quality was assessed by a tool developed by Hoy and colleagues and classified as low, moderate, or high risk of bias. We performed a random effects model and sub-group analysis by age group, region, and diagnostic methods. The protocol was registered in the PROSPERO (CRD42024584354).

RESULTS

A total of 24 cross-sectional studies with 19,169 participants from 10 Sub-Saharan Africa countries were included in the analyses under the age of 15 years. The overall prevalence of asymptomatic malaria was 25% (95% CI: 20-30%) and showed no evidence of publication bias. Utilization of insecticide-treated nets was significantly associated with asymptomatic malaria. In addition, the overall prevalence of anemia in asymptomatic Plasmodium-infected children under the age of 15 was found to be 35% (95% CI: 24-46%). Subgroup analysis showed significant regional and diagnostic tool differences in asymptomatic Plasmodium infection.

CONCLUSION

The findings of this study revealed a high prevalence of asymptomatic plasmodium infection in children with significant regional variations. There was a significant association with anemia and the utilization of insecticide-treated nets.

Prevalence and drivers of malaria infection among asymptomatic and symptomatic community members in five regions with varying transmission intensity in mainland Tanzania

BACKGROUND

Despite implementation of effective interventions in the past two decades, malaria is still a major public health problem in Tanzania. This study assessed the prevalence and drivers of malaria infections among symptomatic and asymptomatic members of selected communities from five regions with varying endemicity in mainland Tanzania.

METHODS

A cross-sectional community survey was conducted in five districts, including one district/region in Kagera, Kigoma, Njombe, Ruvuma and Tanga from July to August 2023. Participants aged ≥ 6 months were recruited and tested using rapid diagnostic tests (RDTs). Demographic, anthropometric, clinical, parasitological, type of house, and socio-economic status (SES) data were captured using structured questionnaires. Associations between parasite prevalence and potential drivers were determined by logistic regression, and the results were presented as crude (cOR) and adjusted odds ratios (aOR), with 95% confidence intervals (CIs).

RESULTS

Among 10,228 individuals tested, 3515 (34.4%) had positive results by RDTs. The prevalence of malaria varied from 21.6% in Tanga to 44.4% in Kagera, and from 14.4% to 68.5% among the different villages (P < 0.001). The odds of malaria infections were higher in males (aOR = 1.32, 95% CI 1.19-1.48, P < 0.001), under-fives (aOR = 2.02, 95% CI 1.74-2.40, P < 0.001), schoolchildren [aged 5-9 years (aOR = 3.23, 95% CI 1.19-1.48, P < 0.001) and 10-14 years (aOR = 3.53, 95% CI 3.03-4.11, P < 0.001)], and non-bednet users (aOR = 1.49, 95% CI 1.29-1.72, P < 0.001). Individuals from households with low SES (aOR = 1.40, 95% CI 1.16-1.69, P < 0.001), or living in houses with open windows (aOR = 1.24, 95% CI 1.06-1.45, P < 0.001) and/or holes on the walls (aOR = 1.43, 95% CI 1.14-1.81, P < 0.001) also had higher odds.

CONCLUSIONS

Malaria prevalence varied widely across regions and villages, and the odds of infections were higher in males, schoolchildren, non-bednet users, and individuals with low SES or living in houses with open windows and/or holes on the walls. The identified vulnerable groups and hotspots should be targeted with specific interventions to reduce the disease burden and support the ongoing malaria elimination efforts in Tanzania.

Prevalence and associated factors of malaria among the displaced population in refugee camps in Africa: a systematic review and meta-analysis

BACKGROUND

The increased occurrence of malaria among Africa's displaced communities poses a new humanitarian problem. Understanding malaria epidemiology among the displaced population in African refugee camps is a vital step for implementing effective malaria control and elimination measures. As a result, this study aimed to generate comprehensive and conclusive data from diverse investigations undertaken in Africa.

METHODS

This review adhered to PRISMA standards, involving searches across electronic data bases such as Google Scholar, PubMed, Web of Science, Scopus, and Science Direct. In addition, grey literature was retrieved from several professional associations. The quality of selected studies was evaluated using the Newcastle-Ottawa Quality Assessment Scale. Data extraction was executed using Microsoft Excel, and the meta-analysis was performed with STATA 14 software. A random-effects model was used to estimate the pooled prevalence and associated factors of malaria. Meta-regression and subgroup analysis were used to identify heterogeneity, while funnel plots and Egger's statistical tests assessed the publication bias. Furthermore, a sensitivity analysis was performed.

RESULTS

The overall random-effects pooled prevalence of malaria infection (comprising symptomatic and asymptomatic cases) across all included studies was 35.93% (95% CI 24.71-47.15). This study showed a high level of heterogeneity between studies (I2 = 97.1; P < 0.001). Of the identified Plasmodium species, Plasmodium falciparum constituted 99.3%. The frost plot indicated that the overall prevalence of P. falciparum was 34.94% (95% CI 24.34-45.53). Subgroup analysis revealed significant variation (P < 0.001) in malaria prevalence between asymptomatic and symptomatic cases, with a prevalence of 4.39% (95% CI 2.57-6.21) and 45.10% (95% CI 27.28-62.92), respectively. Lack of insecticide-treated mosquito net utilization (AOR 2.43; 95% CI 1.01-5.88) and living near mosquito breeding sites (AOR 2.76, 95% CI 1.56-4.87) were risk factors of malaria.

CONCLUSION

This study determined that the pooled prevalence of malaria among displaced individuals in refugee camps was high and exhibited variations across different population groups. This signifying there is still a need to improve and recheck existing malaria prevention and control strategies to establish an effective malaria control and elimination programme in Africa.

Assessment of uptake of sulphadoxine-pyrimethamine for intermittent preventive treatment among pregnant women in Osun State, Nigeria

BACKGROUND

About 32 million pregnant women are at the risk of malaria infection yearly in malaria-endemic sub-Saharan Africa. To mitigate the risks associated with malaria in pregnancy, the WHO recommends ≥3 doses of intermittent preventive treatment in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP), covering from the second trimester of pregnancy until delivery.

METHODS

This cross-sectional study assessed the uptake and extent of adherence with IPTp-SP among pregnant women in Osun State, Nigeria, from October 2020 to March 2021. Assessment of the uptake was done by extracting information from the validated case report forms. Venous blood samples were obtained to assess the levels of sulphadoxine in plasma through HPLC-UV.

RESULTS

In total, 49.24%, 38.17% and 12.58% of the study participants obtained 1, 2 and ≥3 doses of IPTp-SP, respectively. In assessing the extent of adherence, 46.67% obtained their last dose within 28 d before sample collection. Uptake of IPTp-SP is not associated with gravidity (p=0.603), but is weakly associated with the age of the study participants (p=0.04). The median (IQR) plasma sulphadoxine concentration was 10.6248 (2.8124-27.1242) ug/mL.

CONCLUSIONS

Utilisation of the intervention is still very low and adherence appears to be inadequate among the study population, suggesting that more advocacy on the IPTp-SP strategy and the implementation of directly observed therapy is necessary.

Asymptomatic Plasmodium falciparum infections and determinants of carriage in a seasonal malaria chemoprevention setting in Northern Cameroon and south Senegal (Kedougou)

BACKGROUND

Among the several strategies recommended for the fight against malaria, seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine combination (SPAQ) targets children 3 months to 5 years in Sahel regions of Africa to reduce mortality and mortality. Since SMC with SPAQ is administered to symptoms-free children for prevention of malaria, it is anticipated that a proportion of asymptomatic parasitaemic children will also be treated and may result in a drop in both the overall population prevalence of asymptomatic malaria infections, subsequent risk of symptomatic malaria infections and transmission. Age-specific carriage of asymptomatic Plasmodium spp. infections (API) was evaluated in target children and adults in Cameroon and Senegal, prior to the 2018 SMC campaign in both countries.

METHODS

A baseline household survey was carried out in August 2018 in two areas in Cameroon and one in Senegal just before the beginning of distribution of SPAQ for SMC. The survey included collection of fingerpick blood for malaria rapid diagnostic testing (RDT) and administration of a pre-tested questionnaire on demographics and malaria risk factors to participants. The age-specific prevalence of API in all study sites was analysed, first as a distribution of RDT-positives in 5-year age categories and secondly, with age as a continuous variable in the whole sample, using the Wilcoxon rank sum test. Risk factors for carriage of asymptomatic infections were examined using logistic regression analysis in STATA v.16 and Rv4.1.2.

RESULTS

In total, 6098 participants were surveyed. In Cameroon, overall prevalence of API was 34.0% (32.1-36.0%) in Adamaoua, and 43.5% (41.0-45.7%) in the North. The median age of RDT positivity was higher in Senegal: 11 years (IQR 7-16) than in Cameroon-Adamaoua: 8 years (4-17) and North: 8 years (4-12) and significantly different between the three study regions. In all three study sites, asymptomatic carriage was significantly higher in the older age group (5-10 in Cameroon, and 7-14 in Senegal), compared to the younger age group, although the median age of participants was lower among RDT-negatives in the North compared to RDT-positives. Health area, gender and last infection within past year significantly confounded the relationship between age and parasite carriage in Adamaoua and Senegal but not in North Cameroon. Absence of bed net and previous infection within one month of the survey all independently predicted carriage of asymptomatic parasites in multivariate regression analysis.

CONCLUSION

Under five years asymptomatic Plasmodium infection in northern Cameroon prior to SMC season remained high in 2018, irrespective of history of SMC implementation in the study areas in Cameroon. Compared to Adamaoua, peak asymptomatic malaria parasite rate was observed in children 5-10 years, which is out of the SMC target age-range. Health area, last infection within the past month and to a lesser extent gender affected the association between age and asymptomatic carriage in all sites except the North region of Cameroon, indicating wide heterogeneity in risk of malaria among the general population in that geography. Follow-up studies designed to measure SMC effects in Cameroon are warranted as it may become necessary to extend age of SMC eligibility to 10 years, as is practiced in Senegal.

What do women in the highest malaria burden country know about ways to prevent malaria? A multi-level analysis of the 2021 Nigeria Malaria Indicator Survey data

BACKGROUND

With Nigeria accounting for 31% of the estimated 608,000 deaths due to malaria globally, good knowledge of malaria prevention is essential for effective malaria control. The objective of this study was to examine the knowledge of malaria prevention and its associated factors among Nigerian women.

METHODS

This study analysed secondary data from the 2021 Nigeria Malaria Indicator Survey. The sample included 14,476 women of reproductive age (15-49 years). A multilevel multivariable logistic regression was used to examine individual, household, and community-level factors associated with having good knowledge of malaria prevention.

RESULTS

The weighted prevalence of having good knowledge of malaria prevention was 43.5% (95%CI: 41.7-45.2%). Women with secondary/higher education had 2.35 higher odds of good knowledge of malaria prevention, when compared with those with no formal/primary education (aOR = 2.35; 95% CI: 2.00-2.75). Those exposed to malaria messages had 2.62 higher odds of good knowledge of malaria prevention, when compared with no exposure to malaria messages (aOR = 2.62; 95% CI: 2.31-2.97). Women from non-poor households had 1.42 higher odds of good knowledge of malaria prevention, when compared with those from poor households (aOR = 1.42; 95% CI: 1.17-1.71). Rural dwellers had 39.0% reduction in the odds of good knowledge of malaria prevention, when compared with their urban counterparts (aOR = 0.61; 95% CI: 0.46-0.80). In addition, women from communities with high level of education (aOR = 2.24; 95%CI: 1.38-3.64), moderately exposed to malaria messages (aOR = 1.43; 95%CI: 1.08-1.88) and highly exposed to malaria messages (aOR = 1.71; 95%CI: 1.27-2.30), had higher odds of good knowledge of malaria prevention, when compared with women from communities with low education and low exposure to malaria messages, respectively.

CONCLUSION

The knowledge of malaria prevention was found to be low. The study identified education, religion, exposure to malaria messages, wealth, region, place of residence, community-level poverty, education and exposure to malaria messages as factors associated with the knowledge of malaria prevention. Addressing these factors through targeted interventions, such as improving educational opportunities for women and enhancing media-driven public health campaigns are essential to enhancing malaria knowledge among this critical demographic group.

Cross sectional survey of maternal and newborn quality of care in Niger: Selected findings, lessons learned and recommendations

Comprehensive assessments of quality of care (QoC) are essential for monitoring progress towards meeting global and national maternal and newborn health (MNH) targets. Liverpool School of Tropical Medicine (LSTM) and the Niger Ministry of Public Health adapted a 2014 WHO QoC tool to cover antenatal care (ANC) and postnatal care (PNC) and include client voices through exit interviews. The objectives of the study were to assess quality of MNH care in Niger and to document lessons learnt from implementing the LSTM QoC tool. Quality of Care (QoC) was assessed using five tools: health facility survey (using register and official record data), partograph reviews, healthcare provider knowledge assessment, exit interviews with clients, and observation of antenatal and postnatal care. A nationally representative sample of 110 public healthcare facilities at three levels (integrated health centres, district hospitals and mother-child hospitals) and 2153 women were included. Descriptive analysis with 95% confidence intervals was presented. The health facility survey showed variable access to electricity (63% [53-72]), water (72% [62-81]), and transportation (40% [31-50]). Tests and treatment for HIV, TB, and malaria were found in more than 90% of relevant facilities. During observation of first ANC visit, 62% [48-74] women were tested for HIV; 13% [5-30] for pre-eclampsia and 22% [12-36] for anaemia. Observation of PNC showed much lower rates of screening (15% [7-27] tested for HIV and 4% [0;11] for malaria). Partographs were used in 86% of deliveries with inconsistent completion. At client interviews, respectful care indicators were variable, with providers not always explaining results to clients (59% [50-67]). Targeted allocation of resources and training could impact on QoC and reduce missed opportunities for prevention, screening and management of diseases among pregnant women and babies. The QoC assessment tool proved capable of offering a comprehensive overview of priorities in MNH, while maintaining feasibility in the Nigerien context.

Determinants of Hemoglobin Among Pregnant Women at Agro-Pastoralist Communities in South Omo Zone, Ethiopia: Community Based Cross-Sectional Study, Nutrition Experience from Movable Community

Background

Low hemoglobin level is the most common public health problem during pregnancy in developing countries including Ethiopia, which is affecting both mother and fetus. However, the determinants of anemia among pregnant women are not well studied.

Objective

To assess the determinates of hemoglobin among pregnant women in rural agro-pastoralist communities in the South Omo zone, Ethiopia.

Method

Community-based cross-sectional study was done in rural agro-pastoralist communities. A multistage stratified sampling technique was used to select 526 pregnant women. Data were collected by using structured questionnaires. Hemoglobin level was measured by using HemoCue ® Hb301. Data were analyzed by using a statistical package for the social science version 26. Descriptive (Mean, standard deviation, frequency, range), bivariate and multivariate analysis was carried out to check the association between lower hemoglobin levels and independent variables. The output is presented in tables and figures.

Result

The mean (±SD) of hemoglobin concentration was 11.8 ± 1.7. The overall prevalence of anemia was 39.9% [95% CI: 35.5, 44.4], 19.4% (95% CI: 16.0, 23.2) was mild, 19.6% (95% CI: 16.27, 2.5) was moderate and 0.9% (95% CI: 0.25, 2.25) was severe anemia. Not taking IFA (AOR = 5.7(3.3, 9.8)), severe under nutrition (AOR = 8.9(2.1, 37.3)), no fish food (AOR = 2.4(1.3, 4.5)), drinking coffee (AOR = 1.6(1.0, 2.6)), moderate food insecurity (AOR = 2.5(1.4, 4.6)), and no malaria infection (AOR = 0.6(0.4, 0.9)) were statistically significant with anemia.

Conclusion

The anaemia is a public health problem in this study area. Therefore, nutrition education and counselling to enhance iron supplementation, dietary diversity and a flesh diets are very essential to enhance haemoglobin levels.

Asymptomatic malaria in pregnancy and associated risk factors in Majang Zone, Gambella Region, Southwest Ethiopia: a hard-to-reach malaria hotspot

BACKGROUND

Asymptomatic malaria in pregnancy (AMiP) is a daunting public health problem with multifaceted adverse outcomes for mothers, fetuses, newborns and beyond. This study aimed to assess the prevalence and risk factors of AMiP and anaemia in Majang Zone, Gambella, Southwest Ethiopia.

METHODS

A facility-based cross-sectional study was conducted among 425 pregnant women attending the antenatal care (ANC) clinics of five health facilities in the Majang Zone from November 2022 to February 2023. Sociodemographic, obstetric, and anti-malarial intervention data were collected using an interviewer-administered questionnaire. A capillary blood specimen was collected to diagnose malaria and anaemia as well as determine the blood group. Malaria was diagnosed by rapid diagnostic test (RDT), microscopy, and quantitative polymerase chain reaction (qPCR). Statistical analyses were done by Statistical Package for Social Science (SPSS) version 26.0. The association between dependent and independent variables was assessed by multivariable binary logistic regression, considering P < 0.05 statistically significant. The magnitude of associations was quantified with the adjusted odds ratio (AOR) along with the corresponding 95% confidence interval (CI).

RESULTS

The overall prevalence of AMiP was 15.3% (95% CI 12.1, 18.9). It was 11.3% (95% CI 8.4, 14.7) by RDT, 11.8% (95% CI 8.9, 15.2) by microscopy and 17.6% (95% CI 11.7, 24.9) by qPCR. Plasmodium falciparum, moderate parasitaemia and submicroscopic infection accounted for 55.4% of the AMiP prevalence, 50.8% of the parasite density, and 41.6% of the qPCR-positive AMiP, respectively. Nearly 32.3% of pregnant women with AMiP carried gametocytes. Risk factors of AMiP were: not utilizing insecticide-treated net (ITN) within the previous week (AOR: 9.43 95% CI 1.57, 56.62), having a history of malaria within the previous year (AOR: 2.26 95% CI 1.16, 4.42), lack of indoor residual spraying (IRS) within the previous year (AOR: 3.00 95% CI 1.50, 6.00), and ANC contact below two rounds (AOR: 4.28 95% CI 2.06, 8.87). The prevalence of anaemia was 27.7% (95% CI 23.6, 32.1), and it was higher among AMiP-positives (56.9%) than the negatives (22.5%) (P: 000).

CONCLUSION

The prevalence of AMiP and anaemia was high, and remained as a critical public health problem in the study area. Focus on the identified risk factors and introduction of more sensitive diagnostic tools should be considered to mitigate AMiP in the study area.

Prospective study of malaria in pregnancy, placental and congenital malaria in Northwest Colombia

BACKGROUND

Pregnancy Associated Malaria (PAM) include malaria in pregnancy (MiP), placental malaria (PM), and congenital malaria (CM). The evidence available in Colombia on PAM focuses on one of the presentations (MiP, PM or CM), and no study longitudinally analyses the infection from the pregnant woman, passing through the placenta, until culminating in the newborn. This study determined the frequency of MiP, PM, and CM caused by Plasmodium vivax, Plasmodium falciparum, or mixed infections, according to Thick Blood Smear (TBS) and quantitative Polymerase Chain Reaction (qPCR). Identifying associated factors of PAM and clinical-epidemiological outcomes in northwestern Colombia.

METHODS

Prospective study of 431 pregnant women, their placenta, and newborns registered in the data bank of the research Group "Salud y Comunidad César Uribe Piedrahíta" which collected information between 2014 and 2020 in endemic municipalities of the departments of Córdoba and Antioquia. The frequency of infection was determined with 95% confidence intervals. Comparisons were made with the Chi-square test, Student t-test, prevalence ratios, and control for confounding variables by log-binomial regression.

RESULTS

The frequency of MiP was 22.3% (4.6% using TBS), PM 24.8% (1.4% using TBS), and CM 11.8% (0% using TBS). Using TBS predominated P. vivax. Using qPCR the proportions of P. vivax and P. falciparum were similar for MiP and PM, but P. falciparum predominated in CM. The frequency was higher in nulliparous, and women with previous malaria. The main clinical effects of PAM were anaemia, low birth weight, and abnormal APGAR score.

CONCLUSIONS

The magnitude of infections was not detected with TBS because most cases were submicroscopic (TBS-negative, qPCR-positive). This confirmed the importance of improving the molecular detection of cases. PAM continue being underestimated in the country due to that in Colombia the control programme is based on TBS, despite its outcomes on maternal, and congenital health.

Malaria in pregnancy: Meta-analyses of prevalence and associated complications

This review aims to assess the prevalence of malaria in pregnancy during antenatal visits and delivery, species-specific burden together with regional variation in the burden of disease. It also aims to estimate the proportions of adverse pregnancy outcomes in malaria-positive women. Based on the PRISMA guidelines, a thorough and systematic search was conducted in July 2023 across two electronic databases (including PubMed and CENTRAL). Forest plots were constructed for each outcome of interest highlighting the effect measure, confidence interval, sample size, and its associated weightage. All the statistical meta-analysis were conducted using R-Studio version 2022.07. Sensitivity analyses, publication bias assessment, and meta-regression analyses were also performed to ensure robustness of the review. According to the pooled estimates of 253 studies, the overall prevalence of malaria was 18.95% (95% CI: 16.95-21.11), during antenatal visits was 20.09% (95% CI: 17.43-23.06), and at delivery was 17.32% (95% CI: 14.47-20.61). The highest proportion of malarial infection was observed in Africa approximating 21.50% (95% CI: 18.52-24.81) during ANC and 20.41% (95% CI: 17.04-24.24) at the time of delivery. Our analysis also revealed that the odds of having anaemia were 2.40 times (95% CI: 1.87-3.06), having low birthweight were 1.99 times (95% CI: 1.60-2.48), having preterm birth were 1.65 times (95% CI: 1.29-2.10), and having stillbirths were 1.40 times (95% CI: 1.15-1.71) in pregnant women with malaria.

Asymptomatic malaria infection and its associated factors among pregnant women in Ethiopia; a systematic review and meta-analysis

Background

Asymptomatic malaria during pregnancy is a significant public health concern in malaria-endemic regions, which worsens the various effects of malaria on the mother and fetus and increases maternal and neonatal mortality. To date, no meta-analysis has been conducted on asymptomatic malaria in pregnant women in Ethiopia. Thus, we aimed to estimate the pooled prevalence of asymptomatic malaria and its associated factors in pregnant women in Ethiopia.

Methods

PubMed/Medline, Google Scholar, Web of Science, Cochrane, AJOL, and Ethiopian University repositories were systematically searched to identify studies reporting the prevalence of asymptomatic malaria infection among pregnant women in Ethiopia. A random effects model was used to perform the analysis. The heterogeneity of the studies was assessed with the I-squared tests, and subgroup analyses were performed to identify the sources of heterogeneity.

Results

Ten articles with 3277 study participants were included in this review. The pooled prevalence of asymptomatic malaria infection among pregnant women in Ethiopia was 7.03% (95% CI: 6.23-9.12); I2 = 81.2%). In the species-specific pooled prevalence estimate, Plasmodium falciparum prevalence was 5.34% (95%CI: 3.38-7.3; I2 = 87.8%), and Plasmodium vivax prevalence was 1.69% (95%CI: 1.2-5; I2 = 91.5%).Not using insecticide-treated bed nets [OR = 7.36, 95% CI (2.75, 19.73)], being primi-gravida [OR = 1.86, 95% CI (1.23, 2.82)]; lack of health education about malaria prevention [OR = 6.86, 95% CI (2.90, 11.44)] were predictors of asymptomatic malaria infection during pregnancy.

Conclusion

This study revealed that asymptomatic malaria was prevalent among pregnant women in Ethiopia. This suggests that relying merely on reported symptoms may result in missed malaria cases. Therefore, regular screening and treatment protocols for malaria are recommended in antenatal care. It is also crucial to ensure that pregnant women have access to insecticide-treated bed nets and other effective malaria prevention measures.

Implications of asymptomatic malaria infections on hematologic parameters in adults living with HIV in malaria-endemic regions with varying transmission intensities

OBJECTIVES

HIV and malaria coinfection impacts disease management and clinical outcomes. This study investigated hematologic abnormalities in malaria-asymptomatic people living with HIV (PLHIV) in regions with differing malaria transmission.

METHODS

Study participants were enrolled in the African Cohort Study: two sites in Kenya, one in Uganda, and one in Nigeria. Data was collected at enrollment and every 6 months. Logistic regression estimated odds ratios for associations between HIV/malaria status and anemia, thrombocytopenia, and leucopenia.

RESULTS

Samples from 1587 participants with one or more visits comprising 1471 (92.7%) from PLHIV and 116 (7.3%) without HIV were analyzed. Parasite point prevalence significantly differed across the study sites (P <0.001). PLHIV had higher odds of anemia, with males at lower odds compared to females; the odds of anemia decreased with age, reaching significance in those ≥50 years old. Participants in Kisumu, Kenya had higher odds of anemia compared to other sites. PLHIV had higher odds of leucopenia, but malaria co-infection was not associated with worsened leucopenia. The odds of thrombocytopenia were decreased in HIV/malaria co-infection compared to the uninfected group.

CONCLUSION

Hematological parameters are important indicators of health and disease. In PLHIV with asymptomatic malaria co-infection enrolled across four geographic sites in three African countries, abnormalities in hematologic parameters differ in different malaria transmission settings and are region-specific.

The potential of addressing asymptomatic malaria in the context of malaria elimination in Ethiopia: Scoping review

Objectives

Currently, evidence synthesis targeting asymptomatic malaria infections in Ethiopia are scarce. This review intended to collect and organize information on asymptomatic malaria.

Methods

A Joanna Briggs Institute, scoping review protocol was used. Searches for peer-reviewed articles published between 01 January 2010 and 10 August 2022, were done through a variety of databases, and gray literatures.

Results

17 articles were included out of 7672 articles identified. There was no any longitudinal study to trace forward these asymptomatic malaria cases. The reviewed studies did not address how asymptomatic malaria could be treated. Moreover, living in index houses, their neighbours and family sizes were the main predictors and more associated with onward transmission of malaria. Asymptomatic malaria (ASM) infection might persist in all seasons except June-August, for which data is lacking.

Conclusions

Therefore, as implication of research and policy, it would be necessary to focus on index families and their neighbours in prevention of ASM, conducting longitudinal studies to ascertain when and how many asymptomatic malaria cases without fever during diagnosis would develop clinical malaria. As well, establishing a more sensitive diagnostic technique of malaria surveillance. It is also necessary to provide information regarding the feasibility of treating asymptomatic malaria cases in Ethiopia.

High burden of asymptomatic malaria and anaemia despite high adherence to malaria control measures: a cross-sectional study among pregnant women across two seasons in a malaria-endemic setting in Ghana

PURPOSE

Anaemia remains a serious concern among pregnant women, and thus, it is closely monitored from the onset of pregnancy through to delivery to help prevent adverse maternal and neonatal outcomes. In malaria-endemic settings, continuous low-level carriage of P. falciparum parasites is common and its contribution to maternal anaemia should not be underestimated. In this study, we evaluated the impact of adherence to malaria control measures [number of antenatal clinics (ANC) attended, supervised intake of sulphadoxine pyrimethamine (SP), and use of insecticide treated bed nets (ITNs)] on asymptomatic malaria and anaemia outcomes among pregnant women on ANC in hospitals in the Central region of Ghana.

METHODS

The study was conducted during two seasons; October-November 2020 (dry season, n = 124) and May-June 2021 (rainy season, n = 145). Among the women, there was a high adherence to the control measures for both seasons (ANC ≥ 3 visits; ~ 82.0%, intake of SP; ~ 80.0% and ITNs use; ~ 75.0%).

RESULTS

Asymptomatic P. falciparum carriage was high for both seasons (44.4% for the dry season; 46.9% for the rainy season). Correspondingly, the occurrence of anaemia was high for both seasons (57.3% for the dry season; 68.3% for the rainy season) and was strongly predicted by carriage of P. falciparum parasites. Despite the high adherence to ANC protocols, asymptomatic P. falciparum infection was common and contributed to the high burden of maternal anaemia.

CONCLUSIONS

Our findings emphasize the need for improved control measures that can clear asymptomatic/sub-microscopic P. falciparum infection and protect against malaria-induced anaemia among pregnant women attending ANC in malaria endemic-settings.

Diagnostic performance of ultrasensitive rapid diagnostic test for the detection of Plasmodium falciparum infections in asymptomatic individuals in Kisangani, Northeast Democratic Republic of Congo

BACKGROUND

Ultrasensitive rapid diagnostic test (usRDT) was recently developed to improve the detection of low-density Plasmodium falciparum infections. However, its diagnostic performance has not been evaluated in the Democratic Republic of Congo (DRC). This study aims to determine the performance of the usRDT in malaria diagnosis in asymptomatic individuals under field condition in Kisangani, Northeast of DRC.

METHODS

A community-based cross-sectional study was carried out from June to August 2022 on 312 asymptomatic individuals residing in the city of Kisangani. Capillary blood samples were collected by finger prick for microscopic examination of thick and thin blood film, RDTs, and nested polymerase chain reaction (PCR). Alere™ Malaria Ag P.f usRDT and conventional RDT (cRDT/SD Bioline Malaria Ag P.f) kits were used for the detection of Plasmodium histidine rich protein 2 (HRP2) antigen as a proxy for the presence of P. falciparum. The diagnostic performance of the usRDT was compared with cRDT, microscopy and PCR.

RESULTS

The prevalence of asymptomatic P. falciparum malaria was 40.4%, 42.0%, 47.1% and 54.2% by cRDT, microscopy, usRDT and PCR, respectively. By using PCR as a reference, usRDT had sensitivity and specificity of 87.0% (95% CI 81.4-91.7) and 100.0% (95% CI 97.5-100.0), respectively, whereas the cRDT had sensitivity and specificity of 74.6% (95% CI 67.3-80.9) and 100% (95% CI 97.1-100.0), respectively. By using microscopy as a reference, usRDT had sensitivity and specificity of 96.9% (95% CI 92.4-99.2) and 89.0% (95% CI 83.5-93.1), respectively, while the cRDT had sensitivity and specificity of 96.2% (95% CI 92.3-98.7) and 100% (95% CI 97.9-100.0), respectively.

CONCLUSION

The usRDT showed better diagnostic performance with higher sensitivity than the cRDT which is currently in use as point-of-care test. Further research is necessary to assess the access and cost-effectiveness of the usRDTs to use for malaria surveillance.

Prevalence of asymptomatic malaria and associated factors among pregnant women in Ethiopia: systematic review and meta-analysis

The proactive identification of asymptomatic patients and the mitigation of associated problems are essential to the elimination of malaria. For asymptomatic malaria and related variables among pregnant women in Ethiopia, there are no national pooled estimates. As a result, the goal of this study is to compile thorough and compelling data from several Ethiopian investigations. Google Scholar, PubMed, Scopes, the Web of Science, the Cochrane Library, and African Journals Online were a few of the electronic resources that were accessed. The investigation included all observational studies. STATA version 15 was used to extract the data from the Microsoft Excel file and conduct the analysis. The estimated pooled prevalence of asymptomatic malaria among pregnant women was calculated using a random-effects model. An inverse variance index (I2) analysis was utilized to find heterogeneity. To assess the publication bias, funnel plots, and Egger's statistical tests were used. The study determined that the combined prevalence of asymptomatic malaria among pregnant women was 7.20 (95% confidence interval = 4.22, 10.18) and 4.69 (95% confidence interval = 2.77, 6.62) by microscopy and rapid diagnostic test, respectively. The presence of stagnant water near their home (odds ratio = 4.31; 95% confidence interval = 1.66, 11.20); not using insecticide-treated nets (odds ratio = 6.93; 95% confidence interval = 3.27, 14.71); the lack of indoor residual spray service (odds ratio = 2.68; 95% confidence interval = 1.63, 4.40); and the presence of pregnant women in their neighborhood (odds ratio = 3.14; 95% confidence interval = 1.4). This study showed that pregnant women have a high pooled prevalence of asymptomatic malaria. Women living in rural areas near stagnant water and those who never used insecticide-treated nets had a two-, four-, or six-fold higher prevalence of asymptomatic malaria, respectively. The use of advanced diagnostic techniques could produce a higher magnitude of the disease. For effective intervention toward elimination, active case detection at the community level is also advised.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023411385; identifier, CRD42023411385.

The question of the early diagnosis of asymptomatic and subpatent malaria in pregnancy: Implications for diagnostic tools in a malaria endemic area

Objectives

Malaria in pregnancy (MIP) is a major healthcare challenge in low-income countries with high malaria endemicity. Early but accurate diagnosis and appropriate treatment is the hallmark of preventing disease progression/adverse outcomes in the mother, foetus and neonates. We assessed the comparative diagnostic performance of Malaria Rapid Diagnostic Test (mRDT), microscopy and PCR for malaria diagnosis in pregnant women for early detection of asymptomatic malaria in pregnant women.

Study design

Five hundred and twenty Pregnant women attending study clinics within Ikene and Remo North LGAs with gestational age between 16 and 29 weeks, willing and consented; were enrolled into the study. Blood samples collected via venepuncture were screened for malaria using microscopy, mRDTs kits, and PCR techniques on their first visit (V1) and at delivery. The parasite positivity rates, sensitivity and specificity were calculated and compared for each technique using PCR as the standard. Data was entered into REDCap® online database and analysis done using Stata and MedCalc®.

Results and conclusions

Average age of enrolled women was 28.8 years and mean gestational age was 21.0 weeks. The parasite positivity rates were 4.3%, 8.8% and 25.0% for microscopy, mRDT and PCR at V1 and was 2.4%, 3.4% and 43.4% at delivery, respectively. Sensitivity for microscopy and mRDT was 11.2% and 30.3% respectively at V1, while specificity was 98.2% and 98.5%. At delivery, the sensitivity reduced to 1.6% and 4.9%; while specificity was 96.9% and 97.6% respectively. Only 2.3% cases correlated with all three diagnostic methods. Our data showed a decrease in sensitivity of the diagnostic methods as pregnancy progressed, which may be due to very low parasitaemia, but high specificity. Our study demonstrated a high rate of subpatent parasitaemia amongst pregnant women. This finding therefore raises the question of the effect of subpatent parasitaemia on the health of the mother and foetus.

Detecting temporal and spatial malaria patterns from first antenatal care visits

Pregnant women attending first antenatal care (ANC) visits represent a promising malaria surveillance target in Sub-Saharan Africa. We assessed the spatio-temporal relationship between malaria trends at ANC (n = 6471) and in children in the community (n = 3933) and at health facilities (n = 15,467) in southern Mozambique (2016-2019). ANC P. falciparum rates detected by quantitative polymerase chain reaction mirrored rates in children, regardless of gravidity and HIV status (Pearson correlation coefficient [PCC] > 0.8, χ²<1.1), with a 2-3 months lag. Only at rapid diagnostic test detection limits at moderate-to-high transmission, did multigravidae show lower rates than children (PCC = 0.61, 95%CI[-0.12-0.94]). Seroprevalence against the pregnancy-specific antigen VAR2CSA reflected declining malaria trends (PCC = 0.74, 95%CI[0.24-0.77]). 60% (9/15) of hotspots detected from health facility data (n = 6662) using a novel hotspot detector, EpiFRIenDs, were also identified with ANC data (n = 3616). Taken together, we show that ANC-based malaria surveillance offers contemporary information on temporal trends and geographic distribution of malaria burden in the community.

Intermittent preventive treatment with Sulfadoxine pyrimethamine for malaria: a global overview and challenges affecting optimal drug uptake in pregnant women

Malaria in Pregnancy (MiP) leading to morbidity and mortality is a major public health problem that poses significant risk to pregnant women and their fetus. To cope with this alarming situation, administration of Sulfadoxine-pyrimethamine (SP) drugs to pregnant women as an intermittent preventive treatment (IPT) from 16 weeks of gestation is recommended by the World Health Organization (WHO) guidelines. We conducted a comprehensive search of published articles related to MiP in last 10 years with predefined keywords or their synonyms. The mapping of malaria in pregnant women showed a prevalence rate up to 35% in many countries. Although IPTp-SP has been implemented in endemic regions since several years but the IPTp-SP coverage percentage vary from country to country and continue to remain below the target of 80%. Major reasons for low IPTp-SP involve gestational age at first prenatal visit, level of education, place of residence, knowledge of IPTp-SP benefits, and use of antenatal services. Several challenges including the emergence of septuple and octuple SP-resistant parasites is reported from many countries which make the prophylactic use of IPTp-SP currently debatable. This narrative review addresses the barriers for optimal use of IPTp-SP and discusses alternative approaches to increase the use and effectiveness of SP intervention for preventing MiP. The COVID pandemic has drastically affected the public health disrupting the management of diseases worldwide. In view of this, a brief summary of COVID impact on MiP situation is also included.

Synthesis of Qualitative Evidence on Malaria in Pregnancy, 2005-2022: A Systematic Review

Qualitative research on malaria in pregnancy (MiP) is incipient, therefore its contextual, experiential and symbolic associated factors are unknown. This study systematizes the qualitative research on MiP, describes knowledge, perceptions and behaviors about MiP, and compiles individual, socioeconomic, cultural and health system determinants of MiP through a meta-synthesis in 10 databases. A total of 48 studies were included with 2600 pregnant women, 1300 healthcare workers, and 2200 relatives or community members. Extensive knowledge was demonstrated on ITN and case management, but it was lacking on SP-IPTp, risks and consequences of MiP. Attitudes were negative towards ANC and MiP prevention. There were high trustfulness scores and preference for traditional medicine and distrust in the safety of drugs. The main determinants of the Health System were rationing, copayments, delay in payment to clinics, high out-of-pocket expenses, shortage, low workforce and work overload, shortcomings in care quality, low knowledges of healthcare workers on MiP and negative attitude in care. The socioeconomic and cultural determinants were poverty and low educational level of pregnant women, distance to the hospital, patriarchal-sexist gender roles, and predominance of local conceptions on maternal-fetal-neonatal health. The meta-synthesis demonstrates the difficulty to detect MiP determinants and the importance of performed qualitative research before implementing MiP strategies to understand the multidimensionality of the disease.

Effects of maternal antenatal treatment with two doses of azithromycin added to monthly sulfadoxine-pyrimethamine for the prevention of low birth weight in Burkina Faso: an open-label randomized controlled trial

BACKGROUND

Exposure during pregnancy to malaria and sexually-transmitted infections is associated with adverse birth outcomes including low birth weight (LBW). This study aimed at assessing if the adjunction of two doses of azithromycin to sulfadoxine-pyrimethamine for the intermittent preventive treatment of malaria in pregnancy can reduce LBW.

METHODS

A two parallel-groups, open-label randomized controlled trial involving pregnant women (16 to 35 years of age and 12 to 24 weeks of gestation as confirmed by last menstrual period or fundal height) was conducted in rural Burkina Faso. Women were assigned in a 1:1 ratio either to use azithromycin (1 g daily for 2 days) during the second and third trimesters of pregnancy plus monthly sulfadoxine-pyrimethamine (1500/75 mg) (SPAZ) (intervention) or to continue using a monthly sulfadoxine-pyrimethamine (1500/75 mg) (SP) (control). Primary outcome was a LBW (birth weight measured within 24 h after birth < 2500 g). Secondary outcomes including stillbirth, preterm birth or miscarriage are reported together with safety data.

RESULTS

A total of 992 pregnant women underwent randomization (496 per group) and 898 (90.5%) valid birth weights were available (450 in SPAZ and 448 in SP). LBW incidence was 8.7% (39/450) in SPAZ and 9.4% (42/448) in controls (p-value = 0.79). Compared with controls, pregnant women with SPAZ showed a risk ratio (RR) of 1.16 (95% confidence interval (CI 0.64-2.08]) for preterm births, 0.75 (95% CI 0.17-3.35) for miscarriage and 0.64 (95% CI 0.25-1.64) for stillbirths. No treatment-related serious adverse events (SAEs) have been observed, and there was no significant difference in the number of SAEs (13.5% [67/496] in SPAZ, 16.7% [83/496] in SP, p-value = 0.18) or AEs (17.1% [85/496] in SPAZ, 18.8% [93/496] in SP, p-value = 0.56).

CONCLUSION

Adequate prevention regimen with monthly sulfadoxine-pyrimethamine given to all pregnant women has been proved to reduce the risk of LBW in malaria endemic areas. Adding azithromycin to the regimen does not offer further benefits, as far as women receive a malaria prevention regimen early enough during pregnancy. Trial registration Pan African Clinical Trial Registry ( https://pactr.samrc.ac.za/Search.aspx ): PACTR201808177464681. Registered 21 August 2018.

A snapshot of the prevalence of dihydropteroate synthase-431V mutation and other sulfadoxine-pyrimethamine resistance markers in Plasmodium falciparum isolates in Nigeria

BACKGROUND

Malaria is a major public health issue with substantial risks among vulnerable populations. Currently, the World Health Organization (WHO) recommends SP-IPTp in the second and third trimesters. However, the efficacy of SP-IPTp is threatened by the emergence of sulfadoxine-pyrimethamine resistant malaria parasites due to single nucleotide polymorphisms in the Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthetase genes. This study aimed to assess the current prevalence of Pfdhfr/Pfdhps mutations in P. falciparum isolates collected from individuals residing in Ile-Ife, Nigeria, and also present maps of the prevalence of Pfdhps 431V and 581G within Nigeria and surrounding countries.

METHODS

Between October 2020 and April 2021, samples were collected as dried blood spots among 188 participants who showed malaria positivity with a histidine-rich-protein-based rapid diagnostic test (RDT). Nested PCR assays were used to confirm falciparum in the samples with RDT positivity, and to amplify fragments of the Pfdhfr/Pfdhps genes followed by targeted amplicon sequencing. Published data since 2007 on the prevalence of the Pfdhps genotypes in Nigeria and the neighbouring countries were used to produce maps to show the distribution of the mutant genotypes.

RESULTS

Only 74 and 61 samples were successfully amplified for the Pfdhfr and Pfdhps genes, respectively. At codons resulting in N51I, C59R, and S108N, Pfdhfr carried mutant alleles of 97.3% (72/74), 97.3% (72/74) and 98.6% (73/74), respectively. The Pfdhps gene carried mutations at codons resulting in amino acid changes at 431-436-437-540-581-613; I431V [45.9%, (28/61)], A581G [31.1% (19/61)] and A613S [49.2% (30/61)]. Constructed haplotypes were mainly the triple Pfdhfr mutant 51I-59R-108N (95.9%), and the most common haplotypes observed for the Pfdhps gene were the ISGKAA (32.8%), ISGKGS (8.2%), VAGKAA (14.8%), VAGKAS (9.8%) and VAGKGS (14.8%). In the context of the previously published data, a high prevalence of 431V/581G mutations was found in the study population. It seems quite evident that the Pfdhps 431V, 581G and 613S often co-occur as Pfdhps-VAGKGS haplotype.

CONCLUSION

This study showed that the prevalence of VAGKGS haplotype seems to be increasing in prevalence. If this is similar in effect to the emergence of 581G in East Africa, the efficacy of SP-IPTp in the presence of these novel Pfdhps mutants should be re-assessed.

Detecting temporal and spatial malaria patterns from first antenatal care visits

Pregnant women attending first antenatal care (ANC) visits represent a promising malaria surveillance target in Sub-Saharan Africa. Here we assessed the spatio-temporal relationship between malaria at ANC (n=6,471), in children at the community(n=9,362) and at health facilities (n=15,467) in southern Mozambique (2016-2019). ANC P. falciparum rates detected by quantitative polymerase chain reaction mirrored rates in children, regardless of gravidity and HIV status (Pearson correlation coefficient [PCC]>0.8, χ²<1.1), with a 2-3 months lag. Only at rapid diagnostic test detection limits at moderate-to-high transmission, multigravidae showed lower rates than children (PCC=0.61, 95%CI[-0.12-0.94]). Seroprevalence against the pregnancy-specific antigen VAR2CSA reflected declining malaria trends (PCC=0.74, 95%CI[0.24-0.77]). 80% (12/15) of hotspots detected from health facility data using a novel hotspot detector, EpiFRIenDs, were also identified with ANC data. The results show that ANC-based malaria surveillance offers contemporary information on temporal trends and the geographic distribution of malaria burden in the community.

Can helminth and malaria infections affect sex ratio at birth in sub-Saharan Africa? Ideas and hypothesis

The sex ratio (ratio of boys to girls) at birth (SRB) is about 1.05 (about 105 males to 100 females) under normal conditions and could be an indicator for monitoring demographic changes. Generally, in comparison with female fetuses, the male fetus is biologically weaker and more vulnerable to prenatal events. SRB is influenced by various factors, such as maternal malnourishment. Remarkably, maternal malnourishment and less energy intake are pivotal factors for declining SRB in humans. As estimates, the SRB is below the normal range in sub-Saharan Africa (1.03) than the normal range (1.05). On the other hand, both malaria and helminth infections are hyperendemic in sub-Saharan Africa and both diseases are associated with maternal malnourishment. Hence, an important question arises, could declining SRB in sub-Saharan Africa be influenced by malaria and helminth infections? Cumulative evidence suggests that malaria and helminth infections could influence SRB by induction of maternal malnourishment. This hypothesis provides new ideas about the variation of SRB in some regions of the world where helminths and malaria are endemic.

Impact of long lasting insecticidal nets on asymptomatic malaria during pregnancy, in a rural and urban setting in Cameroon

According to the world malaria report more malaria cases were reported in 2020 than in 2019, due to disruptions in the distribution of insecticide treated nets, caused by the COVID-19 pandemic. Consequently a projected 34.32% (11.6 million out of 33.8 million) pregnancies were exposed to malaria in the WHO African Region in 2020. This study was therefore designed to assess the impact of long lasting insecticidal nets (LLINs) on asymptomatic malaria in the pregnant women attending the Foumbot District Hospital (rural setting) and the Bamenda Regional Hospital (urban setting). This was a hospital based cross-sectional study done within three months from February to April 2021. A structured questionnaire and the CareStart™ Pf Malaria HRP2 qualitative rapid diagnostic test were used for data collection. Data were analysed using descriptive statistics, and Chi-square test. The relative risk, attributable risk, odds ratio, and likelihood ratio of malaria occurrence in exposed patients were determined by Chi-square (and Fisher's exact) test. The prevalence of asymptomatic malaria was 10.14% (63/621), with a higher prevalence among the pregnant women in the rural setting (12.21%; 37/303), than the urban setting (8.18%; 26/318). As indicated by the attributable risk, 21% of malaria incidence was attributed to absence of LLINs distribution in neighborhoods of the rural setting meanwhile 10% of malaria incidence is attributed to absence of LLINs distribution in neighborhoods of the urban setting. Regular screening for asymptomatic malaria in pregnancy and consistent free distribution of LLINs are recommended in endemic areas, especially in the rural settings.

Malaria Parasite Classification Framework using a Novel Channel Squeezed and Boosted CNN

Malaria is a life-threatening infection that infects the red blood cells (RBCs) that gradually grows throughout the body. The plasmodium parasite is caused by a female anopheles mosquito bite and severely affects numerous individuals within the world every year. Therefore, early detection tests are required to predict infected parasitic cells. The proposed technique exploits deep convolutional neural network (CNN) learning capability to detect the thin-blood smear parasitic patients from healthy individuals. In this regard, the detection is accomplished using a novel STM-SB-RENet block-based CNN that employs the idea of split-transform-merge (STM) and channel Squeezing-Boosting (SB) in a modified fashion. In this connection, a new convolutional block-based STM is developed, which systematically implements region and edge operations to explore the parasitic malaria pattern related to region-homogeneity, structural obstruction, and boundary-defining features. Moreover, the diverse boosted feature maps are achieved by incorporating the new channel SB and Transfer Learning (TL) idea in each STM block at abstract, intermediate, and target levels to capture minor contrast and texture variation between parasitic and normal artifacts. The malaria input images to the proposed models are initially transformed using discrete wavelet transform to generate enhanced and reduced feature space. The proposed architectures are validated using hold-out cross-validation on the National Institute of Health Malaria dataset. The proposed methods outperform the train from scratch, and TL-based fine-tuned existing techniques. The considerable performance (accuracy: 97.98%, sensitivity: 0.988, F-score: 0.980, and AUC: 0.996) of STM-SB-RENet suggests that it can be utilized to screen parasitic malaria patients.

Prevalence of Pregnancy Associated Malaria in India

Malaria in pregnancy is a major public health concern. It results in impaired maternal health and adversely effects fetal and perinatal outcomes. The present systematic review was conducted to assess the prevalence, distribution and adverse pregnancy outcomes in malaria infected females in India. A comprehensive search and review of PubMed and Web of Science based on PRISMA guidelines was carried out to find articles reporting prevalence of malaria in pregnant women from India. Data from 16 studies were analyzed and prevalence of malaria among pregnant women in India was found to be 11.4 % (95 % CI: 7.3, 16.3). Prevalence of malaria among asymptomatic and symptomatic pregnant women was found to be 10.62% (95% CI: 6.05, 16.23) and 13.13% (95% CI: 7.2, 20.52), respectively. P. falciparum and P. vivax were both reported with in the same population. The geospatial distribution of malaria in pregnancy spanned over nine very populous states of India. The review also reported severe maternal and perinatal outcomes. Given the seriousness of malaria in pregnant women and its effects on the fetus and new-born, a stringent district wise guideline for early detection and prophylaxis in regions identified in this review will help in its better control.

Re-orienting anti-malarial drug development to better serve pregnant women

Malaria is one of the most serious infectious diseases affecting predominantly low- and middle-income countries, where pregnant women are among the populations at risk. There are limited options to prevent or treat malaria in pregnancy, particularly in the first trimester, and existing ones may not work optimally in areas where the threat of drug resistance is rising. As malaria elimination is a key goal of the global health community, the inclusion of pregnant women in the adult population to protect from malaria will be key to achieving success. New, safe, and effective options are needed but it can take decades of evidence-gathering before a medicine is recommended for use in pregnancy. This is because pregnant women are typically not included in pre-registration clinical trials due to fear of causing harm. Data to support dosing and safety in pregnancy are subsequently collected in post-licensure studies. There have been growing calls in recent years that this practice needs to change, amplified by the COVID-19 pandemic and increasing public awareness that newly developed medicines generally cannot be administered to pregnant women from the onset. The development of new anti-malarials should ensure that data informing their use in pregnancy and breastfeeding are available earlier. To achieve this, a mindset change and a different approach to medications for pregnant women are needed. Changes in non-clinical, translational, and clinical approaches in the drug development pathway, in line with recent recommendations from the regulatory bodies are proposed in this Comment. The new approach applies to any malaria-endemic region, regardless of the type of Plasmodium responsible for malaria cases. By incorporating intentional and systematic data collection from pre-registration stages of development through post-licensure, it will be possible to inform on the benefit/risk balance of a new anti-malarial earlier and help ensure that the needs of pregnant individuals are addressed in a more timely and equitable manner in the future.

Diagnosis of malaria in pregnancy: accuracy of CareStart™ malaria Pf/PAN against light microscopy among symptomatic pregnant women at the Central Hospital in Yaoundé, Cameroon

Background

The need to start treatment early for pregnant women who present with clinical features of malaria usually conflicts with the need to confirm diagnosis by microscopy (MP) before treatment, due to delays in obtaining results. Parasite sequestration in the placenta is also a problem. Rapid diagnostic tests (RDT), which detect soluble antigens, are a valuable alternative. The objective of this study was to evaluate pretreatment parasite prevalence by microscopy and by RDT and to assess the accuracy of RDT with MP as reference.

Methods

A prospective cross-sectional study was carried out at the obstetrical unit of the Central Hospital in Yaoundé, during the period January-August 2015. Consenting patients with symptoms of suspected malaria in pregnancy were recruited and a blood sample taken for MP and RDT before treatment was started. The estimates of diagnostic performance (with 95% confidence interval) were calculated in OpenEpi online software using the Wilson’s score. The agreement, as reflected by the Cohen’s kappa, was calculated and interpreted using known intervals.

Results

The results showed that, out of the 104 patients recruited, 69.2% (95%CI: 59.1–77.5) were MP positive while 77.94% (95%CI: 63.1–80.9) were RDT positive. The sensitivity of the malaria RDT was 91.67% (95%CI: 83.69–96.77) while the specificity was 53.13% (95%CI: 31.39–65.57). The diagnostic accuracy of the RDT with MP as reference was 79.81% (95%CI: 70.0–86.1). All cases were due to Plasmodium falciparum. A Cohen’s kappa of 0.45 (95%CI: 0.26–0.64) was obtained, consistent with a moderate agreement between the tests.

Conclusions

The diagnostic accuracy of the CareStart™ malaria Pf/PAN compared to microscopy was high, but not as desirable, with a false negative RDT at very high parasitaemia. In tertiary facilities, RDTs appear to provide a better diagnostic solution compared to microscopy. However, future studies with larger sample sizes should make this observation more generalizable; as missing a case could have serious consequences on pregnancy outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04109-6.

Performance and utility of more highly sensitive malaria rapid diagnostic tests

Background

A new more highly sensitive rapid diagnostic test (HS-RDT) for Plasmodium falciparum malaria (Alere™/Abbott Malaria Ag P.f RDT [05FK140], now called NxTek™ Eliminate Malaria Ag Pf) was launched in 2017. The test has already been used in many research studies in a wide range of geographies and use cases.

Methods

In this study, we collate all published and available unpublished studies that use the HS-RDT and assess its performance in (i) prevalence surveys, (ii) clinical diagnosis, (iii) screening pregnant women, and (iv) active case detection. Two individual-level data sets from asymptomatic populations are used to fit logistic regression models to estimate the probability of HS-RDT positivity based on histidine-rich protein 2 (HRP2) concentration and parasite density. The performance of the HS-RDT in prevalence surveys is estimated by calculating the sensitivity and positive proportion in comparison to polymerase chain reaction (PCR) and conventional malaria RDTs.

Results

We find that across 18 studies, in prevalence surveys, the mean sensitivity of the HS-RDT is estimated to be 56.1% (95% confidence interval [CI] 46.9–65.4%) compared to 44.3% (95% CI 32.6–56.0%) for a conventional RDT (co-RDT) when using nucleic acid amplification techniques as the reference standard. In studies where prevalence was estimated using both the HS-RDT and a co-RDT, we found that prevalence was on average 46% higher using a HS-RDT compared to a co-RDT. For use in clinical diagnosis and screening pregnant women, the HS-RDT was not significantly more sensitive than a co-RDT.

Conclusions

Overall, the evidence presented here suggests that the HS-RDT is more sensitive in asymptomatic populations and could provide a marginal improvement in clinical diagnosis and screening pregnant women. Although the HS-RDT has limited temperature stability and shelf-life claims compared to co-RDTs, there is no evidence to suggest, given this test has the same cost as current RDTs, it would have any negative impacts in terms of malaria misdiagnosis if it were widely used in all four population groups explored here.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-07023-5.

Synthesis and antiplasmodial activity of regioisomers and epimers of second-generation dual acting ivermectin hybrids

With its strong effect on vector-borne diseases, and insecticidal effect on mosquito vectors of malaria, inhibition of sporogonic and blood-stage development of Plasmodium falciparum, as well as in vitro and in vivo impairment of the P. berghei development inside hepatocytes, ivermectin (IVM) continues to represent an antimalarial therapeutic worthy of investigation. The in vitro activity of the first-generation IVM hybrids synthesized by appending the IVM macrolide with heterocyclic and organometallic antimalarial pharmacophores, against the blood-stage and liver-stage infections by Plasmodium parasites prompted us to design second-generation molecular hybrids of IVM. Here, a structural modification of IVM to produce novel molecular hybrids by using sub-structures of 4- and 8-aminoquinolines, the time-tested antiplasmodial agents used for treating the blood and hepatic stage of Plasmodium infections, respectively, is presented. Successful isolation of regioisomers and epimers has been demonstrated, and the evaluation of their in vitro antiplasmodial activity against both the blood stages of P. falciparum and the hepatic stages of P. berghei have been undertaken. These compounds displayed structure-dependent antiplasmodial activity, in the nM range, which was more potent than that of IVM, its aglycon or primaquine, highlighting the superiority of this hybridization strategy in designing new antiplasmodial agents.

OUP accepted manuscript

BACKGROUND

Insecticide-treated net (ITN) use is among the most recommended strategies to prevent malaria in pregnancy. We analysed the regional and socio-economic patterns of ITN use among pregnant women in Kenya using data from the 2003, 2008 and 2014 Kenyan Demographic and Health Surveys (KDHSs).

METHODS

Inequality was assessed using four dimensions: economic status, education, place of residence and region. Both relative and absolute summary measures were applied. In addition, simple and complex summary measures, i.e. difference, population attributable fraction, population attributable risk and ratio were considered based on the number of subgroups in each variable.

RESULTS

There was overt inequality in the use of ITNs among pregnant women, with greater use among the better-off group in 2003 and 2014. Greater ITN use was also observed among pregnant women with a higher level of education. Pregnant women from urban settings tended to use ITNs (slept under a net the night before the survey) more than their rural counterparts in the 2003 KDHS. There were significant regional variations across the three surveys in all inequality summary measures, except ratio in the 2014 survey.

CONCLUSIONS

Significant inequality in ITN use among pregnant women was observed at a macro scale.

Malaria and curable sexually transmitted and reproductive tract coinfection among pregnant women in rural Burkina Faso

Background

Malaria and sexually transmitted/reproductive tract infections (STI/RTI) are leading and preventable causes of low birthweight in sub-Saharan Africa. Reducing their impact on pregnancy outcomes requires efficient interventions that can be easily integrated into the antenatal care package. The paucity of data on malaria and STI/RTI coinfection, however, limits efforts to control these infections. This study aimed to determine the prevalence and associated factors of malaria and STI/RTI coinfection among pregnant women in rural Burkina Faso.

Methods

A cross-sectional survey was conducted among 402 pregnant women attending antenatal clinics at the Yako health district. Sociodemographic and behavioral data were collected, and pregnant women were tested for peripheral malaria by microscopy. Hemoglobin levels were also measured by spectrophotometry and curable bacterial STI/RTI were tested on cervico-vaginal swabs using rapid diagnostic test for chlamydia and syphilis, and Gram staining for bacterial vaginosis. A multivariate logistic regression model was used to assess the association of malaria and STI/RTI coinfection with the characteristics of included pregnant women.

Results

The prevalence of malaria and at least one STI/RTI coinfection was 12.9% (95% confidence interval, CI: [9.8–16.7]), malaria and bacterial vaginosis coinfection was 12.2% (95% CI: [9.3–15.9]), malaria and chlamydial coinfection was 1.6% (95% CI: [0.6–3.8]). No coinfection was reported for malaria and syphilis. The individual prevalence was 17.2%, 7.2%, 0.6%, 67.7% and 73.3%, respectively, for malaria infection, chlamydia, syphilis, bacterial vaginosis and STI/RTI combination. Only 10% of coinfections were symptomatic, and thus, 90% of women with coinfection would have been missed by the symptoms-based diagnostic approach. In the multivariate analysis, the first pregnancy (aOR = 2.4 [95% CI: 1.2–4.7]) was the only factor significantly associated with malaria and STI/RTI coinfection. Clinical symptoms were not associated with malaria and STI/RTI coinfection.

Conclusion

The prevalence of malaria and curable STI/RTI coinfection was high among pregnant women. The poor performance of the clinical symptoms to predict coinfection suggests that alternative interventions are needed.