Malaria in pregnancy: challenges for control and the need for urgent action

Safety and efficacy of dihydroartemisinin-piperaquine for intermittent preventive treatment of malaria in pregnant women with HIV from Gabon and Mozambique: a randomised, double-blind, placebo-controlled trial

BACKGROUND

The cornerstone of malaria prevention in pregnancy, intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine, is contraindicated in women with HIV who are receiving co-trimoxazole prophylaxis. We assessed whether IPTp with dihydroartemisinin-piperaquine is safe and effective in reducing the risk of malaria infection in women with HIV receiving co-trimoxazole prophylaxis and antiretroviral drugs.

METHODS

For this randomised, double-blind, placebo-controlled clinical trial, women with HIV attending the first antenatal care clinic visit, resident in the study area, and with a gestational age up to 28 weeks were enrolled at five sites in Gabon and Mozambique. Participants were randomly assigned (1:1) to receive either IPTp with dihydroartemisinin-piperaquine at each scheduled antenatal care visit plus daily co-trimoxazole (intervention group) or placebo at each scheduled antenatal care visit plus daily co-trimoxazole (control group). Randomisation was done centrally via block randomisation (block sizes of eight), stratified by country. IPTp was given over 3 days under direct observation by masked study personnel. The number of daily IPTp tablets was based on bodyweight and according to the treatment guidelines set by WHO (target dose of 4 mg/kg per day [range 2-10 mg/kg per day] of dihydroartemisinin and 18 mg/kg per day [range 16-27 mg/kg per day] of piperaquine given once a day for 3 days). At enrolment, all participants received co-trimoxazole (fixed combination drug containing 800 mg trimethoprim and 160 mg sulfamethoxazole) for daily intake. The primary study outcome was prevalence of peripheral parasitaemia detected by microscopy at delivery. The modified intention-to-treat population included all randomly assigned women who had data for the primary outcome. Secondary outcomes included frequency of adverse events, incidence of clinical malaria during pregnancy, and frequency of poor pregnancy outcomes. All study personnel, investigators, outcome assessors, data analysts, and participants were masked to treatment assignment. This study is registered with ClinicalTrials.gov, NCT03671109.

FINDINGS

From Sept 18, 2019, to Nov 26, 2021, 666 women (mean age 28·5 years [SD 6·4]) were enrolled and randomly assigned to the intervention (n=332) and control (n=334) groups. 294 women in the intervention group and 308 women in the control group had peripheral blood samples taken at delivery and were included in the primary analysis. Peripheral parasitaemia at delivery was detected in one (<1%) of 294 women in the intervention group and none of 308 women in the control group. The incidence of clinical malaria during pregnancy was lower in the intervention group than in the control group (one episode in the intervention group vs six in the control group; relative risk [RR] 0·12, 95% CI 0·03-0·52, p=0·045). In a post-hoc analysis, the composite outcome of overall malaria infection (detected by any diagnostic test during pregnancy or delivery) was lower in the intervention group than in the control group (14 [5%] of 311 women vs 31 [10%] of 320 women; RR 0·48, 95% CI 0·27-0·84, p=0·010). The frequency of serious adverse events and poor pregnancy outcomes (such as miscarriages, stillbirths, premature births, and congenital malformations) did not differ between groups. The most frequently reported drug-related adverse events were gastrointestinal disorder (reported in less than 4% of participants) and headache (reported in less than 2% of participants), with no differences between study groups.

INTERPRETATION

In the context of low malaria transmission, the addition of IPTp with dihydroartemisinin-piperaquine to co-trimoxazole prophylaxis in pregnant women with HIV did not reduce peripheral parasitaemia at delivery. However, the intervention was safe and associated with a decreased risk of clinical malaria and overall Plasmodium falciparum infection, so it should be considered as a strategy to protect pregnant women with HIV from malaria.

FUNDING

European and Developing Countries Clinical Trials Partnership 2 (EDCTP2) and Medicines for Malaria Venture.

TRANSLATIONS

For the Portuguese and French translations of the abstract see Supplementary Materials section.

A comprehensive approach to optimizing malaria prevention in pregnant women: evaluating the efficacy, cost-effectiveness, and resistance of IPTp-SP and IPTp-DP

Malaria during pregnancy is a major global health concern, with approximately 10,000 pregnant women dying from malaria-related anaemia each year. The World Health Organization has suggested intermittent preventive treatment with sulphadoxine-pyrimethamine (IPTp-SP) to avert malaria infection in pregnant women in malaria-endemic areas, but this intermittent preventive (IP) treatment is at risk of becoming ineffective due to parasite resistance and the contraindication in HIV-infected women. This paper argues that alternative IP treatments such as dihydroartemisinin-piperaquine (DP) should be explored, alongside the urgent need to investigate antimalarial cycling strategies. Additionally, the cost-effectiveness of IPTp-DP should be evaluated, as well as potential barriers to IP treatment such as medication stockouts, late attendance at antenatal clinics, lack of autonomy and freedom among women, and lack of knowledge about malaria prevention. Health education focusing on malaria prevention should be incorporated into routine antenatal care programmes to improve patient compliance. A comprehensive approach that includes the administration of IPTp-DP alone along with other measures such as insecticide-treated nets and medical education is the key to addressing the devastating effects of malaria infection in pregnant women.

Insecticide-treated net utilization and associated factors among pregnant women in Ethiopia: a systematic review and meta-analysis

Background

Malaria is a major public health problem in many developing countries, particularly in sub-Saharan Africa. The pregnant woman, fetus, and newborn infant are all at risk from malaria during pregnancy. Hence, insecticide-treated bed net (ITN) use is the most effective and advisable method for preventing malaria during pregnancy. Studies on the prevalence of ITN utilization among pregnant women in Ethiopia are inconsistently reported and highly varied. Therefore, this systematic review and meta-analysis aimed to estimate the pooled prevalence of ITN utilization and associated factors among pregnant women in Ethiopia.

Methods

A comprehensive search of databases such as PubMed, CINAHL, Web of Science, SCOPUS, Science Direct, Google, and Google Scholar was performed to find studies conducted in Ethiopia. All original observational studies that reported the prevalence of ITN utilization were identified and screened. The Newcastle-Ottawa scale tool was used to assess the quality of the studies. Data were extracted in Microsoft Excel 2010 format and analyzed using STATA Version 14. A random-effect meta-analysis model was utilized to estimate the pooled prevalence of ITN utilization. The statistical heterogeneity was checked using the I2 test and subgroup analysis. The publication bias was assessed using funnel plots and Egger's regression test. The size of the pooled effect of the factors influencing the use of ITNs was estimated using an odds ratio (OR) with a 95% confidence interval (CI), and a P-value <0.05 was considered statistically significant.

Results

Twenty-nine cross-sectional studies with 13,957 study participants were included in this meta-analysis. The overall pooled prevalence of ITN utilization among pregnant women in Ethiopia was 51% (95% CI: 43-60). A statistically significant heterogeneity was observed across studies (I2 = 99.09%; P < 0.001). Being literate [OR = 2.93 (95% CI: 2.14-4.01)], rural residence [OR = 1.76 (95% CI: 1.37-2.26)], and having knowledge of ITN [OR = 4.13 (95% CI: 1.57-10.81)] were factors significantly associated with ITN utilization among pregnant women.

Conclusion

The utilization of ITNs among pregnant women was substantially lower than the national target, alarmingly highlighting the need for urgent and effective interventions. Maternal education status, place of residence, and knowledge of ITNs were independent predictors of ITN utilization. Health policymakers and programmers should design and implement the most effective strategies to scale up the utilization of ITNs by pregnant women and reduce malaria-related morbidity during pregnancy.

Systematic Review Registration

CRD42022304432.

Prevention of malaria in pregnancy

Malaria remains one of the most preventable causes of adverse birth outcomes. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine is used to prevent malaria, but resistance to this drug combination has decreased its efficacy and new alternatives are needed. In Africa, a meta-analysis showed three-course or monthly IPTp with sulfadoxine-pyrimethamine to be safe and more effective than the original two-course sulfadoxine-pyrimethamine strategy, prompting WHO to update its policy in 2012. Although resistance to sulfadoxine-pyrimethamine reduces the parasitological efficacy of IPTp, this drug combination remains associated with reduced incidence of low birthweight in areas where prevalence of parasites with quintuple Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) mutations is greater than 90%. Nevertheless, its effectiveness is compromised in women infected with sextuple mutant parasites. Six trials of IPTp showed that neither amodiaquine, mefloquine, nor chloroquine-azithromycin are suitable replacements for sulfadoxine-pyrimethamine because of poor tolerability. Furthermore, four trials showed that intermittent screening and treatment with the current generation of malaria rapid diagnostic tests was not a suitable alternative strategy to IPTp with sulfadoxine-pyrimethamine, even in areas with high prevalence of quintuple mutations. Two trials showed that IPTp with dihydroartemisinin-piperaquine was well tolerated, effective, and acceptable for IPTp, with monthly regimens being the most effective. Coverage of IPTp and insecticide-treated nets continues to lag behind targets. The key barriers to uptake are well documented, and many are open to intervention. Outside of Africa, a single trial suggests a potential role for integrated approaches that combine sulfadoxine-pyrimethamine with azithromycin for IPTp in areas of Papua New Guinea where malaria transmission is high. Modelling analysis suggests the importance of the prevention of malaria early in pregnancy and the need to protect pregnant women declines more slowly than the rate at which transmission declines. Improved funding has led to an increase in the number of prevention trials in the past decade, showing the value of more sustained protection with monthly IPTp regimens. There is a need for confirmatory trials of the safety, efficacy, and feasibility of IPTp with dihydroartemisinin-piperaquine, for studies of intermittent screening and treatment with more sensitive rapid diagnostic tests, for studies of integrated strategies for malaria and other co-infections, and for studies of prevention strategies for malaria in pregnant women who are HIV-positive and living outside of Africa. Additional research is required on how to improve uptake of WHO's updated policy on IPTp with sulfadoxine-pyrimethamine and insecticide-treated nets.

Low Utilization of Insecticide-Treated Bed Net among Pregnant Women in the Middle Belt of Ghana

Background

Malaria in pregnancy leads to low birth weight, premature birth, anaemia, and maternal and neonatal mortality. Use of insecticide-treated nets (ITNs) during pregnancy is one of the proven interventions to reduce the malaria burden. However, Ghana has not achieved its target for ITN use among pregnant women.

Methods

A qualitative study was conducted in seven communities purposively selected from the middle belt of Ghana. Participants who had delivered in the six months prior to this study were selected. In all, seven focus group discussions and twenty-four in-depth interviews were conducted between June and August 2010.

Results

Respondents knew of the importance of ITNs and other malaria-preventive strategies. Factors such as financial access and missed opportunities of free distribution denied some pregnant women the opportunity to own or use an ITN. Reasons for not using ITNs during pregnancy included discomfort resulting from heat, smell of the net, and difficulty in hanging the net. Participants maintained their ITNs by preventing holes in the nets, retreatment, and infrequent washing.

Conclusion

Pregnant women know about the causes and prevention of malaria. However, this knowledge is not transformed into practice due to lack of access to ITNs and sleeping discomforts among other logistical constraints.

Vitamin A and Zinc Supplementation Among Pregnant Women to Prevent Placental Malaria: A Randomized, Double-Blind, Placebo-Controlled Trial in Tanzania

AbstractVitamin A and zinc are important for immune function and may improve host defense against malaria and reduce the risk of adverse pregnancy outcomes. Our objective was to determine whether daily oral supplementation with either or both nutrients starting in the first trimester reduces the risk of placental malaria and adverse pregnancy outcomes. We undertook a randomized, double-blind placebo-controlled trial with a factorial design among 2,500 human immunodeficiency virus-negative primigravid or secundigravid pregnant women in their first trimester of pregnancy in Dar es Salaam, Tanzania. We randomly allocated equal numbers of participants to 2,500 IU of vitamin A, 25 mg of zinc, both 2,500 IU of vitamin A and 25 mg of zinc, or a placebo until delivery. A total of 625 participants were allocated to each treatment group. Our primary outcome, placental malaria infection (past or current), was assessed in all randomized participants for whom placental samples were obtained at delivery (N = 1,404), which represents 56% of total participants and 62% of all pregnancies lasting 28 weeks or longer (N = 2,266). Birth outcomes were obtained for 2,434 of the 2,500 randomized participants. Secondary outcomes included small for gestational age (SGA) births and prematurity. All analyses were intent to treat. Those who received zinc had a lower risk of histopathology-positive placental malaria compared with those who did not receive zinc (risk ratio = 0.64, 95% confidence interval = 0.44, 0.91), but neither nutrient had an effect on polymerase chain reaction-positive malaria, SGA, or prematurity. No safety concerns were identified. We recommend additional studies in other geographic locations to confirm these findings.

Prevention and control of malaria in pregnancy - new threats, new opportunities?

INTRODUCTION

Over 100 million women and their babies are at risk of malaria in pregnancy each year. Malaria prevention in pregnancy relies on long-lasting insecticidal nets (LLINs), and, in Africa, intermittent preventive treatment in pregnancy (IPTp). Increasing resistance of malaria parasites to sulfadoxine-pyrimethamine, the only drug endorsed for IPTp, and increasing mosquito resistance to pyrethroids used in LLINs, threaten the efficacy of these proven strategies, while operational challenges restrict their implementation in areas of great need. Areas Covered: This review summarizes strategies for malaria prevention in pregnancy (both currently used and those undergoing preclinical and clinical evaluation), primarily drawing on publications and study protocols from the last decade. Challenges associated with each strategy are discussed, including the particular problem of HIV and malaria in pregnancy, and areas of further research are highlighted. Expert Commentary: Alternative drugs for IPTp are needed. Dihydroartemisinin-piperaquine is particularly promising, but requires further evaluation, and might contribute to artemisinin resistance. Intermittent screening and treatment in pregnancy (ISTp) is an alternative to IPTp that could reduce unnecessary antenatal drug exposure and resistance risk, but it is not recommended with current, insensitive screening tests. Optimal strategies for areas of low or declining malaria transmission remain to be determined.

Impact of interventions on malaria in internally displaced persons along the China-Myanmar border: 2011-2014

BACKGROUND

Internally displaced persons (IDP) represent vulnerable populations whose public health conditions merit special attention. In the China-Myanmar border area, human movement and resettlements of IDP can influence malaria transmission. Comparison of disease incidence and vector densities between IDP camps and surrounding local villages allows for better understanding of current epidemiology and to evaluate the effectiveness of interventions in the region.

METHODS

Malaria and vector surveillance was conducted in three IDP camps and three local villages neighbouring the camps along the China-Myanmar border in Myanmar. Clinical malaria cases were collected from seven hospitals/clinics from April 2011 to December 2014. Malaria vector population dynamics were monitored using CDC light traps. The use of malaria preventive measures and information on aid agencies and their activities was obtained through questionnaire surveys.

RESULTS

Malaria was confirmed in 1832 patients. Of these cases, 85.4 % were Plasmodium vivax and 11.4 % were Plasmodium falciparum malaria. Annual malaria incidence rates were 38.8 and 127.0 cases/1000 person year in IDP camps and local villages, respectively. Older children of 5-14 years had the highest incidence rate in the camps regardless of gender, while male adults had significantly higher incidence rates than females in local villages and females child-bearing age had significantly lower risk to malaria in IDP camps compare to local villages. Seasonal malaria outbreaks were observed both in the IDP camps and in the local villages from May to August 2013. The proportion of P. vivax remained unchanged in local villages but increased by approximately tenfold in IDP camps from 2011 to 2014. Anopheles vector density was tenfold higher in local villages compared to IDP camps (2.0:0.2 females/trap/night). Over 99 % of households in both communities owned bed nets. While long-lasting insecticidal nets accounted for 61 % of nets used in IDPs, nearly all residents of local villages owned regular nets without insecticide-impregnation. There were more active aid agencies in the camps than in local villages.

CONCLUSION

Malaria in IDP camps was significantly lower than the surrounding villages through effective control management. The observation of P. vivax outbreaks in the study area highlights the need for increased control efforts. Expansion of malaria intervention strategies in IDP camps to local surrounding villages is critical to malaria control in the border area.

Congenital and perinatally-acquired infections in resource-constrained settings

INTRODUCTION

Congenital and perinatal infections are a leading cause of neonatal and infant morbidity and mortality. Maternal screening, vaccines or treatment where available, constitute effective prevention strategies to reduce the burden of these diseases. Data on the burden of congenital and perinatal infections are very limited for low and middle-income regions.

AREAS COVERED

This review aims to summarize the burden of congenital and perinatal infections and the main challenges for their control in resource-limited settings. Articles were identified through the main electronic databases and cover the period 1971-2016. Expert commentary: Estimates from low and middle-income countries indicate that the burden of congenital infections may be higher in these regions than in industrialized countries. As preventive and curative strategies are available to tackle some of these infections, efforts at the international and national levels must be made to implement those and thus reduce their burden in resource-limited countries.

A Public Health Paradox: The Women Most Vulnerable to Malaria Are the Least Protected

Raquel Gonzalez and colleagues highlight an urgent need to evaluate antimalarials that can be safely administered to HIV-infected pregnant women on antiretroviral treatment and cotrimoxazole prophylaxis.