Adverse effects of falciparum and vivax malaria and the safety of antimalarial treatment in early pregnancy: a population-based study

Pharmacovigilance in Pregnancy Studies, Exposures and Outcomes Ascertainment, and Findings from Low- and Middle-Income Countries: A Scoping Review

INTRODUCTION

Pharmacovigilance (PV), or the ongoing safety monitoring after a medication has been licensed, plays a crucial role in pregnancy, as clinical trials often exclude pregnant people. It is important to understand how pregnancy PV projects operate in low- and middle-income countries (LMICs), where there is a disproportionate lack of PV data yet a high burden of adverse pregnancy outcomes. We conducted a scoping review to assess how exposures and outcomes were measured in recently published pregnancy PV projects in LMICs.

METHODS

We utilized a search string, secondary review, and team knowledge to review publications focusing on therapeutic or vaccine exposures among pregnant people in LMICs. We screened abstracts for relevance before conducting a full text review, and documented measurements of exposures and outcomes (categorized as maternal, birth, or neonatal/infant) among other factors, including study topic, setting, and design, comparator groups, and funding sources.

RESULTS

We identified 31 PV publications spanning at least 24 LMICs, all focusing on therapeutics or vaccines for infectious diseases, including HIV (n = 17), tuberculosis (TB; n = 9), malaria (n = 7), pertussis, tetanus, and diphtheria (n = 1), and influenza (n = 3). As for outcomes, n = 15, n = 31, and n = 20 of the publications covered maternal, birth, and neonatal/infant outcomes, respectively. Among HIV-specific publications, the primary exposure-outcome relationship of focus was exposure to maternal antiretroviral therapy and adverse outcomes. For TB-specific publications, the main exposures of interest were second-line drug-resistant TB and isoniazid-based prevention therapeutics for pregnant people living with HIV. For malaria-specific publications, the primary exposure-outcome relationship of interest was antimalarial medication exposure during pregnancy and adverse outcomes. Among vaccine-focused publications, the exposure was assessed during a specific time during pregnancy, with an overall interest in vaccine safety and/or efficacy. The study settings were frequently from Africa, designs varied from cohort or cross-sectional studies to clinical trials, and funding sources were largely from high-income countries.

CONCLUSION

The published pregnancy PV projects were largely centered in Africa and concerned with infectious diseases. This may reflect the disease burden in LMICs but also funding priorities from high-income countries. As the prevalence of non-communicable diseases increases in LMICs, PV projects will have to broaden their scope. Birth and neonatal/infant outcomes were most reported, with fewer reporting on maternal outcomes and none on longer-term child outcomes; additionally, heterogeneity existed in definitions and ascertainment of specific measures. Notably, almost all projects covered a single therapeutic exposure, missing an opportunity to leverage their projects to cover additional exposures, add scientific rigor, create uniformity across health services, and bolster existing health systems. For many publications, the timing of exposure, specifically by trimester, was crucial to maternal and neonatal safety. While currently published pregnancy PV literature offer insights into the PV landscape in LMICs, further work is needed to standardize definitions and measurements, integrate PV projects across health services, and establish longer-term monitoring.

Associations of Plasmodium and Intestinal Helminth Infections with Maternal Anemia and Adverse Pregnancy Outcomes in Northwest Ethiopia

Malaria and intestinal helminth infections are significant public health challenges in Ethiopia. However, little is known about the relationship of Plasmodium and intestinal helminth infections in pregnancy with maternal anemia and adverse pregnancy outcomes. A health-facility-based cross-sectional study was conducted among 526 parturients in northwest Ethiopia to investigate the associations of these parasitic infections with anemia and adverse pregnancy outcomes. Maternal and newborn profiles were collected using questionnaires and checklists. Maternal hematocrit was determined using the micro-hematocrit method. Malaria was diagnosed by microscopy, rapid diagnostic tests, and quantitative polymerase chain reaction, whereas intestinal parasites were detected microscopically using stool wet mount and Kato-Katz preparations. Among the women, 38.6% were anemic, and 36.5% had adverse pregnancy outcomes. Single infections of hookworm (adjusted odds ratio [aOR] = 3.11, 95% CI: 1.64-5.87) in pregnancy were associated with anemia at parturiency, whereas malaria single infections were associated with anemia (aOR = 4.28, 95% CI: 2.17-8.23) and adverse pregnancy outcomes (aOR = 2.94, 95% CI: 1.47-5.91). Moreover, intestinal helminth coinfections in pregnancy were associated with anemia (aOR = 13.3, 95% CI: 4.8-36.8), whereas malaria-helminth coinfections were associated with anemia (aOR = 7.47, 95% CI: 3.71-15.04) and adverse pregnancies (aOR = 4.75, 95% CI: 2.36-9.57). Overall, the study showed that Plasmodium and intestinal helminth infections in pregnancy are associated with anemia and adverse pregnancy outcomes. Thus, strengthening malaria and intestinal parasite infection prevention and control practices in pregnancy is warranted to alleviate the burden of anemia and adverse pregnancy outcomes.

Structure-based design of a Plasmodium vivax Duffy-binding protein immunogen focuses the antibody response to functional epitopes

The Duffy-binding protein (DBP) is a promising antigen for a malaria vaccine that would protect against clinical symptoms caused by Plasmodium vivax infection. Region II of DBP (DBP-II) contains the receptor-binding domain that engages host red blood cells, but DBP-II vaccines elicit many non-neutralizing antibodies that bind distal to the receptor-binding surface. Here, we engineered a truncated DBP-II immunogen that focuses the immune response to the receptor-binding surface. This immunogen contains the receptor-binding subdomain S1S2 and lacks the immunodominant subdomain S3. Structure-based computational design of S1S2 identified combinatorial amino acid changes that stabilized the isolated S1S2 without perturbing neutralizing epitopes. This immunogen elicited DBP-II-specific antibodies in immunized mice that were significantly enriched for blocking activity compared to the native DBP-II antigen. This generalizable design process successfully stabilized an integral core fragment of a protein and focused the immune response to desired epitopes to create a promising new antigen for malaria vaccine development.

First malaria in pregnancy followed in Philippine real-world setting: proof-of-concept of probabilistic record linkage between disease surveillance and hospital administrative data

BACKGROUND

Although the Philippines targets malaria elimination by 2030, it remains to be a disease that causes considerable morbidity in provinces that report malaria. Pregnant women residing in endemic areas are a vulnerable population, because in addition to the risk of developing severe malaria, their pregnancy is not followed through, and the outcome of their pregnancy is unknown. This study determined the utility of real-world data integrated with disease surveillance data set as real-world evidence of pregnancy and delivery outcomes in areas endemic for malaria in the Philippines.

METHODS

For the period of 2015 to 2019, electronic data sets of malaria surveillance data and Ospital ng Palawan hospital admission log of pregnant women residing in the four selected barangays of Rizal, Palawan were merged using probabilistic linkage. The source data for record linkage were first and last names, birth date, and address as the mutual variable. The data used for characteristics of the pregnant women from the hospital data set were admission date, discharge date, admitting and final diagnosis and body weight on admission. From the malaria surveillance data these were date of consultation, and malaria parasite species. The Levenshtein distance formula was used for a fuzzy string-matching algorithm. Chi-square test, and Mann-Whitney U test were used to compare the means of the two data sets.

RESULTS

The prevalence of pregnant women admitted to the tertiary referral hospital, Ospital ng Palawan, was estimated to be 8.34/100 overall, and 11.64/100 from the four study barangays; that of malaria during pregnancy patients was 3.45/100 and 2.64/100, respectively. There was only one true-positive matched case from 238 women from the hospital and 54 women from the surveillance data sets. The overall Levenshstein score was 97.7; for non-matched cases, the mean overall score was 36.6 (35.6-37.7). The matched case was a minor who was hospitalized for severe malaria. The outcome of her pregnancy was detected from neither data set but from village-based records.

CONCLUSIONS

This proof-of-concept study demonstrated that probabilistic record linkage could match real-world data in the Philippines with further validation required. The study underscored the need for more integrated and comprehensive database to monitor disease intervention impact on pregnancy and its outcome in the Philippines.

Pathogenicity and virulence of malaria: Sticky problems and tricky solutions

Infections with Plasmodium falciparum and Plasmodium vivax cause over 600,000 deaths each year, concentrated in Africa and in young children, but much of the world's population remain at risk of infection. In this article, we review the latest developments in the immunogenicity and pathogenesis of malaria, with a particular focus on P. falciparum, the leading malaria killer. Pathogenic factors include parasite-derived toxins and variant surface antigens on infected erythrocytes that mediate sequestration in the deep vasculature. Host response to parasite toxins and to variant antigens is an important determinant of disease severity. Understanding how parasites sequester, and how antibody to variant antigens could prevent sequestration, may lead to new approaches to treat and prevent disease. Difficulties in malaria diagnosis, drug resistance, and specific challenges of treating P. vivax pose challenges to malaria elimination, but vaccines and other preventive strategies may offer improved disease control.

The effect and control of malaria in pregnancy and lactating women in the Asia-Pacific region

Half of all pregnancies at risk of malaria worldwide occur in the Asia-Pacific region, where Plasmodium falciparum and Plasmodium vivax co-exist. Despite substantial reductions in transmission, malaria remains an important cause of adverse health outcomes for mothers and offspring, including pre-eclampsia. Malaria transmission is heterogeneous, and infections are commonly subpatent and asymptomatic. High-grade antimalarial resistance poses a formidable challenge to malaria control in pregnancy in the region. Intermittent preventive treatment in pregnancy reduces infection risk in meso-endemic New Guinea, whereas screen-and-treat strategies will require more sensitive point-of-care tests to control malaria in pregnancy. In the first trimester, artemether-lumefantrine is approved, and safety data are accumulating for other artemisinin-based combinations. Safety of novel antimalarials to treat artemisinin-resistant P falciparum during pregnancy, and of 8-aminoquinolines during lactation, needs to be established. A more systematic approach to the prevention of malaria in pregnancy in the Asia-Pacific is required.

Designing an effective malaria vaccine targeting Plasmodium vivax Duffy-binding protein

Malaria caused by the Plasmodium vivax parasite is a major global health burden. Immunity against blood-stage infection reduces parasitemia and disease severity. Duffy-binding protein (DBP) is the primary parasite protein responsible for the invasion of red blood cells and it is a leading subunit vaccine candidate. An effective vaccine, however, is still lacking despite decades of interest in DBP as a vaccine candidate. This review discusses the reasons for targeting DBP, the challenges associated with developing a vaccine, and modern structural vaccinology methods that could be used to create an effective DBP vaccine. Next-generation DBP vaccines have the potential to elicit a broadly protective immune response and provide durable and potent protection from P. vivax malaria.

Prevalence and proportion estimate of asymptomatic Plasmodium infection in Asia: a systematic review and meta-analysis

Asymptomatic Plasmodium infection raises a problem for the persistent transmission of malaria in low-endemic areas such as Asia. This systematic review was undertaken to estimate the prevalence and proportion of asymptomatic Plasmodium infection in Asia. The systematic review was registered at PROSPERO (ID: CRD42022373664). The research followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A comprehensive search of five databases, Ovid, Scopus, MEDLINE, PubMed, and Embase, was conducted to identify studies of asymptomatic Plasmodium infection in Asian countries. The pooled prevalence of asymptomatic Plasmodium infection, the pooled proportion of asymptomatic Plasmodium infection among all parasitised individuals, and the associated 95% confidence intervals were estimated using a random-effects model. A total of 916 articles were retrieved, and 87 articles that met the criteria were included in the systematic review. The pooled prevalence of asymptomatic Plasmodium infection among enrolled participants in Southeast Asia, South Asia, and Western Asia was 5.8%, 9.4%, and 8.4%, respectively. The pooled proportion of asymptomatic Plasmodium infection among all parasitised individuals in Southeast Asia, South Asia, and Western Asia was 89.3%, 87.2%, and 64.8%, respectively. There was a low prevalence of asymptomatic Plasmodium infection, but there was a high proportion of asymptomatic Plasmodium infection per all parasitised individuals in different parts of Asia. These results may support and facilitate elimination and control programs for asymptomatic Plasmodium infection in Asia.

Genetic diversity of Plasmodium vivax isolates from pregnant women in the Western Brazilian Amazon: a prospective cohort study

Background

Each year, 92 million pregnant women are at risk of contracting malaria during pregnancy, with the underestimation of the mortality and morbidity burden associated with Plasmodium vivax. During pregnancy, P. vivax infection is associated with low birth weight, maternal anaemia, premature delivery, and stillbirth. In the State of Acre (Brazil), high transmission leaves pregnant women at greater risk of contracting malaria and having a greater number of recurrences. The study of genetic diversity and the association of haplotypes with adverse pregnancy effects is of great importance for the control of the disease. Here we investigate the genetic diversity of P. vivax parasites infecting pregnant women across their pregnancies.

Methods

P. vivax DNA was extracted from 330 samples from 177 women followed during pregnancy, collected in the State of Acre, Brazil. All samples were negative for Plasmodium falciparum DNA. Sequence data for the Pvmsp1 gene was analysed alongside data from six microsatellite (MS) markers. Allelic frequencies, haplotype frequencies, expected heterozygosity (HE) were calculated. Whole genome sequencing (WGS) was conducted on four samples from pregnant women and phylogenetic analysis performed with other samples from South American regions.

Findings

Initially, the pregnant women were stratified into two groups-1 recurrence and 2 or more recurrences-in which no differences were observed in clinical gestational outcomes or in placental histological changes between the two groups. Then we evaluated the parasites genetically. An average of 18.5 distinct alleles were found at each of the MS loci, and the HE calculated for each marker indicates a high genetic diversity occurring within the population. There was a high percentage of polyclonal infections (61.7%, 108/175), and one haplotype (H1) occurred frequently (20%), with only 9 of the haplotypes appearing in more than one patient.

Interpretation

Most pregnant women had polyclonal infections that could be the result of relapses and/or re-infections. The high percentage of H1 parasites, along with the low frequency of many other haplotypes are suggestive of a clonal expansion. Phylogenetic analysis shows that P. vivax population within pregnant women clustered with other Brazilian samples in the region.

Funding

FAPESP and CNPq - Brazil.

Pregnancy outcomes in a malaria-exposed Malian cohort of women of child-bearing age

In Sub-Saharan Africa, malaria continues to be associated with adverse pregnancy outcomes including stillbirth, early neonatal death, preterm delivery, and low birth weight. Current preventive measures are insufficient and new interventions are urgently needed. However, before such interventions can be tested in pregnant women, background information on pregnancy outcomes in this target population must be collected. We conducted an observational study in Ouélessébougou, Mali, a malaria-endemic area where first antenatal visit commonly occurs during the second trimester of pregnancy, hindering calculation of miscarriage rate in the population. To accurately determine the rate of miscarriage, 799 non-pregnant women of child-bearing age were enrolled and surveyed via monthly follow up visits that included pregnancy tests. Out of 505 women that completed the study, 364 became pregnant and 358 pregnancies were analyzed: 43 (12%) resulted in miscarriage, 28 (65.1%) occurred during the first trimester of pregnancy. We also determined rates of stillbirth, neonatal death, preterm delivery, and small for gestational age. The results showed high rate of miscarriage during the first trimester and established a basis to evaluate new interventions to prevent pregnancy malaria. This survey design enabled identification of first trimester miscarriages that are often missed by studies conducted in antenatal clinics.

Clinical trial registration

[https://clinicaltrials.gov/], identifier [NCT0297 4608].

Safety of Treating Malaria with Artemisinin-Based Combination Therapy in the First Trimester of Pregnancy

There have been recent calls for the use of artemisinin-based combination therapies (ACTs) for uncomplicated malaria in the first trimester of pregnancy. Nevertheless, the 2021 WHO Guidelines for Malaria reaffirmed their position that there is not adequate clinical safety data on artemisinins to support that usage. The WHO's position is consistent with several issues with the existing clinical data. First, first trimester safety results from multiple ACTs were lumped in a meta-analysis which does not demonstrate that each of the included ACTs is equally safe. Second, safety results from all periods of the first trimester were lumped in the meta-analysis which does not demonstrate the same level of safety for all subperiods, particularly gestational Weeks 6 to 8 which is likely to be the most sensitive period. Third, even if there is evidence of a lack of an effect on miscarriage for a particular ACT, it does not follow then there are no developmental effects for any ACT. In monkeys, artesunate caused marked embryonal anemia leading to embryo death but the long-term consequences of lower levels of embryonal anemia are not known. Fourth, there have been advances in the sensitivity and usage of rapid diagnostic tests that will lead to diagnoses of malaria earlier in gestation which is less well studied and more likely sensitive to artemisinins. Any clinical studies of the safety of ACTs in the first trimester need to evaluate the results of treatment with individual ACTs during different 1- to 2-week periods of the first trimester.

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.

A novel murine model of post-implantation malaria-induced preterm birth

Despite major advances made in malaria treatment and control over recent decades, the development of new models for studying disease pathogenesis remains a vital part of malaria research efforts. The study of malaria infection during pregnancy is particularly reliant on mouse models, as a means of circumventing many challenges and costs associated with pregnancy studies in endemic human populations. Here, we introduce a novel murine model that will further our understanding of how malaria infection affects pregnancy outcome. When C57BL/6J (B6) mice are infected with Plasmodium chabaudi chabaudi AS on either embryonic day (E) 6.5, 8.5, or 10.5, preterm birth occurs in all animals by E16.5, E17.5, or E18.5 respectively, with no evidence of intrauterine growth restriction. Despite having the same outcome, we found that the time to delivery, placental inflammatory and antioxidant transcript upregulation, and the relationships between parasitemia and transcript expression prior to preterm birth differed based on the embryonic day of infection. On the day before preterm delivery, E6.5 infected mice did not experience significant upregulation of the inflammatory or antioxidant gene transcripts examined; however, peripheral and placental parasitemia correlated positively with Il1β, Cox1, Cat, and Hmox1 placental transcript abundance. E8.5 infected mice had elevated transcripts for Ifnγ, Tnf, Il10, Cox1, Cox2, Sod1, Sod2, Cat, and Nrf2, while Sod3 was the only transcript that correlated with parasitemia. Finally, E10.5 infected mice had elevated transcripts for Ifnγ only, with a tendency for Tnf transcripts to correlate with peripheral parasitemia. Tumor necrosis factor deficient (TNF-/-) and TNF receptor 1 deficient (TNFR1-/-) mice infected on E8.5 experienced preterm birth at the same time as B6 controls. Further characterization of this model is necessary to discover the mechanism(s) and/or trigger(s) responsible for malaria-driven preterm birth caused by maternal infection during early pregnancy.

Clinical impact of vivax malaria: A collection review

BACKGROUND

Plasmodium vivax infects an estimated 7 million people every year. Previously, vivax malaria was perceived as a benign condition, particularly when compared to falciparum malaria. Reports of the severe clinical impacts of vivax malaria have been increasing over the last decade.

METHODS AND FINDINGS

We describe the main clinical impacts of vivax malaria, incorporating a rapid systematic review of severe disease with meta-analysis of data from studies with clearly defined denominators, stratified by hospitalization status. Severe anemia is a serious consequence of relapsing infections in children in endemic areas, in whom vivax malaria causes increased morbidity and mortality and impaired school performance. P. vivax infection in pregnancy is associated with maternal anemia, prematurity, fetal loss, and low birth weight. More than 11,658 patients with severe vivax malaria have been reported since 1929, with 15,954 manifestations of severe malaria, of which only 7,157 (45%) conformed to the World Health Organization (WHO) diagnostic criteria. Out of 423 articles, 311 (74%) were published since 2010. In a random-effects meta-analysis of 85 studies, 68 of which were in hospitalized patients with vivax malaria, we estimated the proportion of patients with WHO-defined severe disease as 0.7% [95% confidence interval (CI) 0.19% to 2.57%] in all patients with vivax malaria and 7.11% [95% CI 4.30% to 11.55%] in hospitalized patients. We estimated the mortality from vivax malaria as 0.01% [95% CI 0.00% to 0.07%] in all patients and 0.56% [95% CI 0.35% to 0.92%] in hospital settings. WHO-defined cerebral, respiratory, and renal severe complications were generally estimated to occur in fewer than 0.5% patients in all included studies. Limitations of this review include the observational nature and small size of most of the studies of severe vivax malaria, high heterogeneity of included studies which were predominantly in hospitalized patients (who were therefore more likely to be severely unwell), and high risk of bias including small study effects.

CONCLUSIONS

Young children and pregnant women are particularly vulnerable to adverse clinical impacts of vivax malaria, and preventing infections and relapse in this groups is a priority. Substantial evidence of severe presentations of vivax malaria has accrued over the last 10 years, but reporting is inconsistent. There are major knowledge gaps, for example, limited understanding of the underlying pathophysiology and the reason for the heterogenous geographical distribution of reported complications. An adapted case definition of severe vivax malaria would facilitate surveillance and future research to better understand this condition.

Peripheral Plasmodium falciparum Infection in Early Pregnancy Is Associated With Increased Maternal Microchimerism in the Offspring

BACKGROUND

Placental malaria has been associated with increased cord blood maternal microchimerism (MMc), which in turn may affect susceptibility to malaria in the offspring. We sought to determine the impact of maternal peripheral Plasmodium falciparum parasitemia during pregnancy on MMc and to determine whether maternal cells expand during primary parasitemia in the offspring.

METHODS

We conducted a nested cohort study of maternal-infant pairs from a prior pregnancy malaria chemoprevention study. Maternal microchimerism was measured by quantitative polymerase chain reaction targeting a maternal-specific marker in genomic DNA from cord blood, first P falciparum parasitemia, and preparasitemia. Logistic and negative binomial regression were used to assess the impact of maternal peripheral parasitemia, symptomatic malaria, and placental malaria on cord blood MMc. Generalized estimating equations were used to assess predictors of MMc during infancy.

RESULTS

Early maternal parasitemia was associated with increased detection of cord blood MMc (adjusted odds ratio = 3.91, P = .03), whereas late parasitemia, symptomatic malaria, and placental malaria were not. The first parasitemia episode in the infant was not associated with increased MMc relative to preparasitemia.

CONCLUSIONS

Maternal parasitemia early in pregnancy may increase the amount of MMc acquired by the fetus. Future work should investigate the impact of this MMc on immune responses in the offspring.

Efficacy and Safety of Artemisinin-Based Combination Therapy for the Treatment of Uncomplicated Malaria in Pregnant Women: A Systematic Review and Meta-Analysis

Introduction

Malaria is one of the infectious diseases with substantial risks for pregnant women, the fetus and the newborn child. Thus, prevention and treatment of malaria with safe and effective drugs is of paramount importance. Pregnant women are mostly excluded from clinical trials, and systematic approaches of pharmacovigilance in pregnancy are limited. This means the safety and efficacy of antimalarial agents during pregnancy are unclear.

Purpose

This study was designed to carry out a systematic review and aggregate data meta-analysis of literature published on efficacy and safety of artemisinin-based combination therapy (ACT) for uncomplicated malaria in pregnant women.

Methods

A search of literature published between 1998 to 2020 on efficacy and safety of artemisinin-based combination therapy (ACT) in pregnant women was made using Cochrane Library, Medline and the Malaria in Pregnancy Consortium Library. Data were extracted independently by two reviewers, and any discrepancies were resolved by consensus. Meta-analysis was carried out using Open Meta-Analyst software. Random effects model was applied, and the heterogeneity of studies was evaluated using Higgins I².

Results

Twenty-four studies that fulfilled the inclusion criteria were included in the final assessment. Overall, days 28 to 63 malaria treatment success rate was 96.1%. Overall days 28 to 63 cure rates for AL, AS+AQ, AS+MQ, DHA+PQ, AS+ATQ+PG and AS+SP were 95.1%, 92.2%, 97.0%,94.3%, 96.5% and 97.4%, respectively. Comparison of ACTs with non-ACTs revealed that the risk of treatment failure was substantially lower in patients treated with ACTs than with non-ACTs (risk ratio 0.20, 95% C.I. 0.09–0.43). The overall prevalences of miscarriage, stillbirth and congenital anomalies were 0.3%, 2.1% and 1.0%, respectively, and found to be comparable among various ACTs. There was comparable tolerability across ACTs during pregnancy.

Conclusion

ACTs demonstrated a high cure rate, safety and tolerability against Plasmodium falciparum infection in pregnant women. The higher treatment success and comparable tolerability could be used as an input for decision makers to support the continued usage of ACTs for treatment of uncomplicated falciparum malaria in pregnant women.

Clinical management of Plasmodium knowlesi malaria

The zoonotic parasite Plasmodium knowlesi has emerged as an important cause of human malaria in parts of Southeast Asia. The parasite is indistinguishable by microscopy from the more benign P. malariae, but can result in high parasitaemias with multiorgan failure, and deaths have been reported. Recognition of severe knowlesi malaria, and prompt initiation of effective therapy is therefore essential to prevent adverse outcomes. Here we review all studies reporting treatment of uncomplicated and severe knowlesi malaria. We report that although chloroquine is effective for the treatment of uncomplicated knowlesi malaria, artemisinin combination treatment is associated with faster parasite clearance times and lower rates of anaemia during follow-up, and should be considered the treatment of choice, particularly given the risk of administering chloroquine to drug-resistant P. vivax or P. falciparum misdiagnosed as P. knowlesi malaria in co-endemic areas. For severe knowlesi malaria, intravenous artesunate has been shown to be highly effective and associated with reduced case-fatality rates, and should be commenced without delay. Regular paracetamol may also be considered for patients with severe knowlesi malaria or for those with acute kidney injury, to attenuate the renal damage resulting from haemolysis-induced lipid peroxidation.

Basic Research of Plasmodium vivax Biology Enabling Its Management as a Clinical and Public Health Problem

The emerging understanding of Plasmodium vivax as an infection seated in extravascular spaces of its human host carries fundamentally important implications for its management as a complex clinical and public health problem. This progress begins to reverse decades of neglected research borne of the false dogma of P. vivax as an intrinsically benign and inconsequential parasite. This Review provides real world context for the on-going laboratory explorations of the molecular and cellular events in the life of this parasite. Chemotherapies against the latent reservoir impose extraordinarily complex and difficult problems of science and medicine, but great strides in studies of the biology of hepatic P. vivax promise solutions. Fundamental assumptions regarding the interpretation of parasitaemia in epidemiology, clinical medicine, and public health are being revisited and reassessed in light of new studies of P. vivax cellular/molecular biology and pathogenesis. By examining these long overlooked complexities of P. vivax malaria, we open multiple new avenues to vaccination, chemoprevention, countermeasures against transmission, epidemiology, diagnosis, chemotherapy, and clinical management. This Review expresses how clarity of vision of biology and pathogenesis may rationally and radically transform the multiple means by which we may combat this insidiously harmful infection.

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

Background

Malaria infections in the first trimester of pregnancy are frequent and deleterious for both mother and child health. To investigate if these early infections are newly acquired or already present in the host, we assessed whether parasites detected before pregnancy and those detected in early pregnancy are the same infection.

Methods

We used data from the preconceptional “RECIPAL” study (Benin, 2014–2017). Sixty-three pregnant women of 411 included who had a malaria infection detected by quantitative polymerase chain reaction both before pregnancy and at the first antenatal care (ANC) visit were selected for this study. Two highly polymorphic markers, msp-2 and glurp, and a fragment-analysis method were used to enumerate the Plasmodium falciparum genotypes and to quantify their proportions within isolates. An infection was considered as persistent when identical msp-2 and glurp genotypes were found in the corresponding prepregnancy and early-pregnancy samples.

Results

The median time between the 2 malaria screenings was 3 months. The median gestational age at the first ANC visit was 6.4 weeks. Most infections before pregnancy were submicroscopic infections. Based on both msp-2 and glurp genotyping, the infection was similar before and in early pregnancy in 46% (29/63) of cases.

Conclusions

Almost half of P. falciparum infections detected in the first trimester originate before pregnancy. Protecting young women from malaria infection before pregnancy might reduce the prevalence of malaria in early pregnancy and its related poor maternal and birth outcomes.

Does hydroxychloroquine still have any role in the COVID-19 pandemic?

Introduction: The 4-aminoquinolines, chloroquine, and hydroxychloroquine have been used for over 70 years for malaria and rheumatological conditions, respectively. Their broad-spectrum antiviral activity, excellent safety profile, tolerability, low cost, and ready availability made them prime repurposing therapeutic candidates at the beginning of the COVID-19 pandemic.Areas covered: Here, the authors discuss the history of hydroxychloroquine and chloroquine, the in vitro data which led to their widespread repurposing and adoption in COVID-19 and their complex pharmacokinetics. The evidence for the use of these drugs is assessed through in vivo animal experiments and the wealth of conflicting data and interpretations published during COVID-19, including the more informative results from randomized controlled trials (RCTs). The safety aspects of these drugs, in particular cardiotoxicity, are then reviewed.Expert opinion: The evidence from clinical trials in COVID-19 supports the well-established safety record of the 4-aminoquinolines at currently recommended dosage. In hospitalized patients with severe COVID-19 RCTs show clearly that the 4-aminoquinolines are not beneficial. The only treatments with proven benefit at this stage of infection are immunomodulators (dexamethasone, IL-6 receptor antagonists). No antiviral drugs have proven life-saving in late-stage COVID-19.

Safety profile of treatments administered in COVID 19 infection in pregnant women

SARS-CoV-2 infection has unexpectedly arrived in our society. In pregnant women, the situation has been similar to general population. Some drugs have been used empirically, and obstetricians have to consider whether the same treatments used in the general population were valid for pregnant women with severe disease, according to their safety profile for both the mother and the fetus. There has been a wide experience with the use of hydroxychloroquine and lopinavir/ritonavir in pregnant women. Tocilizumab and interferon beta could be used if benefits exceed risks. There is no experience using remdesivir in pregnancy.

A randomized controlled trial of dihydroartemisinin-piperaquine, artesunate-mefloquine and extended artemether-lumefantrine treatments for malaria in pregnancy on the Thailand-Myanmar border

BACKGROUND

Artemisinin and artemisinin-based combination therapy (ACT) partner drug resistance in Plasmodium falciparum have spread across the Greater Mekong Subregion compromising antimalarial treatment. The current 3-day artemether-lumefantrine regimen has been associated with high treatment failure rates in pregnant women. Although ACTs are recommended for treating Plasmodium vivax malaria, no clinical trials in pregnancy have been reported.

METHODS

Pregnant women with uncomplicated malaria on the Thailand-Myanmar border participated in an open-label randomized controlled trial comparing dihydroartemisinin-piperaquine (DP), artesunate-mefloquine (ASMQ) and a 4-day artemether-lumefantrine regimen (AL+). The primary endpoint for P. falciparum infections was the PCR-corrected cure rate and for P. vivax infections was recurrent parasitaemia, before delivery or day 63, whichever was longer, assessed by Kaplan-Meier estimate.

RESULTS

Between February 2010 and August 2016, 511 pregnant women with malaria (353 P. vivax, 142 P. falciparum, 15 co-infections, 1 Plasmodium malariae) were randomized to either DP (n=170), ASMQ (n=169) or AL+ (n=172) treatments. Successful malaria elimination efforts in the region resulted in premature termination of the trial. The majority of women had recurrent malaria (mainly P. vivax relapses, which are not prevented by these treatments). Recurrence-free proportions (95% confidence interval [95% CI]) for vivax malaria were 20.6% (5.1-43.4) for DP (n=125), 46.0% (30.9-60.0) for ASMQ (n=117) and 28.7% (10.0-50.8) for AL+ (n=126). DP and ASMQ provided longer recurrence-free intervals. PCR-corrected cure rates (95% CI) for falciparum malaria were 93.7% (81.6-97.9) for DP (n=49), 79.6% (66.1-88.1) for AMSQ (n=55) and 87.5% (74.3-94.2) for AL+ (n=50). Overall 65% (85/130) of P. falciparum infections had Pfkelch13 propeller mutations which increased over time and recrudescence occurred almost exclusively in them; risk ratio 9.42 (95% CI 1.30-68.29). Among the women with falciparum malaria, 24.0% (95% CI 16.8-33.6) had P. vivax parasitaemia within 4 months. Nausea, vomiting, dizziness and sleep disturbance were more frequent with ASMQ. Miscarriage, small-for-gestational-age and preterm birth did not differ significantly among the treatment groups, including first trimester exposures (n=46).

CONCLUSIONS

DP was well tolerated and safe, and was the only drug providing satisfactory efficacy for P. falciparum-infected pregnant woman in this area of widespread artemisinin resistance. Vivax malaria recurrences are very common and warrant chloroquine prophylaxis after antimalarial treatment in this area.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01054248 , registered on 22 January 2010.

Falciparum but not vivax malaria increases the risk of hypertensive disorders of pregnancy in women followed prospectively from the first trimester

BACKGROUND

Malaria and hypertensive disorders of pregnancy (HDoP) affect millions of pregnancies worldwide, particularly those of young, first-time mothers. Small case-control studies suggest a positive association between falciparum malaria and risk of pre-eclampsia but large prospective analyses are lacking.

METHODS

We characterized the relationship between malaria in pregnancy and the development of HDoP in a large, prospectively followed cohort. Pregnant women living along the Thailand-Myanmar border, an area of low seasonal malaria transmission, were followed at antenatal clinics between 1986 and 2016. The relationships between falciparum and vivax malaria during pregnancy and the odds of gestational hypertension, pre-eclampsia, or eclampsia were examined using logistic regression amongst all women and then stratified by gravidity.

RESULTS

There were 23,262 singleton pregnancies in women who presented during the first trimester and were followed fortnightly. Falciparum malaria was associated with gestational hypertension amongst multigravidae (adjusted odds ratio (AOR) 2.59, 95%CI 1.59-4.23), whereas amongst primigravidae, it was associated with the combined outcome of pre-eclampsia/eclampsia (AOR 2.61, 95%CI 1.01-6.79). In contrast, there was no association between vivax malaria and HDoP.

CONCLUSIONS

Falciparum but not vivax malaria during pregnancy is associated with hypertensive disorders of pregnancy.

Neurobehavioral, neurochemical and synaptic plasticity perturbations during postnatal life of rats exposed to chloroquine in-utero

Despite reports that quinoline antimalarials including chloroquine (Chq) exhibit idiosyncratic neuropsychiatric effects even at low doses, the drug continues to be in widespread use during pregnancy. Surprisingly, very few studies have examined the potential neurotoxic action of Chq exposure at different points of gestation or how this phenomenon may affect neurophysiological well-being in later life. We therefore studied behavior, and the expression of specific genes and neurochemicals modulating crucial neural processes in offspring of rats exposed to prophylactic dose of Chq during different stages of gestation. Pregnant rats were injected 5 mg/kg/day (3 times) of Chq either during early- (first week), mid- (second week), late- (third week), or throughout- (all weeks) gestation, while controls received PBS injection. Behavioral characterization of offspring between postnatal days 15-20 in the open field, Y-maze, elevated plus and elevated zero mazes revealed that Chq evoked anxiogenic responses and perturbed spatial memory in rats, although locomotor activity was generally unaltered. In the prefrontal cortex (PFC), hippocampus and cerebellum of rats prenatally exposed to Chq, RT-qPCR analysis revealed decreased mRNA expression of presynaptic marker synaptophysin, which was accompanied by downregulation of postsynaptic marker PSD95. Synaptic marker PICK1 expression was also downregulated in the hippocampus but was unperturbed in the PFC and cerebellum. In addition to recorded SOD downregulation in cortical and hippocampal lysates, induction of oxidative stress in rats prenatally exposed to Chq was corroborated by lipid peroxidation as evinced by increased MDA levels. Offspring of rats infused with Chq at mid-gestation and weekly treatment throughout gestation were particularly susceptible to neurotoxic changes, especially in the hippocampus. Interestingly, Chq did not cause histopathological changes in any of the brain areas. Taken together, our findings causally link intrauterine exposure to Chq with postnatal behavioral impairment and neurotoxic changes in rats.

Malaria infection is common and associated with perinatal mortality and preterm delivery despite widespread use of chemoprevention in Mali: an observational study 2010 to 2014

BACKGROUND

In malaria-endemic areas, pregnant women and especially first-time mothers are more susceptible to Plasmodium falciparum. Malaria diagnosis is often missed during pregnancy, since many women with placental malaria remain asymptomatic or have submicroscopic parasitemia, masking the association between malaria and pregnancy outcomes Severe maternal anemia and low birthweight deliveries are well-established sequelae, but few studies have confirmed the relationship between malaria infection and severe outcomes like perinatal mortality in high transmission zones.

METHODS

Pregnant women of any gestational age enrolled at antenatal clinic into a longitudinal cohort study in Ouelessebougou, Mali, an area of high seasonal malaria transmission. Follow-up visits included scheduled and unscheduled visits throughout pregnancy. Blood smear microscopy and PCR analysis were employed to detect both microscopic and submicroscopic infections, respectively. Intermittent preventative treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) was documented and prompt treatment regardless of symptoms given upon malaria diagnosis.

RESULTS

Of the 1850 women followed through delivery, 72.6% of women received 2 or more IPTp-SP doses, 67.2% of women experienced at least one infection between enrollment up to and including delivery. Malaria infection increased the risks of stillbirth (adjusted-hazard ratio (aHR) 3.87, 95%CI 1.18-12.71) and preterm delivery (aHR 2.41, 95%CI 1.35-4.29) in primigravidae, and early neonatal death (death within 7 days) in secundigravidae and multigravidae (HR 6.30, 95%CI 1.41-28.15).

CONCLUSIONS

Malaria treatment after diagnosis, alongside IPTp-SP, is insufficient to prevent malaria-related stillbirth, early neonatal death and PTD. While IPTp-SP was beneficial in Mali during the study period, new tools are needed to improve pregnancy outcomes.

Taking on Plasmodium vivax malaria: A timely and important challenge

Lorenz von Seidlein and Nicholas White introduce a Collection on Plasmodium vivax malaria.

Reduced birth weight caused by sextuple drug resistant Plasmodium falciparum infection in early 2nd trimester

Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps, particularly the sextuple mutant haplotype threatens the antimalarial effectiveness of sulfadoxine-pyrimethamine as intermittent preventive treatment during pregnancy (IPTp). To explore the impact of sextuple mutant haplotype infections on outcome measures after provision of IPTp-SP, we monitored birth outcomes in women followed from prior to conception or from the first trimester until delivery. Women infected with sextuple haplotypes in early 2 nd trimester specifically, delivered newborns with a lower birth weight (-267g, 95% CI -454; -59, p=0·01) compared to women who did not have malaria during pregnancy and women infected with less SP resistant haplotypes (-461g, 95% CI -877; -44, p=0·03). Thus, sextuple haplotype infections seems to impact the effectiveness of SP for IPTp and directly impact birth outcome by lowering birth weight. Close monitoring and targeted malaria control during early pregnancy is therefore crucial to improve birth outcomes.

Impact of Babesia microti infection on the initiation and course of pregnancy in BALB/c mice

Background

Protozoa in the genus Babesia are transmitted to humans through tick bites and cause babesiosis, a malaria-like illness. Vertical transmission of Babesia spp. has been reported in mammals; however, the exact timing and mechanisms involved are not currently known. The aims of this study were to evaluate the success of vertical transmission of B. microti in female mice infected before pregnancy (mated during the acute or chronic phases of Babesia infection) and that of pregnant mice infected during early and advanced pregnancy; to evaluate the possible influence of pregnancy on the course of parasite infections (parasitaemia); and to assess pathological changes induced by parasitic infection.

Methods

The first set of experiments involved two groups of female mice infected with B. microti before mating, and inseminated on the 7th day and after the 40th day post infection. A second set of experiments involved female mice infected with B. microti during pregnancy, on the 4th and 12th days of pregnancy. Blood smears and PCR targeting the 559 bp 18S rRNA gene fragment were used for the detection of B. microti. Pathology was assessed histologically.

Results

Successful development of pregnancy was recorded only in females mated during the chronic phase of infection. The success of vertical transmission of B. microti in this group was 63%. No evidence of pregnancy was found in females mated during the acute phase of infection or on the 4th day of pregnancy. In the group infected on the 12th day of pregnancy, numerous complications including loss of pregnancy and stillbirths were recorded. During the acute phase of infection, parasitaemia was lower in pregnant females in comparison to infected, non-pregnant control females.

Conclusions

Acute B. microti infection prevents the initiation of pregnancy and embryonic development if it occurs during the first trimester, and causes severe complications in foetal BALB/c mice in the second and third trimesters of pregnancy. Chronic B. microti infection has no detrimental impact on the initiation and development of pregnancy, but results in congenital infection of the offspring. Further study is required to determine the extent to which maternal anti-babesial immune responses contribute to compromise pregnancy in the murine model of congenital Babesia infection.

Drug treatment and prevention of malaria in pregnancy: a critical review of the guidelines

Background

Malaria caused by Plasmodium falciparum in pregnancy can result in adverse maternal and fetal sequelae. This review evaluated the adherence of the national guidelines drawn from World Health Organization (WHO) regions, Africa, Eastern Mediterranean, Southeast Asia, and Western Pacific, to the WHO recommendations on drug treatment and prevention of chloroquine-resistant falciparum malaria in pregnant women.

Methods

Thirty-five updated national guidelines and the President’s Malaria Initiative (PMI), available in English language, were reviewed. The primary outcome measures were the first-line anti-malarial treatment protocols adopted by national guidelines for uncomplicated and complicated falciparum malaria infections in early (first) and late (second and third) trimesters of pregnancy. The strategy of intermittent preventive treatment of malaria in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) was also addressed.

Results

This review evaluated the treatment and prevention of falciparum malaria in pregnancy in 35 national guidelines/PMI-Malaria Operational Plans (MOP) reports out of 95 malaria-endemic countries. Of the 35 national guidelines, 10 (28.6%) recommend oral quinine plus clindamycin as first-line treatment for uncomplicated malaria in the first trimester. As the first-line option, artemether–lumefantrine, an artemisinin-based combination therapy, is adopted by 26 (74.3%) of the guidelines for treating uncomplicated or complicated malaria in the second and third trimesters. Intravenous artesunate is approved by 18 (51.4%) and 31 (88.6%) guidelines for treating complicated malaria during early and late pregnancy, respectively. Of the 23 national guidelines that recommend IPTp-SP strategy, 8 (34.8%) are not explicit about directly observed therapy requirements, and three-quarters, 17 (73.9%), do not specify contra-indication of SP in human immunodeficiency virus (HIV)-infected pregnant women receiving cotrimoxazole prophylaxis. Most of the guidelines (18/23; 78.3%) state the recommended folic acid dose.

Conclusion

Several national guidelines and PMI reports require update revisions to harmonize with international guidelines and emergent trends in managing falciparum malaria in pregnancy. National guidelines and those of donor agencies should comply with those of WHO guideline recommendations although local conditions and delayed guideline updates may call for deviations from WHO evidence-based guidelines.

Improving malaria preventive practices and pregnancy outcomes through a health education intervention: A randomized controlled trial

BACKGROUND

The prevalence of malaria in pregnancy and its complications, remain very high in Nigeria. This study aimed to determine the effects of a malaria health educational intervention based on the information-motivation-behavioural skills (IMB) model on malaria preventive practices and pregnancy outcomes.

METHODS

The study was a randomized controlled parallel-group study, where 372 randomly selected antenatal care attendees were randomly assigned to one of either two groups after collecting baseline data. The intervention group then received a four-hour health education intervention in Hausa language, which was developed based on the IMB model, while the control group received a similarly designed health education on breastfeeding. Follow up data were then collected from the participants at a first (2 months post-intervention) and second (4 months post-intervention) follow up, and at the end of their pregnancies.

RESULTS

For both groups, reported ITN use had increased from baseline (Intervention: Often-14.0%, Almost always-9.1; Control: Often-12.4%; Almost always 16.1%) to the time of second follow up (Intervention: Often -28.10%, Almost always-24.5; Control: Often-17.2%; Almost always 19.5%). Reported IPTp uptake at second follow up was also higher for the intervention group (Intervention: Two doses-59.0%, Three doses 22.3%; Control group: Two doses-48.4%, Three doses-7.0%). The drop in the haematocrit levels was greater for the control group (32.42% to 30.63%) compared to the intervention group (33.09% to 31.93%). The Generalized Linear Mixed Models (GLMM) analysis revealed that the intervention had significantly improved reported ITN use, reported IPTp uptake, and haematocrit levels, but had no significant effect on the incidence of reported malaria diagnosis or babies' birth weights.

CONCLUSIONS

The intervention was effective in improving ITN use, IPTp uptake, and haematocrit levels. It is, therefore, recommended for the modules to be adopted and incorporated into the routine antenatal care programmes in health centres with predominantly Hausa speaking clients.

TRIAL REGISTRATION

Pan African Clinical Trial Registry, PACTR201610001823405. Registered 26 October 2016, www.pactr.org .

Risk assessment of therapeutic agents under consideration to treat COVID-19 in paediatric patients and pregnant women

AIM

Repurposing strategies to address the COVID-19 pandemic have been accelerated. As both pregnant and paediatric patients are likely to be excluded from most planned investigations, the list of repurposed options and the available data on these drugs and vaccines provide a baseline risk assessment and identify gaps for targeted investigation.

METHODS

Clinical trials have been searched and reviewed; 23 repurposed drugs and drug combinations and nine candidate vaccines have been assessed regarding the availability of relevant data in paediatrics and pregnant women and to evaluate expected or unanticipated risk.

RESULTS

Thirteen of the repurposed drugs or drug combinations are indicated for use in paediatrics in some age category albeit for indications other than COVID-19; 10 of these are indicated for use in pregnant women. Even in cases where these drugs are indicated in the populations, source data from which safety and or dosing could be extrapolated for use in COVID-19 is sparse. Vaccine trials are ongoing and generally exclude pregnant women; only in a few instances have paediatric subgroups been planned for enrolment. Data from individual case studies and RWD may suggest that subpopulations of both paediatric patients and pregnant women may be more at risk, particularly those in an increased inflammatory state.

CONCLUSION

In conjunction with more prospective collaboration, plans are evolving to ensure that we will be better prepared to address similar situations especially in paediatrics and pregnant women where experience is limited and actual practice relies heavily on leveraging data from other populations and indications.

Determinants of uptake of first dose of intermittent preventive treatment among pregnant women in a secondary health Centre in Maiduguri, Nigeria

Background

Studies on uptake of first dose of intermittent preventive treatment in pregnancy (IPTp) are lacking, despite it being a predictor of subsequent doses. This study aimed at assessing the determinants of uptake of first dose of IPTp among pregnant women at the State Specialist Hospital, Maiduguri.

Methods

A cross-sectional study was conducted, in which respondents were selected using a systematic random sampling method, and structured questionnaires were used to obtain information from them. Chi-squared test was used to determine factors associated with uptake of first IPTp dose, while a further multivariate logistic regression was performed to determine its predictors.

Results

Three hundred and eighty respondents answered the survey, whose ages ranged from 15 to 45 years, and 86.8% were multigravid. Sixty five percent of them were aware of IPTp, and 34.7% believed that IPTp could be harmful to their pregnancies. Over a half of the respondents (52.9%) believed that taking all their IPTp medicines was very good for their pregnancies, while 45.0% felt that taking their IPTp medicines was very pleasant. Only two respondents (0.5%) stated that it was very untrue that their significant others thought that they should take all their IPTp medicines. Half of the respondents said it was very easy for them to take all their IPTp medicines even if they were experiencing mild discomforts while taking them. Less than a half (42.37%) had received their first dose of IPTp. In bivariate as well as multivariate analysis, only higher level of knowledge was significantly associated with uptake of first IPTp dose. Those with better knowledge of IPTp were about twice more likely to have taken their first dose of IPTp, compared to those with lower knowledge of IPTp (AOR = 1.85; 95% CI: 1.17–2.92).

Conclusions

Knowledge of IPTp as well as its uptake, were sub-optimal in this study. Since knowledge of IPTp significantly predicts uptake of the first dose of IPTp, there is the need to implement health education campaigns to raise the awareness of pregnant women and their families on the need to receive and comply with it.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03388-8.

Malaria and curable sexually transmitted infections in pregnant women: A two-years observational study in rural Burkina Faso

Background

Malaria and curable sexually transmitted infections (STI) are the most common curable infections known to have a severe impact on pregnancy outcomes in sub-Saharan Africa. This study aims to assess the marginal and joint prevalence of symptomatic cases of malaria and STI in pregnant women living in rural settings of Burkina Faso and their associated factors, after more than a decade of the introduction of intermittent preventive treatment (IPT-SP).

Methods

We carried out an observational study in two health districts in rural Burkina, namely Nanoro and Yako. Routine data were collected during antenatal and delivery visits for all women who delivered in the year 2016 and 2017. Logistic regression models were used to assess factors associated with infections.

Results

We collected data from 31639 pregnant women attending health facilities. Malaria, curable STI and their coinfections were diagnosed in 7747 (24.5%; 95%CI: 24.0–25.0%), 1269 (4.0%; 95%CI: 3.8–4.2%) and 388 (1.2%; 95%CI: 1.1–1.4%) women, respectively. In multivariate logistic regression, malaria occurrence was significantly higher in pregnant women < 20 years (Adjusted OR = 2.36; 95% CI: 2.07–2.69) than in women ≥30 years. The prevalence of curable STI was also significantly higher in students (Adjusted OR = 1.93; 95% CI: 1.26–2.95) and compensated workers (Adjusted OR = 1.52; 95% CI: 1.01–2.17) than in uncompensated workers. Women who received no IPT-SP had higher prevalence of malaria (Adjusted OR = 3.33; 95%CI: 3.00–3.70), curable STI (Adjusted OR = 1.96 95%CI: 1.60–2.39) and coinfections (Adjusted OR = 2.11; 95% CI: 1.50–2.95) compared to women who received SP.

Conclusion

Malaria and curable STI remain highly prevalent in rural settings of Burkina Faso, with young pregnant women and women who received no IPT-SP being the most affected. Prevention must be reinforced to improve maternal and infant health.

Teratogen update: Malaria in pregnancy and the use of antimalarial drugs in the first trimester

Malaria is a particular problem in pregnancy because of enhanced sensitivity, the possibility of placental malaria, and adverse effects on pregnancy outcome. Artemisinin-containing combination therapies (ACTs) are the most effective antimalarials known. WHO recommends 7-day quinine therapy for uncomplicated Plasmodium falciparum malaria in the first trimester despite the superior tolerability and efficacy of 3-day ACT regimens because artemisinins caused embryolethality and/or cardiovascular malformations at relatively low doses in rats, rabbits, and monkeys. The developmental toxicity of artesunate, artemether, and DHA were similar in rats but artesunate was embryotoxic at lower doses in rabbits (5 mg/kg/day) than artemether (no effect level = 25 mg/kg/day). In clinical studies in Africa, treatment with artemether-lumefantrine in the first trimester was observed to be highly efficacious and the miscarriage rate (≤3.1%) was similar to no antimalarial treatment (2.6%). When data from the first-trimester use of largely artesunate-based therapies in Thailand were pooled together, there was no difference in miscarriage rate compared to quinine. However, individually, artesunate-mefloquine was associated with a higher miscarriage rate (15/71 = 21%) compared to other artemisinin-based therapies including 7-day artesunate + clindamycin (2/50 = 4%) and quinine (92/842 = 11%). Thus, appropriate statistical comparisons of individual ACT groups are needed prior to assuming that they all have the same risk for developmental toxicity. Current limitations in the assessment of the safety of ACTs in the first trimester are a lack of exposures early in gestation (gestational weeks 6-7), limited postnatal evaluation for cardiovascular malformations, and the pooling of all ACTs for the assessment of risk.

Deleterious effects of malaria in pregnancy on the developing fetus: a review on prevention and treatment with antimalarial drugs

All malaria infections are harmful to both the pregnant mother and the developing fetus. One in ten maternal deaths in malaria endemic countries are estimated to result from Plasmodium falciparum infection. Malaria is associated with a 3-4 times increased risk of miscarriage and a substantially increased risk of stillbirth. Current treatment and prevention strategies reduce, but do not eliminate, malaria's damaging effects on pregnancy outcomes. Reviewing evidence generated from meta-analyses, systematic reviews, and observational data, the first paper in this Series aims to summarise the adverse effects of malaria in pregnancy on the fetus and how the current drug treatment and prevention strategies can alleviate these effects. Although evidence supports the safety and treatment efficacy of artemisinin-based combination therapies in the first trimester, these therapies have not been recommended by WHO for the treatment of malaria at this stage of pregnancy. Intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine is contraindicated in the first trimester and provides imperfect chemoprevention because of inadequate dosing, poor (few and late) antenatal clinic attendance, increasing antimalarial drug resistance, and decreasing naturally acquired maternal immunity due to the decreased incidence of malaria. Alternative strategies to prevent malaria in pregnancy are needed. The prevention of all malaria infections by providing sustained exposure to effective concentrations of antimalarial drugs is key to reducing the adverse effects of malaria in pregnancy.

Effects of Malaria in the First Trimester of Pregnancy on Poor Maternal and Birth Outcomes in Benin

BACKGROUND

In sub-Saharan Africa, malaria in the first half of pregnancy is harmful for both the mother and her fetus. However, malaria in the first trimester of pregnancy, when women are usually not protected against malaria, has been little investigated. For the first time, we assessed the effects of malaria in the first trimester on maternal and birth outcomes using a preconceptional study design.

METHODS

From June 2014 to March 2017, 1214 women of reproductive age were recruited and followed monthly until 411 became pregnant. The pregnant women were then followed from 5-6 weeks of gestation until delivery. Path analysis was used to assess the direct effect (ie, not mediated by malaria in the second or third trimester) of malaria in the first trimester on maternal anemia and poor birth outcomes. The cumulative effect of infections during pregnancy on the same outcomes was also evaluated.

RESULTS

The prevalence of malaria infections in the first trimester was 21.8%. Malaria in the first trimester was significantly associated with maternal anemia in the third trimester (adjusted odds ratio 2.25, 95% confidence interval 1.11-4.55). While we did not find evidence of any direct effect of first trimester malaria infections on birth outcomes, their association with infections later in pregnancy tended to increase the risk of low birth weights.

CONCLUSIONS

Malaria infections in the first trimester were highly prevalent and have deleterious effects on maternal anemia. They highlight the need for additional preventive measures, starting in early pregnancy or even before conception.

COVID-19 prevention and treatment: A critical analysis of chloroquine and hydroxychloroquine clinical pharmacology

Nicholas White and coauthors discuss chloroquine and hydroxychloroquine pharmacology in the context of possible treatment of SARS-CoV-2 infection.

Primaquine alternative dosing schedules for preventing malaria relapse in people with Plasmodium vivax

BACKGROUND

Plasmodium vivax liver stages (hypnozoites) may cause relapses, prolonging morbidity, and impeding malaria control and elimination. The World Health Organization (WHO) recommends three schedules for primaquine: 0.25 mg/kg/day (standard), or 0.5 mg/kg/day (high standard) for 14 days, or 0.75 mg/kg once weekly for eight weeks, all of which can be difficult to complete. Since primaquine can cause haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, clinicians may be reluctant to prescribe primaquine without G6PD testing, and recommendations when G6PD status is unknown must be based on an assessment of the risks and benefits of prescribing primaquine. Alternative safe and efficacious regimens are needed.

OBJECTIVES

To assess the efficacy and safety of alternative primaquine regimens for radical cure of P vivax malaria compared to the standard or high-standard 14-day courses.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (PubMed); Embase (Ovid); LILACS (BIREME); WHO International Clinical Trials Registry Platform and ClinicalTrials.gov up to 2 September 2019, and checked the reference lists of all identified studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of adults and children with P vivax malaria using either chloroquine or artemisinin-based combination therapy plus primaquine at a total adult dose of at least 210 mg, compared with the WHO-recommended regimens of 0.25 or 0.5 mg/kg/day for 14 days.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and quality, and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous data. We grouped efficacy data according to length of follow-up, partner drug, and trial location. We analysed safety data where included.

MAIN RESULTS

0.5 mg/kg/day for seven days versus standard 0.25 mg/kg/day for 14 days There may be little or no difference in P vivax recurrences at six to seven months when using the same total dose (210 mg adult dose) over seven days compared to 14 days (RR 0.96, 95% CI 0.66 to 1.39; 4 RCTs, 1211 participants; low-certainty evidence). No serious adverse events were reported. We do not know if there is any difference in the number of adverse events resulting in discontinuation of primaquine (RR 1.04, 95% CI 0.15 to 7.38; 5 RCTs, 1427 participants) or in the frequency of anaemia (RR 3.00, 95% CI 0.12 to 72.91, 1 RCT, 240 participants) between the shorter and longer regimens (very low-certainty evidence). Three trials excluded people with G6PD deficiency; two did not provide this information. Pregnant and lactating women were either excluded or no details were provided. High-standard 0.5 mg/kg/day for 14 days versus standard 0.25 mg/kg/day for 14 days There may be little or no difference in P vivax recurrences at six months with 0.5 mg/kg/day primaquine for 14 days compared to 0.25 mg/kg/day for 14 days (RR 0.84 (95% CI 0.49 to 1.43; 2 RCTs, 677 participants, low-certainty evidence). No serious adverse events were reported. We do not know whether there is a difference in adverse events resulting in discontinuation of treatment with the high-standard dosage (RR 4.19, 95% CI 0.90 to 19.60; 1 RCT, 778 participants, very low-certainty evidence). People with G6PD deficiency and pregnant or lactating women were excluded. 0.75 mg/kg/week for eight weeks versus high-standard 0.5 mg/kg/day for 14 days We do not know whether weekly primaquine increases or decreases recurrences of P vivax compared to high-standard 0.5 mg/kg/day for 14 days, at 11 months' follow-up (RR 3.18, 95% CI 0.37 to 27.60; 1 RCT, 122 participants; very low-certainty evidence). No serious adverse events and no episodes of anaemia were reported. G6PD-deficient patients were not randomized but included in the weekly primaquine group (only one patient detected). 1 mg/kg/day for seven days versus high standard 0.5 mg/kg/day for 14 days There is probably little or no difference in P vivax recurrences at 12 months between 1.0 mg/kg/day primaquine for seven days and the high-standard 0.5 mg/kg/day for 14 days (RR 1.03, 95% CI 0.82 to 1.30; 2 RCTs, 2526 participants; moderate-certainty evidence). There may be moderate to large increase in serious adverse events in the 1.0 mg/kg/day primaquine for seven days compared with the high-standard 0.5 mg/kg/day for 14 days, during 42 days follow-up (RR 12.03, 95% CI 1.57 to 92.30; 1 RCT, 1872 participants, low-certainty evidence). We do not know if there is a difference between 1.0 mg/kg/day primaquine for seven days and high-standard 0.5 mg/kg/day for 14 days in adverse events that resulted in discontinuation of treatment (RR 2.50, 95% CI 0.49 to 12.87; 1 RCT, 2526 participants, very low-certainty evidence), nor if there is difference in frequency of anaemia by 42 days (RR 0.93, 95% CI 0.62 to 1.41; 2 RCTs, 2440 participants, very low-certainty evidence). People with G6PD deficiency were excluded. Other regimens Two RCTs evaluated other rarely-used doses of primaquine, one of which had very high loss to follow-up. Adverse events were not reported. People with G6PD deficiency and pregnant or lactating women were excluded.

AUTHORS' CONCLUSIONS

Trials available to date do not detect a difference in recurrence between the following regimens: 1) 0.5 mg/kg/day for seven days versus standard 0.25 mg/kg/day for 14 days; 2) high-standard 0.5 mg/kg/day for 14 days versus standard 0.25 mg/kg/day for 14 days; 3) 0.75 mg/kg/week for eight weeks versus high-standard 0.5 mg/kg/day for 14 days; 4) 1 mg/kg/day for seven days versus high-standard 0.5 mg/kg/day for 14 days. There were no differences detected in adverse events for Comparisons 1, 2 or 3, but there may be more serious adverse events with the high seven-day course in Comparison 4. The shorter regimen of 0.5 mg/kg/day for seven days versus standard 0.25 mg/kg/day for 14 days may suit G6PD-normal patients. Further research will help increase the certainty of the findings and applicability in different settings.

Safety of Artemisinin Derivatives in the First Trimester of Pregnancy: A Controversial Story

Artemisinin combination therapy (ACT) is recommended by the World Health Organization (WHO) as first line treatment for uncomplicated malaria both in adults and children. During pregnancy, ACT is considered safe only in the second and third trimester, since animal studies have demonstrated that artemisinin derivatives can cause foetal death and congenital malformation within a narrow time window in early embryogenesis. During this period, artemisinin derivatives induce defective embryonic erythropoiesis and vasculogenesis/angiogenesis in experimental models. However, clinical data on the safety profile of ACT in pregnant women have not shown an increased risk of miscarriage, stillbirth, or congenital malformation, nor low birth weight, associated with exposure to artemisinins in the first trimester. Although further studies are needed, the evidence collected up to now is prompting the WHO towards a change in the guidelines for the treatment of uncomplicated malaria, allowing the use of ACT also in the first trimester of pregnancy.

Placental transfer and safety in pregnancy of medications under investigation to treat coronavirus disease 2019

Objective

Treatment of coronavirus disease 2019 is mostly symptomatic, but a wide range of medications are under investigation against severe acute respiratory syndrome coronavirus 2. Although pregnant women are excluded from clinical trials, they will inevitably receive therapies whenever they seem effective in nonpregnant patients and even under compassionate use.

Methods

We conducted a review of the literature on placental transfer and pregnancy safety data of drugs under current investigation for coronavirus disease 2019.

Results

Regarding remdesivir, there are no data in pregnant women. Several other candidates already have safety data in pregnant women, because they are repurposed drugs already used for their established indications. Thus, they may be used in pregnancy, although their safety in the context of coronavirus disease 2019 may differ from conventional use. These include HIV protease inhibitors such as lopinavir/ritonavir that have low placental transfer, interferon that does not cross the placental barrier, and hydroxychloroquine or chloroquine that has high placental transfer. There are also pregnancy safety and placental transfer data for colchicine, steroids, oseltamivir, azithromycin, and some monoclonal antibodies. However, some drugs are strictly prohibited in pregnancy because of known teratogenicity (thalidomide) or fetal toxicities (renin-angiotensin system blockers). Other candidates including tocilizumab, other interleukin 6 inhibitors, umifenovir, and favipiravir have insufficient data on pregnancy outcomes.

Conclusion

In life-threatening cases of coronavirus disease 2019, the potential risks of therapy to the fetus may be more than offset by the benefit of curing the mother. Although preclinical and placental transfer studies are required for a number of potential anti-severe acute respiratory syndrome coronavirus 2 drugs, several medications can already be used in pregnant women.

Plasmodium vivax in the Era of the Shrinking P. falciparum Map

Plasmodium vivax is an important cause of malaria, associated with a significant public health burden. Whilst enhanced malaria-control activities have successfully reduced the incidence of Plasmodium falciparum malaria in many areas, there has been a consistent increase in the proportion of malaria due to P. vivax in regions where both parasites coexist. This article reviews the epidemiology and biology of P. vivax, how the parasite differs from P. falciparum, and the key features that render it more difficult to control and eliminate. Since transmission of the parasite is driven largely by relapses from dormant liver stages, its timely elimination will require widespread access to safe and effective radical cure.

Adverse pregnancy outcomes between the anti-malarial drugs: Is there a difference between the drugs recommended by World Health Organization? Results of a mixed treatment comparison analysis of randomized clinical trials and cohort studies

BACKGROUND

Data regarding the relative safety profile of anti-malarial drugs in pregnancy is sparse mainly limited by the absence of head-to-head clinical trials. The present study is a network meta-analysis of safety of anti-malarial drugs used to treat malaria in pregnant women.

METHODS

A thorough literature search using the search strategy "Malaria [tiab] AND (Pregnant [tiab] OR Pregnancy [tiab])" was carried out for either randomized controlled trials or prospective cohort studies in pregnant malarial women prescribed any of the recommended anti-malarial drugs by World Health Organization (WHO) and that have reported adverse pregnancy outcomes such as miscarriage, still birth, and neonatal deaths. Odds ratio with 95% confidence interval was used as the effect estimate. Random-effects model and Markov Chain Monte Carlo simulation method was used to generate pooled estimates. Sensitivity analysis was performed excluding data from first trimester and GRADE approach was used to categorize the quality of evidence.

RESULTS

A total of 1242 papers were obtained with the search strategy, of which seven evaluating 10 treatment arms in a total of 5510 participants were included in the present meta-analysis. The pooled estimates revealed significantly lower risks of abortion with quinine and artemisinin-lumefantrine compared to dihydroartemisinin-piperaquine, artesunate with mefloquine and artesunate with amodiaquine. But when a cohort study that was conducted in the first trimester of pregnancy was excluded, no significant differences were observed in the risk of abortion between the anti-malarial drugs. No significant differences in the risk of either stillbirths or neonatal deaths were observed with any of the drugs. The quality of evidence was found to be very low due to serious limitations in both the precision and indirectness.

CONCLUSION

WHO recommended anti-malarials in pregnancy have similar risk profiles with regard to abortion, stillbirth and neonatal deaths.

Pregnancy-specific malarial immunity and risk of malaria in pregnancy and adverse birth outcomes: a systematic review

BACKGROUND

In endemic areas, pregnant women are highly susceptible to Plasmodium falciparum malaria characterized by the accumulation of parasitized red blood cells (pRBC) in the placenta. In subsequent pregnancies, women develop protective immunity to pregnancy-associated malaria and this has been hypothesized to be due to the acquisition of antibodies to the parasite variant surface antigen VAR2CSA. In this systematic review we provide the first synthesis of the association between antibodies to pregnancy-specific P. falciparum antigens and pregnancy and birth outcomes.

METHODS

We conducted a systematic review and meta-analysis of population-based studies (published up to 07 June 2019) of pregnant women living in P. falciparum endemic areas that examined antibody responses to pregnancy-specific P. falciparum antigens and outcomes including placental malaria, low birthweight, preterm birth, peripheral parasitaemia, maternal anaemia, and severe malaria.

RESULTS

We searched 6 databases and identified 33 studies (30 from Africa) that met predetermined inclusion and quality criteria: 16 studies contributed estimates in a format enabling inclusion in meta-analysis and 17 were included in narrative form only. Estimates were mostly from cross-sectional data (10 studies) and were heterogeneous in terms of magnitude and direction of effect. Included studies varied in terms of antigens tested, methodology used to measure antibody responses, and epidemiological setting. Antibody responses to pregnancy-specific pRBC and VAR2CSA antigens, measured at delivery, were associated with placental malaria (9 studies) and may therefore represent markers of infection, rather than correlates of protection. Antibody responses to pregnancy-specific pRBC, but not recombinant VAR2CSA antigens, were associated with trends towards protection from low birthweight (5 studies).

CONCLUSIONS

Whilst antibody responses to several antigens were positively associated with the presence of placental and peripheral infections, this review did not identify evidence that any specific antibody response is associated with protection from pregnancy-associated malaria across multiple populations. Further prospective cohort studies using standardized laboratory methods to examine responses to a broad range of antigens in different epidemiological settings and throughout the gestational period, will be necessary to identify and prioritize pregnancy-specific P. falciparum antigens to advance the development of vaccines and serosurveillance tools targeting pregnant women.

Association of Angiopoietin Dysregulation in Placental Malaria with Adverse Birth Outcomes

Malaria in pregnancy causes adverse birth outcomes due to sequestration of Plasmodium falciparum-infected erythrocytes in the placenta. Angiopoietins are critical regulators of vascular development and formation of placental villous vasculature. Angiopoietin-1 and Angiopoietin-2 concentrations were measured in peripheral and placental plasma samples from 70 malaria-infected and 216 control women using commercially available DuoSet ELISA development kit. Angiopoietins increased in placental plasma (ANG1-5833.5 pg/ml and ANG2-9580.6 pg/ml) as compared to peripheral plasma (ANG1-2293.1 pg/ml and ANG2-1198.9 pg/ml, p < 0.0001). The concentration of placental and peripheral ANG1 (6099.23 pg/ml and 2320.5 pg/ml) was significantly lower (5013.5 pg/ml, 2208.5 pg/ml), and ANG2 (9553.3 pg/ml, 1180.92 pg/ml) was significantly higher (9664.6 pg/ml, 1254.4 pg/ml) in malaria-positive cases as compared to malaria-negative (p < 0.0001). The association of dysregulated angiopoietins in malaria with adverse birth outcomes showed that the peripheral and placental ANG1 concentration was lower and ANG2 concentration was higher in low-birth-weight baby and stillbirth birth outcome as compared to normal deliveries among malaria-positive group. Therefore, ANG1 and ANG2 could be considered a biomarker for adverse outcome during malaria in pregnancy.

Immunobiological aspects of vaccines in pregnancy: Maternal perspective

Immunization during pregnancy is an efficient strategy to protect both the mother and the newborn infant against infectious pathogens. Pregnant women have an increased susceptibility to severe infections caused by some pathogens, but the mechanisms involved remain poorly understood. Pregnancy is associated with dynamic changes in maternal immune system that are critical for tolerance of the fetus. These changes could also play an important role in shaping maternal immune components that are transferred to the newborn infant following natural infection or vaccination to prevent infectious diseases in early life. As the momentum for maternal immunization is growing, there is a need to increase our understanding of the immunobiology of maternal immunization in order to better prevent infectious diseases in the pregnant women and the young infant.

8-Aminoquinoline Therapy for Latent Malaria

The technical genesis and practice of 8-aminoquinoline therapy of latent malaria offer singular scientific, clinical, and public health insights. The 8-aminoquinolines brought revolutionary scientific discoveries, dogmatic practices, benign neglect, and, finally, enduring promise against endemic malaria. The clinical use of plasmochin-the first rationally synthesized blood schizontocide and the first gametocytocide, tissue schizontocide, and hypnozoitocide of any kind-commenced in 1926. Plasmochin became known to sometimes provoke fatal hemolytic crises. World War II delivered a newer 8-aminoquinoline, primaquine, and the discovery of glucose-6-phosphate dehydrogenase (G6PD) deficiency as the basis of its hemolytic toxicity came in 1956. Primaquine nonetheless became the sole therapeutic option against latent malaria. After 40 years of fitful development, in 2018 the U.S. Food and Drug Administration registered the 8-aminoquinoline called tafenoquine for the prevention of all malarias and the treatment of those that relapse. Tafenoquine also cannot be used in G6PD-unknown or -deficient patients. The hemolytic toxicity of the 8-aminoquinolines impedes their great potential, but this problem has not been a research priority. This review explores the complex technical dimensions of the history of 8-aminoquinolines. The therapeutic principles thus examined may be leveraged in improved practice and in understanding the bright prospect of discovery of newer drugs that cannot harm G6PD-deficient patients.