Evaluation of sulphadoxine-pyrimethamine for intermittent preventive treatment of malaria in pregnancy: a retrospective birth outcomes study in Mansa, Zambia

Impact on pregnancy outcomes of intermittent preventive treatment with sulfadoxine-pyrimethamine in urban and peri-urban Papua New Guinea: a retrospective cohort study

BACKGROUND

Intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) reduces malaria-attributable adverse pregnancy outcomes and may also prevent low birth weight (< 2,500 g) through mechanisms independent of malaria. Malaria transmission in Papua New Guinea (PNG) is highly heterogeneous. The impact of IPTp-SP on adverse birth outcomes in settings with little or no malaria transmission, such as PNG's capital city Port Moresby, is unknown.

METHODS

A retrospective cohort study was conducted amongst HIV-negative women with a singleton pregnancy who delivered at Port Moresby General Hospital between 18 July and 21 August 2022. The impact of IPTp-SP doses on adverse birth outcomes and anaemia was assessed using logistic and linear regression models, as appropriate.

RESULTS

Of 1,140 eligible women amongst 1,228 consecutive births, 1,110 had a live birth with a documented birth weight. A total of 156 women (13.7%) did not receive any IPTp-SP, 347 women (30.4%) received one, 333 (29.2%) received two, and 304 (26.7%) received the recommended ≥ 3 doses of IPTp-SP. A total of 65 of 1,110 liveborn babies (5.9%) had low birth weight and there were 34 perinatal deaths (3.0%). Anaemia (haemoglobin < 100 g/L) was observed in 30.6% (243/793) of women, and 14 (1.2%) had clinical malaria in pregnancy. Compared to women receiving 0-1 dose of IPTp-SP, women receiving ≥ 2 doses had lower odds of LBW (adjusted odds ratio [aOR] 0.50; 95% confidence interval [CI] 0.26, 0.96), preterm birth (aOR 0.58; 95% CI 0.32, 1.04), perinatal death (aOR 0.49; 95% CI 0.18, 1.38), LBW/perinatal death (aOR 0.55; 95% CI 0.27, 1.12), and anaemia (OR 0.50; 95% CI 0.36, 0.69). Women who received 2 doses versus 0-1 had 45% lower odds of LBW (aOR 0.55, 95% CI 0.27, 1.10), and a 16% further (total 61%) reduction with ≥ 3 doses (aOR 0.39, 95% CI 0.14, 1.05). Birth weights for women who received 2 or ≥ 3 doses versus 0-1 were 81 g (95% CI -3, 166) higher, and 151 g (58, 246) higher, respectively.

CONCLUSIONS

Provision of IPTp-SP in a low malaria-transmission setting in PNG appears to translate into substantial health benefits, in a dose-response manner, supporting the strengthening IPTp-SP uptake across all transmission settings in PNG.

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

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

Uptake of four or more doses of sulfadoxine pyrimethamine for intermittent preventive treatment of malaria during pregnancy in Zambia: findings from the 2018 malaria in pregnancy survey

OBJECTIVE

To determine the prevalence and predictors of the uptake of four or more doses of sulfadoxine pyrimethamine (IPTp-SP 4+) in Zambia.

DESIGN

A cross-sectional study using secondary data from the malaria in pregnancy survey (Malaria Indicator Survey) data set conducted from April to May 2018.

SETTING

The primary survey was conducted at community level and covered all the 10 provinces of Zambia.

PARTICIPANTS

A total of 3686 women of reproductive age (15-45 years) who gave birth within the 5 years before the survey.

PRIMARY OUTCOME

Proportion of participants with four or more doses of IPTp-SP.

STATISTICAL ANALYSIS

All analyses were conducted using RStudio statistical software V.4.2.1. Descriptive statistics were computed to summarise participant characteristics and IPTp-SP uptake. Univariate logistic regression was carried out to determine association between the explanatory and outcome variables. Explanatory variables with a p value less than 0.20 on univariate analysis were included in the multivariable logistic regression model and crude and adjusted ORs (aORs) along with their 95% CIs were computed (p<0.05).

RESULTS

Of the total sample of 1163, only 7.5% of participants received IPTp-SP 4+. Province of residence and wealth tertile were associated with uptake of IPTp-SP doses; participants from Luapula (aOR=8.72, 95% CI (1.72 to 44.26, p=0.009)) and Muchinga (aOR=6.67, 95% CI (1.19 to 37.47, p=0.031)) provinces were more likely to receive IPTp-SP 4+ compared with to those from Copperbelt province. Conversely, women in the highest wealth tertile were less likely to receive IPTp-SP 4+ doses compared with those in the lowest quintile (aOR=0.32; 95% CI (0.13 to 0.79, p=0.014)).

CONCLUSION

These findings confirm a low uptake of four or more doses of IPTp-SP in the country. Strategies should focus on increased coverage of IPTp-SP in provinces with much higher malaria burden where the risk is greatest and the ability to afford healthcare lowest.

Effectiveness of antenatal intermittent preventive treatment for malaria with sulphadoxine-pyrimethamine on peripartum outcomes

Background

Following the World Health Organization (WHO) recommendations for 4-weekly antenatal intermittent preventive treatment of malaria in pregnancy using sulphadoxine-pyrimethamine (IPTp-SP), there is a need to evaluate the drug performance in order to determine their effectiveness as tools in malaria control policy.

Objectives

To determine prevalence of cord blood malaria, compliance gap and adverse pregnancy outcomes (anaemia, preterm delivery, spontaneous abortion, intra-uterine foetal death and low birth weight) among antenatal IPTp-SP users compared with non-users.

Methods

A cross-sectional analytical study was conducted among consenting 390 participants who were administered a questionnaire, and paired blood samples were collected from the venous blood of participants and neonatal cord immediately after delivery. The participants were categorised as IPTp-SP users and non-users. Adverse pregnancy outcomes were assessed. Neonatal birth weights were also measured within 1 h after delivery. Malaria parasitaemia and anaemia were analysed using standard parasitological and haematological methods of examination. Data were analysed using SPSS version 25 for Windows and p-value of < 0.05 considered significant.

Results

Of 390 women, 336 (86.2%) were IPTp-SP users, while 54 (13.8%) were non-users. The compliance gap was 13.8%. Malaria parasitemia in pregnant women (21.7% versus 53.7%; p < 0.001) and their babies (12.2% versus 25.4%; p = 0.002) were observed for IPTp-SP users and non-users, respectively. The prevalence of maternal anaemia was 27(8.0%) in IPTp-SP users and 5 (9.3%) in non-users (p = 0.789). Mean parasite density was reduced in IPTp-SP users than in non-users (p < 0.001). Correlation of birth weight according to their sex showed a weak correlation [correlation coefficient (r) = 0.027; p = 0.736]. Pregnant women with preterm delivery, spontaneous abortion, intra-uterine foetal death, and low birth weight were significantly lower (p < 0.001, for all) in IPTp-SP users compared with non-users.

Conclusion

Although the compliance gap was low, IPTp-SP users had significantly better pregnancy and foetal outcomes compared with non-users. Efforts should be intensified towards achieving total compliance in IPTp-SP usage by pregnant women.

Surveillance of molecular markers for antimalarial resistance in Zambia: Polymorphism of Pfkelch 13, Pfmdr1 and Pfdhfr/Pfdhps genes

Antimalarial resistance is an inevitable feature of control efforts and a key threat to achieving malaria elimination. Plasmodium falciparum, the deadliest of several species causing human malaria, has developed resistance to essentially all antimalarials. This study sought to investigate the prevalence of molecular markers associated with resistance to sulfadoxine-pyrimethamine (SP) and artemether-lumefantrine (AL) in Southern and Western provinces in Zambia. SP is used primarily for intermittent preventive treatment during pregnancy, while AL is the first-line antimalarial for uncomplicated malaria in Zambia. Blood samples were collected from household members of all ages in a cross-sectional survey conducted during peak malaria transmission, April to May of 2017, and amplified by polymerase chain reaction (PCR). Amplicons were then analysed by high-resolution melt following PCR to identify mutations associated with SP resistance in the P. falciparum dihydrofolate reductase (Pfdhfr) and P. falciparum dihydropteroate synthase (Pfdhps) genes and lumefantrine resistance in the P. falciparum multi-drug resistance 1 (Pfmdr1) gene. Finally, artemether resistance was assessed in the P. falciparum Kelch 13 (PfK13) gene using nested PCR followed by amplicon sequencing. The results showed a high frequency of genotypic-resistant Pfdhps A437G (93.2%) and Pfdhfr C59R (86.7%), N51I (80.9%), and S108N (80.8%) of which a high proportion (82.4%) were quadruple mutants (Pfdhfr N51I, C59R, S108N +Pfdhps A437G). Pfmrd1 N86Y, Y186F, and D1246Y - NFD mutant haplotypes were observed in 41.9% of isolates. The high prevalence of quadruple dhps/dhfr mutants indicates strong antifolate drug pressure from SP or other drugs (e.g., co-trimoxazole). Three samples contained PfK13 mutations, two synonymous (T478 and V666) and one non-synonymous (A578S), none of which have been associated with delayed clearance. This suggests that artemisinin remains efficacious in Zambia, however, the moderately high prevalence of approximately 40% Pfmdr1 NFD mutations calls for close monitoring of AL.

The Effectiveness of the Revised Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine (IPTp-SP) in the Prevention of Malaria among Pregnant Women in Northern Ghana

This study investigated the effectiveness of the World Health Organization (WHO)-revised Intermittent Preventive Treatment using Sulphadoxine Pyrimethamine (IPTp-SP) dosage regimen in the prevention of malaria infections in pregnancy. The study involved a prospective cohort of pregnant women who attended the antenatal clinic in four health facilities (Tamale Teaching Hospital, Tamale West Hospital, Tamale Central Hospital, and Tamale SDA Hospital) within the Tamale metropolis. Data collection spanned a period of 12 months, from September 2016 to August 2017, to help account for seasonality in malaria. The study included 1181 pregnant women who attended antenatal clinics in four hospitals within the metropolis. The registers at the facilities served as a sampling frame, and the respondents were randomly sampled out from the number of pregnant women available during each visit. They were enrolled consecutively as they kept reporting to the facility to receive antenatal care. The participants were stratified into three groups; the no IPTp-SP, <3 doses of IPTp-SP, and ≥3 doses of IPTp-SP. The participants were followed up until 36 weeks of gestation, and blood samples were analyzed to detect the presence of peripheral malaria parasites. At the end of the study, 42.4% of the women had taken at least 3 doses of SP based on the revised WHO IPTp-SP policy. Pregnant women who had taken at least 3 doses of IPTp-SP had a malaria prevalence of 16.9% at 36 weeks of gestation, compared to 35.8% of those who had not taken IPTp-SP. In the multivariable logistic regression, those who had taken ≥3 doses of SP were associated with 56% reduced odds (aOR 0.44, CI 0.27-0.70, P = 0.001) of late gestational peripheral malaria, compared with those who did not take SP. IPTp-SP served under three or more doses provided a dose-dependent protection of 56% against maternal peripheral malaria parasitaemia detectable at the later stages of gestation (36 weeks). Since the dose-dependent potency of IPTp-SP depletes with time, there is the need for research into more sustainable approaches that offer longer protection.

Malaria preventive practices and delivery outcomes: A cross-sectional study of parturient women in a tertiary hospital in Eastern Uganda

BACKGROUND

Uganda ranks third in the number of deaths attributable to malaria and has some of the highest recorded malaria transmission rates in the general population. Malaria in Pregnancy is associated with detrimental effects for the mother and unborn baby and these effects seem to have long term effects and consequences on the life of the baby. Despite the preventive measures put in place by the World Health Organization in antenatal care, the burden of malaria in pregnancy is still high. We determined the use of malaria preventive strategies during pregnancy and the presence of plasmodium infection, anemia, and low birth weight babies at delivery among parturient women at Mbale regional referral hospital in eastern Uganda.

METHODS

A cross-sectional study was conducted among 210 women delivering at MRRH between July 2017 and January 2018. Information on demographics, antenatal care, and prevention practices was collected using an interviewer-administered questionnaire. Maternal venous blood and cord blood samples were screened for Plasmodium infection by both microscopy of Giemsa-stained blood films and Plasmodium falciparum rapid diagnostic test (pf. HPR2 mRDT). Polymerase Chain Reaction (PCR) was done on cord blood. The presence of anemia was determined by the use of an automated hemoglobin analyzer. Data were analyzed using descriptive and analytical statistics.

RESULTS

Of the 210 women, 3 (1.4%) and 19(9.1%) tested positive for malaria by using Giemsa stained blood smear microscopy and malaria rapid diagnosticMRDT tests respectively. PCR detected 4(%) of Plasmodium in cord blood. Twenty-nine percent of the women had anaemia and 11 (5.2%) had low birth weight babies. Only 23.3% of the women received at least three doses of IPTp-SP and 57.9% reported sleeping under an Insecticide Treated Net the night before the survey. The women who reported sleeping under a mosquito net the previous night (OR 0.67, 95% CI: 0.24-1.86) and those who reported taking fansidar as a directly observed therapy (OR 0.31, 95% CI: 0.04-2.39) appeared to have few chances of getting plasmodium infection though the findings were not statistically significant.

CONCLUSION

The effective use of malaria preventive strategies (IPT-SP and Insecticide Treated Nets) was generally low. Most of the women took less than three doses of SP and there was no strict adherence to the recommended directly observed therapy. The prevalence of Plasmodium infection during pregnancy was low though maternal anaemia and low birth weight were relatively high.

Determinants of preterm birth among mothers who gave birth in East Africa: systematic review and meta-analysis

BACKGROUND

Preterm birth (PTB) can be caused by different factors. The factors can be classified into different categories: socio demographic, obstetric, reproductive health, medical, behavioral and nutritional related. The objective of this review was identifying determinants of PTB among mothers who gave birth in East African countries.

METHODS

We have searched the following electronic bibliographic databases: PubMed, Google scholar, Cochrane library, AJOL (African journal online). Cross sectional, case control and cohort study published in English were included. There was no restriction on publication period. Studies with no abstracts and or full texts, editorials, and qualitative in design were excluded. Funnel plot was used to check publication bias. I-squared statistic was used to check heterogeneity. Pooled analysis was done by using fixed and random effect model. The Joanna Briggs Critical Appraisal Tools for review and meta-analysis was used to check the study quality.

RESULTS

A total of 58 studies with 134,801 participants were used to identify determinants of PTB. On pooled analysis, PTB was associated with age < 20 years (AOR 1.76, 95% CI: 1.33-2.32), birth interval less than 24 months (AOR 2.03, 95% CI 1.57-2.62), multiple pregnancy (AOR 3.44,95% CI: 3.02-3.91), < 4 antenatal care (ANC) visits (AOR 5.52, 95% CI: 4.32-7.05), and absence of ANC (AOR 5.77, 95% CI: 4.27-7.79). Other determinants of PTB included: Antepartum hemorrhage (APH) (AOR 4.90, 95% CI: 3.48-6.89), pregnancy induced hypertension (PIH) (AOR 3.10, 95% CI: 2.34-4.09), premature rupture of membrane (PROM) (AOR 5.90, 95% CI: 4.39-7.93), history of PTB (AOR 3.45, 95% CI: 2.72-4.38), and history of still birth/abortion (AOR 3.93, 95% CI: 2.70-5.70). Furthermore, Anemia (AOR 4.58, 95% CI: 2.63-7.96), HIV infection (AOR 2.59, 95% CI: 1.84-3.66), urinary tract infection (UTI) (AOR 5.27, 95% CI: 2.98-9.31), presence of vaginal discharge (AOR 5.33, 95% CI: 3.19-8.92), and malaria (AOR 3.08, 95% CI: 2.32-4.10) were significantly associated with PTB.

CONCLUSIONS

There are many determinants of PTB in East Africa. This review could provide policy makers, clinicians, and program officers to design intervention on preventing occurrence of PTB.

Intermittent Preventive Treatment of Malaria in Pregnancy: Assessment of the Sulfadoxine-Pyrimethamine Three-Dose Policy on Birth Outcomes in Rural Northern Ghana

BACKGROUND

Intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) decreases placental parasitaemia and improves birth outcomes. Currently, WHO recommends three or more doses of SP given during antenatal care (ANC), spaced one month apart after 16 weeks of gestation till delivery. This study determined the level of uptake of SP and its association with birth outcomes in rural northern Ghana.

METHODS

A survey was carried out at the War Memorial Hospital in Navrongo, Ghana, among mothers who had delivered within ten weeks and were seeking postnatal care. Data on time of first ANC, number of visits, receipt of IPTp-SP, and birth outcomes were extracted from the antenatal records of 254 mothers. Mothers were interviewed on their background characteristics and obstetric history. Chi-square tests and logistic regression were carried out to determine association between antenatal indicators, uptake of IPTp-SP, and birth outcomes using Stata version 13.

RESULTS

Uptake of three-five doses of SP was IPT3 =76.4%, IPT4 =37.3%, and IPT5 = 16.0%. Receipt of first dose of SP at 16, 17-24, and 25-36 weeks of gestation was 16.9%, 56.7%, and 26.4%, respectively. Taking the first dose of SP during the second trimester allowed for taking ≥3 doses of SP compared to taking the first dose during the third trimester (χ2 = 60.1, p<0.001). Women who made ≥4 visits were more likely to receive ≥3 doses of SP compared to those who made <4 visits (χ2 = 87.6, p<0.001). Women who received ≥ 3 doses of SP were more likely (OR = 3.3; 95% CI: 1.69-6.33) to give birth at term and also have normal weight babies (OR =4.0; 95% CI: 1.98-8.06).

CONCLUSION

Uptake of three or more doses of SP contributed to improved pregnancy outcomes. Increased efforts towards improving early ANC attendance could increase uptake of SP and improve pregnancy outcomes.

Has doxycycline, in combination with anti-malarial drugs, a role to play in intermittent preventive treatment of Plasmodium falciparum malaria infection in pregnant women in Africa?

According to the World Health Organization (WHO), Plasmodium falciparum malaria during pregnancy is responsible for deleterious consequences for the mother and her child. The administration of intermittent preventive treatment (IPTp) with sulfadoxine–pyrimethamine (SP) at each antenatal care visit as early as 13 weeks of gestation until the time of delivery is a strategy that is currently recommended by WHO for the prevention of malaria in pregnancy. However, the emergence and the spread of the resistance to SP in Africa raise the question of the short-term effectiveness of the strategy. Dihydroartemisinin–piperaquine 120 mg/960 mg once a day for 3 consecutive days administered at least three times during the pregnancy might be an option for IPTp. The combination of 200 mg of doxycycline once a day for 3 consecutive days seems to be a good option to retard the emergence and the spread of resistance to artemisinin-based combination therapy (ACT) in Africa and improve the effectiveness of ACT in term of preterm births, neonatal morbidity and mortality. Contrary to preconceived ideas, scientific and medical data suggest that the risk of congenital malformations in the fetus or of tooth staining in infants whose mothers take doxycycline and hepatotoxicity during pregnancy is very low or non-existent. Additionally, the use of doxycycline during the first and second trimesters leads to an increase in gestational age at delivery, a decrease in the number of preterm births and a reduction in neonatal morbidity and mortality due to the beneficial antimicrobial activity of doxycycline against other infections during pregnancy. Furthermore, doxycycline has anti-malarial properties and is already recommended as prophylaxis for travellers and for treatment of falciparum malaria in combination with other anti-malarial drugs.

Use of a novel supplementary food and measures to control inflammation in malnourished pregnant women in Sierra Leone to improve birth outcomes: study protocol for a prospective, randomized, controlled clinical effectiveness trial

Background

The negative synergy between poor nutritional status and infectious diseases is doubly detrimental in pregnancy. In Sierra Leone, maternal malnutrition is amongst the highest in the world, while maternal mortality is high at 1320/100,000 live births and stunting in under-five is 37.9%, ranked 110/132 worldwide. Maternal malnutrition has been associated with preterm birth, small-for-gestational age infants, and poor maternal outcomes. Infants born prematurely or small-for-gestational age experience higher mortality and are at risk for stunting and decreased cognitive performance. Nutritional interventions alone during pregnancy may not be as effective in the setting of increased inflammation from repeated infections. Interventions are needed to improve maternal outcomes and reduce stunting in this population.

Methods/design

This will be a prospective, randomized, controlled clinical effectiveness trial of an improved supplementary food plus anti-infective therapies compared to standard therapy in malnourished pregnant women. Pregnant women will be randomized to receive a low water activity, ready-to-use supplementary food plus five anti-infective interventions or the standard of care which is 3.5 kg corn/ soy blended flour with 350 mL vegetable oil every two weeks. The five anti-infective interventions are 1) insecticide-treated mosquito net at the time of enrollment into the study, 2) sulfadoxine-pyrimethamine given every 4 weeks, beginning at enrollment or at 13 weeks’ gestation, whichever is later, 3)azithromycin at a dose of 1 g given once at enrollment (after first trimester)and again during 28–34 weeks of gestation, 4)single dose 400 mg albendazole given in second trimester, and 5) testing and treatment for bacterial vaginosis at enrollment and again at 28–34 weeks of gestation. Treatment will be provided for the duration of the pregnancy. The primary outcome measure will be birth length. Secondary outcomes in the mothers will include rates of maternal weight gain and increase in mid-upper arm circumference, and time to maternal anthropometric recovery. Secondary outcomes in the infants will include birth weight, birth head circumference, and linear and ponderal growth.

Discussion

Malnutrition remains a major problem in the developing world with lasting maternal and infant consequences. Maternal malnutrition has been associated with intrauterine growth retardation, low birth weight (LBW), pre-term delivery and poor cognitive development. Nutritional interventions alone have not been successful in reducing stunting. By bundling nutritional and anti-infective interventions, we aim to reduce intrauterine growth restriction and low birth weight in moderately malnourished pregnant women in Sierra Leone. If successful, this bundle can easily be implemented by governments or non-governmental organizations.

Trial registration

Clinicaltrials.govNCT03079388; Date: March 5, 2017.

Comparative effectiveness of malaria prevention measures: a systematic review and network meta-analysis

Background

Malaria causes significant morbidity and mortality worldwide. There are several preventive measures that are currently employed, including insecticide-treated nets (ITNs, including long-lasting insecticidal nets and insecticidal-treated bed nets), indoor residual spraying (IRS), prophylactic drugs (PD), and untreated nets (UN). However, it is unclear which measure is the most effective for malaria prevention. We therefore undertook a network meta-analysis to compare the efficacy of different preventive measures on incidence of malaria infection.

Methods

A systematic literature review was undertaken across four medical and life sciences databases (PubMed, Cochrane Central, Embase, and Web of Science) from their inception to July 2016 to compare the effectiveness of different preventive measures on malaria incidence. Data from the included studies were analysed for the effectiveness of several measures against no intervention (NI). This was carried out using an automated generalized pairwise modeling (GPM) framework for network meta-analysis to generate mixed treatment effects against a common comparator of no intervention (NI).

Results

There were 30 studies that met the inclusion criteria from 1998–2016. The GPM framework led to a final ranking of effectiveness of measures in the following order from best to worst: PD, ITN, IRS and UN, in comparison with NI. However, only ITN (RR: 0.49, 95% CI: 0.32–0.74) showed precision while other methods [PD (RR: 0.24, 95% CI: 0.004–15.43), IRS (RR: 0.55, 95% CI: 0.20–1.56) and UN (RR: 0.73, 95% CI: 0.28–1.90)] demonstrating considerable uncertainty associated with their point estimates.

Conclusion

Current evidence is strong for the protective effect of ITN interventions in malaria prevention. Even though ITNs were found to be the only preventive measure with statistical support for their effectiveness, the role of other malaria control measures may be important adjuncts in the global drive to eliminate malaria.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2783-y) contains supplementary material, which is available to authorized users.

The protective effectiveness of control interventions for malaria prevention: a systematic review of the literature

Background: Thanks to a considerable increase in funding, malaria control interventions (MCI) whose efficacy had been demonstrated by controlled trials have been largely scaled up during the last decade. Nevertheless, it was not systematically investigated whether this efficacy had been preserved once deployed on the field. Therefore, we sought the literature to assess the disparities between efficacy and effectiveness and the effort to measure the protective effectiveness (PE) of MCI.

Methods: The PubMed database was searched for references with keywords related to malaria, to control interventions for prevention and to study designs that allow for the measure of the PE against parasitemia or against clinical outcomes.

Results: Our search retrieved 1423 references, and 162 articles were included in the review. Publications were scarce before the year 2000 but dramatically increased afterwards. Bed nets was the MCI most studied (82.1%). The study design most used was a cross-sectional study (65.4%). Two thirds (67.3%) were conducted at the district level or below, and the majority (56.8%) included only children even if the MCI didn’t target only children. Not all studies demonstrated a significant PE from exposure to MCI: 60.6% of studies evaluating bed nets, 50.0% of those evaluating indoor residual spraying, and 4/8 showed an added PE of using both interventions as compared with one only; this proportion was 62.5% for intermittent preventive treatment of pregnant women, and 20.0% for domestic use of insecticides.

Conclusions: This review identified numerous local findings of low, non-significant PE –or even the absence of a protective effect provided by these MCIs. The identification of such failures in the effectiveness of MCIs advocates for the investigation of the causes of the problem found. Ideal evaluations of the PE of MCIs should incorporate both a large representativeness and an evaluation of the PE stratified by subpopulations.

Quantification of the association between malaria in pregnancy and stillbirth: a systematic review and meta-analysis

BACKGROUND

2·6 million stillbirths occur annually worldwide. The association between malaria in pregnancy and stillbirth has yet to be comprehensively quantified. We aimed to quantify the association between malaria in pregnancy and stillbirth, and to assess the influence of malaria endemicity on the association.

METHODS

We did a systematic review of the association between confirmed malaria in pregnancy and stillbirth. We included population-based cross-sectional, cohort, or case-control studies (in which cases were stillbirths or perinatal deaths), and randomised controlled trials of malaria in pregnancy interventions, identified before Feb 28, 2017. We excluded studies in which malaria in pregnancy was not confirmed by PCR, light microscopy, rapid diagnostic test, or histology. The primary outcome was stillbirth. We pooled estimates of the association between malaria in pregnancy and stillbirth using meta-analysis. We used meta-regression to assess the influence of endemicity. The study protocol is registered with PROSPERO, protocol number CRD42016038742.

FINDINGS

We included 59 studies of 995 records identified, consisting of 141 415 women and 3387 stillbirths. Plasmodium falciparum malaria detected at delivery in peripheral samples increased the odds of stillbirth (odds ratio [OR] 1·81 [95% CI 1·42-2·30]; I²=26·1%; 34 estimates), as did P falciparum detected in placental samples (OR 1·95 [1·48-2·57]; I²=33·6%; 31 estimates). P falciparum malaria detected and treated during pregnancy was also associated with stillbirth, but to a lesser extent (OR 1·47 [95% CI 1·13-1·92]; 19 estimates). Plasmodium vivax malaria increased the odds of stillbirth when detected at delivery (2·81 [0·77-10·22]; three estimates), but not when detected and treated during pregnancy (1·09 [0·76-1·57]; four estimates). The association between P falciparum malaria in pregnancy and stillbirth was two times greater in areas of low-to-intermediate endemicity than in areas of high endemicity (ratio of ORs 1·96 [95% CI 1·34-2·89]). Assuming all women with malaria are still parasitaemic at delivery, an estimated 20% of the 1 059 700 stillbirths in malaria-endemic sub-Saharan Africa are attributed to P falciparum malaria in pregnancy; the population attributable fraction decreases to 12%, assuming all women with malaria are treated during pregnancy.

INTERPRETATION

P falciparum and P vivax malaria in pregnancy both increase stillbirth risk. The risk of malaria-associated stillbirth is likely to increase as endemicity declines. There is a pressing need for context-appropriate, evidence-based interventions for malaria in pregnancy in low-endemicity settings.

FUNDING

Australian Commonwealth Government, National Health and Medical Research Council, Australian Research Council.

Malaria during Pregnancy

One hundred and twenty-five million women in malaria-endemic areas become pregnant each year (see Dellicour et al. PLoS Med7: e1000221 [2010]) and require protection from infection to avoid disease and death for themselves and their offspring. Chloroquine prophylaxis was once a safe approach to prevention but has been abandoned because of drug-resistant parasites, and intermittent presumptive treatment with sulfadoxine-pyrimethamine, which is currently used to protect pregnant women throughout Africa, is rapidly losing its benefits for the same reason. No other drugs have yet been shown to be safe, tolerable, and effective as prevention for pregnant women, although monthly dihydroartemisinin-piperaquine has shown promise for reducing poor pregnancy outcomes. Insecticide-treated nets provide some benefits, such as reducing placental malaria and low birth weight. However, this leaves a heavy burden of maternal, fetal, and infant morbidity and mortality that could be avoided. Women naturally acquire resistance to Plasmodium falciparum over successive pregnancies as they acquire antibodies against parasitized red cells that bind chondroitin sulfate A in the placenta, suggesting that a vaccine is feasible. Pregnant women are an important reservoir of parasites in the community, and women of reproductive age must be included in any elimination effort, but several features of malaria during pregnancy will require special consideration during the implementation of elimination programs.

In vivo antiplasmodial activity and toxicological assessment of hydroethanolic crude extract of Ajuga remota

BACKGROUND

Malaria is one of the most life-threatening health problems worldwide and treatment has been compromised by drug resistance. Identifying lead molecules from natural products might help to find better anti-malarial drugs, since those obtained from natural sources are still effective against malarial parasites. This study aimed at investigating the in vivo antiplasmodial activity of crude extract of the leaves of Ajuga remota together with its safety in mice models.

METHODS

In vivo parasite growth inhibitory effect of crude extract was assessed in mice inoculated with Plasmodium berghei (ANKA strain). The in vivo antiplasmodial activity of the test extract was performed against early infection (4-day suppressive test), curative effect against established infection and prophylactic effect against residual infection. Acute and sub-acute toxicity were carried out according to OECD guidelines.

RESULTS

In vivo parasite growth inhibition effect of hydroethanolic crude extract of A. remota was evaluated at 30, 50 and 100 mg/kg dose levels. It suppressed parasitaemia by 77.34% at 100 mg/kg dose level in the 4-day test. In curative and prophylactic potential tests, it suppressed parasitaemia by 66.67 and 59.66% at 100 mg/kg dose level, respectively. In vivo toxicity tests revealed no toxicity. All parasitaemia suppressions were statistically significant at P < 0.05 as compared to the vehicle-treated group. The crude extract also prolonged survival time in a dose dependent manner.

CONCLUSIONS

The investigation results suggest that the leave extract of Ajuga remota possesses antimalarial activity.

Burden of Placental Malaria among Pregnant Women Who Use or Do Not Use Intermittent Preventive Treatment at Mulago Hospital, Kampala

Intermittent preventive treatment of malaria in pregnancy with sulphadoxine-pyrimethamine (SP-IPTp) is widely used to reduce the incidence of adverse pregnancy outcomes. As a monitor for continued effectiveness of this intervention amidst SP resistance, we aimed to assess malaria burden among pregnant women who use or do not use SP-IPTp. In a descriptive cohort study at Mulago Hospital, Kampala, 87 women who received two supervised doses of SP-IPTp were followed up until delivery. Controls were pregnant women presenting in early labour without history of SP-IPTp. Histopathological investigation for placental malaria (PM) was performed using the Bulmer classification criterion. Thirty-eight of the 87 women returned for delivery and 33 placentas were successfully collected and processed along with 33 placentas from SP nonusers. Overall, 12% (4/33) of the users had evidence of PM compared to 48% (16/33) of nonusers. Among nonusers, 17/33, 8/33, 2/33, and 6/33 had no placental infection, active infection, active-chronic infection, and past-chronic infection, respectively. Among users, respective proportions were 29/33, 2/33, 0/33, and 2/33. No difference in birth weights was apparent between the two groups, probably due to a higher proportion of infections occurring later in pregnancy. Histological evidence here suggests that SP continues to offer substantial benefit as IPTp.

Impact of Sulfadoxine-Pyrimethamine Resistance on Effectiveness of Intermittent Preventive Therapy for Malaria in Pregnancy at Clearing Infections and Preventing Low Birth Weight

BACKGROUND

Owing to increasing sulfadoxine-pyrimethamine (SP) resistance in sub-Saharan Africa, monitoring the effectiveness of intermittent preventive therapy in pregnancy (IPTp) with SP is crucial.

METHODS

Between 2009 and 2013, both the efficacy of IPTp-SP at clearing existing peripheral malaria infections and the effectiveness of IPTp-SP at reducing low birth weight (LBW) were assessed among human immunodeficiency virus-uninfected participants in 8 sites in 6 countries. Sites were classified as high, medium, or low resistance after measuring parasite mutations conferring SP resistance. An individual-level prospective pooled analysis was conducted.

RESULTS

Among 1222 parasitemic pregnant women, overall polymerase chain reaction-uncorrected and -corrected failure rates by day 42 were 21.3% and 10.0%, respectively (39.7% and 21.1% in high-resistance areas; 4.9% and 1.1% in low-resistance areas). Median time to recurrence decreased with increasing prevalence of Pfdhps-K540E. Among 6099 women at delivery, IPTp-SP was associated with a 22% reduction in the risk of LBW (prevalence ratio [PR], 0.78; 95% confidence interval [CI], .69-.88; P < .001). This association was not modified by insecticide-treated net use or gravidity, and remained significant in areas with high SP resistance (PR, 0.81; 95% CI, .67-.97; P = .02).

CONCLUSIONS

The efficacy of SP to clear peripheral parasites and prevent new infections during pregnancy is compromised in areas with >90% prevalence of Pfdhps-K540E. Nevertheless, in these high-resistance areas, IPTp-SP use remains associated with increases in birth weight and maternal hemoglobin. The effectiveness of IPTp in eastern and southern Africa is threatened by further increases in SP resistance and reinforces the need to evaluate alternative drugs and strategies for the control of malaria in pregnancy.

In vivo efficacy of sulphadoxine-pyrimethamine for the treatment of asymptomatic parasitaemia in pregnant women in Machinga District, Malawi

Background

The effectiveness of sulphadoxine-pyrimethamine (SP) intermittent preventive treatment of malaria in pregnancy (IPTp) might be compromised by high prevalence of resistance-associated Plasmodium falciparum dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutations. As a proxy for IPTp-SP effectiveness, the in vivo efficacy of SP to clear parasitaemia and prevent reinfection in asymptomatic parasitaemic pregnant women in an area with high SP resistance prevalence was assessed.

Methods

Pregnant women 16–26 weeks’ gestation with asymptomatic parasitaemia presenting for antenatal care were given IPTp-SP and followed for 42 days. The primary outcome was polymerase chain reaction (PCR) uncorrected 42-day survival rate; the per cent of patients without recrudescence or reinfection by day 42. PCR was used to distinguish recrudescence from reinfection. DNA was sequenced to detect resistance-associated dhfr and dhps mutations.

Results

Of 245 pregnant women included in the intention-to-treat analysis, 93.9% cleared their parasitaemia by day 7. The day 42 PCR-uncorrected survival rate was 58.1% (95% confidence interval (CI) 51.5-65.7) and day 42 PCR-corrected survival was 68.7% (CI 61.4-76.0). Recrudescence was more common among primi- than among multigravid women; recrudescence rate 33.3% (CI 25.1-42.4%) versus 21.4% (CI 15.0-29.0%) (log rank test p-value 0.006). The quintuple mutant was present in nearly all samples (95%), while 2% were sextuple mutants with an additional mutation at dhps A581G.

Conclusions

SP efficacy for acute malaria treatment has been compromised by resistance, but SP retains partial activity among pregnant women with asymptomatic parasitaemia, and thus might be useful for IPTp. Nonetheless, research on non-SP IPTp regimens should continue.

Trial registration

ClinicalTrials.gov NCT01120145.