Comprehensive and contemporary estimates of the number of pregnancies at risk of malaria are not currently available, particularly for endemic areas outside of Africa. We derived global estimates of ...the number of women who became pregnant in 2007 in areas with Plasmodium falciparum and P. vivax transmission.
A recently published map of the global limits of P. falciparum transmission and an updated map of the limits of P. vivax transmission were combined with gridded population data and growth rates to estimate total populations at risk of malaria in 2007. Country-specific demographic data from the United Nations on age, sex, and total fertility rates were used to estimate the number of women of child-bearing age and the annual rate of live births. Subregional estimates of the number of induced abortions and country-specific stillbirths rates were obtained from recently published reviews. The number of miscarriages was estimated from the number of live births and corrected for induced abortion rates. The number of clinically recognised pregnancies at risk was then calculated as the sum of the number of live births, induced abortions, spontaneous miscarriages, and stillbirths among the population at risk in 2007. In 2007, 125.2 million pregnancies occurred in areas with P. falciparum and/or P. vivax transmission resulting in 82.6 million live births. This included 77.4, 30.3, 13.1, and 4.3 million pregnancies in the countries falling under the World Health Organization (WHO) regional offices for South-East-Asia (SEARO) and the Western-Pacific (WPRO) combined, Africa (AFRO), Europe and the Eastern Mediterranean (EURO/EMRO), and the Americas (AMRO), respectively. Of 85.3 million pregnancies in areas with P. falciparum transmission, 54.7 million occurred in areas with stable transmission and 30.6 million in areas with unstable transmission (clinical incidence <1 per 10,000 population/year); 92.9 million occurred in areas with P. vivax transmission, 53.0 million of which occurred in areas in which P. falciparum and P. vivax co-exist and 39.9 million in temperate regions with P. vivax transmission only.
In 2007, 54.7 million pregnancies occurred in areas with stable P. falciparum malaria and a further 70.5 million in areas with exceptionally low malaria transmission or with P. vivax only. These represent the first contemporary estimates of the global distribution of the number of pregnancies at risk of P. falciparum and P. vivax malaria and provide a first step towards a more informed estimate of the geographical distribution of infection rates and the corresponding disease burden of malaria in pregnancy.
Malaria in pregnancy has important consequences for mother and baby. Coverage with the World Health Organization-recommended prevention strategy for pregnant women in sub-Saharan Africa of ...intermittent preventive treatment in pregnancy (IPTp) and insecticide-treated nets (ITNs) is low. We conducted a systematic review to explore factors affecting delivery, access, and use of IPTp and ITNs among healthcare providers and women.
We searched the Malaria in Pregnancy Library and Global Health Database from 1 January 1990 to 23 April 2013, without language restriction. Data extraction was performed by two investigators independently, and data was appraised for quality and content. Data on barriers and facilitators, and the effect of interventions, were explored using content analysis and narrative synthesis. We conducted a meta-analysis of determinants of IPTp and ITN uptake using random effects models, and performed subgroup analysis to evaluate consistency across interventions and study populations, countries, and enrolment sites. We did not perform a meta-ethnography of qualitative data. Ninety-eight articles were included, of which 20 were intervention studies. Key barriers to the provision of IPTp and ITNs were unclear policy and guidance on IPTp; general healthcare system issues, such as stockouts and user fees; health facility issues stemming from poor organisation, leading to poor quality of care; poor healthcare provider performance, including confusion over the timing of each IPTp dose; and women's poor antenatal attendance, affecting IPTp uptake. Key determinants of IPTp coverage were education, knowledge about malaria/IPTp, socio-economic status, parity, and number and timing of antenatal clinic visits. Key determinants of ITN coverage were employment status, education, knowledge about malaria/ITNs, age, and marital status. Predictors showed regional variations.
Delivery of ITNs through antenatal clinics presents fewer problems than delivery of IPTp. Many obstacles to IPTp delivery are relatively simple barriers that could be resolved in the short term. Other barriers are more entrenched within the overall healthcare system or socio-economic/cultural contexts, and will require medium- to long-term strategies. Please see later in the article for the Editors' Summary.
Prevention of malaria in pregnancy Desai, Meghna; Hill, Jenny; Fernandes, Silke ...
The Lancet infectious diseases,
April 2018, 2018-04-00, 20180401, Volume:
18, Issue:
4
Journal Article
Peer reviewed
Malaria remains one of the most preventable causes of adverse birth outcomes. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine–pyrimethamine is used to prevent malaria, but ...resistance to this drug combination has decreased its efficacy and new alternatives are needed. In Africa, a meta-analysis showed three-course or monthly IPTp with sulfadoxine–pyrimethamine to be safe and more effective than the original two-course sulfadoxine–pyrimethamine strategy, prompting WHO to update its policy in 2012. Although resistance to sulfadoxine–pyrimethamine reduces the parasitological efficacy of IPTp, this drug combination remains associated with reduced incidence of low birthweight in areas where prevalence of parasites with quintuple Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) mutations is greater than 90%. Nevertheless, its effectiveness is compromised in women infected with sextuple mutant parasites. Six trials of IPTp showed that neither amodiaquine, mefloquine, nor chloroquine–azithromycin are suitable replacements for sulfadoxine–pyrimethamine because of poor tolerability. Furthermore, four trials showed that intermittent screening and treatment with the current generation of malaria rapid diagnostic tests was not a suitable alternative strategy to IPTp with sulfadoxine–pyrimethamine, even in areas with high prevalence of quintuple mutations. Two trials showed that IPTp with dihydroartemisinin–piperaquine was well tolerated, effective, and acceptable for IPTp, with monthly regimens being the most effective. Coverage of IPTp and insecticide-treated nets continues to lag behind targets. The key barriers to uptake are well documented, and many are open to intervention. Outside of Africa, a single trial suggests a potential role for integrated approaches that combine sulfadoxine–pyrimethamine with azithromycin for IPTp in areas of Papua New Guinea where malaria transmission is high. Modelling analysis suggests the importance of the prevention of malaria early in pregnancy and the need to protect pregnant women declines more slowly than the rate at which transmission declines. Improved funding has led to an increase in the number of prevention trials in the past decade, showing the value of more sustained protection with monthly IPTp regimens. There is a need for confirmatory trials of the safety, efficacy, and feasibility of IPTp with dihydroartemisinin–piperaquine, for studies of intermittent screening and treatment with more sensitive rapid diagnostic tests, for studies of integrated strategies for malaria and other co-infections, and for studies of prevention strategies for malaria in pregnant women who are HIV-positive and living outside of Africa. Additional research is required on how to improve uptake of WHO's updated policy on IPTp with sulfadoxine–pyrimethamine and insecticide-treated nets.
In Africa, most plasmodium infections during pregnancy remain asymptomatic, yet are associated with maternal anemia and low birthweight. WHO recommends intermittent preventive therapy in pregnancy ...with sulfadoxine-pyrimethamine (IPTp-SP). However, sulfadoxine-pyrimethamine (SP) efficacy is threatened by high-level parasite resistance. We conducted a trial to evaluate the efficacy and safety of scheduled intermittent screening with malaria rapid diagnostic tests (RDTs) and treatment of RDT-positive women with dihydroartemisinin-piperaquine (DP) as an alternative strategy to IPTp-SP.
This was an open-label, two-arm individually randomized superiority trial among HIV-seronegative women at three sites in Malawi with high SP resistance. The intervention consisted of three or four scheduled visits in the second and third trimester, 4 to 6 wk apart. Women in the IPTp-SP arm received SP at each visit. Women in the intermittent screening and treatment in pregnancy with DP (ISTp-DP) arm were screened for malaria at every visit and treated with DP if RDT-positive. The primary outcomes were adverse live birth outcome (composite of small for gestational age, low birthweight <2,500 g, or preterm birth <37 wk) in paucigravidae (first or second pregnancy) and maternal or placental plasmodium infection at delivery in multigravidae (third pregnancy or higher). Analysis was by intention to treat. Between 21 July 2011 and 18 March 2013, 1,873 women were recruited (1,155 paucigravidae and 718 multigravidae). The prevalence of adverse live birth outcome was similar in the ISTp-DP (29.9%) and IPTp-SP (28.8%) arms (risk difference = 1.08% 95% CI -3.25% to 5.41%; all women: relative risk RR = 1.04 95% CI 0.90-1.20, p = 0.625; paucigravidae: RR = 1.10 95% CI 0.92-1.31, p = 0.282; multigravidae: RR = 0.92 95% CI 0.71-1.20, p = 0.543). The prevalence of malaria at delivery was higher in the ISTp-DP arm (48.7% versus 40.8%; risk difference = 7.85%, 95% CI 3.07%-12.63%; all women: RR = 1.19 95% CI 1.07-1.33, p = 0.007; paucigravidae: RR = 1.16 95% CI 1.04-1.31, p = 0.011; multigravidae: RR = 1.29 95% CI 1.02-1.63, p = 0.037). Fetal loss was more common with ISTp-DP (2.6% versus 1.3%; RR = 2.06 95% CI 1.01-4.21, p = 0.046) and highest among non-DP-recipients (3.1%) in the ISTp-DP arm. Limitations included the open-label design.
Scheduled screening for malaria parasites with the current generation of RDTs three to four times during pregnancy as part of focused antenatal care was not superior to IPTp-SP in this area with high malaria transmission and high SP resistance and was associated with higher fetal loss and more malaria at delivery.
Pan African Clinical Trials Registry PACTR201103000280319; ISRCTN Registry ISRCTN69800930.
Summary Background Intermittent preventive treatment (IPT) for malaria is used in infants, children, adults, and pregnant women. Dihydroartemisinin-piperaquine (DP) is an effective, well tolerated ...artemisinin-based combination therapy. The long half-life of piperaquine makes it attractive for IPT. We conducted a systematic review and meta-analysis to establish the efficacy and safety of repeated treatment with DP. Methods Following PRISMA guidelines, we searched multiple databases on Sept 1, 2016, with the terms: “human” AND “dihydroartemisinin-piperaquine” OR “DHA-PPQ”. Studies were eligible if they were randomised controlled trials (RCTs) or prospective cohort studies involving repeat exposures to standard 3-day courses of DP for either seasonal malaria chemoprevention, mass drug administration, or treatment of clinical malaria, conducted at any time and in any geographic location. Random-effects meta-analysis was used to generate pooled incidence rate ratios and relative risks, or risk differences. Findings 11 studies were included: two repeat treatment studies (one in children younger than 5 years and one in pregnant women), and nine IPT trials (five in children younger than 5 years, one in schoolchildren, one in adults, two in pregnant women). Comparator interventions included placebo, artemether-lumefantrine, sulfadoxine-pyrimethamine (SP), SP+amodiaquine, SP+piperaquine, SP+chloroquine, and co-trimoxazole. Of 14 628 participants, 3935 received multiple DP courses (2–18). Monthly IPT-DP was associated with an 84% reduction in the incidence of malaria parasitaemia measured by microscopy compared with placebo. Monthly IPT-DP was associated with fewer serious adverse events than placebo, daily co-trimoxazole, or monthly SP. Among 56 IPT-DP recipients (26 children, 30 pregnant women) with cardiac parameters, all QTc intervals were within normal limits, with no significant increase in QTc prolongation with increasing courses of DP. Interpretation Monthly DP appears well tolerated and effective for IPT. Additional data are needed in pregnancy and to further explore the cardiac safety with monthly dosing. Funding Bill & Melinda Gates Foundation and NIH.
Malaria transmission has declined substantially in the 21st century, but pregnant women in areas of sustained transmission still require protection to prevent the adverse pregnancy and birth outcomes ...associated with malaria in pregnancy (MiP). A recent call to action has been issued to address the continuing low coverage of intermittent preventive treatment of malaria in pregnancy (IPTp). This call has, however, been questioned by some, in part due to concerns about resistance to sulphadoxine-pyrimethamine (SP), the only drug currently recommended for IPTp.
Using an existing mathematical model of MiP, we combined estimates of the changing endemicity of malaria across Africa with maps of SP resistance mutations and current coverage of antenatal access and IPTp with SP (IPTp-SP) across Africa. Using estimates of the relationship between SP resistance mutations and the parasitological efficacy of SP during pregnancy, we estimated the varying impact of IPTp-SP across Africa and the incremental value of enhancing IPTp-SP uptake to match current antenatal care (ANC) coverage. The risks of MiP and malaria-attributable low birthweight (mLBW) in unprotected pregnancies (i.e., those not using insecticide-treated nets ITNs) leading to live births fell by 37% (33%-41% 95% credible interval crI) and 31% (27%-34% 95% crI), respectively, from 2000 to 2015 across endemic areas in sub-Saharan Africa. However, these gains are fragile, and coverage is far from optimal. In 2015, 9.5 million (8.3 million-10.4 million 95% crI) of 30.6 million pregnancies in these areas would still have been infected with Plasmodium falciparum without intervention, leading to 750,000 (390,000-1.1 million 95% crI) mLBW deliveries. In all, 6.6 million (5.6 million-7.3 million 95% crI) of these 9.5 million (69.3%) pregnancies at risk of infection (and 53.4% 16.3 million/30.6 million of all pregnancies) occurred in settings with near-perfect SP curative efficacy (>99%) based on the most recent estimates of resistance. Forty-four percent of these pregnancies (23% of all pregnancies) were not receiving any IPTp-SP despite making ≥3 ANC visits, representing 160,000 (94,000-236,000 95% crI) preventable low birthweight (LBW) deliveries. Only 4% (1.4 million) of pregnancies occurred in settings with >10% prevalence of the sextuple haplotype associated with compromised SP effectiveness. Forty-two percent of all pregnancies occurred in settings where the quintuple dhfr/dhps haplotype had become established but where in vivo efficacy data suggest SP maintains the majority of its effectiveness in clearing infections. Not accounting for protection from the use of ITNs during pregnancy, expanding IPTp-SP to all women with ≥3 ANC visits in Africa could prevent an additional 215,000 (128,000-318,000 95% crI) LBW deliveries. In 26 countries with sufficient recent data to estimate ITN impact (population-based ITN usage data that can be stratified by gravidity), we estimate that, due primarily to low ITN use by primigravidae, only 16.5% of the potential LBW births prevented by scaling up IPTp-SP would in fact have already have been prevented through ITN use. Our analysis also highlights the difficulties associated with estimating the relationship between the effectiveness of interventions against parasitological endpoints such as placental infection at delivery and health outcomes including birthweight, which is also determined by a wide range of unrelated factors. We also did not capture other aspects of malaria burden such as clinical malaria, maternal and neonatal anaemia, and miscarriage, all of which increase the overall importance of effective preventative strategies but have their own relationship with transmission intensity, parity, and SP resistance.
Despite recent declines in malaria transmission in Africa, the burden of MiP in the absence of adequate prevention remains substantial. Even accounting for SP resistance, extending IPTp-SP to all women attending ANC, as well as long-lasting insecticidal net distribution targeted towards first-time mothers, would have a sizeable impact upon maternal and infant health in almost all malaria-endemic settings in sub-Saharan Africa.
Protection from malaria with insecticide-treated bednets (ITNs) during pregnancy is widely advocated, but evidence of benefit has been inconsistent. We undertook a systematic review of randomised ...trials.
Three cluster-randomised and two individually randomised trials met the inclusion criteria; four from Africa (n = 6,418) and one from Thailand (n = 223). In Africa, ITNs compared to no nets increased mean birth weight by 55 g (95% confidence interval CI 21-88), reduced low birth weight by 23% (relative risk RR 0.77, 95% CI 0.61-0.98), and reduced miscarriages/stillbirths by 33% (RR 0.67, 0.47-0.97) in the first few pregnancies. Placental parasitaemia was reduced by 23% in all gravidae (RR 0.77, 0.66-0.90). The effects were apparent in the cluster-randomised trials and the one individually randomised trial in Africa. The trial in Thailand, which randomised individuals to ITNs or untreated nets, showed reductions in anaemia and fetal loss in all gravidae, but not reductions in clinical malaria or low birth weight.
ITNs used throughout pregnancy or from mid-pregnancy onwards have a beneficial impact on pregnancy outcome in malaria-endemic Africa in the first few pregnancies. The potential impact of ITNs in pregnant women and their newborns in malaria regions outside Africa requires further research.
Summary Background Every year, more than 32 million pregnancies in sub-Saharan Africa are at risk of malaria infection and its adverse consequences. The effectiveness of the intermittent preventive ...treatment with sulfadoxine–pyrimethamine strategy recommended by WHO is threatened by high levels of parasite resistance. We aimed to assess the efficacy and safety of two alternative strategies: intermittent screening with malaria rapid diagnostic tests and treatment of women who test positive with dihydroartemisinin–piperaquine, and intermittent preventive treatment with dihydroartemisinin–piperaquine. Methods We did this open-label, three-group, randomised controlled superiority trial at four sites in western Kenya with high malaria transmission and sulfadoxine–pyrimethamine resistance. HIV-negative pregnant women between 16 and 32 weeks' gestation were randomly assigned (1:1:1), via computer-generated permuted-block randomisation (block sizes of three, six, and nine), to receive intermittent screening and treatment with dihydroartemisinin–piperaquine, intermittent preventive treatment with dihydroartemisinin–piperaquine, or intermittent preventive treatment with sulfadoxine–pyrimethamine. Study participants, study clinic nurses, and the study coordinator were aware of treatment allocation, but allocation was concealed from study investigators, delivery unit nurses, and laboratory staff. The primary outcome was malaria infection at delivery, defined as a composite of peripheral or placental parasitaemia detected by placental histology, microscopy, or rapid diagnostic test. The primary analysis was by modified intention to treat. This study is registered with ClinicalTrials.gov , number NCT01669941. Findings Between Aug 21, 2012, and June 19, 2014, we randomly assigned 1546 women to receive intermittent screening and treatment with dihydroartemisinin–piperaquine (n=515), intermittent preventive treatment with dihydroartemisinin–piperaquine (n=516), or intermittent preventive treatment with sulfadoxine–pyrimethamine (n=515); 1368 (88%) women comprised the intention-to-treat population for the primary endpoint. Prevalence of malaria infection at delivery was lower in the intermittent preventive treatment with dihydroartemisinin–piperaquine group than in the intermittent preventive treatment with sulfadoxine–pyrimethamine group (15 3% of 457 women vs 47 10% of 459 women; relative risk 0·32, 95% CI 0·18–0·56; p<0·0001), but not in the intermittent screening and treatment with dihydroartemisinin–piperaquine group (57 13% of 452 women; 1·23, 0·86–1·77; p=0·26). Compared with intermittent preventive treatment with sulfadoxine–pyrimethamine, intermittent preventive treatment with dihydroartemisinin–piperaquine was associated with a lower incidence of malaria infection during pregnancy (192·0 vs 54·4 events per 100 person-years; incidence rate ratio IRR 0·28, 95% CI 0·22–0·36; p<0·0001) and clinical malaria during pregnancy (37·9 vs 6·1 events; 0·16, 0·08–0·33; p<0·0001), whereas intermittent screening and treatment with dihydroartemisinin–piperaquine was associated with a higher incidence of malaria infection (232·0 events; 1·21, 1·03–1·41; p=0·0177) and clinical malaria (53·4 events; 1·41, 1·00–1·98; p=0·0475). We recorded 303 maternal and infant serious adverse events, which were least frequent in the intermittent preventive treatment with dihydroartemisinin–piperaquine group. Interpretation At current levels of rapid diagnostic test sensitivity, intermittent screening and treatment is not a suitable alternative to intermittent preventive treatment with sulfadoxine–pyrimethamine in the context of high sulfadoxine–pyrimethamine resistance and malaria transmission. However, dihydroartemisinin–piperaquine is a promising alternative drug to replace sulfadoxine–pyrimethamine for intermittent preventive treatment. Future studies should investigate the efficacy, safety, operational feasibility, and cost-effectiveness of intermittent preventive treatment with dihydroartemisinin–piperaquine. Funding The Malaria in Pregnancy Consortium , which is funded through a grant from the Bill & Melinda Gates Foundation to the Liverpool School of Tropical Medicine.
Low- and middle-income countries continue to experience a large burden of stunting; 148 million children were estimated to be stunted, around 30-40% of all children in 2011. In many of these ...countries, foetal growth restriction (FGR) is common, as is subsequent growth faltering in the first 2 years. Although there is agreement that stunting involves both prenatal and postnatal growth failure, the extent to which FGR contributes to stunting and other indicators of nutritional status is uncertain.
Using extant longitudinal birth cohorts (n=19) with data on birthweight, gestational age and child anthropometry (12-60 months), we estimated study-specific and pooled risk estimates of stunting, wasting and underweight by small-for-gestational age (SGA) and preterm birth.
We grouped children according to four combinations of SGA and gestational age: adequate size-for-gestational age (AGA) and preterm; SGA and term; SGA and preterm; and AGA and term (the reference group). Relative to AGA and term, the OR (95% confidence interval) for stunting associated with AGA and preterm, SGA and term, and SGA and preterm was 1.93 (1.71, 2.18), 2.43 (2.22, 2.66) and 4.51 (3.42, 5.93), respectively. A similar magnitude of risk was also observed for wasting and underweight. Low birthweight was associated with 2.5-3.5-fold higher odds of wasting, stunting and underweight. The population attributable risk for overall SGA for outcomes of childhood stunting and wasting was 20% and 30%, respectively.
This analysis estimates that childhood undernutrition may have its origins in the foetal period, suggesting a need to intervene early, ideally during pregnancy, with interventions known to reduce FGR and preterm birth.
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