Plasmodium falciparum and Plasmodium vivax infections are important causes of adverse pregnancy outcomes in the Asia-Pacific region. We hypothesised that monthly intermittent preventive treatment (IPT) or intermittent screening and treatment (IST) with dihydroartemisinin-piperaquine is more effective in reducing malaria in pregnancy than the existing single screening and treatment (SST) strategy, which is used to screen women for malaria infections at the first antenatal visit followed by passive case detection, with management of febrile cases.
Few studies have assessed placental malaria infections from low transmission areas by histopathology to define their impact and underlying mechanisms. Peripheral smears and rapid diagnostic tests (RDTs), placental smears and histological samples, birth weight and gestational age were collected from 2,282 deliveries in three hospitals during a one-year (2006–2007) continuous cross-sectional survey in Madhya Pradesh. Placental histopathology included all 50 cases positive by microscopy or RDT plus 456 randomly selected samples of women negative for malaria by microscopy or RDT. Histological examination included parasites, inflammatory cells, pigment in fibrin, and morphological changes. There were 52 histology-positive cases; 38 (73.1%) active (acute and chronic) and 14 past infections. Intervillous parasitaemia was low (60% had < 1% parasitaemia) and monocytosis mostly mild (63%). Compared with uninfected placentas, acute Plasmodium falciparum infections were associated with stillbirth (RR 3.8, 95% CI 1.2-12.1), lower maternal haemoglobin (mean difference: 1.5 g/dL, 95% CI 0.5-2.5), lower birth weight (mean difference 451 g, 95% CI 169–609) and shorter gestation (mean difference 0.8 weeks, 95% CI 0.2-1.4). Chronic or past infections were not associated with these outcomes. Among the 11 peripheral Plasmodium vivax cases, placental parasites were absent, but they were associated with increased placental polymorphonuclear cells. Malaria associated stillbirth and low birth weight in women with low protective immunity may result, at least in part, from a shortened gestation triggered by acute infection, stressing the importance of early malaria detection.
Dihydroartemisinin-piperaquine (DP) is a long-acting artemisinin combination treatment that provides effective chemoprevention and has been proposed as an alternative antimalarial drug for intermittent preventive therapy in pregnancy (IPTp). Several pharmacokinetic studies have shown that dose adjustment may not be needed for the treatment of malaria in pregnancy with DP. However, there are limited data on the optimal dosing for IPTp. This study aimed to evaluate the population pharmacokinetics of piperaquine given as IPTp in pregnant women. Pregnant women were enrolled in clinical trials conducted in Kenya and Indonesia and treated with standard 3-day courses of DP, administered in 4- to 8-week intervals from the second trimester until delivery. Pharmacokinetic blood samples were collected for piperaquine drug measurements before each treatment round, at the time of breakthrough symptomatic malaria, and at delivery. Piperaquine population pharmacokinetic properties were investigated using nonlinear mixed-effects modeling with a prior approach. In total, data from 366 Kenyan and 101 Indonesian women were analyzed. The pharmacokinetic properties of piperaquine were adequately described using a flexible transit absorption (n = 5) followed by a three-compartment disposition model. Gestational age did not affect the pharmacokinetic parameters of piperaquine. After three rounds of monthly IPTp, 9.45% (95% confidence interval [CI], 1.8 to 26.5%) of pregnant women had trough piperaquine concentrations below the suggested target concentration (10.3 ng/ml). Translational simulations suggest that providing the full treatment course of DP at monthly intervals provides sufficient protection to prevent malaria infection. Monthly administration of DP has the potential to offer optimal prevention of malaria during pregnancy. (This study has been registered at ClinicalTrials.gov under identifier NCT01669941 and in the ISRCTN under number ISRCTN34010937.).
Indonesia introduced single screening and treatment (SST) of pregnant women for the control of malaria in pregnancy in 2012. Under this policy pregnant women are screened for malaria at their first antenatal clinic (ANC) visit and on subsequent visits are tested for malaria only if symptomatic. The implementation of this policy in two districts of Indonesia was evaluated. Cross sectional survey structured observations of the ANC visit and exit interviews with pregnant women were conducted to assess health provider compliance with SST guidelines. Systems effectiveness analysis was performed on components of the strategy. Multiple logistic regression was used to test for predictors of women being screened at their first ANC visit. A total of 865 and 895 ANC visits in Mimika and West Sumba across seven and ten health facilities (plus managed health posts) respectively, were included in the study. Adherence to malaria screening at first ANC visit among pregnant women was 51.4% (95% CI 11.9, 89.2) in health facilities in Mimika (94.8% in health centres) and 24.8% (95% CI 10.3, 48.9) in West Sumba (60.0% in health centres). Reported fever was low amongst women presenting for their second and above ANC visit (2.8% in Mimika and 3.5% in West Sumba) with 89.5% and 46.2% of these women tested for malaria in Mimka and West Sumba, respectively. Cumulative systems effectiveness for SST on first visit to ANC was 7.6% for Mimika and 0.1% for West Sumba; and for second or above visits to ANC was 0.7% in Mimika and 0% in West Sumba. Being screened on a 1st visit to ANC was associated with level of health facility in both sites. Cumulative systems effectiveness of the SST strategy was poor in both sites. Both elements of the SST strategy, screening on first visit and passive case detection on second and above visits, was driven by the difference in implementation of malaria testing in health centres and health posts, and by low malaria transmission levels and reported fever.
Abstract Background The sensitivity of rapid diagnostic tests (RDTs) for malaria is inadequate for detecting low-density, often asymptomatic infections, such as those that can occur when screening pregnant women for malaria. The performance of the Alere™ Ultra-sensitive Malaria Ag Plasmodium falciparum RDT (uRDT) was assessed retrospectively in pregnant women in Indonesia. Methods The diagnostic performance of the uRDT and the CareStart™ Malaria HRP2/pLDH VOM ( Plasmodium vivax, Plasmodium ovale and Plasmodium malariae ) Combo RDT (csRDT) were assessed using 270 stored red blood cell pellets and plasma samples from asymptomatic pregnant women. These included 112 P. falciparum negative and 158 P. falciparum positive samples detected by a composite test (qPCR, LAMP, nPCR) as reference standard. Diagnostic indicators: sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), diagnostic odds ratio (DOR) and the level of agreement (kappa) were calculated for comparison. Results Compared with the reference test, the uRDT had a sensitivity of 19.6% (95% CI 13.9–26.8) and specificity of 98.2% (93.1–99.7%). The csRDT was 22.8% (16.7–30.3) sensitive and 95.5% (89.4–98.3) specific for P. falciparum infections. Performance of the uRDT was non-significantly different to the csRDT (p = 0.169). RDT outcome was stratified by qPCR cycling threshold (Ct), and performance of the RDTs was found to be comparable across parasite loads. Conclusion The uRDT performed similarly to the currently used csRDTs in detecting P. falciparum infections in asymptomatic pregnant women. In these settings, molecular diagnostics are currently the most sensitive for malaria.
The control of malaria in pregnancy in much of Asia relies on screening asymptomatic women for malaria infection, followed by passive case detection and prevention with insecticide-treated nets. In 2012, Indonesia introduced screening for malaria by microscopy or rapid diagnostic tests (RDTs) at pregnant women’s first antenatal care (ANC) visit to detect and treat malaria infections regardless of the presence of symptoms. Acceptability among health providers and pregnant women of the current ‘single screen and treat’ (SSTp) strategy compared to two alternative strategies that were intermittent preventive treatment (IPTp) and intermittent screening and treatment (ISTp) was assessed in the context of a clinical trial in two malaria endemic provinces of Eastern Indonesia. Qualitative data were collected through in-depth interviews with 121 health providers working in provision of antenatal care, heads of health facilities and District Health Office staff. Trial staff were also interviewed. Focus group discussions were conducted with 16 groups of pregnant women (N = 106) to discuss their experiences of each intervention in the trial. Health providers and pregnant women were receptive to screening for malaria at every ANC visit due to the increased opportunity to detect and treat asymptomatic infections. A primary concern for providers was the accuracy and availability of RDTs used for screening in the SSTp and ISTp arms, which they considered less accurate than microscopy. Providers had reservations about giving anti-malarials presumptively as IPTp, due to concerns of causing potential harm to mother and baby and as a possible driver of drug resistance. Pregnant women were accepting of all three interventions. Women in the IPTp arm were happy to take anti-malarials presumptively to protect themselves and their babies against malaria. The findings indicate that, within a trial context, malaria screening of pregnant women at every ANC visit ISTp was an acceptable strategy among both health providers and pregnant women owing to an existing culture of screening and treatment. The adoption of IPTp however would require a considerable shift in health provider attitudes and a clear communication strategy. By contrast, pregnant women welcomed the opportunity to prevent malaria infections during pregnancy.
anaemia (Hb ≤9 g/dL); [RR 2.2 (95% CI 1.7-2.9) P. vivax RR 0.5 (0.3-0.9)] whereas with sub-microscopic infections both species were associated with increased risk of moderate to severe anaemia [P. falciparum: RR 2.1 (95% CI 1.6-2.8) and P. vivax: RR 1.9 (95% CI 1.3-2.7)]. The prevalence of placental malaria was 4.8% (72/1632) by PCR and 3.3% sub-microscopically; this was 2.4% in primigravidae, 3.1% in secundi and 1.7% in multigravidae (≥3 pregnancies). The mean difference in birth weight in women with patent placental P. falciparum infection compared with uninfected women was 101 g (95% CI 70-273 g) with RR 2.1 (95% CI 1.2-3.0) for low birth weight. The reduction in birth weight with sub-microscopic infection was 70 g (63-204 g) with low birth weight RR 1.7 (95% CI 1.0-2.5). Corresponding figures for P. vivax were: patent placental infections: 252 g (57560 g), low birth weight RR 4.7 (95% CI 2.2-67); and for sub-microscopic infections the mean difference in birth weight was 146 (70-364 g); low birth weight RR 2.9 (95% CI 1.6-3.4). Conclusions
Malaria in pregnancy poses a major public health problem in Indonesia with an estimated six million pregnancies at risk of Plasmodium falciparum or Plasmodium vivax malaria annually. In 2010, Indonesia introduced a screen and treat policy for the control of malaria in pregnancy at first antenatal visit using microscopy or rapid diagnostic tests (RDTs). A diagnostic study was conducted in Sumba, Indonesia to compare the performance of four different RDTs in predominately asymptomatic pregnant women under field condition. Women were screened for malaria at antenatal visits using field microscopy and four HRP-2/pLDH combination RDTs (Carestart™, First-Response®, Parascreen® and SD-Bioline®). The test results were compared with expert microscopy and nested PCR. End user experience of the RDTs in the field was assessed by questionnaire. Overall 950 were recruited and 98.7 % were asymptomatic. The prevalence of malaria was 3.0–3.4 % by RDTs, and 3.6, 5.0 and 6.6 % by field microscopy, expert microscopy and PCR, respectively. The geometric-mean parasite density was low (P. falciparum = 418, P. vivax = 147 parasites/µL). Compared with PCR, the overall sensitivity of the RDTs and field microscopy to detect any species was 24.6–31.1 %; specificities were >98.4 %. Relative to PCR, First-Response® had the best diagnostic accuracy (any species): sensitivity = 31.1 %, specificity = 98.9 % and diagnostic odds ratio = 39.0 (DOR). The DOR values for Carestart™, Parascreen®, SD-Bioline®, and field microscopy were 23.4, 23.7, 23.5 and 29.2, respectively. The sensitivity of Pan-pLDH bands to detect PCR confirmed P. vivax mono-infection were 8.6–13.0 %. The sensitivity of the HRP-2 band alone to detect PCR confirmed P. falciparum was 10.3–17.9 %. Pan-pLDH detected P. falciparum cases undetected by the HRP-2 band resulting in a better test performance when both bands were combined. First Response® was preferred by end-users for the overall practicality. The diagnostic accuracy to detect malaria among mostly asymptomatic pregnant women and perceived ease of use was slightly better with First-Response®, but overall, differences between the four RDTs were small and performance comparable to field microscopy. Combination RDTs are a suitable alternative to field microscopy to screen for malaria in pregnancy in rural Indonesia. The clinical relevance of low density malaria infections detected by PCR, but undetected by RDTs or microscopy needs to be determined.
BackgroundMalaria infection during pregnancy is associated with serious adverse maternal and birth outcomes. A randomised controlled trial in Papua, Indonesia, comparing the efficacy of intermittent preventive treatment with dihydroartemisinin-piperaquine with the current strategy of single screening and treatment showed that intermittent preventive treatment is a promising alternative treatment for the reduction of malaria in pregnancy. We aimed to estimate the incremental cost-effectiveness of intermittent preventive treatment with dihydroartemisinin-piperaquine compared with single screening and treatment with dihydroartemisinin-piperaquine.MethodsWe did a provider perspective analysis. A decision tree model was analysed from a health provider perspective over a lifetime horizon. Model parameters were used in deterministic and probabilistic sensitivity analyses. Simulations were run in hypothetical cohorts of 1000 women who received intermittent preventive treatment or single screening and treatment. Disability-adjusted life-years (DALYs) for fetal loss or neonatal death, low birthweight, moderate or severe maternal anaemia, and clinical malaria were calculated from trial data and cost estimates in 2016 US dollars from observational studies, health facility costings and public procurement databases. The main outcome measure was the incremental cost per DALY averted.FindingsRelative to single screening and treatment, intermittent preventive treatment resulted in an incremental cost of US$5657 (95% CI 1827 to 9448) and 107·4 incremental DALYs averted (–719·7 to 904·1) per 1000 women; the average incremental cost-effectiveness ratio was $53 per DALY averted.InterpretationIntermittent preventive treatment with dihydroartemisinin-piperaquine offers a cost-effective alternative to single screening and treatment for the prevention of the adverse effects of malaria infection in pregnancy in the context of the moderate malaria transmission setting of Papua. The higher cost of intermittent preventive treatment was driven by monthly administration, as compared with single-administration single screening and treatment. However, acceptability and feasibility considerations will also be needed to inform decision making.FundingMedical Research Council, Department for International Development, and Wellcome Trust.
Malaria infection during pregnancy is a significant global health problem with substantial risks for pregnant women, her foetus, and the newborn child. Infant malaria is a major public health concern in Timika, Papua. The aim of the study was to investigate the impact of malaria during pregnancy on infant’s susceptibility to malaria infections, the timing of its occurrence, the number of malaria infections during pregnancy. This was a cohort prospective study conducted in Timika, Papua from October 2013 to September 2016. Malaria investigation was done by microscopic and PCR methods. Demographic data and malaria status of mother-infant pairs were collected and analyzed by SPSS 22.0 version. One hundred seventy-eight infants consisting of 95 (53.37%) infants born to mothers with malaria and 83 (46.63%) without malaria 91 (51.12%) boys and 87 (48.88%) girls were involved in the study. The mean of mothers’ ages were 25.35 ± 6.30 vs. 26.0 ± 5.69 years. At the ages of 6 and 12 months, infants born to malaria positive mothers were more susceptible to malaria infections compared to infants born to malaria negative mothers with RR = 3.49; 95%CI: 1.02-11.96; p = 0.03 and RR = 8.74; 95%CI: 1.14- 66.81; p = 0.01, respectively. Independent risk factors of infant susceptibility to malaria infection during the first year of life were malaria in pregnancy (MiP) in 2nd trimester (RR = 4.50; 95%CI: 1.5-13.49; p = 0.07), pregnant women who only got malaria infection 1 time during pregnancy (RR=2.95; 95%CI: 1.04-8.33; p = 0.04), and Papuan ethnicity (RR=3.58; 95%CI: 1.22-10.59; p = 0.02). In conclusion, infant susceptibility to malaria is associated with maternal malaria status during pregnancy. MiP in second trimester, pregnant women who only had malaria once and Papuan ethnicity were independent risk factors for infant’s increased susceptibility to malaria infection.