Prevalence of molecular markers of sulfadoxine-pyrimethamine resistance in Plasmodium falciparum isolates from West Africa during 2012-2022.

Sulfadoxine-pyrimethamine (SP) is a key drug recommended by the World Health Organization for the chemoprevention of malaria. However, the strategy is affected by the parasite resistance to SP. This study evaluated Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes, associated with SP resistance, from 508 P. falciparum isolates imported from West African countries to Henan Province, China, during 2012-2022. High mutant prevalence of the genes Pfdhfr (94.7%) and Pfdhps (96.8%) was observed. The mutants Pfdhfr N51I, C59R, S108N, and Pfdhps A437G were at high frequency in all countries analyzed. The overall prevalence of the mutant Pfdhps K540E was low (3.4%), but with a high frequency in Liberia (24.3%). The frequency of mutants Pfdhps I431V, A581G, and A613S was 11.7%, 9.8%, and 16.2%, respectively, all of which had the highest mutant prevalence in Nigeria. The mutant Pfdhps A581G and A613S were identified in the absence of K540E. The partially resistant haplotype (I51R59N108 - G437) was the most common (72.6%), and the fully resistant haplotype (I51R59N108 - G437E540) had a low prevalence of 3.4% and mainly occurred in Liberia. No super resistant haplotype was identified. The mutant Pfdhps I431V and the octuple mutant haplotype I51R59N108 - V431A436G437G581S613 deserve more attention. In areas of high SP resistance, the intervention still reduces low birthweight and maternal anaemia. SP should continue to be used in areas of high SP resistance until more effective alternatives for malaria chemoprevention are found. It is important to continuously monitor the molecular markers associated with SP resistance to better implement intermittent preventive treatment policies in pregnancy (IPTp) and infants (IPTi).

Evolution of Pfdhps and Pfdhfr mutations before and after adopting seasonal malaria chemoprevention in Nanoro, Burkina Faso.

Seasonal Malaria Chemoprevention consisting of monthly administration of amodiaquine/sulfadoxine-pyrimethamine to children aged 3-59 months during the transmission season could promote SP-resistance. Mutations in dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes were assessed before and after SMC adoption in Burkina Faso. A total of 769 dried blood spots were selected from studies conducted in Nanoro, Burkina Faso, between 2010 and 2020. Of those, 299 were pre-SMC (2010-2012) and 470 were post-SMC-samples. Pfdhps and Pfdhfr genes were PCR-amplified and sequenced. A systematic review/meta-analysis of published studies conducted in Burkina Faso (2009-2023) was additionally performed. In Nanoro, the prevalence of Pfdhfr triple mutations (CIRNI) rose from 43.6% pre-SMC to 89.4% post-SMC (p < 0.0001). There was no mutation in Pfdhfr 164 and Pfdhps 540; Pfdhps A437G mutation increased from 63.9% (2010-2012) to 84.7% (2020) (p < 0.0001). The VAGKGS haplotype was 2.8% (2020). Pfdhfr/Pfdhps quintuple mutant IRN-436A437G rose from 18.6% (2010-2012) to 58.3% (2020) (p < 0.0001). Meta-analysis results from Burkina Faso showed an increase in mutations at Pfdhfr N51I, C59R, S108N, and Pfdhps A437G after SMC adoption. Post-SMC, the pyrimethamine-resistance marker prevalence increased, while the sulfadoxine-resistance marker prevalence remained stable. Detection of emerging PfdhpsVAGKGS haplotypes in 2020 underscores the importance of continuous SP-resistance monitoring.

Evaluation of nitazoxanide in the treatment of experimental murine neurotoxoplasmosis.

Toxoplasmosis is a widespread zoonotic disease that poses significant public health concern globally, with neurotoxoplasmosis being a severe complication associated with high mortality rates. The standard therapy for neurotoxoplasmosis involves a combination of sulfadiazine and pyrimethamine, which, despite its efficacy, is often limited by adverse effects leading to treatment discontinuation. This study aimed to evaluate the in vivo efficacy of nitazoxanide in treating neurotoxoplasmosis in mice infected with the Me49 strain. The study comprised two groups: Group I, including subgroups of uninfected, infected and treated with saline, and infected and untreated mice; and Group II, comprising infected mice treated with nitazoxanide at 100 mg/kg/day, nitazoxanide at 150 mg/kg/day, and pyrimethamine combined with sulfadiazine. After 14 days of treatment, the mice were euthanized for organ collection. Histopathological examination of the brains revealed that the highest dose of nitazoxanide reduced parasitic load and cerebral hemorrhages. Biochemical and histopathological analyses of liver and kidney tissues demonstrated toxicological profiles comparable to pyrimethamine and sulfadiazine. However, despite showing efficacy and similar toxicity levels, nitazoxanide treatment was less effective regimen in controlling neurotoxoplasmosis in this experimental model compared to the pyrimethamine and sulfadiazine. Thus, while nitazoxanide presents potential in neurotoxoplasmosis treatment, pyrimethamine combined with sulfadiazine remains the preferred therapeutic choice based on better efficacy observed in this study.

Adherence to sulfadoxine-pyrimethamine five-dose policy among pregnant women in an urban slum in Ghana: a mixed-methods study.

BACKGROUND: Malaria in pregnancy (MiP) is a public health concern especially for pregnant women living in slums. The World Health Organization recommends at least three doses of Sulfadoxine-Pyrimethamine (SP) to prevent MiP. In Ghana, it is recommended that pregnant women receive a minimum of five doses of the medication. This study sought to determine the level of adherence to IPT5 policy and factors associated with adherence among pregnant women in a slum community in Ghana. METHODS: This was a cross-sectional study involving 232 nursing mothers and four healthcare workers at the St. Martin's Memorial Hospital, Sukura, Ghana. Sociodemographic characteristics of nursing mothers were obtained using an interview-administered questionnaire. Data on the number of SP doses and other obstetrics characteristics were collected by reviewing the antenatal record books. To obtain information about healthcare and health system factors associated with adherence to the five-dose policy, four healthcare providers were interviewed. A data extraction form was used to obtain information about the availability of SP at the facility. RESULTS: The level of adherence to IPT5 was 8.6% (20/232) (95% CI 5.0-12.3) among the participants. Only 8.4% of the participants received their first dose at 16 weeks. Respondents who began ANC in the second trimester were 81% less likely to adhere to IPT5 than those who began in the first trimester (aOR = 0.19, 95% CI 90.01-0.65, p < 0.008). Healthcare provider and health system factors that influence IPT5 uptake include healthcare providers' knowledge of IPTp-SP guidelines, the practice of Directly Observed Therapy, education of pregnant women, training of healthcare providers, and availability of water. SP was available at the facility during the period of review. CONCLUSION: Adherence to the IPTp-SP five-dose policy was suboptimal. Pregnant women who started ANC early were more likely to adhere to the policy. Provider knowledge, DOT practice, training, education of pregnant women and water availability were also found to influence adherence. Encouraging early ANC visits and providing healthcare workers with necessary training can substantially improve adherence in slum areas.

REIV-TOXO Project: Results from a Spanish cohort of congenital toxoplasmosis (2015-2022). The beneficial effects of prenatal treatment on clinical outcomes of infected newborns.

BACKGROUND: Some regions of Spain are withdrawing their pregnancy screening program for congenital toxoplasmosis (CT). The Spanish Research Network of Congenital Toxoplasmosis (REIV-TOXO) was created to describe the current status of CT in Spain. The aims of this study were to describe the epidemiological and clinical characteristics of CT and to evaluate the effect of prenatal treatment on clinical outcomes to inform decision-making policies. METHODS: Ambispective observational study including CT cases recorded in the REIV-TOXO database that includes 122 hospitals (2015-2022). Inclusion criteria were one or more of the following: positive PCR in maternal amniotic fluid; positive Toxoplasma gondii-specific IgM or IgA antibodies at birth; positive PCR in the placenta, newborn blood, urine or CSF; increase of specific IgG levels during infant follow-up; or specific IgG persistence beyond age 12 months. FINDINGS: Fifty-six newborns (54 pregnancies) were included. Prenatal screening allowed 92.8% of cases to be identified. The time of maternal infection was well documented in 90.7% of cases, with 61.1% occurring in the third trimester. A total of 66.6% (36/54) pregnant women received antiparasitic treatment: 24/36 spiramycin, 8/36 pyrimethamine, sulfadiazine, and folinic acid, and 4/36 both treatments sequentially. Most cases were asymptomatic at birth (62.5%, 35/56), and 84% (47/56) newborns completed one year of treatment. Median follow-up was 24 months (IQR = 3-72): 14.2% children exhibited new complications, mainly ocular. Newborns born to mothers treated prenatally had four-fold lower risk of CT clinical features at birth (p = 0.03) and six-fold lower risk of further complications during follow-up (p = 0.04) with no treatment-related differences during pregnancy. CONCLUSIONS: While diagnosis based only on neonatal assessment misses a significant number of CT cases, prenatal screening allows treatment to be started during pregnancy, with better clinical outcomes at birth and during follow-up. REIV-TOXO provides valuable information about CT in Spain, highlighting the need for universal maternal screening.

Parasite clearance and protection from Plasmodium falciparum infection (PCPI): a three-arm, parallel, double-blinded, placebo-controlled, randomised trial of presumptive sulfadoxine-pyrimethamine versus sulfadoxine-pyrimethamine plus amodiaquine versus artesunate monotherapy among asymptomatic children 3-5 years of age in Cameroon.

BACKGROUND: The World Health Organization 2022 malaria chemoprevention guidelines recommend providing a full course of antimalarial treatment at pre-defined intervals, regardless of malaria status to prevent illness among children resident in moderate to high perennial malaria transmission settings as perennial malaria chemoprevention (PMC) with sulfadoxine-pyrimethamine (SP). The dhps I431V mutation circulating in West Africa has unknown effect on SP protective efficacy. METHODS: This protocol is for a three-arm, parallel, double-blinded, placebo-controlled, randomised trial in Cameroon among children randomly assigned to one of three directly-observed treatment groups: (i) Group 1 (n = 450) receives daily artesunate (AS) placebo on days - 7 to -1, then active SP plus placebo amodiaquine (AQ) on day 0, and placebo AQ on days 1 and 2; (ii) Group 2 (n = 250) receives placebo AS on days - 7 to -1, then active SP and AQ on day 0, and active AQ on days 1 and 2; and (iii) Group 3 (n = 200) receives active AS on days - 7 to -1, then placebo SP on day 0 and placebo AQ on days 0 to 2. On days 0, 2, 5, 7, and thereafter weekly until day 28, children provide blood for thick smear slides. Dried blood spots are collected on the same days and weekly from day 28 to day 63 for quantitative polymerase chain reaction (qPCR) and genotype analyses. DISCUSSION: Our aim is to quantify the chemopreventive efficacy of SP, and SP plus AQ, and measure the effect of the parasite genotypes associated with SP resistance on parasite clearance and protection from infection when exposed to SP chemoprevention. We will report unblinded results including: (i) time-to-parasite clearance among SP and SP plus AQ recipients who were positive on day 0 by qPCR and followed to day 63; (ii) mean duration of SP and SP plus AQ protection against infection, and (iii) mean duration of symptom-free status among SP and SP plus AQ recipients who were parasite free on day 0 by qPCR. Our study is designed to compare the 28-day follow-up of the new WHO malaria chemoprevention efficacy study protocol with extended follow-up to day 63. TRIAL REGISTRATION: ClinicalTrials.gov NCT06173206; 15/12/2023.

Knowledge, and attitude of service user of intermittent preventive treatment of malaria in pregnancy using sulfadoxine pyrimethamine in the Volta Region of Ghana.

BACKGROUND: Malaria in pregnancy (MiP) is a condition that can be prevented by using intermittent preventive treatment using Sulfadoxine-pyrimethamine. However, despite all the effort to reduce the consequences of MiP for the woman, the unborn child, and the neonate, the knowledge of Intermittent Preventive Treatment of Malaria in pregnancy using sulfadoxine-pyrimethamine (IPTp-SP) is low in most malaria-endemic countries, including Ghana. Thus, the need to examine knowledge, and attitude of service users of intermittent preventive treatment of malaria in pregnancy using sulfadoxine-pyrimethamine. METHODS: The study was a cross-sectional survey of two selected districts in the Volta Region of Ghana. The study participants were randomly selected from communities within Nkwanta North and North Tongu District. In all a total of 438 mothers who have delivered in the past 24 months were selected for the study. The women were interviewed using a structured questionnaire and the bivariate and multivariable logistic regression results presented in tables. RESULTS: The level of knowledge, and attitude were reported as 45.9% and 58.9% respectively. Knowledge of the service user is determined by the level of education of the women. The attitude of the service user is determined by making 4-7 visits during ANC, Gestational age at booking for ANC is 4-7 weeks, income level between 100 to 999, partner educational level above Middle/JHS/JSS, and age of a partner is above 40 years. CONCLUSION: The findings from the present studies highlighted important factor such as number of antenatal visits that affect both knowledge of services and attitude to use IPTp-SP. Therefore, a community-based health promotion programmes to help to increase knowledges and improved attitude on timely and regular antenatal attendance to promote the benefit of IPTp-SP should be encouraged.

Effectiveness of malaria chemoprevention in the first two years of life in Cameroon and Côte d'Ivoire compared to standard of care: study protocol for a population-based prospective cohort impact evaluation study.

BACKGROUND: Perennial malaria chemoprevention (PMC) is a chemoprevention strategy endorsed by the World Health Organization (WHO) and is increasingly being adopted by National Malaria Programmes. PMC aims to reduce morbidity and mortality caused by malaria and anaemia in in young children through provision of antimalarial drugs at routine contact points with the local health system. This study aims to evaluate the impact of the programmatically-implemented country-tailored PMC programmes targeting children up to two years of age using sulfadoxine-pyrimethamine (SP) on the incidence of malaria and anaemia in children in Cameroon and Côte d'Ivoire. METHODS: We will assess the impact of PMC using passive and active monitoring of a prospective observational cohort of children up to 36 months of age at recruitment in selected study sites in Cameroon and Côte d'Ivoire. The primary and secondary outcomes include malaria, anaemia and malnutrition incidence. We will also conduct a time-series analysis of passively detected malaria and anaemia cases comparing the periods before and after PMC introduction. This study is powered to detect a 30% and 40% reduction of malaria incidence compared to the standard of care in Cameroon and Côte d'Ivoire, respectively. DISCUSSION: This multi-country study aims to provide evidence of the effectiveness of PMC targeting children in the first two years of life on malaria and anaemia and will provide important information to inform optimal operationalization and evaluation of this strategy. TRIAL REGISTRATION: Cameroon - NCT05889052; Côte d'Ivoire - NCT05856357.

Impact of oral azithromycin and intermittent preventive treatment with sulfadoxine-pyrimethamine regimen on child mortality in Sierra Leone: trial protocol for a randomised, two-arm, double-blinded, placebo-controlled clinical trial (ICARIA).

BACKGROUND: Azithromycin has been shown to be beneficial in preventing infectious diseases, including malaria, infectious diarrhoea and pneumonia. A cluster randomised control trial on azithromycin MDA in children in Niger, Malawi and Tanzania found a reduction in all-cause under-five (U5) mortality in communities who received azithromycin compared to placebo. However, the reduction was largest and statistically significant only in Niger. The purpose of this trial is to evaluate the impact of azithromycin plus intermittent preventive treatment in infants (IPTi), recently renamed by the World Health Organisation as perennial malaria chemoprevention (PMC), with sulfadoxine-pyrimethamine (SP) on all-cause mortality up to 18 months of age in children living in areas of high mortality burden through the Expanded Program on Immunisation (EPI) in Sierra Leone. METHODS: The Improving Care through Azithromycin Research for Infants in Africa (ICARIA) trial is a phase III two-arm, individually randomised, double-blinded, placebo-controlled trial administering oral AZI (20 mg/kg bodyweight) at three time points to children attending EPI visits in Sierra Leone. A total of 20,560 infants attending the first EPI contact at around 6 weeks of age are recruited and randomised to AZI or placebo in a 1:1 ratio. The second and third AZI/placebo doses are given at 9 and 15 months of age. The primary outcome of the trial is all-cause mortality rate at 18 months of age assessed through mortality surveillance. Other trial outcomes include the impact on antimicrobial resistance, and on the immune response to certain key routine EPI immunisations, the safety of the intervention, the prevalence of SP resistance markers and the feasibility, and acceptability of adding AZI to the EPI programme. DISCUSSION: The trial will provide the evidence needed to inform policy regarding the adoption and large-scale implementation of AZI in areas of high-mortality burden in sub-Saharan Africa. TRIAL REGISTRATION: ClinicalTrials.gov NCT04235816. Registered on 22 January 2020. Pan-African Clinical Trials Registry PACTR202004540256535. Registered on 14 April 2020.

The demand for intermittent preventive treatment of malaria in pregnancy using sulfadoxine-pyrimethamine in the Volta Region of Ghana.

BACKGROUND: Malaria in pregnancy (MiP) is a preventable condition leading to maternal and neonatal morbidity and mortality. Invariably, with all the knowledge about the serious consequences of MiP for the woman, the unborn child, and the neonate, the uptake of Intermittent Preventive Treatment of Malaria in pregnancy using sulfadoxine-pyrimethamine (IPTp-SP) is low in most malaria-endemic countries, including Ghana. This study sought to examine the uptake and service user predictors of the implementation of IPTp-SP after the policy upgrade in 2014. METHODS: This cross-sectional survey was carried out in two selected districts in the Volta Region. The study participants were randomly selected from communities within Nkwanta North and North Tongu District. A total of 438 mothers who have delivered in the past 24 months were selected for the study. The women were interviewed on their background, knowledge, and attitude toward the use of IPTp-SP using a structured questionnaire. Multiple logistic regression was done to determine the factors that influence the demand for IPTp-SP. The results were presented in the form of tables. RESULTS: The mean number of antenatal care (ANC) attendance was 5 (SD:2.6) visits per client, with 262 (59.82%) of them getting the 3+ doses of IPTp-SP. Also, a significant 44 (10.1%) of the mothers did not receive any dose of IPTp-SP. Respondents who attended antenatal clinics 4-7 times had 7 (CI:3.9-12.3) times higher uptake of 3+ doses of IPTp-SP as compared to others who attended less than 4 visits. Similarly, women who had 8 or more visits had a 16.1 (CI: 5.9-43.6) times higher chance of getting more than 2 doses of IPTp-SP compared with others who had fewer than 4 attendances. CONCLUSION: The uptake of 3+ doses of IPTp-SP is still lower than the global target of 80%. Thus, the need for innovative interventions aimed at improving antenatal attendance and early booking for IPTp-SP are recommended.

Intermittent preventive treatment regimens for malaria in HIV-positive pregnant women.

BACKGROUND: Malaria and HIV infection overlap geographically in sub-Saharan Africa and share risk factors. HIV infection increases malaria's severity, especially in pregnant women. The World Health Organization (WHO) recommends intermittent preventive treatment in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) for pregnant women living in areas of stable malaria transmission. However, HIV-positive women on daily cotrimoxazole prophylaxis (recommended for prevention of opportunistic infections in people with HIV) cannot receive SP due to adverse drug interactions, so malaria prevention in this vulnerable population currently relies on daily cotrimoxazole prophylaxis alone. This review is based on a new protocol and provides an update to the 2011 Cochrane Review that evaluated alternative drugs for IPTp to prevent malaria in HIV-positive women. OBJECTIVES: To compare the safety and efficacy of intermittent preventive treatment regimens for malaria prevention in HIV-positive pregnant women. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, three other databases, and two trial registries to 31 January 2024. To identify relevant additional studies or unpublished work, we checked references and contacted study authors and other researchers working on malaria and HIV. SELECTION CRITERIA: We included randomized controlled trials (RCTs) comparing any intermittent preventive treatment regimen for preventing malaria in HIV-positive pregnant women against daily cotrimoxazole prophylaxis alone, placebo, current or previous standard of care, or combinations of these options. By 'standard of care' we refer to the country's recommended drug regimen to prevent malaria in pregnancy among HIV-positive women, or the treatment that a trial's research team considered to be the standard of care. DATA COLLECTION AND ANALYSIS: Review authors, in pairs, independently screened all records identified by the search strategy, applied inclusion criteria, assessed risk of bias in included trials, and extracted data. We contacted trial authors when additional information was required. We presented dichotomous outcomes using risk ratios (RRs), count outcomes as incidence rate ratios (IRRs), and continuous outcomes as mean differences (MDs). We presented all measures of effect with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach for what we considered to be the main comparisons and outcomes. MAIN RESULTS: We included 14 RCTs, with a total of 4976 HIV-positive pregnant women initially randomized. All trials assessed the efficacy and safety of one antimalarial used as IPTp (mefloquine, dihydroartemisinin/piperaquine, SP, or azithromycin) with or without daily cotrimoxazole, compared to daily cotrimoxazole alone, placebo, or a standard of care regimen. We grouped the trials into nine comparisons. Our main comparison evaluated the current standard of care (daily cotrimoxazole) with another drug regimen (mefloquine or dihydroartemisinin/piperaquine) versus daily cotrimoxazole with or without placebo. In this comparison, two trials evaluated mefloquine and three evaluated dihydroartemisinin/piperaquine. We conducted meta-analyses that included trials evaluating dihydroartemisinin/piperaquine plus cotrimoxazole, and trials that evaluated mefloquine plus cotrimoxazole, as we considered there to be no qualitative or quantitative heterogeneity among trials for most outcomes. We considered drug-related adverse events and HIV-related outcomes to be drug-specific. Daily cotrimoxazole prophylaxis plus another drug regimen (mefloquine or dihydroartemisinin/piperaquine) probably results in lower risk of maternal peripheral parasitaemia at delivery (RR 0.62, 95% CI 0.41 to 0.95; 2406 participants, 5 trials; moderate-certainty evidence). It results in little or no difference in maternal anaemia cases at delivery (RR 0.98, 95% CI 0.90 to 1.07; 2417 participants, 3 trials; high-certainty evidence). It probably results in a decrease in placental malaria measured by blood smear (RR 0.54, 95% CI 0.31 to 0.93; 1337 participants, 3 trials; moderate-certainty evidence), and probably results in little or no difference in low birth weight (RR 1.16, 95% CI 0.95 to 1.41; 2915 participants, 5 trials; moderate-certainty evidence). There is insufficient evidence to ascertain whether daily cotrimoxazole prophylaxis plus another drug regimen affects the risk of cord blood parasitaemia (RR 0.27, 95% CI 0.04 to 1.64; 2696 participants, 5 trials; very low-certainty evidence). Daily cotrimoxazole prophylaxis plus another drug regimen probably results in little or no difference in foetal loss (RR 1.03, 95% CI 0.73 to 1.46; 2957 participants, 5 trials; moderate-certainty evidence), and may result in little or no difference in neonatal mortality (RR 1.21, 95% CI 0.68 to 2.14; 2706 participants, 4 trials; low-certainty evidence). Due to the probability of an increased risk of mother-to-child HIV transmission and some adverse drug effects noted with mefloquine, we also looked at the results for dihydroartemisinin/piperaquine specifically. Dihydroartemisinin/piperaquine plus daily contrimoxazole probably results in little to no difference in maternal peripheral parasitaemia (RR 0.59, 95% CI 0.31 to 1.11; 1517 participants, 3 trials; moderate-certainty evidence) or anaemia at delivery (RR 0.95, 95% CI 0.82 to 1.10; 1454 participants, 2 trials; moderate-certainty evidence), but leads to fewer women having placental malaria when measured by histopathologic analysis (RR 0.67, 95% CI 0.50 to 0.90; 1570 participants, 3 trials; high-certainty evidence). The addition of dihydroartemisinin/piperaquine to daily cotrimoxazole probably made little to no difference to rates of low birth weight (RR 1.13, 95% CI 0.87 to 1.48; 1695 participants, 3 trials), foetal loss (RR 1.14, 95% CI 0.68 to 1.90; 1610 participants, 3 trials), or neonatal mortality (RR 1.03, 95% CI 0.39 to 2.72; 1467 participants, 2 trials) (all moderate-certainty evidence). We found low-certainty evidence of no increased risk of gastrointestinal drug-related adverse events (RR 1.42, 95% CI 0.51 to 3.98; 1447 participants, 2 trials) or mother-to-child HIV transmission (RR 1.54, 95% CI 0.26 to 9.19; 1063 participants, 2 trials). AUTHORS' CONCLUSIONS: Dihydroartemisinin/piperaquine and mefloquine added to daily cotrimoxazole seem to be efficacious in preventing malaria infection in HIV-positive pregnant women compared to daily cotrimoxazole alone. However, increased risk of HIV transmission to the foetus and poor drug tolerability may be barriers to implementation of mefloquine in practice. In contrast, the evidence suggests that dihydroartemisinin/piperaquine does not increase the risk of HIV mother-to-child transmission and is well tolerated.

Knowledge, attitude and practices on intermittent preventive treatment in pregnant women with malaria: a mixed method facility-based study in Western Kenya.

Introduction: intermittent preventive treatment remains a core strategy for malaria prevention in pregnancy. Sulfadoxine-pyrimethamine is recommended for all pregnant women in malaria-prone zones. It is scheduled monthly at each antenatal care visit for up to 36 weeks. Here, we sought to assess the knowledge, attitude, and practices of intermittent preventive treatment among pregnant women with malaria in Webuye Hospital. Methods: a total of 140 participants aged between 18 and 49 years and at approximately 16 weeks of gestation were enrolled in this study, which utilized a mixed qualitative-quantitative method. Before enrollment, malaria testing was conducted using microscopy, and participants were divided into two cohorts: malaria-positive and malaria-negative. Close-ended and open-ended questionnaires were used. Qualitative-quantitative data analyses were performed. Results: our analysis revealed a significant difference between the proportion of mothers in the negative and positive groups in terms of their knowledge about side effects (p ≤ 0.001) and different doses (p ≤ 0.012) of intermittent preventive treatment. The proportion of mothers who knew side effects and different doses was higher among the malaria-positive group as compared to malaria-negative group with 37(52.9%, n=70) versus 18(25.7%, n=70) and 14(20.0%, n=70) versus 4(5.7%, n=70) respectively. Additionally, there was also a significant difference in knowledge about intermittent preventive treatment before administration (p ≤ 0.003) between the two groups. Conclusion: good knowledge, attitude and practices on intermittent preventive treatment (IPT) benefits, side effects, safety, doses and other prior information should be leveraged to empower pregnant women in malaria-endemic zones.

Delivery effectiveness of and adherence to intermittent preventive treatment for malaria in pregnancy with dihydroartemisinin-piperaquine with or without targeted information transfer or sulfadoxine-pyrimethamine in western Kenya: a three-armed, pragmatic, open-label, cluster-randomised trial.

BACKGROUND: High-level resistance to sulfadoxine-pyrimethamine threatens the efficacy of WHO-recommended intermittent preventive treatment in pregnancy (IPTp) with single-dose sulfadoxine-pyrimethamine to prevent malaria. Monthly IPTp with dihydroartemisinin-piperaquine, a 3-day regimen, is an emerging alternative, but this regimen poses potential implementation and adherence challenges. We aimed to assess adherence to a multiday IPTp with dihydroartemisinin-piperaquine regimen and its delivery effectiveness in routine antenatal care settings in western Kenya. METHODS: We conducted a pragmatic, three-armed, open-label, cluster-randomised trial in antenatal clinics in 18 health-care facilities (six facilities per group) in Kisumu County and Homa Bay County in western Kenya. Clusters were facilities offering routine antenatal care services provided by trained Ministry of Health staff with 100 or more antenatal clinic attendances per month between July, 2018, and June, 2019. Private or mission hospitals, dispensaries, referral hospitals, and trial sites were excluded. Individuals in their first trimester, living with HIV, or who were not attending a scheduled antenatal clinic visit were excluded. The 18 antenatal clinics were grouped into matched triplets stratified by location and clinics in each matched triplet were randomly assigned to one of the three study groups (1:1:1). Masking was not possible. Two groups were given IPTp with dihydroartemisinin-piperaquine (one group with a targeted information transfer intervention and one group without any additional interventions) and one group was given the standard of care (ie, IPTp with sulfadoxine-pyrimethamine). The primary endpoint, adherence, was defined as the proportion of participants completing their most recent 3-day IPTp with dihydroartemisinin-piperaquine regimen. This completion was verified by pill counts during home visits no more than 2 days after participants' 3-day regimens ended. The secondary endpoint, delivery effectiveness, was defined as the proportion of participants who received the correct number of IPTp tablets and correctly repeated dosing instructions (ie, correctly recalled the instructions they received about self-administered dihydroartemisinin-piperaquine doses and the number of sulfadoxine-pyrimethamine tablets they had received) at their exit from the antenatal clinic. Individuals receiving treatment for malaria, visiting a clinic for registration only, or interviewed during IPTp drug stock-outs were excluded from analyses. We used generalised linear mixed models to compare endpoints among the IPTp with dihydroartemisinin-piperaquine groups. This trial was registered with ClinicalTrials.gov, NCT04160026, and is complete. FINDINGS: 15 facilities (five per group) completed the trial, with 1189 participants having exit interviews (377 in the IPTp with sulfadoxine-pyrimethamine group, 408 in the IPTp with dihydroartemisinin-piperaquine only group, and 404 in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group) and 586 participants having home visits (267 in the IPTp with dihydroartemisinin-piperaquine only group and 319 in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group) from Sept 8 to Dec 10, 2020. Relative to the IPTp with dihydroartemisinin-piperaquine only group, adherence was 16% higher in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group (266 [83%] of 319 participants vs 196 [73%] of 267 participants; adjusted relative risk [RR] 1·16, 95% CI 1·03-1·31; p=0·0140). Delivery effectiveness in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group was not significantly different from that in the IPTp with sulfadoxine-pyrimethamine group (352 [87%] of 403 participants vs 335 [89%] of 375 participants; adjusted RR 0·97, 95% CI 0·90-1·05; p=0·4810). However, delivery effectiveness in the IPTp with dihydroartemisinin-piperaquine only group was significantly lower than in the IPTp with sulfadoxine-pyrimethamine group (300 [74%] of 404 participants vs 335 [89%] of 375 participants; 0·84, 0·75-0·95; p=0·0030). INTERPRETATION: Targeted information transfer interventions to health-care providers and pregnant individuals boost antenatal care delivery adherence to a multiday regimen with dihydroartemisinin-piperaquine. FUNDING: European and Developing Countries Clinical Trials Partnership 2, UK Joint Global Health Trials Scheme of the Foreign, Commonwealth and Development Office, Medical Research Council, National Institute for Health and Care Research, and Wellcome Trust; and Swedish International Development Cooperation Agency.

folA thyA knockout E. coli as a suitable surrogate model for evaluation of antifolate sensitivity against PfDHFR-TS.

A new superior bacteria complementation model was achieved for testing antifolate compounds and investigating antifolate resistance in the dihydrofolate reductase (DHFR) enzyme of the malaria parasite. Earlier models depended on the addition of trimethoprim (TMP) to chemically suppress the host Escherichia coli (Ec) DHFR function. However, incomplete suppression of EcDHFR and potential interference of antibiotics needed to maintain plasmids for complementary gene expression can complicate the interpretations. To overcome such limitations, the folA (F) and thyA (T) genes were genetically knocked out (Δ) in E. coli BL21(DE3). The resulting EcΔFΔT cells were thymidine auxotroph where thymidine supplementation or functional complementation with heterologous DHFR-thymidylate synthase (TS) is needed to restore the loss of gene functions. When tested against pyrimethamine (PYR) and its analogs designed to target Plasmodium falciparum (Pf) DHFR-TS, the 50 % inhibitory concentration values obtained from EcΔFΔT surrogates expressing wildtype (PfTM4) or double mutant (PfK1) DHFR-TS showed strong correlations to the results obtained from the standard in vitro P. falciparum growth inhibition assay. Interestingly, while TMP had little effect on the susceptibility to PYR and analogs in EcΔFΔT expressing PfDHFR-TS, it hypersensitized the chemically knockdown E. coli BL21(DE3) expressing PfTM4 DHFR-TS but desensitized the one carrying PfK1 DHFR-TS. The low intrinsic expression level of PfTM4 in E. coli BL21(DE3) by western blot analysis may explain the hypersensitive to antifolates of chemical knockdown bacteria surrogate. These results demonstrated the usefulness of EcΔFΔT surrogate as a new tool for antifolate antimalarial screening with potential application for investigation of antifolate resistance mechanism.

Prevalence and dynamics of antimalarial drug resistance mutations among the Plasmodium falciparum isolates in TAK Province, Thailand, during the period of 1998-2001.

Despite the overall decline in malaria cases in Thailand, continuous surveillance in endemic areas remains crucial. This retrospective analysis examined Plasmodium falciparum samples from Tak province, Thailand, collected in 1998, 1999, and 2001, to investigate the prevalence and evolution of antimalarial genotypic drug resistance. The study revealed a high prevalence of drug-resistant P. falciparum, particularly to mefloquine and sulfadoxine/pyrimethamine, with significant mutations in genes associated with resistance. Notably, mutations indicative of artemisinin resistance, such as those in the kelch13 gene, were detected at low frequencies, suggesting an evolving resistance pattern. The underlying cause of these resistance mutations appears to be the historical and widespread use of these antimalarial drugs, which exerted selective pressure on the parasite population. These findings underscore the necessity of ongoing surveillance and adaptive control strategies to manage drug resistance, guide treatment policies, and prevent potential outbreaks, even as malaria cases decrease. Continuous monitoring and research are imperative to sustain malaria elimination efforts and address the dynamic challenges posed by evolving drug-resistant strains.

A retrospective analysis of P. falciparum drug resistance markers detects an early (2016/17) high prevalence of the k13 C469Y mutation in asymptomatic infections in Northern Uganda.

The emergence of drug-resistant Plasmodium falciparum parasites in sub-Saharan Africa will substantially challenge malaria control. Here, we evaluated the frequency of common drug resistance markers among adolescents from Northern Uganda with asymptomatic infections. We used an established amplicon deep sequencing strategy to screen dried blood spot samples collected from 2016 to 2017 during a reported malaria epidemic within the districts of Kitgum and Pader in Northern Uganda. We screened single-nucleotide polymorphisms within: kelch13 (Pfk13), dihydropteroate synthase (Pfdhps), multidrug resistance-1 (Pfmdr1), dihydrofolate reductase (Pfdhfr), and apical membrane antigen (Pfama1) genes. Within the study population, the median age was 15 years (14.3-15.0, 95% CI), and 54.9% (78/142) were Plasmodium positive by 18S rRNA qPCR, which were subsequently targeted for sequencing analysis. We observed a high frequency of resistance markers particularly for sulfadoxine-pyrimethamine (SP), with no wild-type-only parasites observed for Pfdhfr (N51I, C59R, and S108N) and Pfdhps (A437G and K540E) mutations. Within Pfmdr1, mixed infections were common for NF/NY (98.5%). While for artemisinin resistance, in kelch13, there was a high frequency of C469Y (34%). Using the pattern for Pfama1, we found a high level of polygenomic infections with all individuals presenting with complexity of infection greater than 2 with a median of 6.9. The high frequency of the quintuple SP drug-resistant parasites and the C469Y artemisinin resistance-associated mutation in asymptomatic individuals suggests an earlier high prevalence than previously reported from symptomatic malaria surveillance studies (in 2016/2017). Our data demonstrate the urgency for routine genomic surveillance programs throughout Africa and the value of deep sequencing.

Adaptation of lot quality assurance sampling to monitor seasonal malaria chemoprevention delivery performance.

Malaria Consortium supports delivery of seasonal malaria chemoprevention (SMC) to children ages 3-59 months using sulfadoxine-pyrimethamine plus amodiaquine. Lot quality assurance sampling (LQAS) was adapted as a cost-efficient method for end-of-cycle SMC monitoring surveys across supported countries and an implementation challenges reporting system was established in Nigeria. We present a case study of its application in Nasarawa State. LQAS facilitated timely local performance assessment across 16 indicators. Development of new reporting tools has played a key role in stimulating national-level discussions on improvements to SMC supervisory processes and implementer training and provided a framework for engagement with local stakeholders.

Community-based strategies to increase coverage of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine in sub-Saharan Africa: a systematic review, meta-analysis, meta-ethnography, and economic assessment.

BACKGROUND: Community-based approaches might increase uptake of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP). We assessed the effects of community-based approaches on IPTp-SP and antenatal care coverage, and barriers and facilitators to implementation in sub-Saharan Africa. METHODS: We did a systematic review, meta-analysis, meta-ethnography, and economic assessment. We searched the WHO International Clinical Trials Registry Platform, PubMed, the Malaria in Pregnancy Library database, Medline, Global Health and Global Health Archives, and the Cochrane Library for trials, mixed-methods, qualitative, and cost-effectiveness studies of community health worker promotion of antenatal care, IPTp-SP delivery, or both, with no language restrictions, published before March 21, 2024. Information on interventions, number of IPTp-SP doses, antenatal care visits, and barriers and facilitators were extracted. We did a meta-analysis (random effects) comparing effects on two or more or three or more IPTp-SP doses and one or more or four or more antenatal care visits. We followed Noblit and Hare's method of meta-ethnography to synthesise qualitative findings, using reciprocal translation and line-of-argument synthesis. We developed a theory for increased community IPTp-SP uptake. We also summarised cost and cost-effectiveness studies. This study is registered with PROSPERO, CRD42022364114. FINDINGS: Of 4753 records screened, we included 23 (0·5%) reporting on 15 studies. Community health worker involvement was associated with an increase in two or more IPTp-SP doses (pooled risk ratio 1·48, [95% CI 1·24-1·75]; 12 sub-studies; I2 94·7%) and three or more IPTp-SP doses (1·73 [1·19-2·50]; ten sub-studies, I2 97·5%), with no decrease in four or more antenatal care visits (1·17 [1·00-1·36]; 13 sub-studies; I2 90·3%). Cluster-randomised controlled trials showed a lower increase in coverage of three or more IPTp-SP doses (1·08 [1·00-1·16]; I2 0·0%; six studies) compared with before-and-after studies (2·86 [1·29-6·33]; I2 98·9%; four studies; subgroup analysis p=0·019). Barriers to community health worker delivery of IPTp-SP included women's fear of side-effects, lack of knowledge, lack of trust in community health workers, and sociocultural factors. Community sensitisation, engagement of husbands, pre-established community health worker networks, and trained and supported community health workers facilitated IPTp-SP delivery by community health workers. Incremental cost-effectiveness ratios ranged from $1·1 to $543 per disability-adjusted life-year averted. INTERPRETATION: Community-based approaches increased IPTp-SP coverage and might have a positive effect on the number of antenatal care visits in addition to being cost-effective, although we found high heterogeneity among studies. Community sensitisation and engagement in addition to established, trained, and supported community health workers can facilitate acceptability, delivery, and uptake of IPTp-SP delivered by community health workers. FUNDING: EDCTP-2 supported by the European Union. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Prevalence of mutations associated with artemisinin partial resistance and sulfadoxine-pyrimethamine resistance in 13 regions in Tanzania in 2021: a cross-sectional survey.

BACKGROUND: The emergence of the artemisinin partial resistance (ART-R) mutation in the Plasmodium falciparum kelch13 gene (k13), Arg561His, in Rwanda and the regional presence of polymorphisms affecting sulfadoxine-pyrimethamine have raised concern in neighbouring Tanzania. The goal of this study was to assess the status of antimalarial resistance in Tanzania, with a focus on the border with Rwanda, to understand the distribution of the Arg561His mutation, partner drug resistance, and resistance to chemoprevention drugs. METHODS: In this cross-sectional survey, capillary dried blood spots were collected from malaria positive asymptomatic individuals in the community and symptomatic individuals in health facilities aged 6 months and older, in 13 regions of mainland Tanzania from Jan 31 to June 26, 2021. Exclusion criteria included residence of the areas other than the target sites, presenting to the health facility for care and treatment of conditions other than malaria, and not providing informed consent. Samples were assessed for antimalarial resistance polymorphisms and genetic relatedness using molecular inversion probes targeting P falciparum and short-read whole-genome sequencing. The primary outcome was the prevalence of molecular markers of antimalarial resistance at the region level, as well as at the district level in Kagera, a region in the northwest of the country at the border with Rwanda. FINDINGS: 6855 (88·1%) of 7782 capillary dried blood spot samples collected were successfully genotyped. The overall prevalence of k13 Arg561His in Kagera was 7·7% (90% CI 6·0-9·4; 50 of 649), with the highest prevalence in the districts near the Rwandan border (22·8% [31 of 136] in Karagwe, 14·4% [17 of 118]) in Kyerwa, and 1·4% [two of 144] in Ngara). k13 Arg561His was uncommon in the other regions. Haplotype analysis suggested that some of these parasites are related to isolates collected in Rwanda in 2015, supporting regional spread of Arg561His. However, a novel k13 Arg561His haplotype was observed, potentially indicating a second origin in the region. Other validated k13 resistance polymorphisms (one Arg622Ile and two Ala675Val isolates) were also identified. A region of prevalent dihydrofolate reductase Ile164Leu mutation, associated with sulfadoxine-pyrimethamine resistance, was also identified in Kagera (15·2% [12·6-17·8%]; 80 of 526). The mutant crt Lys76Thr mutation, associated with chloroquine and amodiaquine resistance, was uncommon, occurring only in 75 of 2861 genotyped isolates, whereases the wild-type mdr1 Asn86Tyr allele, associated with reduced sensitivity to lumefantrine, was found in 99·7% (3819 of 3830) of samples countrywide. INTERPRETATION: These findings show that the k13 Arg561His mutation is common in northwest Tanzania and that multiple emergences of ART-R, similar as to what was seen in southeast Asia, have occurred. Mutations associated with high levels of sulfadoxine-pyrimethamine resistance are common. These results raise concerns about the long-term efficacy of artemisinin and chemoprevention antimalarials in the region. Understanding how multiple emergences interact with drivers of regional spread is essential for combating ART-R in Africa. FUNDING: This study was funded by the Bill & Melinda Gates Foundation and the National Institutes of Health.

Determinants of the optimal uptake of sulfadoxine-pyrimethamine doses for intermittent treatment of malaria in pregnancy in urban Nigeria.

Malaria is a leading cause of maternal and child mortality in urban Nigeria. Intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) during pregnancy can prevent malaria but uptake is suboptimal. This cross-sectional study analyzed secondary data on 1159 urban Nigerian women from the 2015 Malaria Indicator Survey using descriptive statistics and logistic regression. The primary outcome was optimal IPTp-SP uptake (≥ 3 doses). 67% of women took any SP during pregnancy but only 39% took ≥ 3 IPTp-SP doses as recommended. Region and wealth index significantly predicted optimal IPTp-SP uptake while education did not. Women from lower-income regions in the urban areas were less likely to receive optimal IPTp-SP. Strategies to increase IPTp-SP uptake in urban Nigeria should target low-income regions and women of lower socioeconomic status. Logistic regression identified actionable factors for improving antenatal malaria prevention. Optimal IPTp-SP uptake remains suboptimal across urban Nigeria, threatening maternal and child health.