Prevalence Of Parasitaemia Research Articles

Prevalence of asymptomatic parasitaemia among household members of children under seasonal malaria chemoprevention coverage and comparison of the performance of standard rapid diagnostic tests versus ultrasensitive RDT for the detection of asymptomatic parasitaemia in Nanoro, Burkina Faso.

Asymptomatic carriers of Plasmodium falciparum represent important parasite reservoirs maintaining malaria transmission in the community. This study aimed on the one hand to screen the other household members living with children under seasonal malaria chemoprevention (SMC) coverage in order to determine the level of malaria infection in this population and on the other hand to determine the appropriate type of rapid diagnostic test (RDT) for this screening to detect these asymptomatic carriers in the community. During the 2022 SMC campaign (July to October), a cross-sectional survey was carried out in 745 participants who were screened by ultrasensitive rapid diagnostic test (usRDT), standard rapid diagnostic test (rRDT) and microscopy. Out of them, 395 had microscopy results available and were included in the data analysis. The prevalence of asymptomatic carriers of asexual forms of Plasmodium falciparum was 26.58% (105/395) while sexual forms were found in 5.32% (21/395) of the study population. Children from 5 to 15 years had the highest prevalence of P. falciparum asexual forms 35.76% (59/165) compared with older participants. Malaria positivity rate for rRDT and usRDT was 29.40% (219/745) and 40.49% (305/745) respectively. The usRDT had a higher sensitivity than the rRDT (72.38% (95% CI 62.8-80.66) vs. 60.95% (95% CI 50.94-70.33)). In terms of specificity, rRDT had a higher specificity 82.41% (95% CI 77.53-86.62) versus 69.66% (95% CI 64.01-74.89) for usRDT. This study reports a high prevalence of parasite carriers in household members of children under SMC coverage in Nanoro, Burkina Faso. In conclusion, usRDT seems more appropriate for strategies based on detection and treatment of parasite carriers within the community.

Association of first-line combination antiretroviral therapy with malaria among adult HIV-infected persons in Jos, Nigeria: a pilot cross sectional study

BackgroundMalaria and human immunodeficiency virus (HIV) infection coexist in significant numbers in some geographic areas including sub-Sahara Africa (SSA). HIV-infected patients are a World Health Organization (WHO) recognized high risk group for increased malaria morbidity. Majority of HIV-infected patients undertaking treatment in SSA are on WHO recognized first-line combination antiretroviral therapy (cART). Considering the immunity-enhancing capacity of antiretroviral therapies on people living with HIV, this study aimed to explore the association between first-line combination antiretroviral therapy (cART) with malaria parasitaemia and antigenaemia in adult HIV-infected persons and to determine the predictors of malaria antigenaemia in adult persons living with HIV.MethodsThe study was conducted at the AIDS Prevention Initiative in Nigeria (APIN) Centre, Jos University Teaching Hospital, Jos, Plateau State, from August 2018 to February 2019. Epi Info statistical tool was used to determine the sample size and power of the study. The study population consisted of three groups. The first group comprised first-line cART-experienced adult HIV-seropositive subjects, the second group comprised ARV-naïve HIV-seropositive adults and the third group comprised HIV-seronegative adults. For this pilot study, 60 persons were recruited into each group via convenience sampling. Malaria rapid diagnostic test (RDT) was performed according to manufacturer’s instruction for all the study participants using SD Bioline Malaria Ag P.f (HRP2/pLDH) (Standard Diagnostics, Hagal-Dong, Korea). All the study participants also had thick and thin blood film malaria microscopy. Data collected was processed and analyzed using the Stata statistical software version 15 (StataCorp, College Station, Texas). Chi square was used to test the association between malaria and first-line cART exposure. Univariate and multivariate analysis were also done to identify factors that were independently associated with malaria antigenaemia.ResultsA total of 180 persons participated in the study and involved 60 participants recruited in each of the three study groups. Overall, the predominant study participants were females (56.67%), traders (27.78%), secondary school leavers (43.33%) and urban dwellers (88.89%). Their mean age and standard deviation was 37.07 ± 11.53 years. Using malaria microscopy, the prevalence of malaria parasitaemia in ARV-naïve HIV-infected persons was 5% and 0% in the first-line cART-experienced HIV-infected persons as well as the HIV-negative persons. Malaria RDT result was positive in 7/60 (11.67%) of the first-line cART experienced HIV-infected participants, 6/60 (10%) of the ARV-naïve HIV-infected group and 1/60 (1.67%) of the HIV-negative group. Of the seven positive malaria RDT results in those on first-line cART, five persons were receiving zidovudine/lamivudine/nevirapine (AZT/3TC/NVP) while the remaining two were receiving tenofovir disoproxil fumarate/lamivudine/efavirenz (TDF/3TC/EFV), thus making an antigenaemia proportion of 16.67% and 6.67% respectively. Being an HIV-infected person on first-line cART (OR = 16.20, p = 0.04), having a headache (OR = 6.21, p = 0.03) and non-usage of window nets (OR = 3.74, p = 0.05) were found to be predictors of malaria antigenaemia.ConclusionMalaria parasite burden in HIV-infected persons on first-line cART is lower than that observed in ARV-naïve HIV-infected persons. Our study suggests that TDF/3TC/EFV may be associated with lower malaria antigenaemia when compared with AZT/3TC/NVP and can be considered an alternative first-line antiretroviral regimen in malaria-endemic regions.

Asymptomatic Plasmodium falciparum and HBV coinfections among inmates at Owo Correctional Facility, Nigeria

BackgroundMalaria and hepatitis B are significant public health infections in Nigeria. Coinfection with both pathogens is common where both diseases are endemic. Epidemiological surveys are essential for determining the burden of diseases and possible coinfection with multiple pathogens in vulnerable populations. There has been a lack of reports on HBV/malaria coinfection, particularly among marginalized groups in Ondo State. Thus, we used malaria microscopy and the HBsAg serological test to examine the prevalence of asymptomatic malaria parasitemia and HBV infections respectively among inmates at the Nigerian Correctional Center in Owo, Ondo State, Nigeria.ResultsOut of the 126 prisoners and staff members who were evaluated, 20.6% and 7.9% tested positive for malaria and HBV infections, respectively. It was discovered that 1.6% of the individuals were coinfected with malaria and HBV. Plasmodium falciparum was the only malaria species recovered in malaria-infected individuals. Except for HBV, where gender was found to differ considerably with the proportion of HBV infection, variations in single infections with either pathogen did not vary with demographic characteristics.ConclusionWe suggest that the prison system should be considered in healthcare programs to improve the health of inmates.

Prevalence of dengue virus infection and malaria parasitemia among febrile patients attending the University of Jos health clinic, Plateau State, Nigeria.

Prevalence of dengue virus infection and malaria parasitemia among febrile patients attending the University of Jos health clinic, Plateau State, Nigeria.

Investigation on Malaria Parasitaemia, Knowledge and Attitudes towards Mosquito Control among Residents of Wukari Metropolis

This study was conducted to investigate malaria parasitaemia, knowledge and attitudes towards mosquito control. 162 subjects were selected at random from different locations in Wukari Metropolis and were examined for malaria parasitaemia. Blood samples from each of the subjects were collected by finger pricking for the determination of malaria parasite using the Rapid Diagnostic Test method. Out of 162 samples examined, the prevalence of malaria parasitaemia was 91(56.17%). Female subjects had the highest prevalence of malaria parasitaemia of (72.0%), while the male had (35.0%) and the difference was statistically significant (p<0.05) between the rate of infection and gender. Age group ≥20 years recorded the highest infection rate of (62.12%), age group 14-16 years had the lowest infection rate of (48.94%), and there was no significant difference p>0.05 between malaria prevalence and age groups. The hospital location had the highest prevalence of malaria parasitaemia at (64.44%) and (31.89%) within malaria, while the Fuwukari location had the least prevalence of malaria parasitaemia of (47.22%) and (18.68%) within malaria. The test on knowledge and awareness of malaria indicates that (31.48%) of the subjects have erroneous perception about the cause and means through which malaria is transmitted. It can be concluded that despite the high infectivity rate of malaria in the study area there is much knowledge and awareness of malaria in the study. There is a need for a comprehensive strategy for preventing malaria transmission such as effective use of insecticide-treated nets, public awareness campaigns, proper environmental sanitation and use of drugs.

Parasitic Effects on the Congenital Transmission of Trypanosoma cruzi in Mother-Newborn Pairs.

Maternal parasitemia and placental parasite load were examined in mother-newborn pairs to determine their effect on the congenital transmission of Trypanosoma cruzi. Parasitemia was qualitatively assessed in mothers and newborns by the microhematocrit test; parasite load was determined in the placental tissues of transmitting and non-transmitting mothers by the detection of T. cruzi DNA and by histology. Compared to transmitter mothers, the frequency and prevalence of parasitemia were found to be increased in non-transmitter mothers; however, the frequency and prevalence of parasite load were higher among the transmitter mothers than among their non-transmitter counterparts. Additionally, serum levels of interferon (IFN)-γ were measured by an enzyme-linked immunosorbent assay (ELISA) in peripheral, placental, and cord blood samples. Median values of IFN-γ were significantly increased in the cord blood of uninfected newborns. The median IFN-γ values of transmitter and non-transmitter mothers were not significantly different; however, non-transmitter mothers had the highest total IFN-γ production among the group of mothers. Collectively, the results of this study suggest that the anti-T. cruzi immune response occurring in the placenta and cord is under the influence of the cytokines from the mother's blood and results in the control of parasitemia in uninfected newborns.

Prevalence of Malaria and Helicobacter Pylori Coinfection and Associated Sociodemographic Factors among Blood Donors in Douala General Hospital

Background: The malaria parasite Plasmodium is intra-erythrocyte hence can be transmitted by transfusion of any blood component containing infected red blood cells. Helicobacter pylori infection affects more than half of the human population worldwide. Infection remains asymptomatic in most individuals, although some individuals develop acute gastritis, peptic or duodenal ulcers, gastric cancer, and mucosa associated tissue lymphoma. H. pylori infection have been implicated in some haematological manifestations such as anaemia and micronutrient deficiency. Objective: This research was designed to determine the prevalence of malaria parasitaemia and H. pylori coinfection in association with sociodemographic characteristics among donors in Douala General Hospital. Methodology: The study was a hospital-based study carried out from January to May 2022. The study population comprised of 106 donors who came to the hospital laboratory for blood donation. A structured questionnaire was used to get demographic and clinical data. Two ml of blood was collected from individuals to prepare a thick and thin blood film for malaria parasite determination and to centrifuge at 3000 rpm for 5 minutes to obtain plasma for H. pylori test strip. Results and Discussion: The overall prevalence of H. pylori in the study area was 70.8%. The female donors had a prevalence of 72.0%. A greater proportion of blood group O donors had H. pylori than groups A, AB and B but this difference was not significant (P-value = 0.571). The prevalence of malaria parasites infection was 36.8%. Those of blood group A had a higher prevalence rate of 42.3% (11/26). Out of the 106 donors, 23 (21.7%) had malaria and H. pylori coinfection. 68 (64.2%) donors had a mono-infection that is either having malaria mono-infection or H. pylori mono-infection and 15 (14.2%) had no infection. Malaria and H. pylori coinfection was higher in female donors than males (OR = 1.059, 95% Cl 0.359 -3.119, P =0.917), in donors aged below 25 years old (OR = 0.338, 95% Cl 0.075 - 1.535, P =0.160), replacement donors (OR = 1.350, 95% Cl 0.460 – 3.964, P =0.585); blood donors of blood group AB (OR = 0.654, 95% Cl 0.181 – 2.366, P =0.517) and Rhesus negative donors (OR = 1.500, 95% Cl 0.130 – 17.36, P =0.746). Conclusion: The prevalence of H. pylori infection and Malaria among blood donors in Douala General Hospital were high and coinfection was higher in females than males. Both malaria parasites and H. pylori infections have been implicated in blood parameters such as anaemia and micronutrient deficiency. It is therefore recommended that routine screening for malaria parasites and H. pylori be done in blood banks before transfusion for a high blood quality.

Malaria Parasitaemia, Risk Perception, and Preventive Practices Among Women Attending Ante-Natal Clinics in Ogun State

Malaria contributes over 10% of all deaths among pregnant women. The prevalence of malaria in pregnancy in Nigeria particularly in Ogun State is high. The coverage and uptake of Intermittent Preventive Treatment with Sulphodoxine Pyrimethamine (IPT-SP) and Long-Lasting Insecticidal Nets (LLINs) in Southwest Nigeria is still very low despite their proven cost effectiveness in improving maternal and infant health. This study therefore determined the malaria parasitaemia, risk perception, preventive practices and associated factors among women attending Ante-natal Clinics (ANCs) in Ogun state. A cross-sectional study was carried out using mixed methods. An estimated sample size of 426 was computed and selected from ANCs across the state through multistage sampling technique. Pre-tested semi-structured interviewer administered questionnaire was used to collect information. Also, focused group discussions (FGDs) were conducted among women attending ANC and blood samples were taken from asymptomatic women for laboratory analysis to determine prevalence of malaria parasitaemia. Measures of association between the dependent and independent variables were tested using Chi-square. All tests of significance were done based on a ɑ-level of 0.05. Response rate was 100% for this study. The mean age of respondents was 27.9 ±5.5 years. Risk perception of malaria was observed to be good. Malaria parasitaemia was 2.7% and was 100% due to <i>Plasmodium falciparum</i>. Maternal age was significantly associated with malaria parasitaemia. Therefore, it is recommended that malaria elimination programmes should be sustained; access and affordability of ANC care should be ensured by the Government.

Prevalence of Malaria and Helminth Infections and Their Link to Knowledge on Preventive Strategies among Asymptomatic Pupils in Rural-urban Cameroon

Aim: The aim of our study was to investigate the prevalence of malaria and helminth infection among asymptomatic primary school children in rural and urban Yaoundé-Cameroon, to assess pupils’ knowledge about malaria and STH infection, and to evaluate the association between this knowledge and actual disease prevalence.
 Study Design: This study was a cross-sectional and was carried out between October 2019 and December 2019 in six primary schools in the Centre region of Cameroon.
 Methodology:Pupils in classes 3 to six were recruited for the study. Blood and stool samples were collected and analysed to determine pupils’ disease prevalence. Questionnaires following the KAP and health belief model frameworks were administered to evaluate pupils’ health literacy in malaria and helminths.
 Results: 457 pupils from rural and urban zones participated in this study. 245 (53.6 %) were female and 212 (46.4 %) were male. The prevalence of anaemia was higher in urban than rural zones. Total malaria prevalence was 17.7%. Malaria parasitaemia prevalence classified according to settings revealed rural zones at 28.6% and urban zones at 13.9%. STH infection showed a total prevalence of 4.8% and 7.9% and 3.7% in rural and urban zones respectively. The prevalence of co-infection was 1.2%. Health-literacy gaps in malaria and helminths were identified. Schooling in rural settings and being older were predictors for having a good knowledge of the diseases. However, having good knowledge was not significantly associated to actual malaria parasitaemia or STH prevalence.
 Conclusion: Insights from this study are essential for the implementation of successful, sustainable and targeted health-promotion strategies to improve the health and well-being of pupils.

Relative effects of climate factors and malaria control interventions on changes of parasitaemia risk in Burkina Faso from 2014 to 2017/2018

BackgroundIn Burkina Faso, the prevalence of malaria has decreased over the past two decades, following the scale-up of control interventions. The successful development of malaria parasites depends on several climatic factors. Intervention gains may be reversed by changes in climatic factors. In this study, we investigated the role of malaria control interventions and climatic factors in influencing changes in the risk of malaria parasitaemia.MethodsBayesian logistic geostatistical models were fitted on Malaria Indicator Survey data from Burkina Faso obtained in 2014 and 2017/2018 to estimate the effects of malaria control interventions and climatic factors on the temporal changes of malaria parasite prevalence. Additionally, intervention effects were assessed at regional level, using a spatially varying coefficients model.ResultsTemperature showed a statistically important negative association with the geographic distribution of parasitaemia prevalence in both surveys; however, the effects of insecticide-treated nets (ITNs) use was negative and statistically important only in 2017/2018. Overall, the estimated number of infected children under the age of 5 years decreased from 704,202 in 2014 to 290,189 in 2017/2018. The use of ITNs was related to the decline at national and regional level, but coverage with artemisinin-based combination therapy only at regional level.ConclusionInterventions contributed more than climatic factors to the observed change of parasitaemia risk in Burkina Faso during the period of 2014 to 2017/2018. Intervention effects varied in space. Longer time series analyses are warranted to determine the differential effect of a changing climate on malaria parasitaemia risk.

Safety and efficacy of dihydroartemisinin–piperaquine for intermittent preventive treatment of malaria in pregnant women with HIV from Gabon and Mozambique: a randomised, double-blind, placebo-controlled trial

The cornerstone of malaria prevention in pregnancy, intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine, is contraindicated in women with HIV who are receiving co-trimoxazole prophylaxis. We assessed whether IPTp with dihydroartemisinin-piperaquine is safe and effective in reducing the risk of malaria infection in women with HIV receiving co-trimoxazole prophylaxis and antiretroviral drugs. For this randomised, double-blind, placebo-controlled clinical trial, women with HIV attending the first antenatal care clinic visit, resident in the study area, and with a gestational age up to 28 weeks were enrolled at five sites in Gabon and Mozambique. Participants were randomly assigned (1:1) to receive either IPTp with dihydroartemisinin-piperaquine at each scheduled antenatal care visit plus daily co-trimoxazole (intervention group) or placebo at each scheduled antenatal care visit plus daily co-trimoxazole (control group). Randomisation was done centrally via block randomisation (block sizes of eight), stratified by country. IPTp was given over 3 days under direct observation by masked study personnel. The number of daily IPTp tablets was based on bodyweight and according to the treatment guidelines set by WHO (target dose of 4 mg/kg per day [range 2-10 mg/kg per day] of dihydroartemisinin and 18 mg/kg per day [range 16-27 mg/kg per day] of piperaquine given once a day for 3 days). At enrolment, all participants received co-trimoxazole (fixed combination drug containing 800 mg trimethoprim and 160 mg sulfamethoxazole) for daily intake. The primary study outcome was prevalence of peripheral parasitaemia detected by microscopy at delivery. The modified intention-to-treat population included all randomly assigned women who had data for the primary outcome. Secondary outcomes included frequency of adverse events, incidence of clinical malaria during pregnancy, and frequency of poor pregnancy outcomes. All study personnel, investigators, outcome assessors, data analysts, and participants were masked to treatment assignment. This study is registered with ClinicalTrials.gov, NCT03671109. From Sept 18, 2019, to Nov 26, 2021, 666 women (mean age 28·5 years [SD 6·4]) were enrolled and randomly assigned to the intervention (n=332) and control (n=334) groups. 294 women in the intervention group and 308 women in the control group had peripheral blood samples taken at delivery and were included in the primary analysis. Peripheral parasitaemia at delivery was detected in one (<1%) of 294 women in the intervention group and none of 308 women in the control group. The incidence of clinical malaria during pregnancy was lower in the intervention group than in the control group (one episode in the intervention group vs six in the control group; relative risk [RR] 0·12, 95% CI 0·03-0·52, p=0·045). In a post-hoc analysis, the composite outcome of overall malaria infection (detected by any diagnostic test during pregnancy or delivery) was lower in the intervention group than in the control group (14 [5%] of 311 women vs 31 [10%] of 320 women; RR 0·48, 95% CI 0·27-0·84, p=0·010). The frequency of serious adverse events and poor pregnancy outcomes (such as miscarriages, stillbirths, premature births, and congenital malformations) did not differ between groups. The most frequently reported drug-related adverse events were gastrointestinal disorder (reported in less than 4% of participants) and headache (reported in less than 2% of participants), with no differences between study groups. In the context of low malaria transmission, the addition of IPTp with dihydroartemisinin-piperaquine to co-trimoxazole prophylaxis in pregnant women with HIV did not reduce peripheral parasitaemia at delivery. However, the intervention was safe and associated with a decreased risk of clinical malaria and overall Plasmodium falciparum infection, so it should be considered as a strategy to protect pregnant women with HIV from malaria. European and Developing Countries Clinical Trials Partnership 2 (EDCTP2) and Medicines for Malaria Venture. For the Portuguese and French translations of the abstract see Supplementary Materials section.

Systematic Review and Meta-Analysis of Seasonal Malaria Chemoprevention.

Seasonal malaria chemoprevention (SMC) for children under 5 years of age for up to four monthly cycles during malaria transmission season was recommended by the WHO in 2012 and has been implemented in 13 countries in the Sahel, reaching more than 30 million children annually. Malaria control programs implementing SMC have asked the WHO to consider expanding the age range or number of monthly cycles. We conducted a systematic review and meta-analysis of SMC among children up to 15 years of age and up to six monthly cycles. Twelve randomized studies were included, with outcomes stratified by age (< 5/≥ 5 years), by three or four versus five or six cycles, and by drug where possible. Drug regimens included sulfadoxine-pyrimethamine + amodiaquine, amodiaquine-artesunate, and sulfadoxine-pyrimethamine + artesunate. Included studies were all conducted in Sahelian countries in which high-grade resistance to sulfadoxine-pyrimethamine was rare and in zones with parasite prevalence ranging from 1% to 79%. Seasonal malaria chemoprevention resulted in substantial reductions in uncomplicated malaria incidence measured during that transmission season (rate ratio: 0.27, 95% CI: 0.25-0.29 among children < 5 years; rate ratio: 0.27, 95% CI: 0.25-0.30 among children ≥ 5 years) and in the prevalence of malaria parasitemia measured within 4-6 weeks from the final SMC cycle (risk ratio: 0.38, 95% CI: 0.34-0.43 among children < 5 years; risk ratio: 0.23, 95% CI: 0.11-0.48 among children ≥ 5 years). In high-transmission zones, SMC resulted in a moderately reduced risk of any anemia (risk ratio: 0.77, 95% CI: 0.72-0.83 among children < 5 years; risk ratio: 0.70, 95% CI: 0.52-0.95 among children ≥ 5 years [one study]). Children < 10 years of age had a moderate reduction in severe malaria (risk ratio: 0.53, 95% CI: 0.37-0.76) but no evidence of a mortality reduction. The evidence suggests that in areas in which sulfadoxine-pyrimethamine and amodiaquine remained efficacious, SMC effectively reduced malaria disease burden among children both < 5 and ≥ 5 years old and that the number of cycles should be commensurate with the length of the transmission season, up to six cycles.

Malaria Infection in Patients with Sickle Cell Disease in Nigeria: Association with Markers of Hyposplenism.

Malaria is considered an important cause of morbidity and mortality among people living with sickle cell disease (SCD). This has partly been attributed to the loss of splenic function that occurs early in the disease process. We conducted a cross-sectional study and determined the frequency of malaria infection among SCD patients and explored the association with spleen's presence on ultrasonography and spleen function assessed using the frequency of Howell-Jolly bodies (HJBs). A total of 395 participants consisting of 119 acutely-ill SCD patients, 168 steady-state SCD controls, and 108 healthy non-SCD controls were studied. The prevalence of Plasmodium falciparum parasitemia was 51.3% in acutely-ill SCD patients, 31.7% in steady-state SCD controls, and 11.0% in the healthy non-SCD controls; however, the mean parasite density was significantly higher in the non-SCD controls compared to both SCD groups (p = 0.0001). Among the acutely-ill SCD patients, the prevalence of clinical malaria and severe malaria anemia were highest in children <5 years of age. The prevalence of parasitemia (p = 0.540) and parasite density (p = 0.975) showed no association with spleen presence or absence on ultrasonography. Similarly, the frequency of HJB red cells was not associated with the presence of parasitemia (p = 0.183). Our study highlights the frequency and role of malaria infection in acutely-ill SCD patients, especially in those younger than five years. Although we have found no evidence of an increased risk of malaria parasitemia or parasite density with markers of hyposplenism, the role played by an underlying immunity to malaria among SCD patients in malaria-endemic region is not clear and needs further studies.

Multiple imputation of incomplete multilevel data using Heckman selection models.

Missing data is a common problem in medical research, and is commonly addressed using multiple imputation. Although traditional imputation methods allow for valid statistical inference when data are missing at random (MAR), their implementation is problematic when the presence of missingness depends on unobserved variables, that is, the data are missing not at random (MNAR). Unfortunately, this MNAR situation is rather common, in observational studies, registries and other sources of real-world data. While several imputation methods have been proposed for addressing individual studies when data are MNAR, their application and validity in large datasets with multilevel structure remains unclear. We therefore explored the consequence of MNAR data in hierarchical data in-depth, and proposed a novel multilevel imputation method for common missing patterns in clustered datasets. This method is based on the principles of Heckman selection models and adopts a two-stage meta-analysis approach to impute binary and continuous variables that may be outcomes or predictors and that are systematically or sporadically missing. After evaluating the proposed imputation model in simulated scenarios, we illustrate it use in a cross-sectional community survey to estimate the prevalence of malaria parasitemia in children aged 2-10 years in five regions in Uganda.

Protocol for a randomised, multicentre, four-arm, double-blinded, placebo-controlled trial to assess the benefits and safety of iron supplementation with malaria chemoprevention to children in Malawi: IRMA trial

IntroductionApproximately 40% of children aged 6–59 months worldwide are anaemic. Iron-containing multiple micronutrient powders (MNPs) and iron supplements (syrup/drops) are used to combat anaemia in children in different parts of...

Prevalence of Malaria Parasitemia and Perceptions of the Use of Long-Lasting Insecticide Nets in a Sample of Pregnant Women in a Malaria-Endemic Nigerian Community

Objectives: The objectives of the study were to evaluate the prevalence of malaria and the perception on the use of long-lasting insecticide-treated nets (LLINs) among pregnant women attending antenatal care at Neni Community Health Center, Anaocha Local Government Area, Anambra State, Nigeria. Methods: A sample of 364 pregnant women were randomly selected for the study. Malaria parasitemia and the use of LLINs were critically evaluated among pregnant women in the study area. Two milliliters of venous blood samples was collected by a medical laboratory scientist from each pregnant woman; it was stored in an ethylenediaminetetraacetic acid container. This was done under sterile conditions and examined for malaria parasites using Giemsa-stained thin and thick blood films under a microscope. Interviews and observations were used to collect information from pregnant women regarding their sociodemographic characteristics and use of LLINs. The level of statistical significance was set at Ρ ≤0.05. Results: The prevalence of malaria in relation to parity indicated that primigravidae had the highest proportion (46.2%). In terms of gestational stage, malaria infection was highest among women in their first trimester (37.2%). Based on occupational status, farmers recorded the highest prevalence of 40.7%. There was a significantly higher proportion of pregnant women who were aware of LLINs (χ2 = 25.36, P &lt; 0.05), chose antenatal classes as a source of information on awareness of LLINs (χ2 = 27.33, P &lt; 0.05), and had reasons for noncompliance with LLINs (χ2 = 25.71, P &lt; 0.05). Conclusions: This study reveals a relatively high prevalence of malaria parasitemia and low compliance with the use of long-lasting insecticide nets among pregnant women attending antenatal care at Neni Community Health Center in Anambra State, Nigeria.

High Prevalence of Polyclonal Plasmodium falciparum Infections and Association with Poor IgG Antibody Responses in a Hyper-Endemic Area in Cameroon.

Malaria remains a major public health problem worldwide, with eradication efforts thwarted by drug and insecticide resistance and the lack of a broadly effective malaria vaccine. In continuously exposed communities, polyclonal infections are thought to reduce the risk of severe disease and promote the establishment of asymptomatic infections. We sought to investigate the relationship between the complexity of P. falciparum infection and underlying host adaptive immune responses in an area with a high prevalence of asymptomatic parasitaemia in Cameroon. A cross-sectional study of 353 individuals aged 2 to 86 years (median age = 16 years) was conducted in five villages in the Centre Region of Cameroon. Plasmodium falciparum infection was detected by multiplex nested PCR in 316 samples, of which 278 were successfully genotyped. Of these, 60.1% (167/278) were polyclonal infections, the majority (80.2%) of which were from asymptomatic carriers. Host-parasite factors associated with polyclonal infection in the study population included peripheral blood parasite density, participant age and village of residence. The number of parasite clones per infected sample increased significantly with parasite density (r = 0.3912, p < 0.0001) but decreased with participant age (r = -0.4860, p < 0.0001). Parasitaemia and the number of clones per sample correlated negatively with total plasma levels of IgG antibodies to three highly reactive P. falciparum antigens (MSP-1p19, MSP-3 and EBA175) and two soluble antigen extracts (merozoite and mixed stage antigens). Surprisingly, we observed no association between the frequency of polyclonal infection and susceptibility to clinical disease as assessed by the recent occurrence of malarial symptoms or duration since the previous fever episode. Overall, the data indicate that in areas with the high perennial transmission of P. falciparum, parasite polyclonality is dependent on underlying host antibody responses, with the majority of polyclonal infections occurring in persons with low levels of protective anti-plasmodial antibodies.

Effectiveness and safety of intermittent preventive treatment with dihydroartemisinin–piperaquine or artesunate–amodiaquine for reducing malaria and related morbidities in schoolchildren in Tanzania: a randomised controlled trial

In high transmission settings, most school-aged children harbour malaria parasites without showing symptoms, often leading to anaemia and possibly impaired psychomotor and cognitive abilities. We aimed to assess the effectiveness and safety of intermittent preventive treatment for malaria in school-aged children (IPTsc) living in highly endemic areas. We did an open-label randomised controlled trial in seven primary schools in northeastern Tanzania. Schoolchildren aged 5-15 years were individually randomly assigned (1:1:1) to receive dihydroartemisinin-piperaquine, artesunate-amodiaquine, or standard of care (control) using a balanced block design. Drugs were administered by schoolteachers, with supervision from study nurses, at months 0 (baseline), 4, and 8, and were given in line with manufacturer's recommendations with dose based on the child's bodyweight. The primary endpoints were change from baseline in mean haemoglobin concentration at months 12 and 20, and clinical incidence of malaria and prevalence of parasitaemia at months 12 and 20 in the intervention groups versus the control group. The outcome data were collected through longitudinal surveys conducted every 4 months. Data were analysed on the basis of intention to treat (including all randomised participants) and per protocol (comprising children who completed the full 3-day regimen of all three IPTsc treatment rounds as assigned). This study is registered with ClinicalTrials.gov (NCT03640403). Of the 1797 children scheduled for clinical screening, 1566 were enrolled and randomly allocated (526 to receive dihydroartemisinin-piperaquine, 527 to receive artesunate-amodiaquine, and 513 to receive standard of care). Due to COVID-19-related school closures, only two schools were visited at month 12 (135 children in the dihydroartemisinin-piperaquine group, 131 in the artesunate-amodiaquine group, and 118 in the control group). At month 12, compared with the control group, the change from baseline in mean haemoglobin concentration was increased by 0·5 g/dL (95% CI 0·2 to 0·8; p<0·0001) in the dihydroartemisinin-piperaquine group and 0·5 g/dL (0·2 to 0·7; p=0·0020) in the artesunate-amodiaquine group in the intention-to-treat analysis (with similar findings in the per protocol analysis). In the same period, in the intention-to-treat analysis, the prevalence of malaria parasitaemia increased from 28·5% (138 of 485 participants) to 33·6% (39 of 116) in the control group, but decreased from 28·0% (139 of 497) to 12·0% (15 of 125) in the dihydroartemisinin-piperaquine group (-21·6 percentage points [95% CI -31·9 to -11·3], p=0·0001 vs control at month 12) and from 24·7% (124 of 502) to 16·0% (20 of 125) in the artesunate-amodiaquine group (-17·6 percentage points [-28·4 to -6·9], p=0·0015). The decrease for artesunate-amodiaquine was larger in the per protocol analysis (-25·3 percentage points [-36·3 to -14·2], p<0·0001). The protective effect of IPTsc against malaria parasitaemia was 64% (95% CI 39 to 79; p<0·0001) for dihydroartemisinin-piperaquine and 52% (23 to 70; p=0·0015) for artesunate-amodiaquine in the intention-to-treat analysis, and was slightly higher on per protocol analysis. The protective effect against clinical malaria at month 12 was 20% (95% CI 9 to 29; p=0·0002) for dihydroartemisinin-piperaquine and 19% (8 to 28; p=0·0004) for artesunate-amodiaquine. No significant differences in any primary outcomes between the intervention and control groups were noted at month 20. Dihydroartemisinin-piperaquine and artesunate-amodiaquine were associated with a small number of mild adverse events, and there were no treatment-related serious adverse events or deaths. IPTsc with dihydroartemisinin-piperaquine or artesunate-amodiaquine is a safe and effective approach to reducing malaria parasitaemia, clinical malaria, and related morbidities, and is feasible to implement through programmes delivered by schoolteachers. Flemish Interuniversity Council (VLIRUOS), EU EDCTP2 programme (MaReCa project), and Global Minds 2019. For the Swahili translation of the abstract see Supplementary Materials section.

Prevalence of malaria parasitaemia among pregnant women at booking in Nigeria.

Malaria is a major public health concern among pregnant women in sub-Saharan Africa. Within the region, Nigeria has the highest malaria cases. This study aimed to determine the prevalence and factors associated with malaria parasitaemia among pregnant women at a booking clinic in Ibadan, Nigeria. A cross-sectional study was conducted between January and April 2021 at the University College Hospital in Ibadan, Nigeria. A sample of 300 pregnant women participated, and anaemia and malaria were diagnosed using packed cell volume and Giemsa-stained blood smears, respectively. Data analysis was done using SPSS 25.0. The study found that 26 (8.70%) pregnant women tested positive for malaria parasitaemia. Factors such as age, religion, level of education, and occupation were significantly related to the prevalence of malaria parasitaemia among pregnant women with p < 0.05. Our study identified a high prevalence of malaria parasitaemia among pregnant women with demographic factors such as age, religion, level of education, and occupation significantly associated. Targeted malaria control interventions for pregnant women with low levels of education and low-income occupations are necessary, with more research needed to evaluate their effectiveness.

Permethrin-treated baby wraps for the prevention of malaria in children: Protocol for a double-blind, randomized placebo-controlled controlled trial in western Uganda.

This article details the study protocol for a double-blind, randomized placebo-controlled trial to determine the effectiveness of permethrin-treated baby wraps to prevent Plasmodium falciparum malaria infection in children 6-24 months of age. Participating mother-infant dyads will be randomized to receive either a permethrin-treated or a sham-treated wrap, known locally as a "lesu." After a baseline home visit, during which time all participants will receive new long-lasting insecticidal nets, participants will attend scheduled clinic visits every two weeks for a period of 24 weeks. In the event of an acute febrile illness or other symptoms that may be consistent with malaria (e.g., poor feeding, headache, malaise), participants will be instructed to present to their respective study clinic for evaluation. The primary outcome of interest is the incidence of laboratory-confirmed, symptomatic malaria in participating children. Secondary outcomes of interest include: (1) change in children's hemoglobin levels; (2) change in children's growth parameters; (3) prevalence of asymptomatic parasitemia in children; (4) hospitalization for malaria in children; (5) change in the mother's hemoglobin level; and (6) clinical malaria in the mother. Analyses will be conducted using a modified intent-to-treat approach, with woman-infant dyads who attend one or more clinic visits analyzed according to the arm to which they were randomly assigned. This is the first use of an insecticide-treated baby wrap for prevention of malaria in children. The study began recruitment in June 2022 and is ongoing. ClinicalTrials.gov Identifier: NCT05391230, Registered 25 May 2022.