Malaria and helminth co-infections in children living in endemic countries: A systematic review with meta-analysis

The Burden of Asymptomatic Malaria Infection in Children in Sub-Saharan Africa: A Systematic Review and Meta-Analysis Exploring Barriers to Elimination and Prevention

BACKGROUND

Malaria remains a major public health problem that continues to cause death in under-five children nearly every minute. The purpose of this systematic review and meta-analysis was to determine the pooled prevalence and predictors of asymptomatic malaria in children in Sub-Saharan Africa.

METHODS

Relevant studies were retrieved from Web of Science, Cochrane Library, PubMed, Google Scholar, Gray Literature, Embase, and African Online Journal databases published between 2014 and 2024. Data quality was assessed by a tool developed by Hoy and colleagues and classified as low, moderate, or high risk of bias. We performed a random effects model and sub-group analysis by age group, region, and diagnostic methods. The protocol was registered in the PROSPERO (CRD42024584354).

RESULTS

A total of 24 cross-sectional studies with 19,169 participants from 10 Sub-Saharan Africa countries were included in the analyses under the age of 15 years. The overall prevalence of asymptomatic malaria was 25% (95% CI: 20-30%) and showed no evidence of publication bias. Utilization of insecticide-treated nets was significantly associated with asymptomatic malaria. In addition, the overall prevalence of anemia in asymptomatic Plasmodium-infected children under the age of 15 was found to be 35% (95% CI: 24-46%). Subgroup analysis showed significant regional and diagnostic tool differences in asymptomatic Plasmodium infection.

CONCLUSION

The findings of this study revealed a high prevalence of asymptomatic plasmodium infection in children with significant regional variations. There was a significant association with anemia and the utilization of insecticide-treated nets.

Two-photon NAD(P)H-FLIM reveals unperturbed energy metabolism of Ascaris suum larvae, in contrast to host macrophages upon artemisinin derivatives exposure

Soil-transmitted helminths (STH) are widespread, with Ascaris lumbricoides infecting millions globally. Malaria and STH co-infections are common in co-endemic regions. Artemisinin derivatives (ARTs)-artesunate, artemether, and dihydroartemisinin-are standard malaria treatments and are also known to influence the energy metabolism of parasites, tumors, and immune cells. Herein, we explore the potential of ARTs to influence ascariasis either by directly targeting larvae or indirectly by modifying macrophage responses. Ascaris suum third-stage larvae and porcine IL-4 polarized (M2-like) macrophages were exposed to ARTs in vitro, and their metabolism was evaluated using two-photon NAD(P)H-FLIM. Both larvae and M2-like macrophages exhibited a steady-state bioenergetic profile of high oxidative phosphorylation and low anaerobic glycolysis. In A. suum larvae, two metabolically distinct regions were identified, with particularly high DUOX activity in the pharynx compared to the midgut; however, ARTs did not alter these profiles. In contrast, exposure of M2-like macrophages to ARTs induced a metabolic shift towards high anaerobic glycolysis and reduced metabolic activity, suggesting a possible indirect effect of ARTs on the helminth infection. Overall, two-photon NAD(P)H-FLIM proved to be a powerful tool for studying specific metabolic pathways in Ascaris larvae and host macrophages, offering valuable insights into the metabolic mechanisms of drug action on both parasite and host.

Plasmodium falciparum and Schistosoma mansoni coinfections among the general population in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Due to the overlapping endemic regions and the high burden of both infections, coinfection with Plasmodium falciparum and Schistosoma mansoni poses distinct public health concerns that require coordinated, multifaceted interventions. There are epidemiological studies on the coinfection of these two parasites in Ethiopia, and the results differ and are inconsistent from one region to another. Thus, the goal of this systematic review and meta-analysis was to ascertain Ethiopia's pooled prevalence of P. falciparum and S. mansoni coinfection.

METHODS

The preferred reporting item review and meta-analysis guidelines were followed in this study. PubMed, Google Scholar, Research4Life, Scopus, African-Wider, and EMBASE were the primary search databases. The final analysis included six studies in total. Stata software version 11 was used for analysis after Microsoft Excel was used to extract the data. The critical appraisal tool developed by the Joanna Briggs Institute was used to evaluate the methodological quality of the studies. Publication bias was checked via a funnel plot, Begg's test, and Egger's test. The pooled prevalence of P. falciparum and S. mansoni coinfection was estimated via a random effect model via the Der Simonian-Laird method. The heterogeneity of the studies was evaluated via I2 statistical tests.

RESULTS

The pooled prevalence of P. falciparum and S. mansoni coinfections in Ethiopia was 10.496% (95% CI 6.134, 14.859). Subgroup analysis of geopolitical regions revealed that the highest and lowest pooled prevalence rates of coinfection were 11.808% (95% CI 0.304, 23.312) and 8.600% (95% CI 5.755, 11.445), respectively, in the Amhara and Benishangul Gumuz regions.

CONCLUSIONS

This study highlights the substantial prevalence of P. falciparum and S. mansoni coinfection in Ethiopia's general population, with considerable geographical variation. Targeted and intensive public health interventions are necessary because it has the highest incidence in the Amhara region, and ongoing efforts are needed to address the relatively lower but still considerable prevalence in the Benishangul Gumuz region. These results direct future research, integrated control strategy design, and resource allocation to successfully manage Ethiopia's combined burden of malaria and schistosomiasis.

Low prevalence of soil transmitted helminth infection in Ugandan children hospitalized with severe malaria

Co-infection by intestinal helminths and Plasmodium spp. may be common in endemic communities. Several studies have identified a relationship between helminth infection, Plasmodium spp. infection and malaria severity. However, the relationship is not well defined, and results are inconclusive. We analyzed 202 stool samples from a cohort of children with severe malaria enrolled in two hospitals in Uganda from 2014-2017 and asymptomatic community children from the same household or neighborhood and enrolled at the same time, all 6 months to 48 months of age. We investigated if intestinal helminth infection modified risk of severe malaria. We extracted nucleic acids from stool and tested them for six helminth species (Anyclostoma duodenale, Ascaris lumbricoides, Necator americanus, Strongyloides stercolaris, Trichuris trichiura, Shistosoma mansoni) using highly sensitive quantitative PCR. We found a low prevalence of infection by ≥1 intestinal helminth species in children with severe malaria (5.1%, n=9/177) and community control children (4.0%, n=1/25). Infection by ≥1 of the helminths assessed was not associated with severe malaria (aRR = 1.0, 95% Confidence Interval = 0.82, 1.3, p = 0.78). In 2003 Uganda instituted a national deworming program, with anti-helminth medication provided twice annually to children 6 months to 5 years of age. In these areas of Uganda, the national deworming campaign has been highly successful, as stool-based helminth infection was rare even when using highly sensitive methods of detection and was not a major contributor to risk of severe malaria.

A four-year assessment of the characteristics of Rwandan FDA drug recalls

BACKGROUND

A drug recall is an act of removing products from the market and/or returning them to the manufacturer for disposal or correction when they violate safety laws. Action can be initiated by the manufacturing company or by the order of a regulatory body. This study aimed to assess the characteristics of Rwanda FDA drug recall and determine the association between classes of recall and recall characteristics.

METHODOLOGY

This was a retrospective descriptive cross-sectional study. Data about recalled drugs were collected from the official website of the Rwanda FDA in the section assigned to "Safety alerts". The search included data reported between February 2019 and February 2023 covering four years. Data cleaning was conducted in Microsoft Excel to address missing data and inconsistencies, followed by importation into STATA/SE software version 17.0 for further cleaning and subsequent analysis. Descriptive statistics were computed for independent variables. Categorical variables were described in terms of counts and relative frequencies. Bivariate analyses used Pearson's chi-square test to illustrate the associations between categorical independent variables and recall classes.

RESULTS

The study revealed that a large proportion (33.0%) of the recalled products belonged to Class I. Antibiotics constituted 35.8% of the recalled products, with contamination emerging as a leading cause and responsible for 26.4% of the recalls. India was the leading manufacturing country for the recalled products (29.2%), followed by France (17.9%), China (17.0%), Kenya (13.2%), and Russia (6.6%). An association was found between the class of recall and several recall characteristics, including the year of recall, drug category, safety issues, reporter, and manufacturing country.

CONCLUSION

This study provides a comprehensive overview of the characteristics of drug recalls in Rwanda. The insights gained contribute to a nuanced understanding of recall dynamics and provide evidence-based strategies to enhance drug quality, safety, efficacy, regulatory compliance, and patient welfare.

Reduction in short interval intracortical inhibition from the early stage reflects the pathophysiology in amyotrophic lateral sclerosis: A meta-analysis study

BACKGROUND AND PURPOSE

Cortical hyperexcitability has been identified as a diagnostic and pathogenic biomarker of amyotrophic lateral sclerosis (ALS). Cortical excitability is assessed by transcranial magnetic stimulation (TMS), a non-invasive neurophysiological technique. The TMS biomarkers exhibiting highest sensitivity for cortical hyperexcitability in ALS remain to be elucidated. A meta-analysis was performed to determine the TMS biomarkers exhibiting the highest sensitivity for cortical hyperexcitability in ALS.

METHODS

A systematic literature review was conducted of all relevant studies published in the English language by searching PubMed, MEDLINE, Embase and Scopus electronic databases from 1 January 2006 to 28 February 2023. Inclusion criteria included studies reporting the utility of threshold tracking TMS (serial ascending method) in ALS and controls.

RESULTS

In total, more than 2500 participants, incorporating 1530 ALS patients and 1102 controls (healthy, 907; neuromuscular, 195) were assessed with threshold tracking TMS across 25 studies. Significant reduction of mean short interval intracortical inhibition (interstimulus interval 1-7 ms) exhibited the highest standardized mean difference with moderate heterogeneity (-0.994, 95% confidence interval -1.12 to -0.873, p < 0.001; Q = 38.61, p < 0.05; I2 = 40%). The reduction of cortical silent period duration along with an increase in motor evoked potential amplitude and intracortical facilitation also exhibited significant, albeit smaller, standardized mean differences.

CONCLUSION

This large meta-analysis study disclosed that mean short interval intracortical inhibition reduction exhibited the highest sensitivity for cortical hyperexcitability in ALS. Combined findings from this meta-analysis suggest that research strategies aimed at understanding the cause of inhibitory interneuronal circuit dysfunction could enhance understanding of ALS pathogenesis.

The short-term impact of Schistosoma mansoni infection on health-related quality of life: implications for current elimination policies

The WHO aims to eliminate schistosomiasis as a public health problem by 2030. However, standard morbidity measures poorly correlate to infection intensities, hindering disease monitoring and evaluation. This is exacerbated by insufficient evidence on Schistosoma's impact on health-related quality of life (HRQoL). We conducted community-based cross-sectional surveys and parasitological examinations in moderate-to-high Schistosoma mansoni endemic communities in Uganda. We calculated parasitic infections and used EQ-5D instruments to estimate and compare HRQoL utilities in these populations. We further employed Tobit/linear regression models to predict HRQoL determinants. Two-thirds of the 560 participants were diagnosed with parasitic infection(s), 49% having S. mansoni. No significant negative association was observed between HRQoL and S. mansoni infection status/intensity. However, severity of pain urinating (β = -0.106; s.e. = 0.043) and body swelling (β = -0.326; s.e. = 0.005), increasing age (β = -0.016; s.e. = 0.033), reduced socio-economic status (β = 0.128; s.e. = 0.032), and being unemployed predicted lower HRQoL. Symptom severity and socio-economic status were better predictors of short-term HRQoL than current S. mansoni infection status/intensity. This is key to disentangling the link between infection(s) and short-term health outcomes, and highlights the complexity of correlating current infection(s) with long-term morbidity. Further evidence is needed on long-term schistosomiasis-associated HRQoL, health and economic outcomes to inform the case for upfront investments in schistosomiasis interventions.

Have there been efforts to integrate malaria and schistosomiasis prevention and control programs? A scoping review of the literature

Malaria and schistosomiasis are two important parasitic diseases that are a particular threat to young children and pregnant women in sub-Saharan Africa. Malaria and schistosomiasis prevention and control strategies primarily focus on the distribution of long-lasting insecticidal nets and the delivery of praziquantel tablets to at-risk populations in high burden settings through mass drug administration, respectively. The objective of this scoping review was to identify previous efforts to integrate malaria and schistosomiasis prevention and control programs in the literature and to summarize the strategies and approaches used in these programs following the PRISMA-ScR guidelines. We reviewed published and grey literature using a combination of keywords and search terms following themes surrounding "malaria", "Plasmodium falciparum", "Anopheles", "schistosomiasis", "Schistosoma haematobium", "Schistosoma mansoni", and "snails". Neither a date limit nor relevant terms for prevention and control were used. Out of 6374, eight articles were included in the scoping review-three articles investigated the integration of mass drug administration for schistosomiasis with the administration of antimalarials, four articles investigated the effect of administering antimalarials on malaria, schistosomiasis, and their co-infection, and one article assessed the impact of an educational intervention on malaria and schistosomiasis knowledge and preventative behaviors. Our findings suggest that there is an opportunity to link disease control programs to increase access and coverage of interventions to improve outcomes for malaria, schistosomiasis, and their co-infection. Further research is needed on the potential benefits, feasibility, and cost-effectiveness of integrating malaria and schistosomiasis prevention and control programs.

Feasibility and safety of integrating mass drug administration for helminth control with seasonal malaria chemoprevention among Senegalese children: a randomized controlled, observer-blind trial

BACKGROUND

The overlap in the epidemiology of malaria and helminths has been identified as a potential area to exploit for the development of an integrated control strategy that may help to achieve elimination of malaria and helminths. A randomized, controlled, observer-blind trial was conducted to assess the feasibility and safety of combining mass drug administration (MDA) for schistosomiasis and soil transmitted helminths (STH) with seasonal malaria chemoprevention (SMC) among children living in Senegal.

METHODS

Female and male children aged 1-14 years were randomized 1:1:1, to receive Vitamin A and Zinc on Day 0, followed by SMC drugs (sulfadoxine-pyrimethamine and amodiaquine) on Days 1-3 (control group); or praziquantel and Vitamin A on Day 0, followed by SMC drugs on Days 1-3 (treatment group 1); or albendazole and praziquantel on Day 0, followed by SMC drugs on Days 1-3 (treatment group 2). Safety assessment was performed by collecting adverse events from all children for six subsequent days following administration of the study drugs. Pre- and post-intervention, blood samples were collected for determination of haemoglobin concentration, malaria microscopy, and PCR assays. Stool samples were analyzed using Kato-Katz, Merthiolate-iodine-formalin and PCR methods. Urine filtration, PCR and circulating cathodic antigen tests were also performed.

RESULTS

From 9 to 22 June 2022, 627 children aged 1-14 years were randomized into the three groups described above. Mild, transient vomiting was observed in 12.6% (26/206) of children in treatment group 2, in 10.6% (22/207) in group 1, and in 4.2% (9/214) in the control group (p = 0.005). Pre-intervention, the geometric mean value of Plasmodium falciparum parasite density was highest among children who received albendazole, praziquantel with SMC drugs. Post-intervention, the parasite density was highest among children who received SMC drugs only. Children who received praziquantel and SMC drugs had a lower risk of developing severe anaemia than their counterparts who received SMC drugs alone (OR = 0.81, 95% CI 0.13-5.00, p = 0.63).

CONCLUSIONS

Integration of MDA for helminths with SMC drugs was safe and feasible among Senegalese children. These findings support further evaluation of the integrated control model.

TRIAL REGISTRATION

The study is registered at Clinical Trial.gov NCT05354258.

Soil-transmitted helminths: A critical review of the impact of co-infections and implications for control and elimination

Researchers have raised the possibility that soil-transmitted helminth (STH) infections might modify the host's immune response against other systemic infections. STH infections can alter the immune response towards type 2 immunity that could then affect the likelihood and severity of other illnesses. However, the importance of co-infections is not completely understood, and the impact and direction of their effects vary considerably by infection. This review synthesizes evidence regarding the relevance of STH co-infections, the potential mechanisms that explain their effects, and how they might affect control and elimination efforts. According to the literature reviewed, there are both positive and negative effects associated with STH infections on other diseases such as malaria, human immunodeficiency virus (HIV), tuberculosis, gestational anemia, pediatric anemia, neglected tropical diseases (NTDs) like lymphatic filariasis, onchocerciasis, schistosomiasis, and trachoma, as well as Coronavirus Disease 2019 (COVID-19) and human papillomavirus (HPV). Studies typically describe how STHs can affect the immune system and promote increased susceptibility, survival, and persistence of the infection in the host by causing a TH2-dominated immune response. The co-infection of STH with other diseases has important implications for the development of treatment and control strategies. Eliminating parasites from a human host can be more challenging because the TH2-dominated immune response induced by STH infection can suppress the TH1 immune response required to control other infections, resulting in an increased pathogen load and more severe disease. Preventive chemotherapy and treatment are currently the most common approaches used for the control of STH infections, but these approaches alone may not be adequate to achieve elimination goals. Based on the conclusions drawn from this review, integrated approaches that combine drug administration with water, sanitation and hygiene (WASH) interventions, hygiene education, community engagement, and vaccines are most likely to succeed in interrupting the transmission of STH co-infections. Gaining a better understanding of the behavior and relevance of STH co-infections in the context of elimination efforts is an important intermediate step toward reducing the associated burden of disease.

Malarial and intestinal parasitic co-infections in indigenous populations of the Brazilian Amazon rainforest

The Brazilian Amazon rainforest region has a significant prevalence of malarial and intestinal parasitic infections in indigenous populations, accounting for a disproportionate burden. Thus, a cross-sectional study was conducted to assess the prevalence and association between malarial and intestinal protozoan and helminth infections in four remote indigenous villages in the Brazilian Amazon Forest. A total of 430 individuals participated in the study, and Plasmodium infections were diagnosed by examination of thick blood smears and PCR. Stool samples 295 individuals (69%) were examined by direct smear and the Kato-Katz technique. The overall prevalence of malaria, intestinal protozoan infection, and intestinal helminth infection was 14.2%, 100%, and 39.3%, respectively. Polyparasitism was predominant (83.7%), and most infected individuals had at least two or more different species of intestinal protozoan and/or helminth parasites. The prevalence of co-infection was 49.5%, and in individuals with intestinal protozoa and helminth infections (34%), Entamoeba. coli, Entamoeba histolytica, and Ascaris lumbricoides were the most common parasites. In individuals with malaria and protozoa infections (10.2%), P. vivax, E. coli, and E. histolytica predominated, and in individuals with malaria, protozoa, and helminth infections (5.4%). P. vivax, E. coli, E. histolytica, and A. lumbricoides predominated. Intestinal polyparasitism was common in the study population, and the presence of helminths was associated with an increased number of intestinal parasitic species. However, Plasmodium infections were neither a risk nor a protective factor for helminth infections; the same was true for helminth infections in relation to Plasmodium. The high prevalence of intestinal polyparasitism with Plasmodium co-infections highlights the need for combining strategies that may help control both malaria and intestinal parasite and generate a health approach aligned with indigenous perspectives.

Prevalence and distribution pattern of malaria and soil-transmitted helminth co-endemicity in sub-Saharan Africa, 2000-2018: A geospatial analysis

BACKGROUND

Limited understanding exists about the interactions between malaria and soil-transmitted helminths (STH), their potential geographical overlap and the factors driving it. This study characterised the geographical and co-clustered distribution patterns of malaria and STH infections among vulnerable populations in sub-Saharan Africa (SSA).

METHODOLOGY/PRINCIPAL FINDINGS

We obtained continuous estimates of malaria prevalence from the Malaria Atlas Project (MAP) and STH prevalence surveys from the WHO-driven Expanded Special Project for the Elimination of NTDs (ESPEN) from Jan 1, 2000, to Dec 31, 2018. Although, MAP provides datasets on the estimated prevalence of Plasmodium falciparum at 5km x 5km fine-scale resolution, we calculated the population-weighted prevalence of malaria for each implementation unit to ensure that both malaria and STH datasets were on the same spatial resolution. We incorporated survey data from 5,935 implementation units for STH prevalence and conducted the prevalence point estimates before and after 2003. We used the bivariate local indicator of spatial association (LISA analysis) to explore potential co-clustering of both diseases at the implementation unit levels among children aged 2-10 years for P. falciparum and 5-14 years for STH, living in SSA. Our analysis shows that prior to 2003, a greater number of SSA countries had a high prevalence of co-endemicity with P.falciparium and any STH species than during the period from 2003-2018. Similar prevalence and distribution patterns were observed for the co-endemicity involving P.falciparum-hookworm, P.falciparum-Ascaris lumbricoides and P.falciparum-Trichuris trichiura, before and after 2003. We also observed spatial variations in the estimates of the prevalence of P. falciparum-STH co-endemicity and identified hotspots across many countries in SSA with inter-and intra-country variations. High P. falciparum and high hookworm co-endemicity was more prevalent in West and Central Africa, whereas high P. falciparum with high A. lumbricoides and high P. falciparum with high T. trichiura co-endemicity were more predominant in Central Africa, compared to other sub-regions in SSA.

CONCLUSIONS/SIGNIFICANCE

Wide spatial heterogeneity exists in the prevalence of malaria and STH co-endemicity within the regions and within countries in SSA. The geographical overlap and spatial co-existence of malaria and STH could be exploited to achieve effective control and elimination agendas through the integration of the vertical control programmes designed for malaria and STH into a more comprehensive and sustainable community-based paradigm.

Impact of Epstein-Barr virus co-infection on natural acquired Plasmodium vivax antibody response

Background

The simultaneous infection of Plasmodium falciparum and Epstein-Barr virus (EBV) could promote the development of the aggressive endemic Burkitt’s Lymphoma (eBL) in children living in P. falciparum holoendemic areas. While it is well-established that eBL is not related to other human malaria parasites, the impact of EBV infection on the generation of human malaria immunity remains largely unexplored. Considering that this highly prevalent herpesvirus establishes a lifelong persistent infection on B-cells with possible influence on malaria immunity, we hypothesized that EBV co-infection could have impact on the naturally acquired antibody responses to P. vivax, the most widespread human malaria parasite.

Methodology/Principal findings

The study design involved three cross-sectional surveys at six-month intervals (baseline, 6 and 12 months) among long-term P. vivax exposed individuals living in the Amazon rainforest. The approach focused on a group of malaria-exposed individuals whose EBV-DNA (amplification of balf-5 gene) was persistently detected in the peripheral blood (PersVDNA, n = 27), and an age-matched malaria-exposed group whose EBV-DNA could never be detected during the follow-up (NegVDNA, n = 29). During the follow-up period, the serological detection of EBV antibodies to lytic/ latent viral antigens showed that IgG antibodies to viral capsid antigen (VCA-p18) were significantly different between groups (PersVDNA > NegVDNA). A panel of blood-stage P. vivax antigens covering a wide range of immunogenicity confirmed that in general PersVDNA group showed low levels of antibodies as compared with NegVDNA. Interestingly, more significant differences were observed to a novel DBPII immunogen, named DEKnull-2, which has been associated with long-term neutralizing antibody response. Differences between groups were less pronounced with blood-stage antigens (such as MSP1-19) whose levels can fluctuate according to malaria transmission.

Conclusions/Significance

In a proof-of-concept study we provide evidence that a persistent detection of EBV-DNA in peripheral blood of adults in a P. vivax semi-immune population may impact the long-term immune response to major malaria vaccine candidates.

Malaria serosurvey among acute febrile patients come for health care seeking at the high malaria-endemic setting of North West Ethiopia

Objectives

This study aimed to assess malaria seroprevalence among acute febrile illness cases who come for health care seeking in the high malaria-endemic setting of North West Ethiopia.

Methods

Institutional-based descriptive serosurvey of malaria infections was employed among 18,386 febrile patients from September 2020 to August 2021. Data were entered using Epi Data version 4.2 and exported to STATA (SE) R-14 version statistical software for further analysis. Bi-variable and multivariable regression analyses were conducted to identify malaria infection. Finally, variables with P-value less than 0.05 were considered significant predictors for malaria infection.

Results

The mean (±standard deviation) age of participants was 48.6 (±18.4) years. The overall seroprevalence of malaria infection was estimated as 27.8% (95% confidence interval = 27.2; 28.6, standard error = 0.003). Malaria infection was significantly associated with participants being female (adjusted odds ratio = 2.9; 95% confidence interval = 1.8; 3.7, P = 0.01), age 5-29 years (adjusted odds ratio = 2.2; 95% confidence interval = 1.7; 2.8, P = 0.02), rural (adjusted odds ratio = 3.9; 95% confidence interval = 1.9; 4.4, P = 0.001), and Hgb ⩽11 mg/dL (adjusted odds ratio = 3.4; 95% confidence interval = 1.9; 5.86, P = 0.01).

Conclusion

Nearly every three to ten acute febrile cases were positive for confirmed malaria infection. The risk of malaria infection was significantly associated with respondents being female, aged 5-29 years, rural, and levels of hemoglobin were significantly associated with malaria infection.

Attributable risk factors for asymptomatic malaria and anaemia and their association with cognitive and psychomotor functions in schoolchildren of north-eastern Tanzania

In Africa, children aged 5 to 15 years (school age) comprises more than 50% (>339 million) of the under 19 years population, and are highly burdened by malaria and anaemia that impair cognitive development. For the prospects of improving health in African citizens, understanding malaria and its relation to anaemia in school-aged children, it is crucial to inform targeted interventions for malaria control and accelerate elimination efforts as part of improved school health policy. We conducted a study to determine the risk factors for asymptomatic malaria and their association to anaemia. We explored the prevalence of antimalarial drug resistance as well as the association of asymptomatic malaria infection and anaemia on cognitive and psychomotor functions in school-aged children living in high endemic areas. This study was a comprehensive baseline survey, within the scope of a randomised, controlled trial on the effectiveness and safety of antimalarial drugs in preventing malaria and its related morbidity in schoolchildren. We enrolled 1,587 schoolchildren from 7 primary schools located in Muheza, north-eastern Tanzania. Finger-pricked blood samples were collected for estimation of malaria parasitaemia using a microscope, haemoglobin concentration using a haemoglobinometer, and markers of drug resistance processed from dried blood spots (DBS). Psychomotor and Cognitive functions were assessed using a '20 metre Shuttle run' and a test of everyday attention for children (TEA-Ch), respectively. The prevalence of asymptomatic malaria parasitaemia, anaemia and stunting was 26.4%, 49.8%, and 21.0%, respectively with marked variation across schools. In multivariate models, asymptomatic malaria parasitaemia attributed to 61% of anaemia with a respective population attribution fraction of 16%. Stunting, not sleeping under a bednet and illiterate parent or guardian were other factors attributing to 7%, 9%, and 5% of anaemia in the study population, respectively. Factors such as age group (10-15 years), not sleeping under a bednet, low socioeconomic status, parents' or guardians' with a low level of education, children overcrowding in a household, and fewer rooms in a household were significantly attributed to higher malaria infection. There was no significant association between malaria infection or anaemia and performance on tests of cognitive function (sustained attention) or psychomotor function (VO2 max). However, a history of malaria in the past one month was significantly associated with decreased cognitive scores (aOR = -4.1, 95% CI -7.7-0.6, p = 0.02). Furthermore, stunted children had significantly lower VO2max scores (aOR = -1.9, 95% CI -3.0-0.8, p = 0.001). Regarding the antimalarial drug resistance markers, the most prevalent Pfmdr1 86-184-1034-1042-1246 haplotypes were the NFSND in 47% (n = 88) and the NYSND in 52% (n = 98). The wild type Pfcrt haplotypes (codons 72-76, CVMNK) were found in 99.1% (n = 219) of the samples. Malaria, stunting and parents' or guardians' illiteracy were the key attributable factors for anaemia in schoolchildren. Given malaria infection in schoolchildren is mostly asymptomatic; an addition of interventional programmes such as intermittent preventive treatment of malaria in schoolchildren (IPTsc) would probably act as a potential solution while calling for an improvement in the current tools such as bednet use, school food programme, and community-based (customised) health education with an emphasis on nutrition and malaria control.

Possible Interactions between Malaria, Helminthiases and the Gut Microbiota: A Short Review

Malaria, caused by the Plasmodium species, is an infectious disease responsible for more than 600 thousand deaths and more than 200 million morbidity cases annually. With above 90% of those deaths and cases, sub-Saharan Africa is affected disproportionately. Malaria clinical manifestations range from asymptomatic to simple, mild, and severe disease. External factors such as the gut microbiota and helminthiases have been shown to affect malaria clinical manifestations. However, little is known about whether the gut microbiota has the potential to influence malaria clinical manifestations in humans. Similarly, many previous studies have shown divergent results on the effects of helminths on malaria clinical manifestations. To date, a few studies, mainly murine, have shown the gut microbiota’s capacity to modulate malaria’s prospective risk of infection, transmission, and severity. This short review seeks to summarize recent literature about possible interactions between malaria, helminthiases, and the gut microbiota. The knowledge from this exercise will inform innovation possibilities for future tools, technologies, approaches, and policies around the prevention and management of malaria in endemic countries.

Plasmodium falciparum and Helminth Coinfections Increase IgE and Parasite-Specific IgG Responses

Coinfection with Plasmodium falciparum and helminths may impact the immune response to these parasites because they induce different immune profiles. We studied the effects of coinfections on the antibody profile in a cohort of 715 Mozambican children and adults using the Luminex technology with a panel of 16 antigens from P. falciparum and 11 antigens from helminths (Ascaris lumbricoides, hookworm, Trichuris trichiura, Strongyloides stercoralis, and Schistosoma spp.) and measured antigen-specific IgG and total IgE responses. We compared the antibody profile between groups defined by P. falciparum and helminth previous exposure (based on serology) and/or current infection (determined by microscopy and/or qPCR). In multivariable regression models adjusted by demographic, socioeconomic, water, and sanitation variables, individuals exposed/infected with P. falciparum and helminths had significantly higher total IgE and antigen-specific IgG levels, magnitude (sum of all levels) and breadth of response to both types of parasites compared to individuals exposed/infected with only one type of parasite (P ≤ 0.05). There was a positive association between exposure/infection with P. falciparum and exposure/infection with helminths or the number of helminth species, and vice versa (P ≤ 0.001). In addition, children coexposed/coinfected tended (P = 0.062) to have higher P. falciparum parasitemia than those single exposed/infected. Our results suggest that an increase in the antibody responses in coexposed/coinfected individuals may reflect higher exposure and be due to a more permissive immune environment to infection in the host. IMPORTANCE Coinfection with Plasmodium falciparum and helminths may impact the immune response to these parasites because they induce different immune profiles. We compared the antibody profile between groups of Mozambican individuals defined by P. falciparum and helminth previous exposure and/or current infection. Our results show a significant increase in antibody responses in individuals coexposed/coinfected with P. falciparum and helminths in comparison with individuals exposed/infected with only one of these parasites, and suggest that this increase is due to a more permissive immune environment to infection in the host. Importantly, this study takes previous exposure into account, which is particularly relevant in endemic areas where continuous infections imprint and shape the immune system. Deciphering the implications of coinfections deserves attention because accounting for the real interactions that occur in nature could improve the design of integrated disease control strategies.

Co-infections and Comorbidities of Multiple Parasites and Hepatitis B Virus Infections in the Lowland Area of Western Ethiopia: Implications for Integrated Approaches

Background

In the current study area, the burden of morbidities associated with S. mansoni, soil-transmitted helminths (STHs), asymptomatic malaria, and hepatitis B virus (HBV) infections and co-infection has not been known for the last 20 years. This necessitated a systematic investigation of the status of these infections and their associated morbidities in the lowland areas of the Abbey and Didessa Valleys in Western Ethiopia.

Methods

We used a cross-sectional study design in three schistosomiasis endemic areas. Systematic random sampling and simple random sampling techniques were used to select households and one study participant from each household. Each selected and consented participants were give stool sample for S. mansoni and soil-transmitted helminths screening using duplicate kato-Katz technique; blood sample for screen of asymptomatic malaria using malaria rapid diagnostic test and microscopy and hepatitis B virus using hepatitis B surface antigen kit and anthropometric measurement to assess nutritional status and digital hemoglobin meter to measure hemoglobin and interviewed using structured questionnaire to assess factors associated with infections. A descriptive statistic to summarize the data and a chi-square test, Fisher's exact test, and binary logistic regression models were used to see the associations.

Results

The overall prevalence of studied infections was 74.5%. It was highest for Schistosoma mansoni (53.9%), followed by asymptomatic Plasmodium falciparum infection (23.6%). The prevalence of Schistosoma mansoni co-infection with asymptomatic malaria was 8.6%, Schistosoma mansoni and soil-transmitted helminths co-infection was 6.2%, and the seroprevalence of hepatitis B virus was 2.9%. About half (49.9%) of the study participants were undernourished and about a quarter (24.4%) were anemic. Age group, the younger age group and infection status, those with multiple infections were more anemic and commonly undernourished.

Conclusion

There was a high prevalence of infections in the study area. Morbidities such as undernutrition and anemia were still prominent public health problems. There was a significant association between infection status and undernutrition and anemia.