Chronic helminth infections can modulate immune responses to infection and vaccination. This study explored the association between current helminth infection, including waterborne and soil-transmitted helminths (STHs), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralising antibody (nAb) responses. Samples were collected cross-sectionally from participants across rural (Karonga) and urban (Lilongwe) regions in Malawi. Helminth infections were detected via real-time PCR in stool and urine samples, targeting Schistosoma spp., Ascaris lumbricoides , Ancylostoma duodenale , Necator americanus , and Trichuris trichiura . SARS-CoV-2 nAbs were measured using a human immunodeficiency virus (HIV) pseudotyped virus neutralisation assay. A nucleocapsid (N) protein enzyme linked immunosorbent assay (ELISA) identified prior natural SARS-CoV-2 infection in vaccinated participants. IgG targeting the spike (S) protein was measured using an ELISA. Helminth infection was found to be associated with reduced nAb responses post coronavirus disease 2019 (COVID-19) vaccination, but not after natural SARS-CoV-2 infection. IgG responses were also impaired among those helminth-infected. Generalised additive model analysis confirmed this interaction while considering covariates. This suggests that deworming before vaccination may improve responses in helminth endemic regions.
Abstract Chronic helminth infections can modulate immune responses to infection and vaccination. This study explored the association between current helminth infection, including waterborne and soil-transmitted helminths (STHs), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralising and IgG antibody responses. Samples were collected cross-sectionally from participants across rural (Karonga) and urban (Lilongwe) regions in Malawi. Helminth infections were detected via real-time PCR in stool and urine samples, targeting Schistosoma spp., Ascaris lumbricoides , Ancylostoma duodenale , Necator americanus , and Trichuris trichiura . SARS-CoV-2 nAbs were measured using a human immunodeficiency virus (HIV)-based pseudotyped virus neutralisation assay. A nucleocapsid (N) protein enzyme-linked immunosorbent assay (ELISA) identified prior natural SARS-CoV-2 infection in vaccinated participants. IgG targeting the spike (S) protein was measured using an ELISA. Helminth infection was found to be associated with reduced nAb responses post coronavirus disease 2019 (COVID-19) vaccination, but not after natural SARS-CoV-2 infection. Generalised additive model analysis confirmed this interaction while considering covariates. IgG responses were also impaired among those helminth-infected. It should be investigated whether integrating pre-vaccination deworming improves vaccine responses in helminth-endemic regions.
Trachoma is targeted for global elimination as a public health problem by 2030. Measurement of IgG antibodies in children is being considered for surveillance and programmatic decision-making. There are currently no programmatic guidelines based on serology, which represents a generalizable problem in seroepidemiology and disease elimination. Here, we collate Chlamydia trachomatis Pgp3 and CT694 IgG measurements from 48 serosurveys across Africa, Latin America, and the Pacific Islands (41,168 children ages 1–5 years) and propose a novel approach to estimate the probability that population C. trachomatis transmission is below or above levels requiring ongoing programmatic action. We determine that trachoma programs could halt control measures with >90% certainty when seroconversion rates (SCRs) are ≤2.2 per 100 person-years. Conversely, SCRs ≥4.5 per 100 person-years correspond with >90% certainty that further control interventions are needed. More extreme SCR thresholds correspond with higher levels of confidence of elimination (lower SCR) or ongoing action needed (higher SCR). This study demonstrates a robust approach for using trachoma serosurveys to guide elimination program decisions.
SARS-CoV-2 transmission in Malawi remains unclear due to high proportions of mild/asymptomatic infections and limited diagnostics. Existing seroprevalence studies in Malawi have primarily used convenience samples and enzyme-linked immunosorbent assays (ELISAs). We assessed SARS-CoV-2 neutralisation in a longitudinal Malawian population-based cohort, assessing protective immunity post-infection and vaccination. Sera were obtained from rural (Karonga, n = 958) and urban (Lilongwe, n = 918) based participants at three-monthly intervals (February 2021-April 2022). Neutralising antibodies against SARS-CoV-2 were measured using human immunodeficiency (HIV)-based pseudotype assays in HIV-uninfected participants, and vesicular stomatitis virus-based assays in HIV-infected participants and an HIV-uninfected subset. Nucleocapsid ELISAs identified vaccinated participants also infected. SARS-CoV-2 neutralisation profiles increased in complexity over time from rising vaccination coverage and emerging variants. Neutralising antibody prevalence was higher in Lilongwe than Karonga (68.1% (CI 63.5–72.4) vs. 45.4% (CI 41.6–49.3), Survey 4). Hybrid immune and solely vaccinated participants exhibited higher titres than those solely infected. Children < 15 years had the lowest neutralising antibody titres among infected (not vaccinated) participants. People living with HIV had lower neutralising responses than those HIV-uninfected, particularly post vaccination. We therefore recommend surveillance of children and people living with HIV as low neutralisation responses increase reinfection risk. COVID-19 vaccination should be prioritised for HIV-infected individuals.
Objectives. Vibrio cholerae remains a significant public health threat in Africa, with antimicrobial resistance (AMR) complicating treatment. This study leverages whole-genome sequencing (WGS) of V. cholerae isolates from Côte d’Ivoire, Ghana, Zambia and South Africa to assess genomic diversity, AMR profiles and virulence, demonstrating the utility of WGS for enhanced surveillance within the PulseNet Africa network. Methods. We analysed Vibrio isolates from clinical and environmental sources (2010–2024) using Oxford Nanopore sequencing and hybracter assembly. Phylogenetic analysis, MLST, virulence and AMR gene detection were performed using Terra, Pathogenwatch and Cloud Infrastructure for Microbial Bioinformatics platforms, with comparisons against 118 global reference genomes for broader genomic context. Results. Of 79 high-quality assemblies, 67 were confirmed as V. cholerae , with serogroup O1 accounting for the majority (43 out of 67, 67%). ST69 accounted for 60% (40 out of 67) of isolates, with 8 sequence types identified overall. Thirty-seven isolates formed distinct sub-clades within AFR12 and AFR15 O1 lineages, suggesting local clonal expansions. AMR gene analysis revealed genes associated with resistance to trimethoprim in 96% of isolates and genes associated with resistance to quinolones in 83%, while genes associated with resistance to azithromycin, rifampicin and tetracycline remained low (≤7%). A significant proportion of the serogroup O1 isolates (41 out of 43, 95%) harboured resistance genes in at least 3 antibiotic classes. Conclusions. This study highlights significant genetic diversity and AMR prevalence in African V. cholerae isolates, with expanding AFR12 and AFR15 clades in the region. The widespread presence of genes associated with resistance to trimethoprim and quinolones raises concerns for treatment efficacy, although azithromycin and tetracycline remain viable options. WGS enables precise identification of species and genotyping, reinforcing PulseNet Africa’s pivotal role in advancing genomic surveillance and enabling timely public health responses to cholera outbreaks.
Female genital schistosomiasis (FGS) and male genital schistosomiasis (MGS) are gender-specific manifestations of urogenital schistosomiasis. Morbidity is a consequence of prolonged inflammation in the human genital tract caused by the entrapped eggs of the waterborne parasite, Schistosoma (S.) haematobium. Both diseases affect the sexual and reproductive health (SRH) of millions of people globally, especially in sub-Sahara Africa (SSA). Awareness and knowledge of these diseases is largely absent among affected communities and healthcare workers in endemic countries. Accurate burden of FGS and MGS disease estimates, single and combined, are absent, mostly due to lack of awareness of both diseases and absence of standardized methods for individual or population-based screening and diagnosis. In addition, there are disparities in country-specific FGS and MGS knowledge, research and implementation approaches, and diagnosis and treatment. There are currently no WHO guidelines to inform practice. The BILGENSA (Genital Bilharzia in Southern Africa) Research Network aimed to create a collaborative multidisciplinary network to advance clinical research of FGS and MGS across Southern African endemic countries. The workshop was held in Lusaka, Zambia over two days in November 2022. Over 150 researchers and stakeholders from different schistosomiasis endemic settings attended. Attendees identified challenges and research priorities around FGS and MGS from their respective countries. Key research themes identified across settings included: 1) To increase the knowledge about the local burden of FGS and MGS; 2) To raise awareness among local communities and healthcare workers; 3) To develop effective and scalable guidelines for disease diagnosis and management; 4) To understand the effect of treatment interventions on disease progression, and 5) To integrate FGS and MGS within other existing sexual and reproductive health (SRH) services. In its first meeting, the BILGENSA Network set forth a common research agenda across S. haematobium endemic countries for the control of FGS and MGS.
Asymptomatic malaria infections are common in endemic regions, yet their impact on children’s growth remains inadequately understood. This study investigates the association between asymptomatic malaria and 6-18-month-old children’s growth indices in rural Malawi. Dried blood spots from 840 participants in Lungwena Child Nutrition Intervention 5 (LCNI-5) clinical trial were analysed at the baseline ( N = 697) and every 3 months for a year. The associations between asymptomatic Plasmodium falciparum (determined by real-time PCR), and growth indices (length-for-age Z score (LAZ), weight-for-age Z score (WAZ), and weight-for-length Z score (WLZ)) were examined. Across all ages (6 to 18 months), malaria-positive children had lower mean WAZ (-1.03 vs. -0.87, 95% CI -0.17 − -0.04) and WLZ (-0.03 vs. -0.13, 95% CI -0.22 − -0.06) compared to those uninfected peers, whereas LAZ showed no significant association. However, no significant impact was observed at individual time points, except at 12 months of age. After adjusting for confounders, malaria infection remained associated with poorer children growth outcome. Asymptomatic malaria is linked to impaired growth outcomes among young children in rural Malawi. Targeted interventions aimed at managing asymptomatic malaria could mitigate growth faltering and improve child health in malaria-endemic settings.
Introduction Suboptimal chemotherapy allows Mycobacterium tuberculosis to develop drug resistance owing to development of resistant mutants in the mycobacterial population. Early diagnosis of TB and identification of drug-resistance is of particular importance in human immunodeficiency virus (HIV)-infected individuals, as delay of therapy and subsequent development of drug-resistant TB can be devastating due to compromised immune systems. Methodology We conducted a cross-sectional evaluation study using presumptive M. tuberculosis positive clinical isolates at two urban sites in Malawi (Blantyre and Lilongwe) to assess the presence of mutant genes on first and second line TB drugs using Line Probe Assay (LPA) and the gold standard drug susceptibility test (DST) Results For the Lilongwe site, the incidence of MDR-TB by Line Probe Assay (LPA) was found to be 14.06% (95% CI: 8%-20%) whereas that for RIF mono-resistance was 6.25% (95% CI: 2%-10%). Contrastingly, MDR-TB by DST was 23.44% (95 CI:16% - 21%) while mono-resistance was 6.25% (95% CI:2% -10). There was a substantial agreement on the detection of MDR-TB (kappa statistic was 0.75 with 95% CI of 0.62-0.88). Blantyre site, at 9.5% confidence interval, the point estimate for MDR-TB was 0% while for INH mono-resistance TB was 3.3%. Conclusions There is high incidence of MDR-TB among patients whose samples are sent to the Lilongwe site than previously thought. A short turnaround time to diagnosis, and the ability to simultaneously detect rifampicin and isoniazid resistance, makes LPA a reliable tool for the early detection of multidrug-resistant tuberculosis. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Helse Nord Tuberculosis Initiative ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical clearance was obtained from the College of Medicine Research Ethics Committee (Certificate number COMREC: P.09/21/3418) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors
BACKGROUND:Mass drug administration (MDA) programmes with the macrolide antibiotic azithromycin to reduce childhood mortality are expanding in Africa; however, concerns remain about the long-term effects of these programmes on antimicrobial resistance (AMR). We aimed to evaluate the persistence and spread of Streptococcus pneumoniae AMR following a community-randomised MDA trial. METHODS:This population-based, cross-sectional, pneumococcal carriage survey was conducted in Mangochi, Malawi, 3·5 years after the MORDOR trial, in which communities received twice-yearly azithromycin or placebo for 2 years. Eligible participants in this carriage survey were children aged 4-9 years who lived in an azithromycin-treated or placebo-treated cluster during the MORDOR trial, and children aged 1-3 years who were resident in a cluster but born after the MORDOR trial ended. Nasopharyngeal swabs were collected from participants and analysed by whole genome sequencing; pneumococcal genomes obtained from a distant site in Malawi, in which MDA had not been conducted, were used as reference genomes. The primary outcome was the prevalence of S pneumoniae macrolide resistance, comparing placebo-treated and azithromycin-treated clusters at baseline, 6 months post-MDA, and 3·5 years post-MDA. FINDINGS:Between April 8 and May 14, 2021, 924 children aged 1-9 years were screened, of whom 19 were excluded and 905 were recruited to the follow-up carriage survey: 452 from azithromycin-treated clusters and 453 from placebo-treated clusters of the MORDOR trial. We assessed 426 isolates from these participants (190 from azithromycin-treated clusters and 236 from placebo-treated clusters), as well as samples from the baseline of the MORDOR trial (164 isolates; 83 from azithromycin-treated clusters and 81 from placebo-treated clusters) and from 6 months post-MDA (223 isolates; 119 from azithromycin-treated clusters and 104 from placebo-treated clusters). In azithromycin-treated clusters, macrolide resistance increased from 21·7% (95% CI 14·2-31·7; 18 of 83 isolates) at baseline to 31·9% (24·2-40·8; 38 of 119 isolates) 6 months post-MDA and to 32·1% (25·9-39·0; 61 of 190 isolates) 3·5 years post-MDA. In placebo-treated clusters, resistance increased from 21·0% (13·5-31·1; 17 of 81 isolates) at baseline to 25·0% (17·7-34·1; 26 of 104 isolates) 6 months post-MDA and to 30·9% (25·4-37·1; 73 of 236 isolates) 3·5 years post-MDA. No significant differences were observed in odds ratios between treatment groups across the survey timepoints: 0·97 (95% CI 0·36-2·55) at baseline, 1·46 (0·67-3·17) at 6 months post-MDA, and 1·12 (0·66-1·91) at 3·5 years post-MDA. Macrolide resistance in the non-MDA site remained stable: 16·9% (95% CI 12·8-21·8; 45 of 267 isolates) at baseline, 16·5% (13·3-20·3; 70 of 424 isolates) at 6 months, and 16·5% (12·5-21·4; 44 of 267 isolates) at 2·5 years. Among children born into azithromycin-treated clusters after MDA, macrolide resistance was 36·0% (27·7-45·1; 41 of 114 children). Multidrug resistance to at least three antibiotic classes was significantly higher in azithromycin-treated (p=0·0015) and placebo-treated (p<0·0001) clusters than in the comparator population at 3·5 years post-MDA and was associated with integrative conjugative elements. INTERPRETATION:Azithromycin MDA is associated with macrolide resistance that persists and potentially spreads to untreated populations. The co-existence of multidrug resistance and transmissible resistance on integrative conjugative elements in these populations is a public health concern. Careful monitoring of AMR is essential in areas where MDA is implemented. FUNDING:The Gates Foundation, the National Institute for Health and Care Research, and the Wellcome Trust.
Soil-transmitted helminths (STHs) are intestinal parasites that affect over a billion people worldwide. STH control relies on microscopy-based diagnostics to monitor parasite prevalence and enable post-treatment surveillance; however, molecular diagnostics are rapidly being developed due to increased sensitivity, particularly in low-STH-prevalence settings. The genetic diversity of helminths and its potential impact on molecular diagnostics remain unclear. Using low-coverage genome sequencing, we assess the genetics of STHs within worm, faecal, and purified egg samples from 27 countries, identifying differences in the genetic connectivity and diversity of STH-positive samples across regions and cryptic diversity between closely related human- and pig-infective species. We define substantial copy number and sequence variants in current diagnostic target regions and validate the impact of genetic variation on qPCR diagnostics using in vitro assays. Our study provides insights into the diversity and genomic epidemiology of STHs, highlighting both the challenges and opportunities for developing molecular diagnostics needed to support STH control efforts.
Female genital schistosomiasis (FGS) and male genital schistosomiasis (MGS) are gender-specific manifestations of urogenital schistosomiasis. Morbidity is a consequence of prolonged inflammation in the human genital tract caused by the entrapped eggs of the waterborne parasite, Schistosoma (S.) haematobium. Both diseases affect the sexual and reproductive health (SRH) of millions of people globally, especially in sub-Sahara Africa (SSA). Awareness and knowledge of these diseases is largely absent among affected communities and healthcare workers in endemic countries. Accurate burden of FGS and MGS disease estimates, single and combined, are absent, mostly due to lack of awareness of both diseases and absence of standardized methods for individual or population-based screening and diagnosis. In addition, there are disparities in country-specific FGS and MGS knowledge, research and implementation approaches, and diagnosis and treatment. There are currently no WHO guidelines to inform practice. The BILGENSA (Genital Bilharzia in Southern Africa) Research Network aimed to create a collaborative multidisciplinary network to advance clinical research of FGS and MGS across Southern African endemic countries. The workshop was held in Lusaka, Zambia over two days in November 2022. Over 150 researchers and stakeholders from different schistosomiasis endemic settings attended. Attendees identified challenges and research priorities around FGS and MGS from their respective countries. Key research themes identified across settings included: 1) To increase the knowledge about the local burden of FGS and MGS; 2) To raise awareness among local communities and healthcare workers; 3) To develop effective and scalable guidelines for disease diagnosis and management; 4) To understand the effect of treatment interventions on disease progression, and 5) To integrate FGS and MGS within other existing sexual and reproductive health (SRH) services. In its first meeting, the BILGENSA Network set forth a common research agenda across S. haematobium endemic countries for the control of FGS and MGS.
The World Health Organization End TB strategy aims for a 90% reduction of tuberculosis (TB) incidence by 2035. Systematic testing and treatment of latent TB infection (LTBI) among contacts of active TB patients is recommended as one of the ways to curtail TB incidence. However, there is a shortage of tools to accurately diagnose LTBI. We assessed the appropriateness of whole blood host transcriptomic markers (TM) to diagnose LTBI among household contacts of bacteriologically confirmed index cases compared to HIV negative healthy controls (HC). QuantiFERON-TB Gold Plus Interferon gamma release assay (IGRA) and reverse-transcriptase quantitative PCR were used to determine LTBI and quantify TM expression respectively. Association between TM expression and LTBI was evaluated by logistic regression modelling. A total of 100 participants, 49 TB exposed (TBEx) household contacts and 51 HC, were enrolled. Twenty-five (51%) TBEx individuals tested positive by IGRA, and were denoted as LTBI individuals, and 37 (72.5%) HC were IGRA-negative. Expression of 11 evaluated TM was significantly suppressed among LTBI compared to HC. Out of the 11 TM, ZNF296 and KLF2 expression were strongly associated with LTBI and successfully differentiated LTBI from HC. Paradoxically, 21 (49%) TBEx participants who tested IGRA negative exhibited the same pattern of suppressed TM expression as IGRA positive (LTBI-confirmed individuals). Results suggest that suppression of gene expression underlies LTBI and may be a more sensitive diagnostic biomarker than standard-of-care IGRA.
Malawi experienced its deadliest Vibrio cholerae (Vc) outbreak following devastating cyclones, with >58,000 cases and >1700 deaths reported between March 2022 and May 2023. Here, we use population genomics to investigate the attributes and origin of the Malawi 2022-2023 Vc outbreak isolates. Our results demonstrate the predominance of ST69 clone, also known as the seventh cholera pandemic El Tor (7PET) lineage, expressing O1 Ogawa (similar to 80%) serotype followed by Inaba (similar to 16%) and sporadic non-O1/non-7PET serogroups (similar to 4%). Phylogenetic reconstruction revealed that the Malawi outbreak strains correspond to a recent importation from Asia into Africa (sublineage AFR15). These isolates harboured known antimicrobial resistance and virulence elements, notably the ICEGEN/ICEVchHai1/ICEVchind5 SXT/R391-like integrative conjugative elements and a CTX phi prophage with the ctxB7 genotype compared to historical Malawian Vc isolates. These data suggest that the devastating cyclones coupled with the recent importation of 7PET serogroup O1 strains, may explain the magnitude of the 2022-2023 cholera outbreak in Malawi.
BACKGROUND:Undernutrition and malnutrition in children in low- and middle-income countries contribute to high mortality rates. Stunting, a prevalent form of malnutrition, is associated with educational and productivity losses. Environmental enteric dysfunction (EED) and human immunodeficiency virus (HIV) infection worsen these conditions. This study seeks to investigate the presence of enteropathy using EED fecal biomarkers in HIV-infected children who are stable on antiretroviral therapy (ART) across various nutritional statuses. By understanding the interplay between EED, HIV, and nutritional status, this study aims to provide insights that can inform targeted interventions to optimize nutritional outcomes in HIV infected children. METHODS/PRINCIPAL FINDINGS:This study evaluated the levels of alpha-1-antitrypsin, calprotectin and myeloperoxidase in frozen fecal samples from 61 HIV infected (mean age 9.16 ±3.08 years) and 31 HIV uninfected (6.65 ±3.41 years) children in Malawi. Anthropometric measurements and clinical data were collected. The height-for-age z-score (-1.66 vs -1.27, p = 0.040) and BMI-for-age z-score (-0.36 vs 0.01, p = 0.037) were lower in HIV infected children. Enzyme-linked immunosorbent assays were used to measure biomarker concentrations. Statistical tests were applied to compare biomarker levels based on HIV status and anthropometric parameters. Myeloperoxidase, alpha-1-antitrypsin, and calprotectin concentrations did not differ between HIV infected and HIV uninfected children of different age groups. In HIV infected children from 5-15 years, there is no difference in biomarker concentration between the stunted and non-stunted groups. CONCLUSION/SIGNIFICANCE:Our study found a higher prevalence of stunting in HIV infected children compared to uninfected children, but no significant differences in biomarker concentrations. This suggests no causal relationship between enteropathy and stunting in HIV infected children. These results contribute to the understanding of growth impairment in HIV infected children and emphasize the need for further research, particularly a longitudinal, biopsy-controlled study.
Background The complex interaction between malaria and undernutrition leads to increased mortality and morbidity rate among young children in malaria-endemic regions. Results from previous interventions suggest that improving nutritional status of young children may reduce the burden of malaria. This study tested a hypothesis that provision of lipid-based nutrient supplements (LNS) or corn-soy blend (CSB) supplementation to 6–18-month-old children in Malawi would reduce the prevalence of asymptomatic malaria among them. Methods A total of 840 6-month-old children were enrolled in a randomized trial. The participants received 12-month supplementation with three different daily dietary supplementations: CSB, soy-LNS, or milk-LNS, and one control group without supplementation. The prevalence rate of asymptomatic Plasmodium falciparum was determined by real-time PCR from the participant’s dried blood spots (DBS) collected at the baseline and every 3 months. The global null hypothesis was tested using modified Poisson regression to estimate the prevalence ratio (PR) between the control group and three intervention groups at all ages combined. All the models were adjusted for malaria at baseline, season of DBS sample collection, site of enrolment, and household asset Z-score. Results All children combined, the prevalence of P. falciparum was 14.1% at enrollment, 8.7% at 9 months, 11.2% at 12 months, 13.0% at 15 months and 22.4% at 18 months of age. Among all samples that were taken after enrolment, the prevalence was 12.1% in control group, 12.2% in milk-LNS, 14.0% in soy-LNS, and 17.2% in CSB group. Compared to children in the control group the prevalence ratio of positive malaria tests was 1.19 (95% CI 0.81–1.74; P = 0.372) in the milk-LNS group, 1.32 (95% CI 0.88–1.96; P = 0.177) in the soy-LNS group and 1.72 (95% CI 1.19–2.49; P = 0.004) in the CSB group. Conclusion The study findings do not support a hypothesis that LNS or CSB supplementation would reduce the prevalence of asymptomatic malaria among Malawian children. In contrast, there was a signal of a possible increase in malaria prevalence among children supplemented with CSB.
Background: Aflatoxin (AF) exposure is associated with child growth faltering in cross-sectional studies, with limited findings from longitudinal studies. Objectives: To evaluate the relationship between maternal AF B1-lysine adduct concentration, child AF B1-lysine adduct concentration, and child growth in the first 30 mo of life. Methods: AF B1-lysine adduct was measured in mother-child dyad plasma samples using isotope dilution mass spectrometry. Using linear regression, we assessed the relationship between AF B1-lysine adduct concentration and child weight, height, and head and mid-upper arm circumferences at 1 wk, 6, 12, 18, 24, and 30 mo of age. Results: In adjusted models, maternal prenatal AF B1-lysine adduct (pg/& mu;L) was positively associated with newborn anthropometric outcomes; largest beta coefficients for associations between standardized values were for newborn weight-for-age z-score [& beta; = 0.13; 95% confidence interval (CI): 0.02, 0.24; P < 0.05 and & beta; = 0.11; 95% CI: 0.00, 0.22; P < 0.05 for second and third trimester AF, respectively]. Child AF B1-lysine adduct (pg/& mu;L) at 6 mo was negatively associated with head circumference-for-age z-score at 6, 18, 24, and 30 mo, with beta coefficients ranging from & beta; = -0.15; 95% CI: -0.28, -0.02 to & beta; = -0.17; 95% CI: -0.31, -0.03; P < 0.05); 18-mo AF was negatively associated with anthropometric outcomes at 18, 24, and 30 mo, most consistently with length-for-age z-score (& beta; = -0.18; 95% CI: -0.32, -0.04, & beta; = -0.21; 95% CI: -0.35, -0.07, & beta; = -0.18; 95% CI: -0.32, -0.03 at 18, 24 and 30 mo, respectively). Conclusions: Child AF exposure was associated with impaired child growth, but maternal AF exposure was not. Exposure during infancy was linked to persistent deficit in head circumference, implying reduced brain size lasting beyond the age of 2 years. Exposure at 18 mo was linked to persistent linear growth deficit. Further research should elucidate mechanisms through which AF affects child growth.
Aeromonas caviae is an increasingly recognized etiological agent of acute gastroenteritis. Here, we report five draft genomes of A. caviae isolated from suspected cholera cases during the 2022-2023 cholera outbreak in Malawi.