Maternal exposure to pyrethroid insecticides during pregnancy and repeated measures of infection symptoms among early school-aged children in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE).
Maternal pyrethroid exposure may be related to elevated infection rates among early school-aged children from an IRS area, and results may have global implications.
Abstract
Objective
Indoor residual spraying (IRS) using pyrethroids insecticides to control malaria results in high exposure to local populations. Pyrethroids are immunosuppressant and prenatal exposure has been associated with higher rates of infection-related symptoms such as fever and colds among preschool children. Whether associations persist at older ages is unclear. Furthermore, prior studies assessed symptoms based on recall periods of ≥1 year, which may introduce misclassification. The aim of this study was thus to estimate associations between prenatal exposure to pyrethroids and infections among early school-aged children from an IRS area using shorter recall periods.
Methods
We measured urinary concentrations of four pyrethroid metabolites in peripartum samples collected from mothers enrolled in the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE), a birth cohort study situated in Limpopo, South Africa, where IRS with pyrethroids is conducted annually. From age 5, we collected data on infection symptoms using up to 4 questionnaires each encompassing a three-month recall period. We used Poisson marginal structural models for repeated outcomes to estimate associations between maternal exposure to pyrethroids and infection symptoms.
Results
A 10-fold increase in maternal cis-DCCA, trans-DCCA and 3-PBA was associated with a doubling in the rates of persistent fever (cis-DCCA: Incidence Rate Ratio [IRR] = 1.9, 95% CI = 1.2, 3.2; trans-DCCA: IRR = 2.2, 95% CI = 1.4, 3.5; 3-PBA: IRR = 1.9, 95% CI = 1.0, 3.4). Higher trans-DCCA was also related to a 70% increase in diarrhea rates (IRR = 1.7, 95% CI = 1.0, 2.8).
Conclusion
Maternal pyrethroid exposure may be related to elevated infection rates among early school-aged children from an IRS area. In addition to IRS, pyrethroids are widely used in agriculture and retail products. Results may thus have global implications.
Residents of agricultural regions are exposed to complex mixtures of agricultural and household pesticides, yet determinants of exposure remain poorly characterized in low-and middle-income countries, limiting accurate exposure assessment and health risk evaluation. This study aimed to identify self-reported recent and ever behavioural and environmental factors associated with urinary pesticide biomarker levels among children living in three agricultural areas of the Western Cape, South Africa. Between 2017 and 2019, 533 children aged 9-15 years provided 1,814 spot urine samples and completed exposure questionnaires up to five times. Parents and children provided information on exposure factors such as farm residence, use of household pesticides, seeing spray drifts and various pesticide exposure activities. Fourteen biomarkers of pyrethroids, organophosphates, triazoles and dithiocarbamates were quantified using liquid chromatography-tandem mass spectrometry and corrected for specific gravity. Associations between exposure factors and biomarker levels were evaluated using linear mixed-effects models. Recent household pesticide use was associated with up to 57% higher levels of 12 biomarkers, while recent spray drifts exposure was associated with up to 30% higher levels of eight biomarkers. Ever household pesticide use and ever exposure to spray drifts were associated with up to 30% higher levels of IMPy, 2,4-D and 4F3PBA. Use of open drinking water sources was associated with higher TCPy, BCP and ETU levels. Recent exposure factors were consistently associated with urinary biomarker levels than ever exposure factors. The identified exposure factors can inform pesticide exposure characterization in epidemiological analyses and targeted interventions to reduce children's exposure in agricultural communities.
Regina Ntsubise Molomo, A. Veludo, Marc Grünig et al.· Environmental Pollution· 0 citations
Aflatoxin B1 (AFB1) exposure is a major environmental health concern among vulnerable groups such as pregnant women, yet its determinants in coastal settings remain poorly understood. We aimed to quantify AFB1 exposure and examine its environmental, behavioral, and sociodemographic determinants among pregnant women in Kwale County, a predominantly rural area on Kenya’s southern Indian Ocean coast. In a facility-based cross-sectional study, serum AFB1–albumin adduct concentrations were measured by enzyme-linked immunosorbent assay in 298 pregnant women. Determinants were examined with a pre-specified multivariable linear regression of log-transformed concentrations using heteroscedasticity-consistent (HC3) standard errors, and a secondary Firth penalized logistic model of detectable versus non-detectable exposure. Adducts were detectable in 251 participants (84.2%); the median concentration was 28.1 pg/mL (IQR 13.7–68.7). Exposure was determined primarily by where women lived: it was lowest in the community closest to the coast and progressively higher in two drier, more inland communities (2.02-fold, 95% CI 1.44–2.85; and 3.02-fold, 95% CI 1.89–4.82). Single marital status was associated with modestly higher exposure (1.89-fold; 95% CI 1.17–3.05). Food source, flour storage, maternal education, and age did not predict exposure, and the penalized logistic model reproduced the same geographical pattern. Despite near-universal exposure, only 1.7% of participants had ever heard of aflatoxin. AFB1 exposure was widespread and geographically structured, pointing to place-based rather than individual-level drivers and supporting area-targeted food-safety interventions to protect maternal and fetal health. These findings have implications for food-safety strategies in other tropical regions where climate and subsistence agriculture contribute to chronic aflatoxin exposure.
Richard Wodah-Seme, Gibson Omwansa Javes, J. Changoma et al.· Tropical Medicine and Health· 0 citations
Background: Toxoplasma gondii infection during pregnancy may lead to congenital toxoplasmosis and serious pregnancy complications. In Kenya, however, toxoplasmosis is not screened during routine antenatal care, and there is limited local data on maternal seroprevalence and associated risk factors. This study determined the seroprevalence of T. gondii infections. It examined its association with socio-demographic, obstetric characteristics, awareness levels, and exposure behaviours among pregnant women visiting the antenatal clinic at Pumwani Maternity Hospital in Nairobi, Kenya. Methods: A cross-sectional study was conducted among 298 pregnant women consecutively recruited at Pumwani Maternity Hospital in Nairobi County between July and October 2025. Data on socio-demographics, obstetric characteristics, knowledge, and exposure practices were collected using a structured questionnaire. Blood specimens were obtained from consenting prenatal patients, and anti-T. gondii IgG antibodies were detected by indirect enzyme-linked immunosorbent assay (ELISA). Associations between seropositivity and risk factors were assessed using univariable logistic regression, followed by two separate multivariable models. Variables with p < 0.25 were considered for multivariable analysis, followed by backward likelihood-ratio elimination. Model calibration was assessed using the Hosmer–Lemeshow test. Results: The overall seroprevalence of anti-T. gondii IgG was 24.5% (73 of 298). In the sociodemographic model, women who were self-employed (adjusted odds ratio [AOR] = 0.26, 95% CI: 0.13–0.53) and formally employed (AOR = 0.25, 95% CI: 0.11–0.59) had lower odds of seropositivity than unemployed women. Women aged 25–33 years had higher odds than those aged 18–24 years (AOR = 2.45, 95% CI: 1.06–5.62). Having two children was associated with lower odds than a first birth (AOR = 0.40, 95% CI: 0.18–0.90), while parity of four or more showed a borderline increase in odds (AOR = 3.11, 95% CI: 0.99–9.76). In the knowledge/exposure model, good awareness of population risk groups was linked to higher odds of seropositivity (AOR = 3.34, 95% CI: 1.21–9.24), but exposure-practice variables were not independently associated. Stratified analyses showed significant demographic differences in exposure practices, such as eating undercooked meat in the third trimester of pregnancy (p = 0.021) and unwashed vegetable consumption by pregnant women from Kamkunji Sub-County (p = 0.005). Parity of three increased infection risk (p = 0.007). Conclusions: About 25% of participants showed evidence of prior T. gondii exposure. Seropositivity correlated with specific sociodemographic and obstetric factors as well as awareness of groups at risk. These results endorse targeted antenatal education that emphasises practical food safety and environmental hygiene, aligned with a One Health approach. Further longitudinal and multicenter research, including IgM and IgG avidity testing, is needed to differentiate recent from past infections and to better understand risks associated with congenital toxoplasmosis.
C. J. Tangus, B. E. Lokonon, Ndichu Maingi et al.· Pathogens· 0 citations
Malaria remains a major public health problem among pregnant women in sub-Saharan Africa
and is a significant cause of maternal and neonatal morbidity and mortality. Physiological and
immunological changes during pregnancy increase susceptibility to malaria infection, resulting
in adverse outcomes such as maternal anemia, spontaneous abortion, stillbirth, preterm delivery,
low birth weight, and neonatal mortality. Despite the implementation of preventive measures,
including insecticide-treated mosquito nets (ITNs), intermittent preventive treatment in
pregnancy with sulfadoxine-pyrimethamine (IPTp-SP), and routine antenatal care (ANC)
services, malaria continues to pose a considerable challenge in Cameroon. This study aimed to
determine the prevalence of malaria and identify factors associated with malaria occurrence
among pregnant women attending antenatal care services at the New Bell District Hospital in
Douala, Cameroon. A hospital-based analytical cross-sectional study was conducted among 280
pregnant women attending ANC between November 2024 and July 2025. Data were collected
using a structured interviewer-administered questionnaire covering socio-demographic
characteristics, obstetric history, environmental conditions, malaria prevention practices, and
knowledge of malaria. Malaria diagnosis was confirmed through microscopic examination of
Giemsa-stained thick and thin blood smears. Data were analyzed using descriptive statistics,
Pearson’s Chi-square test, and multivariate logistic regression, with statistical significance set at
p < 0.05. Among the 280 participants, 118 tested positives for malaria parasites, yielding an
overall prevalence of 42.1% (95% CI: 36.3–47.9). Plasmodium falciparum accounted for 94.1%
of infections.
M. C. Mbongueh, Mbabazi Asiati, F. D. A. Bertin et al.· International journal of med...· 0 citations
Acute Respiratory Tract Infection (ARI) is a respiratory infection that frequently affects toddlers and remains a significant health problem. Toddlers are considered a vulnerable group due to their immature immune systems and their susceptibility to environmental risk factors. Prevention efforts are strongly influenced by the role of mothers as primary caregivers, particularly through knowledge of the causes, symptoms, and prevention methods of ARI. This study aims to determine the relationship between maternal knowledge about ARI and ARI prevention efforts in toddlers at the Jembatan Kecil Health Center in Bengkulu City in 2025. This study used a quantitative design with a cross-sectional approach. The sample size was 64 mothers with toddlers aged 0–59 months. Sampling was conducted using accidental sampling, with the sample size determined using the Slovin formula from a population of 230 toddlers. The results showed that the majority of mothers had sufficient knowledge about ARI (56.3%), and the majority of ARI prevention efforts in toddlers were categorized as good (92.2%). The results of the bivariate analysis using the Chi-Square test yielded a p-value of 0.001 (p ≤ 0.05), indicating a significant relationship between maternal knowledge about ARI and ARI prevention efforts in toddlers. It can be concluded that there is a significant relationship between maternal knowledge about ARI and ARI prevention efforts in toddlers. The results of this study are expected to encourage Health Centers to provide increased health education to mothers of toddlers to strengthen ARI prevention at the family level. The better the mother's knowledge, the better the preventive measures taken.
Despite substantial scale-up of prevention of mother-to-child transmission (PMTCT) services, vertical HIV transmission remains a public health concern in sub-Saharan Africa. Facility-level evaluations are essential to assess progress toward elimination targets and identify gaps in care. This study evaluated PMTCT outcomes and associated factors among HIV-exposed infants at Nakuru County Teaching and Referral Hospital, Kenya. A retrospective review of records for 141 HIV-exposed infants was conducted, analyzing demographic characteristics, maternal antiretroviral therapy (ART) status, infant prophylaxis, feeding practices, and HIV testing outcomes at 6 weeks, 6 months, 12 months, and 24 months. The mean infant age at enrollment was 6.36 weeks (SD ±1.69), with 51% being female. Maternal ART coverage during PMTCT was 95.8%. All infants underwent HIV testing at 6 weeks, with an HIV positivity rate of 5.0%, while the overall prevalence from 6 to 24 months was 4.3%. Dual infant prophylaxis using nevirapine and zidovudine was administered to 96.5% of infants at 6 weeks, and exclusive breastfeeding was practiced among 97.2% of infants. The findings indicate that HIV prevalence among HIV-exposed infants was below the WHO elimination threshold, reflecting strong PMTCT implementation. However, retention gaps and continued seroconversion highlight the need for strengthened follow-up systems, sustained ART adherence, and reinforced infant feeding counseling to further advance the elimination of pediatric HIV
S. Wanjohi, Hopekin Nyaribo, Bervon Wendo· African Journal of Pharmacy...· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
