This study analyzes the distribution, genetic diversity, and spread of Anopheles stephensi in Kenya following initial detection in December 2022. A total of 114 larval and 33 adult An. stephensi samples were confirmed in 7 of 18 surveyed counties majorly along transportation routes. Genetic analyses revealed three distinct genetic compositions with different levels of genetic diversity, suggesting multiple introductions into the country. The genetic composition of mosquitoes in most counties resembled southern Ethiopian populations, while those from Turkana showed a unique haplotype. A species distribution model predicts a more extensive range than currently observed, with low precipitation and minimal seasonal temperature variations as key factors influencing distribution. Challenges in adult sampling were noted, with larval sampling revealing co-occurrence with native Anopheles species. The findings have implications for surveillance and control strategies, emphasizing the need for continued monitoring, refined sampling techniques to inform bionomics, and cross-border collaboration.
In western Kenya, a cluster-randomized trial is assessing the impact of attractive targeted sugar baits (ATSBs) on malaria in children enrolled in three consecutive cohorts. Here, characteristics of children and households at enrolment, and factors associated with baseline malaria prevalence are described. Children aged 1 to < 15 years were randomly selected by cluster (n = 70) from a census database. Cohorts were enrolled in March–April 2022, September–October 2022, and March–April 2023. ATSBs were deployed in March 2022. At enrolment, all participants were tested for malaria by rapid diagnostic test (RDT). After enrolment a household survey was conducted. Household structures were classified as ‘improved’ (finished walls and roofs, and closed eaves) or ‘traditional’ (all other construction). A generalized linear mixed model was used to assess factors associated with malaria prevalence. Of 3705 children screened, 220 declined and 523 were excluded, due to plans to leave the study area (n = 392), ineligible age (n = 64) or other reason (n = 67). Overall, 2962 children were enrolled. Bed net use the previous night was more common in children aged 1–4 years (746/777 [96
Attractive targeted sugar baits (ATSBs) are a novel malaria control tool designed to target mosquitoes outdoors. We conducted a cluster-randomised trial to evaluate the impact of ATSBs on malaria indicators in Kenya. Seventy clusters (≥100 households/cluster) in Siaya county were randomly assigned (1:1) to intervention or control. Pyrethroid-only long-lasting insecticidal nets were distributed to all clusters, aiming for universal coverage. Two ATSBs containing dinotefuran were hung outside household structures in intervention clusters. ATSBs were monitored every two months and replaced every six months over two years. Three consecutive cohorts of randomly selected children (1- < 15 years) were enrolled, aiming to accrue 1,260 person-years over two years of follow-up. Incidence of clinical malaria (fever with a positive malaria test) was the primary outcome. A multilevel Poisson regression model was applied, with clusters as a random intercept and study arm as a fixed effect. Secondary outcomes were malaria prevalence in community residents (≥1 month), and parity of mosquitos captured through human landing catches. In March 2022, ATSBs were delivered to 33,180 of 33,419 (99.3%) household structures in intervention clusters. Overall, 268,268 ATSBs were deployed over two years. Of 2,962 cohort children enrolled (intervention = 1,497; control = 1,465), 2,869 (96.9%) were included in the primary analysis (intervention = 1,461; control = 1,408), contributing 1,445 person-years of follow-up. Malaria incidence was 1.32 episodes per person-years in the intervention arm versus 1.20 in the control (unadjusted incidence rate ratio 1.11; 95% CI: 0.75-1.65; p = 0.598). Of 7,488 community residents surveyed (intervention = 3,760; control = 3,728), 1,474 (39.2%) intervention and 1,461 (39.2%) control participants tested positive for malaria (unadjusted odds ratio [OR] 0.98; 95% CI: 0.60-1.59; p = 0.93). Of 6,457 female anopheles mosquitoes collected (intervention = 4,058; control = 2,399), 3,579 (88.2%) intervention and 1,973 (82.2%) control mosquitoes were parous (OR 1.34; 95% CI: 0.91-1.99; p = 0.14). In Kenya, we found no evidence that ATSBs reduced clinical malaria incidence, malaria prevalence, or vector parity. Trial registration Clinicaltrials.gov (NCT05219565), 22 January 2022.
Importance Most of the 2.3 million annual neonatal deaths occur in sub-Saharan Africa and South Asia, with perinatal asphyxia and neonatal sepsis being the leading causes of neonatal mortality. Most neonatal deaths are considered preventable through high-quality clinical care, which includes adherence to clinical care guidelines. Objective To assess adherence to World Health Organization clinical care guidelines for management of perinatal asphyxia and neonatal sepsis and to identify patient-level factors in adherence among neonates who died from these conditions. Design, Setting, and Participants This cross-sectional study obtained data from December 2015 through October 2023 from the Child Health and Mortality Prevention Surveillance (CHAMPS) catchment areas in 7 low- and middle-income countries in sub-Saharan Africa (Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) and South Asia (Bangladesh). Participants were neonates who were born alive and were aged 0 to 28 days at the time of death and had either perinatal asphyxia or neonatal sepsis. Exposure Medical records of neonates who died from perinatal asphyxia or neonatal sepsis determined by postmortem diagnostics. Main Outcomes and Measures The main outcome was the proportion of deceased neonates who received guideline-adherent treatments before they died. Mixed-effect multivariable logistic regression analyses were performed to identify factors associated with administration of at least bag-valve-mask (BVM) ventilation for perinatal asphyxia. Results Of the 1194 neonates (median [IQR] age at the time of death, 2 [1-6] days; 692 males [58.0%]) who died and were enrolled in CHAMPS with available clinical data, 476 (39.9%) died from perinatal asphyxia, 562 (47.0%) died from neonatal sepsis, and 156 (13.1%) from both conditions. These neonates had a median (IQR) birth weight of 2130 (1266-2988) g. For cases with perinatal asphyxia, guideline adherence ranged from 12.2% (n = 77) for adrenaline administration to 85.4% (540) for supplemental oxygen administration. Only 4.4% of neonates (28) with perinatal asphyxia received all recommended treatments. Among cases with neonatal sepsis, antibiotics were administered to 86.8% (623), although the recommended treatment was administered to only 61.0% (438). In multivariable analyses, neonates in whom clinicians accurately identified perinatal asphyxia were more likely to receive BVM ventilation than those who had received discordant antemortem and postmortem diagnoses (adjusted odds ratio, 2.00; 95% CI, 1.29-3.12). Conclusions and Relevance In this cross-sectional study, clinical care guideline adherence was suboptimal among neonates who died from perinatal asphyxia or neonatal sepsis. This finding underscores the critical need to increase adherence in regions with high rates of neonatal mortality and may inform strategies for strengthening health systems to support compliance with clinical care guidelines.
BACKGROUND:Rift Valley fever virus (RVFV) is a zoonotic arbovirus widely distributed across Africa and the Arabian Peninsula, which causes devastating epidemics affecting humans as well as ruminant livestock. The epidemiology of RVFV is difficult to disentangle, as it is transmitted to humans via mosquitos or direct contact with infected animals. Among these direct exposures are milking ruminants and drinking fresh milk, which have been firmly established as risk factors for RVFV exposure. However, no studies to date have addressed the stability of infectious RVFV in milk. METHODS:We assessed the stability of RVFV in milk by spiking cow's and goat's milk with infectious RVFV-MP12 vaccine strain and measuring RNA via quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and infectious viral titers via plaque assay over time in a variety of temperature conditions. RESULTS:We demonstrate that RVFV remains stable for up to 96 hours in refrigerated milk and up to 2 days in milk stored in warm ambient conditions. We also show that RVFV RNA remained detectable via qRT-PCR in milk at all assessed temperatures for up to 96 hours. Finally, we confirmed that commonly performed pasteurization techniques and boiling of milk fully inactivates RVFV in milk. CONCLUSIONS:These results demonstrate that RVFV contaminated milk in the milk supply chain of endemic regions could represent a widespread public health risk, and much of this risk is mitigatable via pasteurization. We also propose use of RVFV RNA detection in milk as a noninvasive source of RVFV surveillance.
