BACKGROUND:Paediatric acute kidney injury (AKI) is a complication of severe malaria, but its long-term outcomes remain poorly defined in low-income and middle-income countries. We aimed to evaluate the long-term association between paediatric AKI and kidney outcomes and mortality following severe malaria. METHODS:We pooled data from two prospective cohorts of Ugandan children (ie, those aged 6 months-12 years) admitted to hospital with severe malaria between 2008 and 2017. Children with stored admission blood samples available for creatinine measurement were included in the analysis. Surviving participants were enrolled in a follow-up study conducted from 2020 to 2023, when kidney function and survival were assessed, using Cox regression with age as the timescale to model mortality risk. Logistic regression was used to estimate the odds of chronic kidney disease (CKD), defined as two or more consecutive low estimated glomerular filtration rates 90 days or more apart, and long-term major adverse kidney events, defined as CKD or death. Adjusted analyses included the following enrolment characteristics: age, sex, height-for-age Z score, study site, study cohort, severe malaria group (ie, cerebral malaria, severe malarial anaemia, respiratory distress, complicated seizures, or prostration), and HIV status. FINDINGS:At enrolment, the median age was 2·5 years (IQR 1·8-3·5), 622 (57·8%) of 1077 were male and 455 (42·2%) were female, with Kidney Disease: Improving Global Outcomes-defined AKI occurring in 431 (40·0%) children. Over a median of 6·5 years (3·7-8·8), 147 (13·6%) of children died, with nearly half of deaths (71 of 147) occurring after hospital discharge. Adjusted odds of long-term major adverse kidney events were higher among children with AKI (adjusted odds ratio [aOR] 3·14, 95% CI 2·23-4·43), driven by a higher mortality risk (adjusted hazard ratio [aHR] 3·36, 95% CI 2·22-5·10) that remained elevated beyond 2 years after the acute episode (aHR 4·53, 1·80-11·37). AKI survivors had higher odds of chronic kidney disease over follow-up (odds ratio 1·77, 1·07-2·93), although not significant after adjustment (aOR 1·47, 95% CI 0·84-2·56; p=0·18). INTERPRETATION:In this paediatric population, AKI was associated with excess long-term mortality, suggesting AKI is a sentinel event that marks sustained vulnerability to death and highlights limitations of acute-care models in malaria-endemic settings. FUNDING:The US National Institute of Neurological Disorders and Stroke, the Fogarty International Center, the US National Institutes of Allergy and Infectious Diseases, and a Ralph W and Grace M Showalter Young Investigator Award.
BACKGROUND:In low-income and middle-income countries, where typhoid fever remains a major public health problem, WHO recommends the use of typhoid conjugate vaccine (TCV). Here, we report vaccine effectiveness up to 8 years following a single dose of TCV in Nepal. METHODS:TyVOID was a prospective cohort study that extended the follow-up of children enrolled in a phase 3, double-blind, randomised controlled trial in Lalitpur, Nepal (TyVAC; Nov 20, 2017, to Oct 20, 2021). Children aged 9 months to 15 years were randomly assigned (1:1) to receive Vi-tetanus toxoid conjugate vaccine (Vi-TT) or a capsular group A meningococcal conjugate (MenA) vaccine. After unmasking and crossover vaccination, our study followed the trial participants until Oct 31, 2025. TyVAC participants who received Vi-TT were eligible for this study and categorised into either the 2017-18 cohort or 2020-21 cohort, depending on when they received the Vi-TT vaccine. The primary outcome, which was assessed in children who received both Vi-TT and MenA vaccines and with known TCV vaccination status during the government catch-up campaign in 2022, was the incidence of blood culture-confirmed typhoid identified through facility-based passive surveillance and medical record review. Adjusted incidence rate ratios (IRRs) were estimated using Poisson regression adjusted for age and sex. Vaccine effectiveness at 1-5 years and 4-8 years post-vaccination was estimated using a test-negative design among febrile children presenting to surveillance clinics, comparing odds of Vi-TT vaccination between culture-confirmed typhoid cases with negative controls. FINDINGS:16 131 TyVAC participants were enrolled at TyVOID baseline, of whom 14 850 provided information on Vi-CRM197 vaccination during the government catch-up campaign. After crossover and unmasking, the primary analysis population included 4941 participants vaccinated with Vi-TT in 2017-18 and 4856 participants vaccinated with Vi-TT in 2020-21. In 4856 participants in the 2020-21 Vi-TT cohort, 2402 (49·5%) were female, 2454 (50·5%) were male, and the median age at Vi-TT vaccination was 10·4 years (IQR 7·3-13·7). In 4941 participants in the 2017-18 Vi-TT cohort, 2482 (50·2%) were female, 2459 (49·8%) were male, and the median age at Vi-TT vaccination was 7·7 years (IQR 4·5-11·0). During a median follow-up of 3·7 years (3·7-3·8), the typhoid incidence rate was 111 per 100 000 person-years (95% CI 64-177) in the 2017-18 cohort and 46 per 100 000 person-years (18-94) in the 2020-21 cohort (adjusted IRR 2·41 [95% CI 1·00-5·80]; one-sided p=0·025). Vaccine effectiveness was 77% (95% CI 46-90; p=0·0006) in the 2020-21 Vi-TT cohort (1-5 years after vaccination), and 53% (8-76; p=0·027) in the 2017-18 Vi-TT cohort (4-8 years after vaccination). INTERPRETATION:A single Vi-TT dose confers strong protection in the first 4 years among Nepali children, with evidence of waning by 8 years. These findings support consideration of a booster dose to sustain protection in school-age children who remain at high risk of typhoid fever. FUNDING:Gates Foundation and Wellcome Trust.
