The seasonality of diarrheal pathogens: A retrospective study of seven sites over three years

Abstract

Diarrheal disease is one of the leading causes of death among young children in the developing world. It is difficult to determine which of a wide variety of pathogens are most responsible for disease, since this differs by location and time of year. Here, we study the seasonal prevalence of several pathogens among children with moderate-to-severe diarrhea across study sites in Africa and South Asia. We found that several pathogens, including rotavirus, had regular annual peaks. Some pathogens were associated with weather conditions, such as heat or rain, or with general seasons of the year, such as summer or winter. We believe that describing the seasonal epidemiology of these pathogens could enable better diagnoses of symptomatic children based on the time of the year. Additionally, weather is a major driver of diarrheal pathogen transmission, and identifying the conditions associated with each pathogen could help us infer pathogen transmission pathways, predict large outbreaks, and develop intervention strategies. January 31, 2019 2/21 Pediatric diarrheal disease is caused by a wide variety of pathogens [1-3]. Various 2 studies have found that some pathogens are seasonal, peaking at different times of the 3 year [4-6]. Frequently, the seasonal periodicity of diarrheal disease is attributed to 4 weather, which could drive incidence by diverse mechanisms. For example, weather 5 conditions can favor the survival and replication of pathogens on fomites [7], the 6 transmission between human hosts through flooding and contamination of drinking 7 water [8], and the prevalence of vectors that transmit disease between hosts [9, 10]. 8 Weather has broadly been shown to be mathematically correlated with diarrhea 9 incidence [11, 12], with some computational studies claiming a causal link [13] despite 10 potential limitations to their methodology [14-16]. 11 However, most studies of disease seasonality have been conducted in temperate 12 climates, and substantially less is known about the seasonality of diseases in tropical 13 countries [17, 18], where diarrheal disease is one of the leading causes of morbidity and 14 mortality among children [19]. The wide variety of climates and populations in the 15 tropics make it challenging to uncover general patterns in the epidemiology of diarrheal 16 disease. Compounding these challenges, most studies are limited to sites within a single 17 country focused on a specific disease. Characterizing the seasonal epidemiology of these 18 pathogens could enable clinicians to better diagnose children based on the time of the 19 year. Additionally, identifying the weather conditions associated with each pathogen 20 could help us infer pathogen transmission pathways, predict large outbreaks, and 21 develop intervention strategies. 22 hydration; dysentery identified by blood in stool; or admission to the hospital for 49 diarrhea or dysentery [2]. To limit the number of enrollments and ensure balanced 50 enrollment by age, 8-9 children in each age strata (0-11 months, 12-23 months, 24-59 51 m...

Clinical predictors for etiology of acute diarrhea in children in resource-limited settings

“…In addition to the information from the GEMS survey, we developed a season variable using temperature and rain information from NOAA weather stations close to the health centers and with data during the GEMS time period [ 12 ]. We defined a rainy season day as a day having a center-aligned 1-month moving rain average greater than the overall rain average within the study period.…”

Poultry Ownership Associated with Increased Risk of Child Diarrhea: Cross-Sectional Evidence from Uganda

“…[43][44][45][46] Seasonal trends and associations with rainfall have also been observed for enteric infections. 47,48 Our study period in April coincided with the very beginning of the rainy season, which started in late April 2018 in our study area. It is possible that there were no major infections circulating during this month-long study window or that our study duration was not sufficiently long to capture trends in infection.…”

Glucagon‐like Peptide 2 Concentrations Vary in Zambian Children During Diarrhoea, in Malnutrition and Seasonally

“…Seasonal variation has been shown in the prevalence of undernutrition ( 34 ) and incidence of diarrhoea ( 35 ). Diarrhoeal pathogens have also been shown to vary seasonally, influenced by factors such as rainfall, temperature, and humidity ( 36 ). We set out to explore if there is any association between GLP-2 release and these factors that vary seasonally, that is, food availability, rainfall, temperature, and pathogens.…”