08. EDA

Josh M. Colston, Abu S. G. Faruque, M. Jahangir Hossain, Debasish Saha, Suman Kanungo, Inácio Mandomando, M. Imran Nisar, Anita K. M. Zaidi, Richard Omore, Robert F. Breiman, Samba O. Sow, Anna Roose, Myron M. Levine, Karen L. Kotloff, Tahmeed Ahmed, Pascal Bessong, Zulfiqar Bhutta , Estomih Mduma, Pablo Penatero Yori, Prakash Sunder Shrestha, Maribel P. Olortegui, Gagandeep Kang, Aldo A. M. Lima, Jean Humphrey, Andrew Prendergast, Francesca Schiaffino, Benjamin F. Zaitchik and Margaret N. Kosek.

Int. J. Environ. Res. Public Health 2020, 17, 8078

Abstract: Diarrheal disease remains a major cause of childhood mortality and morbidity causing
poor health and economic outcomes. In low-resource settings, young children are exposed to
numerous risk factors for enteric pathogen transmission within their dwellings, though the relative
importance of different transmission pathways varies by pathogen species. The objective of this
analysis was to model associations between five household-level risk factors—water, sanitation,
flooring, caregiver education, and crowding—and infection status for endemic enteric pathogens in
children in five surveillance studies. Data were combined from 22 sites in which a total of 58,000
stool samples were tested for 16 specific enteropathogens using qPCR. Risk ratios for pathogen- and
taxon-specific infection status were modeled using generalized linear models along with hazard
ratios for all-cause diarrhea in proportional hazard models, with the five household-level variables
as primary exposures adjusting for covariates. Improved drinking water sources conferred a 17%
reduction in diarrhea risk; however, the direction of its association with particular pathogens was
inconsistent. Improved sanitation was associated with a 9% reduction in diarrhea risk with protective
effects across pathogen species and taxa of around 10–20% risk reduction. A 9% reduction in diarrhea
risk was observed in subjects with covered floors, which were also associated with decreases in
risk for zoonotic enteropathogens. Caregiver education and household crowding showed more
modest, inconclusive results. Combining data from diverse sites, this analysis quantified associations
between five household-level exposures on risk of specific enteric infections, effects which differed by
pathogen species but were broadly consistent with hypothesized transmission mechanisms. Such
estimates may be used within expanded water, sanitation, and hygiene (WASH) programs to target
interventions to the particular pathogen profiles of individual communities and prioritize resources.

Francesca Schiaffino, Dixner Rengifo Trigoso, Josh M. Colston, Maribel Paredes Olortegui, Wagner V. Shapiama Lopez, Paul F. Garcia Bardales, Nora Pisanic, Meghan F. Davis, Pablo Penataro Yori, and Margaret N. Kosek.

Am. J. Trop. Med. Hyg., 104(1), 2021, pp. 372–381

Abstract. Using previously validated microbial source tracking markers, we detected and quantified fecal contamination from avian species and avian exposure, dogs, and humans on household cooking tables and floors. The association among contamination, infrastructure, and socioeconomic covariates was assessed using simple and multiple ordinal logistic regressions. The presence of Campylobacter spp. in surface samples was linked to avian markers. Using molecular methods, animal feces were detected in 75.0% and human feces in 20.2% of 104 households. Floors were more contaminated than tables as detected by the avian marker Av4143, dog marker Bactcan, and human marker Bachum. Wood tables were consistently more contaminated than non-wood surfaces, specifically with the mitochondrial avian markers ND5 and CytB, fecal marker Av4143, and canine marker Bactcan. Final multivariable models with socioeconomic and infrastructure characteristics included as covariates indicate that detection of avian feces and avian exposure was associated with the presence of chickens, maternal age, and length of tenancy, whereas detection of human markers was associated with unimproved water source. Detection of Campylobacter in surface samples was associated with the avian fecal marker Av4143. We highlight the critical need to detect and measure the burden of animal
fecal waste when evaluating household water, hygiene, and sanitation interventions, and the possibility of decreasing risk of exposure through the modification of surfaces to permit more effective household disinfection practices. Animals may be a more important source of household fecal contamination than humans in many low-resource settings, although interventions have historically focused almost exclusively on managing human waste.

François, R., Peñataro, P., Rouhani, S., Siguas, M., Paredes, M., Rengifo, D., Pisanic, N., Burga, R., Meza, R., Meza, G., Gregory, M., Houpt, E., Platts-Mills, J., and Kosek, M.,

PLoS Negl Trop Dis. 2018 Feb; 12(2): e0006200.

Campylobacter is one of the main causes of gastroenteritis worldwide. Most of the current knowledge about the epidemiology of this food-borne infection concerns two species, C. coli and C. jejuni. Recent studies conducted in developing countries and using novel diagnostic techniques have generated evidence of the increasing burden and importance of other Campylobacter species, i.e. non-C. coli/jejuni. We performed a nested case-control study to compare the prevalence of C. coli/jejuni and other Campylobacterin children with clinical dysentery and severe diarrhea as well as without diarrhea to better understand the clinical importance of infections with Campylobacter species other than C. coli/jejuni.

Platts-Mills, JA., Babji, S., Bodhidatta, L., Gratz, J., Haque, R., Havt, A., McCormick, BJ., McGrath, M., Olortegui, MP., Samie, A., Shakoor, S., Mondal, D., Lima, IF., Hariraju, D., Rayamajhi, BB., Qureshi, S., Kabir, F., Yori, PP., Mufamadi, B., Amour, C., Carreon, JD., Richard, SA., Lang, D., Bessong, P., Mduma, E., Ahmed, T., Lima, AA., Mason, CJ., Zaidi, AK., Bhutta, ZA., Kosek, M., Guerrant, RL., Gottlieb, M., Miller, M., Kang, G., Houpt, ER.; MAL-ED Network Investigators.

Lancet Glob Health. 2015 Sep;3(9)

Abstract

BACKGROUND:

Most studies of the causes of diarrhoea in low-income and middle-income countries have looked at severe disease in people presenting for care, and there are few estimates of pathogen-specific diarrhoea burdens in the community.

METHODS:

We undertook a birth cohort study with not only intensive community surveillance for diarrhoea but also routine collection of non-diarrhoeal stools from eight sites in South America, Africa, and Asia. We enrolled children within 17 days of birth, and diarrhoeal episodes (defined as maternal report of three or more loose stools in 24 h, or one loose stool with visible blood) were identified through twice-weekly home visits by fieldworkers over a follow-up period of 24 months. Non-diarrhoeal stool specimens were also collected for surveillance for months 1-12, 15, 18, 21, and 24. Stools were analysed for a broad range of enteropathogens using culture, enzyme immunoassay, and PCR. We used the adjusted attributable fraction (AF) to estimate pathogen-specific burdens of diarrhoea.

FINDINGS:

Between November 26, 2009, and February 25, 2014, we tested 7318 diarrhoeal and 24 310 non-diarrhoeal stools collected from 2145 children aged 0-24 months. Pathogen detection was common in non-diarrhoeal stools but was higher with diarrhoea. Norovirus GII (AF 5·2%, 95% CI 3·0-7·1), rotavirus (4·8%, 4·5-5·0), Campylobacter spp (3·5%, 0·4-6·3), astrovirus (2·7%, 2·2-3·1), and Cryptosporidium spp (2·0%, 1·3-2·6) exhibited the highest attributable burdens of diarrhoea in the first year of life. The major pathogens associated with diarrhoea in the second year of life were Campylobacter spp (7·9%, 3·1-12·1), norovirus GII (5·4%, 2·1-7·8), rotavirus (4·9%, 4·4-5·2), astrovirus (4·2%, 3·5-4·7), and Shigella spp (4·0%, 3·6-4·3). Rotavirus had the highest AF for sites without rotavirus vaccination and the fifth highest AF for sites with the vaccination. There was substantial variation in pathogens according to geography, diarrhoea severity, and season. Bloody diarrhoea was primarily associated with Campylobacter spp and Shigella spp, fever and vomiting with rotavirus, and vomiting with norovirus GII.

INTERPRETATION:

There was substantial heterogeneity in pathogen-specific burdens of diarrhoea, with important determinants including age, geography, season, rotavirus vaccine usage, and symptoms. These findings suggest that although single-pathogen strategies have an important role in the reduction of the burden of severe diarrhoeal disease, the effect of such interventions on total diarrhoeal incidence at the community level might be limited.

Copyright © 2015 Platts-Mills et al. Open access article published under the terms of CC BY-NC-ND. Published by Elsevier Ltd.. All rights reserved.

Cama VA, Bern C, Roberts J, Cabrera L, Sterling CR, Ortega Y, Gilman RH, Xiao L.

Emerg Infect Dis. 2008 Oct;14(10):1567-74.

To determine whether clinical manifestations are associated with genotypes or subtypes of Cryptosporidium spp., we studied a 4-year longitudinal birth cohort of 533 children in Peru. A total of 156 infection episodes were found in 109 children. Data from first infections showed that C. hominis was associated with diarrhea, nausea, vomiting, general malaise, and increased oocyst shedding intensity and duration. In contrast, C. parvum, C. meleagridis, C. canis, and C. felis were associated with diarrhea only. C. hominis subtype families were identified (Ia, Ib, Id, and Ie); all were associated with diarrhea. Ib was also associated with nausea, vomiting, and general malaise. All C. parvum specimens belonged to subtype family IIc. Analysis of risk factors did not show associations with specific Cryptosporidium spp. genotypes or subtypes. These findings strongly suggest that Cryptosporidium spp. and subtypes are linked to different clinical manifestations in children.

Lee, G., Peñataro, P., Paredes, M., Caulfield, L., Sack, D., Fischer-Walker, C., Black, R., Kosek, M.

BMJ Open. 2014; 4(6)