TY  - JOUR
AU  - Tadesse, Birkneh Tilahun
AU  - Khanam, Farhana
AU  - Ahmmed, Faisal
AU  - Liu, Xinxue
AU  - Islam, Md Taufiqul
AU  - Kim, Deok Ryun
AU  - Kang, Sophie SY
AU  - Im, Justin
AU  - Chowdhury, Fahima
AU  - Ahmed, Tasnuva
AU  - Aziz, Asma Binte
AU  - Hoque, Masuma
AU  - Park, Juyeon
AU  - Pak, Gideok
AU  - Jeon, Hyon Jin
AU  - Zaman, Khalequ
AU  - Khan, Ashraful Islam
AU  - Kim, Jerome H
AU  - Marks, Florian
AU  - Qadri, Firdausi
AU  - Clemens, John D
PY  - 2023
DA  - 2023/11/20
TI  - Association Among Household Water, Sanitation, and Hygiene (WASH) Status and Typhoid Risk in Urban Slums: Prospective Cohort Study in Bangladesh
JO  - JMIR Public Health Surveill
SP  - e41207
VL  - 9
KW  - water
KW  - sanitation
KW  - sanitary
KW  - contaminated
KW  - contamination
KW  - hygiene
KW  - hygienic
KW  - WASH
KW  - water, sanitation and hygiene
KW  - typhoid fever
KW  - enteric fever
KW  - typhus
KW  - typhoid
KW  - enteric
KW  - salmonella
KW  - protection
KW  - recursive partitioning
KW  - Bangladesh
KW  - low- and middle-income countries
KW  - LMIC
KW  - bacteria
KW  - bacterial
KW  - bacterial infection
KW  - machine learning
KW  - algorithm
KW  - algorithms
KW  - model
KW  - low income
KW  - slum
KW  - slums
KW  - risk
KW  - infection control
KW  - incidence
KW  - prevalence
KW  - epidemiology
KW  - epidemiological
KW  - poverty
AB  - Background: Typhoid fever, or enteric fever, is a highly fatal infectious disease that affects over 9 million people worldwide each year, resulting in more than 110,000 deaths. Reduction in the burden of typhoid in low-income countries is crucial for public health and requires the implementation of feasible water, sanitation, and hygiene (WASH) interventions, especially in densely populated urban slums. Objective: In this study, conducted in Mirpur, Bangladesh, we aimed to assess the association between household WASH status and typhoid risk in a training subpopulation of a large prospective cohort (n=98,087), and to evaluate the performance of a machine learning algorithm in creating a composite WASH variable. Further, we investigated the protection associated with living in households with improved WASH facilities and in clusters with increasing prevalence of such facilities during a 2-year follow-up period. Methods: We used a machine learning algorithm to create a dichotomous composite variable (“Better” and “Not Better”) based on 3 WASH variables: private toilet facility, safe drinking water source, and presence of water filter. The algorithm was trained using data from the training subpopulation and then validated in a distinct subpopulation (n=65,286) to assess its sensitivity and specificity. Cox regression models were used to evaluate the protective effect of living in “Better” WASH households and in clusters with increasing levels of “Better” WASH prevalence. Results: We found that residence in households with improved WASH facilities was associated with a 38% reduction in typhoid risk (adjusted hazard ratio=0.62, 95% CI 0.49-0.78; P<.001). This reduction was particularly pronounced in individuals younger than 10 years at the first census participation, with an adjusted hazard ratio of 0.49 (95% CI 0.36-0.66; P<.001). Furthermore, we observed an inverse relationship between the prevalence of “Better” WASH facilities in clusters and the incidence of typhoid, although this association was not statistically significant in the multivariable model. Specifically, the adjusted hazard of typhoid decreased by 0.996 (95% CI 0.986-1.006) for each percent increase in the prevalence of “Better” WASH in the cluster (P=.39). Conclusions: Our findings demonstrate that existing variations in household WASH are associated with differences in the risk of typhoid in densely populated urban slums. This suggests that attainable improvements in WASH facilities can contribute to enhanced typhoid control, especially in settings where major infrastructural improvements are challenging. These findings underscore the importance of implementing and promoting comprehensive WASH interventions in low-income countries as a means to reduce the burden of typhoid and improve public health outcomes in vulnerable populations. 
SN  - 2369-2960
UR  - https://publichealth.jmir.org/2023/1/e41207
UR  - https://doi.org/10.2196/41207
UR  - http://www.ncbi.nlm.nih.gov/pubmed/37983081
DO  - 10.2196/41207
ID  - info:doi/10.2196/41207
ER  -