A Pilot Study on Integrating Videography and Environmental Microbial Sampling to Model Fecal Bacterial Exposures in Peri-Urban Tanzania

PLoS One. 2015 Aug 21;10(8):e0136158. doi: 10.1371/journal.pone.0136158. eCollection 2015.

Abstract

Diarrheal diseases are a leading cause of under-five mortality and morbidity in sub-Saharan Africa. Quantitative exposure modeling provides opportunities to investigate the relative importance of fecal-oral transmission routes (e.g. hands, water, food) responsible for diarrheal disease. Modeling, however, requires accurate descriptions of individuals' interactions with the environment (i.e., activity data). Such activity data are largely lacking for people in low-income settings. In the present study, we collected activity data and microbiological sampling data to develop a quantitative microbial exposure model for two female caretakers in peri-urban Tanzania. Activity data were combined with microbiological data of contacted surfaces and fomites (e.g. broom handle, soil, clothing) to develop example exposure profiles describing second-by-second estimates of fecal indicator bacteria (E. coli and enterococci) concentrations on the caretaker's hands. The study demonstrates the application and utility of video activity data to quantify exposure factors for people in low-income countries and apply these factors to understand fecal contamination exposure pathways. This study provides both a methodological approach for the design and implementation of larger studies, and preliminary data suggesting contacts with dirt and sand may be important mechanisms of hand contamination. Increasing the scale of activity data collection and modeling to investigate individual-level exposure profiles within target populations for specific exposure scenarios would provide opportunities to identify the relative importance of fecal-oral disease transmission routes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Caregivers / ethics*
  • Child, Preschool
  • Diarrhea / prevention & control*
  • Enterococcus / growth & development
  • Environmental Monitoring*
  • Escherichia coli / growth & development
  • Escherichia coli Infections / transmission
  • Feces / microbiology*
  • Female
  • Gram-Positive Bacterial Infections / transmission
  • Hand Disinfection
  • Humans
  • Models, Statistical*
  • Pilot Projects
  • Poverty
  • Tanzania
  • Urban Population
  • Video Recording

Grants and funding

This work was funded by Stanford University’s School of Earth Sciences, Center for African Studies and Woods Institute for the Environment. TRJ received support from the United States Environmental Protection Agency (EPA); EPA has not officially endorsed this publication, and the views expressed herein may not reflect the views of the EPA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.