Publications Directory

Publications Directory

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

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). This 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.

Water, Sanitation and Health Sub-Saharan Africa Friday, August 21, 2015 Visit Website
Quantification of Human Norovirus GII on Hands of Mothers with Children Under the Age of Five Years in Bagamoyo, Tanzania
Mia Catharine Mattioli, Ali Boehm, Jenna Davis, Mwifadhi Mrisho

Research results suggest mothers' hands may be a source of norovirus exposure for children in households in Tanzania.

WASH and Development, Water, Sanitation and Health Sub-Saharan Africa Monday, July 6, 2015 Visit Website
Impact of Intensive Handwashing Promotion on Secondary Household Influenza-Like Illness in Rural Bangladesh: Findings from a Randomized Controlled Trial
Stephen Luby, P.K. Ram, M.A. DiVita, K. Khatun-e_Jannat, M. Islam, K. Krytus, E. Cercone, B. Sohel, M. Ahmend, A. Mahmud, Q. Rahman, M. Rahman, J. Yu, A. Brooks, E. Azziz-Baumgartner, A. Fry

After a household member became ill in rural Bangladesh, starting a handwashing promotion did not protect against influenza-like illness. This may be because behavior did not change quickly enough.

WASH and Development South Asia Thursday, June 11, 2015 Visit Website
Household-level risk factors for influenza among young children in Dhaka, Bangladesh: a case–control study
Saumil Doshi, Benjamin J. Silk, Dhiman Dutt, Moshtaq Ahmed, Adam L. Cohen, Thomas H. Taylor, W. Abdullah Brooks, Doli Goswami, Stephen Luby, Alicia M. Fry, Pavani K. Ram

We conducted a case–control study using existing active surveillance for respiratory illness. Handwashing with soap was practiced infrequently and was not associated with paediatric influenza in this community. Interventions aimed at crowded households may reduce influenza incidence in young children.

Water, Sanitation and Health South Asia Monday, May 4, 2015 Visit Website
Container-based sanitation: assessing costs and effectiveness of excreta management in Cap Haitien, Haiti
Sebastien Tilmans, Kory Russel, Jenna Davis

Among households that used the waterless toilet and collection service called Container-Based Sanitation (CBS), re.source co-founders Sebastien Tilmans and Kory Russel found a 3.5-fold reduction in open defecation

Sustainable Service Models Latin America/Caribbean Wednesday, April 1, 2015 Visit Website
Explaining low rates of sustained use of siphon water filter: evidence from follow-up of a randomised controlled trial in Bangladesh
Nusrat Najnin, Shaila Arman, Jaynal Abedin, Leanne Unicomb, David I. Levine, Minhaj Mahmud, Karin Leder, Farzana Yeasmin, Jill E. Luoto, Jeff Albert, Stephen Luby

The technological, psychosocial and contextual dimensions of integrated behavior model for water, sanitation, and hygiene contributed to understanding the factors related to sustained use of siphon filter. Given the low regular usage rate and the hardware-related problems reported, the contribution of siphon filters to improving water quality in low-income urban communities in Bangladesh is likely to be minimal.

Expanding Access South Asia Thursday, March 5, 2015 Visit Website
Differences in Field Effectiveness and Adoption between a Novel Automated Chlorination System and Household Manual Chlorination of Drinking Water in Dhaka, Bangladesh: A Randomized Controlled Trial
Amy Pickering, Yoshika Crider, Nuhu Amin, Valerie Bauza, Leanne Unicomb, Jenna Davis, Stephen Luby

This study compares a novel low-cost technology designed to passively (automatically) dispense chlorine at shared handpumps with a household-level intervention providing water disinfection tablets (Aquatab), safe water storage containers, and behavior promotion. Twenty compounds were enrolled in Dhaka, Bangladesh, and randomly assigned to one of three groups: passive chlorinator, Aquatabs, or control. Over a 10-month intervention period, the mean percentage of households whose stored drinking water had detectable total chlorine was 75% in compounds with access to the passive chlorinator, 72% in compounds receiving Aquatabs, and 6% in control compounds. Both interventions also significantly improved microbial water quality. The study findings suggest high potential for an automated decentralized water treatment system to increase consistent access to clean water in low-income urban communities.

WASH and Development, Sustainable Service Models, Water, Sanitation and Health South Asia Tuesday, March 3, 2015 Visit Website
Genotypic and phenotypic characterization of Escherichia coli isolated from feces, hands, and soils in rural Bangladesh using the Colilert Quanti-Tray System (IDEXX)
Timothy R. Julian, M. Aminul Islam, Amy Pickering, Subarna Roy, Erica R. Fuhrmeister, Ayse Ercumen, Angela Harris, Jason Bishai, Kellogg J. Schwab

The increased awareness of the role of environmental matrices in enteric disease transmission has resulted in the need for rapid, field-based methods for fecal indicator bacteria and pathogen detection. We found that Colilert, and likely other β-glucuronidase-based assays, is appropriate for detection of E. coli on hands and in soils with low false-positive rates. Also, E. coli isolated from hands and soils in Bangladeshi households are diverse and indistinguishable from cattle, chicken, and human fecal isolates, using traditional biochemical assays and phylogrouping.

Water, Sanitation and Health South Asia Sunday, March 1, 2015 Visit Website
Hand-to-mouth contacts result in greater ingestion of feces than dietary water consumption in Tanzania: A quantitative fecal exposure assessment model
Mia Catharine Mattioli, Jenna Davis, Ali Boehm

This research evaluated the relative contribution of two important environmental transmission routes of diarrhea-causing pathogens to young children in low-income countries-hands and water. A Monte Carlo simulation was used to model the amount of human feces ingested by children under five years old from exposure via hand-to-mouth contacts and stored drinking water ingestion in Bagamoyo, Tanzania. The model results show that Tanzanian children ingest a significantly greater amount of feces each day from hand-to-mouth contacts than from drinking water, which may help elucidate why interventions focused on water without also addressing hygiene often see little to no effect on reported incidence of diarrhea.

Water, Sanitation and Health Sub-Saharan Africa Monday, January 5, 2015 Visit Website
Video Surveillance Captures Student Hand Hygiene Behavior, Reactivity to Observation, and Peer Influence in Kenyan Primary Schools
Amy Pickering, Annalise Blum, Robert F. Breiman, Pavani K. Ram, Jenna Davis

Student hand cleaning behavior was monitored with video surveillance and in-person structured observation, both simultaneously and separately, at four primary schools in urban Kenya over a study period of 8 weeks. Video surveillance of hand hygiene behavior yields results comparable to in-person observation among schools in a resource-constrained setting and has certain advantages over in-person observation, including rapid data processing and the capability to capture new behavioral insights. The results showed that peer influence can significantly improve student hand cleaning behavior and, when possible, should be exploited in the design and implementation of school hand hygiene programs.

Water, Sanitation and Health Sub-Saharan Africa Thursday, March 27, 2014 Visit Website
Enteric Pathogens in Stored Drinking Water and on Caregiver’s Hands in Tanzanian Households with and without Reported Cases of Child Diarrhea
Mia Catharine Mattioli, Ali Boehm, Jenna Davis, Angela Harris, Amy Pickering

The presence of molecular markers for three enteric viruses (enterovirus, adenovirus, and rotavirus), seven Escherichia coli virulence genes, and human-specific Bacteroidales was assessed in hand rinses and household stored drinking water of Tanzanian households with and without cases of childhood diarrhea. Surprisingly, better stored water quality was found among households with diarrhea, indicating that caregivers with sick children may be more likely to ensure safe drinking water in the home. The analysis also showed that interventions to increase the quantity of water available for hand washing, and to improve food hygiene, may reduce exposure to enteric pathogens in the domestic environment.

Water, Sanitation and Health Sub-Saharan Africa Thursday, January 2, 2014 Visit Website
Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study
Blythe A. Layton, Yiping Cao, Darcy L. Ebentier, Kaitlyn Hanley, Elisenda Ballesté, João Brandão, Muruleedhara Byappanahalli, Reagan Converse, Andreas H. Farnleitner, Jennifer Gentry-Shields, Maribeth L. Gidley, Michèle Gourmelon, Chang Soo Lee, Jiyoung Lee, Solen Lozach, Tania Madi, Wim G. Meijer, Rachel Noble, Lindsay Peed, Georg H. Reischer, Raquel Rodrigues, Joan B. Rose, Alexander Schriewer, Chris Sinigalliano, Sangeetha Srinivasan, Jill Stewart, Laurie C. Van De Werfhorst, Dan Wang, Richard Whitman, Stefan Wuertz, Jenny Jay, Patricia A. Holden, Ali Boehm, Orin Shanks

Is stool, septage, and sewage all the same in regards to microbial source tracking? This is another paper resulting from the Source Identification Protocol Project (SIPP). It looks specifically at performance of human fecal-associated PCR-based assays and dives into three important issues. First, they discuss the impact of detectable but not quantifiable samples on assay performance. Second, they look at performance for all filter sample units of measure. Third, they determine how the source of the sample (stool, septage, sewage) influences performance.

Water, Sanitation and Health North America Friday, November 15, 2013 Visit Website
Performance of Viruses and Bacteriophages for Fecal Source Determination in a Multi-Laboratory, Comparative Study
Valerie J. Harwood, Ali Boehm, Lauren M. Sassoubre, Kannappan Vijayavel, Jill R. Stewart, Theng-Theng Fong, Marie-Paule Caprais, Reagan R. Converse, David Diston, James Ebdon, Jed A. Fuhrman, Michele Gourmelon, Jennifer Gentry-Shields, John F. Griffith, Donna R. Kashian, Rachel T. Noble, Huw Taylor, Melanie Wicki

Interested in microbial source tracking? This study constitutes the largest multi-laboratory study on microbial source tracking (MST) to date. The Source Identification Protocol Project (SIPP) covers a wide range of MST methods; this paper looks specifically at virus and bacteriophage methods targeting human fecal or sewage contamination. The advantages of using viruses for MST are that they may provide a more accurate measure of gastrointestinal illness risk and non-pathogenic viruses exhibit similar fate and transport to viral pathogens in the environment. Additionally, viruses are highly host-specific, which improves confidence in identification of pollution sources.

Water, Sanitation and Health North America Friday, November 15, 2013 Visit Website
The challenge of global water access monitoring: evaluating straight-line distance versus self-reported travel time among rural households in Mozambique

"Access to improved water supply“ is currently monitored globally without consideration of time and/or distance considerations despite almost half of the world's population leaving their home to fetch water. And although support is growing for the incorporation of fetching time and/or distance considerations into global monitoring, current efforts typically rely on self-reported distance and/or travel time data that have been shown to be unreliable. To aid in developing policy, this study provides a head-to-head comparison of such indicators with other possible distance/time metrics, finding that the share of households classified as having versus lacking access would differ by more than 70 percentage points depending on the particular indicator employed.

Water, Sanitation and Health, Expanding Access Sub-Saharan Africa Friday, September 13, 2013 Visit Website
Mechanisms of post-supply contamination of drinking water in Bagamoyo, Tanzania
Angela Harris, Jenna Davis, Ali Boehm

In Tanzania we found that the microbiological quality of households' stored drinking water varies significantly over the course of the day. We tested for fecal indicator bacteria in the water during its collection at the source, while being stored in the home, and following any extraction from the storage container. Levels of contamination increased after filling the storage container, as well as after stored water was extracted, even when using strategies considered to be relatively safe. As in-home water storage is likely to be the norm for millions of households in the foreseeable future, additional efforts are needed to prevent contamination from storage containers and during extraction.

Water, Sanitation and Health Sub-Saharan Africa Sunday, September 1, 2013 Visit Website