France Daigle of the University of Montreal in Canada will identify the microorganisms that enable the survival of the typhoid fever-causing bacterium, Salmonella enterica serovar Typhi, at low levels in water, and thereby enhances disease spread. Typhoid fever spreads through contaminated food and water, and results in over 125,000 deaths annually worldwide. S. Typhi are so-called auxotrophic bacteria because they rely on an external source of the essential amino acids that they need to grow. Microbial interactions may provide nutrients and also increase bacterial fitness and support persistence by protecting them from the environment, thereby increasing the rate of disease transmission. They will assemble a microbial community in water consisting of three components: one protozoan (from a group known to promote bacterial survival); a defined consortium of bacteria representative of the human fecal microbiota; and fluorescently-tagged S. Typhi. They will evaluate the ability of S. Typhi to grow in these microcosms, and how they grow, such as in biofilms or inside the protozoa. They will also determine whether these persistent S. Typhi are better able to infect and survive in human cells. Finally, water samples from an endemic region in East Africa will be analyzed for the presence of S. Typhi and identified beneficial microbial partners using quantitative PCR.

Feng Fu of Dartmouth College in the U.S. will use social networks to promote positive attitudes and overcome negative views of vaccinations and thereby increase demand. The success of vaccinations has led to steep declines in the incidence of many serious diseases. However, this has decreased the perception of disease risk and thereby lowered vaccination coverage as parents concerns switch to other factors, such as cost and the perceived risk of the vaccination itself, which are fueled via social media channels. These current low vaccination rates exhibit so-called hysteresis whereby the past concerns about safety or necessity prevent the rates from increasing even when the concerns have been disproven. To overcome this, they will use computer modeling approaches to test the ability of targeting social networks to leverage social "contagion" (i.e., spread) of positive attitudes to vaccine knowledge. They will use a healthcare intervention dataset from a network of rural villages in Honduras to model how one or more health-related behaviors or beliefs of an individual affects the group to simulate the social contagion process related to vaccines. They will also evaluate the potential positive impact of influential individuals who publicly support vaccination. The results will be used to develop social network targeting algorithms to increase the demand for vaccination. Their modeling results will be validated using the real data from the village networks.

Caroline Aura from the University of Nairobi in Kenya will teach frontline health workers and caregivers new skills so they can apply simple techniques such as swaddling and rocking to lessen the pain and distress of infants during injections to improve vaccination rates. Vaccination rates are still too low in many low-resource settings, which may be due in part to the discomfort they cause infants. This in turn makes caregivers reluctant to obtain all the recommended vaccinations for their children. Methods exist to reduce the associated pain of injections, but health workers lack the knowledge and skills to implement them. To test their approach, they will recruit vaccinators and community health workers at four rural immunization centers and use seminars and workshops to teach them pain-relieving techniques, including using specific positions and making soothing sounds. They will also develop audio-visual training tools and illustrative guides to help teach the techniques to parents for them to use at home as well. All healthy children under 12 months old visiting the centers for a vaccination will also receive one of the pain relief techniques. They will evaluate the ability of the health workers to manage pain, the level of distress of the infants, and the experience of the caregivers.

Robert Kingsley of the Quadram Institute Bioscience in the United Kingdom will locate the typhoid fever-causing bacteria S. Typhi in water reservoirs in Harare, Zimbabwe, and identify any associated protozoa species present in the water that may be supporting disease spread. Typhoid fever is endemic in Zimbabwe, with several major outbreaks reported in the last decade. The bacteria persist in unclean aquatic environments, possibly supported by protozoa, and are transmitted to humans through ingestion of contaminated drinking water. They will detect S. Typhi in sewage effluent and low-quality drinking water in hotspots of typhoid transmission by enrichment culture and PCR, and use whole genome sequencing to establish the phylogenetic relationship between these bacteria and clinical typhoid isolates in the same city. They will also amplify 18S rDNA from the sewage and drinking water samples to characterize the microbial community in water and define the protozoa population. These data will help identify potential synergistic interactions between S. Typhi and other microbes to inform prevention strategies.