Electromagnetic Studies of Mesons, Nucleons, and Nuclei

Professor Baker was a faculty member at Hampton University in Hampton, Virginia, and, jointly, a Staff Physicist at Jefferson Lab in nearby Newport News from September 1989 to July 2006. The Department of Energy (DOE) funded the grant DE-FG02-97ER41035 Electromagnetic Studies of Mesons, Nucleons, and Nuclei, while Baker was in this joint appointment. Baker sent a closeout report on these activities to Hampton University’s Sponsored Research Office some years ago, shortly after joining Yale University in 2006. In the period around 2001, the research grant with Baker as the Principal Investigator (PI) was put under the supervision of Professor Liguang Tang at Hampton University. Baker continued to pursue the research while in this join appointment, however the administrative responsibilities with the DOE and with Hampton University rested with Professor Tang after 2001, to my recollection. What is written in this document is from Baker’s memory of the research activities, which he has not pursued since joining the Yale University faculty

Fecal Fingerprints of Enteric Pathogen Contamination in Public Environments of Kisumu, Kenya, Associated with Human Sanitation Conditions and Domestic Animals.

Young children are infected by a diverse range of enteric pathogens in high disease burden settings, suggesting pathogen contamination of the environment is equally diverse. This study aimed to characterize across- and within-neighborhood diversity in enteric pathogen contamination of public domains in urban informal settlements of Kisumu, Kenya, and to assess the relationship between pathogen detection patterns and human and domestic animal sanitation conditions. Microbial contamination of soil and surface water from 166 public sites in three Kisumu neighborhoods was measured by enterococcal assays and quantitative reverse transcription polymerase chain reaction (qRT-PCR) for 19 enteric pathogens. Regression was used to assess the association between observed sanitary indicators of contamination with enterococci and pathogen presence and concentration, and pathogen diversity. Seventeen types of pathogens were detected in Kisumu public domains. Enteric pathogens were codetected in 33% of soil and 65% of surface water samples. Greater pathogen diversity was associated with the presence of domestic animal feces but not with human open defecation, deteriorating latrines, flies, or disposal of human feces. Sanitary conditions were not associated with enterococcal bacteria, specific pathogen concentrations, or "any pathogen". Young children played at 40% of observed sites. Managing domestic animal feces may be required to reduce enteric pathogen environmental contamination in high-burden settings

Realities and experiences of community health volunteers as agents for behaviour change: evidence from an informal urban settlement in Kisumu, Kenya.

BACKGROUND: Community health workers play an important role in health service delivery and are increasingly involved in behaviour change interventions, including for hygiene-related behaviour change. However, their role and capacity to deliver behaviour change interventions, particularly in high-density urban settlements, remain under-researched. This study examines the behaviour change-related activities of community health volunteers (CHVs)-community health workers affiliated with the Kenyan Ministry of Health-in a peri-urban settlement in Kenya, in order to assess their capabilities, opportunities to work effectively, and sources of motivation. METHODS: This mixed-methods study included a census of 16 CHVs who work in the study area. All CHVs participated in structured observations of their daily duties, structured questionnaires, in-depth interviews, and two focus group discussions. Structured data were analysed descriptively. Thematic content analysis was followed for qualitative data. Results were synthesized and interpreted using the capability, opportunity, motivation for behaviour change framework, COM-B. RESULTS: In addition to their responsibilities with the Ministry of Health, CHVs partnered with a range of non-governmental organizations engaged in health and development programming, often receiving small stipends from these organizations. CHVs reported employing a limited number of behaviour change techniques when interacting with community members at the household level. Capability: While supervision and support from the MOH was robust, CHV training was inconsistent and inadequate with regard to behaviour change and CHVs often lacked material resources necessary for their work. Opportunity: CHVs spent very little time with the households in their allocated catchment area. The number of households contacted per day was insufficient to reach all assigned households within a given month as required and the brief time spent with households limited the quality of engagement. MOTIVATION: Lack of compensation was noted as a demotivating factor for CHVs. This was compounded by the challenging social environment and CHVs' low motivation to encourage behaviour change in local communities. CONCLUSIONS: In a complex urban environment, CHVs faced challenges that limited their capacity to be involved in behaviour change interventions. More resources, better coordination, and additional training in modern behaviour change approaches are needed to ensure their optimal performance in implementing health programmes

Designing a Food Hygiene Intervention in Low-Income, Peri-Urban Context of Kisumu, Kenya: Application of the Trials of Improved Practices Methodology.

Food contamination during weaning and complementary feeding can result in high diarrheal incidence among infants. Caregiver practices are important determinants of exposure to foodborne pathogens, and can therefore play a role in reduction in infant food contamination. Through a qualitative approach, we used the Trials of Improved Practices methodology to design a food hygiene intervention in a low-income settlement of Kisumu city in Kenya. These settlements in Kisumu city host a large portion of the city's population and are faced with a high diarrheal disease burden. Caregivers were selected if they had a child aged 6-9 months, and together, we codesigned a combination of hardware and messaging components targeting handwashing with soap, hygienic feeding, reheating, and hygienic storage of infant food. Caregivers received up to six engagement visits with the research team. The visits were aimed at improving the designed hardware and messaging components. Results showed that feeding items were easily adopted by caregivers, whereas reheating of food was less observed. Households reportedly improved their food storage and handwashing practices. As a result, the hardware components were further refined and tested among the caregivers. Messaging components spurred the aspirations that caregivers had for their children and acted as reminders of practicing good food hygiene. The outcomes of the codesign process provided valuable insights on the knowledge of caregivers, a delivery approach for implementing the intervention, and further informed a subsequent trial that adopted the designed intervention to target early childhood exposure to enteric pathogens through contaminated food

Community health volunteers’ capacity for hygiene behaviour change: evidence from urban Kenya

Community health volunteers (CHVs) play an important role in health service delivery and are increasingly involved in water, sanitation and hygiene (WASH) behaviour change promotion. However, the realities of CHVs work, engagement with the health sector, and daily challenges remain undocumented. This mixed-methods study explored CHVs capacity to deliver an infant hygiene intervention in an urban informal settlement in Kenya. Findings suggest that CHVs are overburdened, receive inconsistent training, and forced to compromise their commitments in order to sustain their own livelihood. Sustained efforts in appreciating the work of CHVs, sustained supplies for CHVs, operational training in communication behaviour change methods and notable efforts in breaking the vicious circle of poverty in informal settlements would go a long way in promoting healthy seeking behaviours

The Safe Start trial to assess the effect of an infant hygiene intervention on enteric infections and diarrhoea in low-income informal neighbourhoods of Kisumu, Kenya: a study protocol for a cluster randomized controlled trial.

BACKGROUND: Symptomatic and asymptomatic enteric infections in early childhood are associated with negative effects on childhood growth and development, especially in low and middle-income countries, and food may be an important transmission route. Although basic food hygiene practices might reduce exposure to faecal pathogens and resulting infections, there have been few rigorous interventions studies to assess this, and no studies in low income urban settings where risks are plausibly very high. The aim of this study is to evaluate the impact of a novel infant food hygiene intervention on infant enteric infections and diarrhoea in peri-urban settlements of Kisumu, Kenya. METHODS: This is a cluster randomized control trial with 50 clusters, representing the catchment areas of Community Health Volunteers (CHVs), randomly assigned to intervention or control, and a total of 750 infants recruited on a rolling basis at 22 weeks of age and then followed for 15 weeks. The intervention targeted four key caregiver behaviours related to food hygiene: 1) hand washing with soap before infant food preparation and feeding; 2) bringing all infant food to the boil before feeding, including when reheating or reserving; 3) storing all infant food in sealed containers; and, 4) using only specific utensils for infant feeding which are kept separate and clean. RESULTS: The primary outcome of interest is the prevalence of one or more of 23 pre-specified enteric infections, determined using quantitative real-time polymerase chain reaction for enteric pathogen gene targets. In addition, infant food samples were collected at 33 weeks, and faecal indicator bacteria (Enterococcus) isolated and enumerated to assess the impact of the intervention on infant food contamination. CONCLUSION: To our knowledge this is the first randomized controlled trial to assess the effect of an infant food hygiene intervention on enteric infections in a high burden, low income urban setting. Our trial responds to growing evidence that food may be a key pathway for early childhood enteric infection and disease and that basic food hygiene behaviours may be able to mitigate these risks. The Safe Start trial seeks to provide new evidence as to whether a locally appropriate infant food hygiene intervention delivered through the local health extension system can improve the health of young children. TRIAL REGISTRATION: The trial was registered at clinicaltrial.gov on March 16th 2018 before enrolment of any participants (https://clinicaltrials.gov/ct2/show/NCT03468114)

Transmission or within-host dynamics driving pulses of zoonotic viruses in reservoir-host populations

Progress in combatting zoonoses that emerge from wildlife is often constrained by limited knowledge of the biology of pathogens within reservoir hosts. We focus on the host–pathogen dynamics of four emerging viruses associated with bats: Hendra, Nipah, Ebola, and Marburg viruses. Spillover of bat infections to humans and domestic animals often coincides with pulses of viral excretion within bat populations, but the mechanisms driving such pulses are unclear. Three hypotheses dominate current research on these emerging bat infections. First, pulses of viral excretion could reflect seasonal epidemic cycles driven by natural variations in population densities and contact rates among hosts. If lifelong immunity follows recovery, viruses may disappear locally but persist globally through migration; in either case, new outbreaks occur once births replenish the susceptible pool. Second, epidemic cycles could be the result of waning immunity within bats, allowing local circulation of viruses through oscillating herd immunity. Third, pulses could be generated by episodic shedding from persistently infected bats through a combination of physiological and ecological factors. The three scenarios can yield similar patterns in epidemiological surveys, but strategies to predict or manage spillover risk resulting from each scenario will be different. We outline an agenda for research on viruses emerging from bats that would allow for differentiation among the scenarios and inform development of evidence-based interventions to limit threats to human and animal health. These concepts and methods are applicable to a wide range of pathogens that affect humans, domestic animals, and wildlife

Risk factors for child food contamination in low-income neighbourhoods of Maputo, Mozambique: An exploratory, cross-sectional study.

In low- and middle-income countries, food may be a critical transmission route for pathogens causing childhood diarrhoea, but basic food hygiene is often overlooked in public health strategies. Characterising child food contamination and its risk factors could help prioritise interventions to reduce foodborne diarrhoeal disease, especially in low-income urban areas where the diarrhoeal disease burden is often high. This cross-sectional study comprised a caregiver questionnaire coupled with food sampling, and food preparation observations, among the study population of an ongoing sanitation trial in Maputo. The aim was to determine the prevalence of child food contamination and associated risk factors. The prevalence of Enterococcus spp., as an indicator of faecal contamination, was estimated in food samples. Risk factor analyses were performed through zero-inflated negative binomial regression on colony counts. A modified hazard analysis and critical control point approach was used to determine critical control points (CCPs) that might effectively reduce risk. Fifty-eight linked caregiver questionnaires and food samples were collected, and 59 food preparation observations were conducted. The prevalence of enterococci in child foods exceeding 10 colony forming units per gram was 53% (95% confidence interval [40%, 67%]). Risk factors for child food contamination were identified, including type of food, food preparation practices, and hygiene behaviours. CCPs included cooking/reheating of food and food storage and handling. This exploratory study highlights the need for more research into diarrhoeagenic pathogens and foodborne risks for children living in these challenging urban environments