GPS-based fine-scale mapping surveys for schistosomiasis assessment: a practical introduction and documentation of field implementation

Background Fine-scale mapping of schistosomiasis to guide micro-targeting of interventions will gain importance in elimination settings, where the heterogeneity of transmission is often pronounced. Novel mobile applications offer new opportunities for disease mapping. We provide a practical introduction and documentation of the strengths and shortcomings of GPS-based household identification and participant recruitment using tablet-based applications for fine-scale schistosomiasis mapping at sub-district level in a remote area in Pemba, Tanzania. Methods A community-based household survey for urogenital schistosomiasis assessment was conducted from November 2020 until February 2021 in 20 small administrative areas in Pemba. For the survey, 1400 housing structures were prospectively and randomly selected from shapefile data. To identify pre-selected structures and collect survey-related data, field enumerators searched for the houses’ geolocation using the mobile applications Open Data Kit (ODK) and MAPS.ME. The number of inhabited and uninhabited structures, the median distance between the pre-selected and recorded locations, and the dropout rates due to non-participation or non-submission of urine samples of sufficient volume for schistosomiasis testing was assessed. Results Among the 1400 randomly selected housing structures, 1396 (99.7%) were identified by the enumerators. The median distance between the pre-selected and recorded structures was 5.4 m. A total of 1098 (78.7%) were residential houses. Among them, 99 (9.0%) were dropped due to continuous absence of residents and 40 (3.6%) households refused to participate. In 797 (83.1%) among the 959 participating households, all eligible household members or all but one provided a urine sample of sufficient volume. Conclusions The fine-scale mapping approach using a combination of ODK and an offline navigation application installed on tablet computers allows a very precise identification of housing structures. Dropouts due to non-residential housing structures, absence, non-participation and lack of urine need to be considered in survey designs. Our findings can guide the planning and implementation of future household-based mapping or longitudinal surveys and thus support micro-targeting and follow-up of interventions for schistosomiasis control and elimination in remote areas. Trial registration ISRCTN, ISCRCTN91431493. Registered 11 February 2020, https://www.isrctn.com/ISRCTN91431493

A cluster randomized trial of interferon ß-1a for the reduction of transmission of SARS-Cov-2: protocol for the Containing Coronavirus Disease 19 trial (ConCorD-19)

Background SARS-CoV-2 infection rapidly spreads in populations due to the high rates of community transmission. Interrupting the shedding of SARS-CoV-2 may reduce the incidence of Coronavirus Disease 19 (COVID-19). Herein we provide a protocol for a cluster randomized trial that will examine the effectiveness of treatment with interferon (IFN) ß-1a compared to standard of care in limiting the transmission of SARS-CoV-2. Co-primary objectives are to determine whether IFN therapy reduces (a) the proportion of infected cases shedding SARS-CoV-2 at day 11 post randomization and (b) the incidence of transmission of SARS-CoV-2 infection from index cases to treatment-eligible household post-exposure contacts at day 11 after randomization. Secondary objectives include assessing the impact of IFN treatment on duration of viral clearance, hospitalizations and fatalities, and evaluating the safety of IFN treatment. Methods Three hundred and ten households, each including an index case with a recent COVID-19 diagnosis and at least one asymptomatic treatment-eligible household contact, will be randomized to receive 3 doses of 125 μg IFN ß-1a by subcutaneous administration (days 1, 6, and 11), or standard of care. All participants will be followed until day 29. Discussion The results from this trial will identify whether IFN ß treatment of mild or moderate COVID-19 cases accelerates viral clearance and prevents disease progression and whether IFN ß treatment of post-exposure contacts of COVID-19 cases reduces transmission of infection. Trial Registration: This trial is registered at ClinicalTrials.gov NCT04552379; date of registration September 17, 2020.

Socioeconomic factors and lifestyles influencing the incidence of calcaneal fractures, a national population-based survey in China

Background We aimed to do a national survey on the population-based incidence of calcaneal fracture in China. Methods All the data on calcaneal fractures were available from the China National Fracture Survey (CNFS) between January and May in 2015. And in the CNFS, all eligible household members were sampled from 8 provinces, 24 urban cities and 24 rural counties in China, using stratified random sampling and the probability proportional to size method. Questionnaires were sent to every participant for data collection and quality control was accomplished by our research team members. Results A total of 512187 valid questionnaires were collected and relevant data were abstracted and analyzed. There were 59 patients with 62 calcaneal fractures occurring in 2014, indicating that the incidence was 11.5/100,000 person-years, 17.3/100,000 in males, and 5.5/100,000 in females. BMI ≥ 28.0 kg/m2, scarce meat consumption, smoking, alcohol consumption, average sleep time < 7 h/day, and previous history of fracture were identified as independent risk factors for calcaneal fracture. Conclusions Specific public health policies focusing on quitting smoking, decreasing alcohol consumption, and encouraging individuals to obtain sufficient sleep should be implemented. Reasonable meat consumption and maintaining a normal body weight should be emphasized in individuals, especially in those with previous fracture.

STEP UP THE HEAT: A REGRESSION DISCONTINUITY ANALYSIS OF THE EFFECT OF HOME HEATING SUBSIDY ON ENERGY EXPENDITURE

Using a recent housing survey micro level dataset, this paper estimates the causal effects of receiving a home heating subsidy on different types of energy expenditure. Applying a regression discontinuity design quasi-experimental framework, identification for the causal treatment effect of energy subsidy is achieved by exploiting exogenous variations generated from the subsidy eligibility rule. Results are obtained from three model estimations: first-stage, reduced-form, and second stage estimations. The main finding from each of these estimations are: (i) energy subsidy eligibility increases the probability of receiving the subsidy, (ii) subsidy eligibility decreases energy expenditure, and (iii) subsidy receipt decreases energy expenditure. For an eligible household, its probability of receiving the subsidy increases between 2 to 8 percentage points at the threshold. Just by virtue of being eligible, such households see an approximate 8% to 25% decrease in their total energy expenditure at the threshold. Households that receive energy subsidies decrease their total energy expenditure by about half to three-quarters at the threshold.Keywords: Energy Subsidy; HEAP; Energy Expenditure; Home Space Heating; Regression Discontinuity.

Estimating the prevalence of activeHelicobacter pyloriinfection in a rural community with global positioning system technology-assisted sampling

SUMMARYWe investigated a possible outbreak ofH. pyloriin a rural Northern Plains community. In a cross-sectional survey, we randomly sampled 244 households from a geocoded emergency medical system database. We used a complex survey design and global positioning system units to locate houses and randomly selected one eligible household member to administer a questionnaire and a13C-urea breath test for activeH. pyloriinfection (n = 166). In weighted analyses, activeH. pyloriinfection was detected in 55·0% of the sample. Factors associated with infection on multivariate analysis included using a public drinking-water supply [odds ratio (OR) 12·2, 95% confidence interval (CI) 2·9–50·7] and current cigarette smoking (OR 4·1, 95% CI 1·7–9·6). People who lived in houses with more rooms, a possible indicator of decreased crowding in the home, were less likely to have activeH. pyloriinfections (OR 0·7, 95% CI 0·5–0·9 for each additional room).