Neglected tropical zoonotic diseases in Tigray region, northern Ethiopia: Spatial distribution and trend analysis of rabies, tuberculosis, schistosomiasis, and visceral leishmaniasis in humans

Pulmonary hypertension

Pulmonary hypertension encompasses a range of conditions directly or indirectly leading to elevated pressures within the pulmonary arteries. Five main groups of pulmonary hypertension are recognized, all defined by a mean pulmonary artery pressure of >20 mmHg: pulmonary arterial hypertension (rare), pulmonary hypertension associated with left-sided heart disease (very common), pulmonary hypertension associated with lung disease (common), pulmonary hypertension associated with pulmonary artery obstructions, usually related to thromboembolic disease (rare), and pulmonary hypertension with unclear and/or multifactorial mechanisms (rare). At least 1% of the world's population is affected, with a greater burden more likely in low-income and middle-income countries. Across all its forms, pulmonary hypertension is associated with adverse vascular remodelling with obstruction, stiffening and vasoconstriction of the pulmonary vasculature. Without proactive management this leads to hypertrophy and ultimately failure of the right ventricle, the main cause of death. In older individuals, dyspnoea is the most common symptom. Stepwise investigation precedes definitive diagnosis with right heart catheterization. Medical and surgical treatments are approved for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. There are emerging treatments for other forms of pulmonary hypertension; but current therapy primarily targets the underlying cause. There are still major gaps in basic, clinical and translational knowledge; thus, further research, with a focus on vulnerable populations, is needed to better characterize, detect and effectively treat all forms of pulmonary hypertension.

Animal care professionals' practice towards zoonotic disease management and infection control practice in selected districts of Wolaita zone, Southern Ethiopia

Veterinary practices or activities expose professionals to occupational hazards, including infection with zoonotic diseases, during contact with animals. To assess animal care professionals' practice towards zoonotic disease management and infection control practices (ICPs) in selected areas of the Wolaita zone, a cross-sectional survey was conducted using a structured questionnaire survey. A total of 287 animal care professionals were registered by the Wolaita zone livestock and fishery office and working in nine different districts of the Wolaita zone. Of these, 135 animal care professionals working across nine different districts of the Wolaita zone were interviewed in the current study. The survey showed that about 55% (74/135) of respondents were animal health assistants, and about 84% (114/135) of the professionals were males. In terms of utilization of ICP, about 72% of professionals routinely wash their hands before eating and drinking in their workplace. However, approximately 7% of professionals sometimes eat or drink at the workplace. Additionally, almost 32% of the professionals always wash their hands between patient contacts. In the survey, approximately 49% of veterinarians said they sterilized and reused disposable needles. When dealing with an animal suspected of carrying a zoonotic infection, nearly 25% of experts isolate or quarantine diseased animals, and only about 25% of the experts remove their personal protective equipment (PPE) before interacting with other animals. Approximately 62% of responders said they used outwear (PPE) when carrying out surgery and 28% when performing a necropsy. Nearly 39% of veterinarians reported using gloves and gowns when assisting with parturition or handling conception products, and around 36% of practitioners utilized proper PPE when handling blood samples. Our findings show that the veterinary community in the Wolaita Zone's selected sites needs to be educated about ICPs regularly. A better understanding of the risk of zoonotic disease exposure, as well as alternatives for reducing this risk and liability problems, may encourage the use of infection control measures. Successful partnerships across multiple professional sectors should use a One Health approach that includes stakeholders from the human, animal, and environmental categories.

Public Health Policy Pillars for the Sustainable Elimination of Zoonotic Schistosomiasis

Schistosomiasis is a parasitic disease acquired through contact with contaminated freshwater. The definitive hosts are terrestrial mammals, including humans, with some Schistosoma species crossing the animal-human boundary through zoonotic transmission. An estimated 12 million people live at risk of zoonotic schistosomiasis caused by Schistosoma japonicum and Schistosoma mekongi, largely in the World Health Organization’s Western Pacific Region and in Indonesia. Mathematical models have played a vital role in our understanding of the biology, transmission, and impact of intervention strategies, however, these have mostly focused on non-zoonotic Schistosoma species. Whilst these non-zoonotic-based models capture some aspects of zoonotic schistosomiasis transmission dynamics, the commonly-used frameworks are yet to adequately capture the complex epi-ecology of multi-host zoonotic transmission. However, overcoming these knowledge gaps goes beyond transmission dynamics modelling. To improve model utility and enhance zoonotic schistosomiasis control programmes, we highlight three pillars that we believe are vital to sustainable interventions at the implementation (community) and policy-level, and discuss the pillars in the context of a One-Health approach, recognising the interconnection between humans, animals and their shared environment. These pillars are: (1) human and animal epi-ecological understanding; (2) economic considerations (such as treatment costs and animal losses); and (3) sociological understanding, including inter- and intra-human and animal interactions. These pillars must be built on a strong foundation of trust, support and commitment of stakeholders and involved institutions.

Predictive Risk Mapping of Schistosomiasis in Madagascar Using Ecological Niche Modeling and Precision Mapping

Schistosomiasis is a neglected tropical disease (NTD) found throughout tropical and subtropical Africa. In Madagascar, the condition is widespread and endemic in 74% of all administrative districts in the country. Despite the significant burden of the disease, high-resolution risk maps have yet to be produced to guide national control programs. This study used an ecological niche modeling (ENM) and precision mapping approach to estimate environmental suitability and disease transmission risk. The results show that suitability for schistosomiasis is widespread and covers 264,781 km2 (102,232 sq miles). Covariates of significance to the model were the accessibility to cities, distance to water, enhanced vegetation index (EVI), annual mean temperature, land surface temperature (LST), clay content, and annual precipitation. Disease transmission risk is greatest in the central highlands, tropical east coast, arid-southwest, and northwest. An estimated 14.9 million people could be at risk of schistosomiasis; 11.4 million reside in rural areas, while 3.5 million are in urban areas. This study provides valuable insight into the geography of schistosomiasis in Madagascar and its potential risk to human populations. Because of the focal nature of the disease, these maps can inform national surveillance programs while improving understanding of areas in need of medical interventions.

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.

Five-year trend analysis of tuberculosis in Bahir Dar, Northwest Ethiopia, 2015-2019

Background

Tuberculosis (TB) remains a major cause of morbidity and mortality in Ethiopia despite the increased availability of effective treatments. Trend analysis of issues and priorities affecting TB programs across different regions of the country is critical to ensure equitable and sustainable TB outcomes. We aimed to analyze the trends of TB in Bahir Dar, Northwest Ethiopia, over 5 years from 2015 to 2019.

Methods

An institution-based, retrospective cross-sectional study was conducted in Bahir Dar, the capital city of the Amhara Region in Ethiopia. Five-year data and records of individual TB cases were reviewed from all public and private health-care facilities and health bureaus in Bahir Dar. Using a standard checklist adapted from the World Health Organization, data were abstracted relevant to sociodemographic characteristics of the patients, year and type of TB infection, and HIV status. SPSS version 20 software was used for data analysis.

Results

Data of 4275 patients with TB were identified, of which 929 (21.7%) were smear-positive pulmonary TB, 1195 (28%) were smear-negative pulmonary TB, and 2151 (50.3%) were extrapulmonary TB patients. TB was more prevalent in the age group 15-34 years (51.2%), and females (55.5%). In the years from 2015 to 2019, the prevalence of all forms of TB was 922 (21.6%), 812 (19.0%), 843 (19.7%), 876 (20.5%), and 822 (19.2%), respectively, demonstrating a decreasing trend though inconsistent. The variables sex (adjusted odds ratio [AOR]: 1.734, 95% confidence interval [CI] [1.390-2.187]), HIV co-infection (AOR: 1.875, 95% CI [1.553-2.265]), and age <15 years (AOR: 1.372, 95% CI [1.121-1.680]) showed a significant association with TB infection.

Conclusions

The prevalence of TB in Bahir Dar, Northwest Ethiopia, demonstrated a decreasing trend over the years from 2015 to 2019 but with inconsistencies. HIV co-infection significantly increased the risk of developing TB, and productive age groups and females were at the greater prevalence of TB, highlighting the importance of strengthening sustainable TB care and prevention interventions toward these groups of people.