Plague is a zoonotic disease caused by Yersinia pestis, and it is endemic in Madagascar. The plague cycle involves wild and commensal rodents and their fleas; humans are an accidental host. Madagascar is the country where plague burden is the highest. Plague re-emerged in Mahajanga, the western coast of Madagascar, in the 1990s and infected populations in the popular and insalubrious zones. Sanitation is considered a primary barrier to infection by excluding pathogens from the environment and reservoirs. Poor housing and hygiene and proximity to rodents and fleas in everyday life are major and unchanged risk factors of plague. The aim of this study was to measure the impact of sanitation on Yersinia pestis bacteria in human and small mammal reservoirs and flea vectors. This study was conducted on 282 households within 14 neighborhoods. Two sessions of sampling were conducted in 2013 and 2016. Small mammals were trapped inside and around houses using live traps. Fleas, blood and spleen were sampled to detect Y. pestis infection and antibodies and determine the level of plague circulation before and after the installation of sanitation in order to assess the impact of sanitation improvement on inhabitant health. Two major types of housing can be described, i.e., formal and informal (traditional), scattered in all the suburbs. Among the small mammals captured, 48.5% were Suncus murinus, and 70% of houses were infested. After sanitation, only 30% of houses remained infested, and most of them were located around the market. Fleas were mostly Xenopsylla cheopis. Before and after intervention, the overall prevalence of fleas was the same (index 4.5) across the 14 suburbs. However, the number of houses with fleas drastically decreased, and the flea index increased significantly in rodent-infested houses. Rodent abundance also decreased from 17.4% to 6.1% before and after intervention, respectively. A serology study highlights that plague is still circulating in Mahajanga, suggesting that small mammals maintain enzootic plague transmission in the city.

INTRODUCTION

The health systems of countries in the South and the North have been directly affected by the COVID-19 pandemic. Healthcare workers have paid a high price. The aim of this study was to better describe the personnel who are on the front line when patients visit health care facilities and to analyze their risk factors for exposure, their perception of infection and the prevention practices implemented by these health care workers.

METHODS

A cross-sectional study was conducted over a 6-month period from October 2021 to March 2022 (i.e., at a distance from the index cases) among health care workers in 62 integrated health centers and five public urban hospitals in Niamey and Dosso. Information on socio-demographic characteristics, clinical symptoms, co-morbidities, knowledge and attitudes, and vaccination status was collected by means of a questionnaire. Blood samples were taken for serological analysis for each agent included.

RESULTS

A total of 733 agents were included, mostly women (628, 85.67%) with a mean age of 40.5 years. Only 5.5% (40/733) of the workers reported having been in contact with a positive case of Covid-19. The most common method of protection was the use of alcohol and soap for hand hygiene. 76% of them reported having been vaccinated against the SARS-CoV2 virus. However, only 7.7% reported having used a Covid-19 diagnostic test in the last few months. IgM and IgG COVID-19 serologies were positive in 1.2% and 92.2% of the health care workers, respectively, during the survey period.

CONCLUSION

In Niger, frontline health workers have been widely exposed to SARS CoV-2, but most of them don't think so. As a result, in their daily practice, they make poor use of means to prevent and control COVID-19 infection and rarely use diagnostic tests in case of illness. Vaccination was widely accepted by these staff, according to their statements.