Health and Environment

Introduction: Cholera is endemo-epidemic in Bukavu. The aim of the study was to assess the environmental determinants of permanent contamination of spring and well water and to evaluate some of the chemical factors responsible for the persistence of Vibrio cholerae in water consumed by cholera patients.
Methods: Conducted in the Bukavu health district from September 2020 to September 2021, this was a cross-sectional. The potential of hydrogen (pH) of the water was evaluated before comparing it with the survival of Vibrio cholerae. A total of 641 latrines, 92 water sources, and wells were surveyed, with 298 samples analyzed in the laboratory.
Results: Out of the 641 latrines surveyed, 367 (57%) were found to be unsanitary; 54 (59%) of the water sources and wells were also deemed unsanitary. In total, 57% of the water samples were found to contain Vibrio cholerae, with 90% exhibiting an alkaline pH, of which 54% tested positive for the bacteria. Conversely, 10% of the samples had an acidic pH, with 80% of those containing Vibrio cholerae. The pH levels of the water remained alkaline both during the epidemic (95%) and post-epidemic (84%), thereby favoring the survival of Vibrio cholerae serotypes Ogawa and Inaba in these water sources. An acidic pH was observed to increase the likelihood of Vibrio cholerae survival in these waters by a factor of 3.39.
Conclusion: Spring and well water are consistently contaminated with Vibrio cholerae due to the unsanitary conditions of nearby latrines. The presence of Vibrio cholerae serotypes Inaba and Ogawa in these water sources is further influenced by the alkaline and acidic pH levels.

This study focuses on thermal comfort in  some classroom school buildings of the Malagasy Ministry of National Education, located in the city of Diego-Suarez, characterized by a warm tropical climate throughout the year. This study was  carried out in December 2023, then between January and February 2024. The analysis is based on the adaptive approach, using questionnaires and taking measurements of thermal parameters via weather sensor. During study hours from 7:30 a.m. to 11:30 a.m. in the morning and 2:30 p.m. to 5:30 p.m. in the afternoon, the questionnaires are completed at the same time as in-situ measurements are taken. In total, 223 questionnaires were completed by the occupants including (students and teachers), distributed in four classrooms of two different primary schools. The results reveal that the percentage of thermal acceptance inside the old school reaches 35%, compared to only 15% for the modern school. The majority of respondents believe that the air flow speed is more favorable in the old building, with a perception of comfort at 60%, compared to 40% for the modern building.