Bacteriological and Physico-Chemical Characterisation of Liquid Wastes: The Case of the University Hospital Centre (UHC) of Yaoundé-Cameroon

Abstract

The untreated effluents generated by hospital activities contribute to the dissemination of pathogenic germs and multi-resistant bacteria, thus presenting a great potential danger for health and the environment. The objective of this study was to evaluate the microbiological and physico-chemical quality of the effluents of the Yaoundé University Hospital Centre and their impact on the environment. It was a prospective and analytical study on three sites where hospital effluents from the intensive care unit (Station A), the upstream of the wastewater treatment plant (Station B), and the gynaecology, surgery and hospitalisation departments (Station C) were sampled. Samples were collected in sterile glass bottles for bacteriological analyses and polyethylene bottles for physico-chemical analyses. The bacteriological parameters measured showed that the density of the bacterial species sought was very high at Station B with a predominance of the species Escherichia coli (57.36%). At Station A, total coliforms were very abundant (50.12%) and at Station C, the genus Pseudomonas was predominant (14.69%). Bacteria of the genus Streptococcus were represented by three species, namely: Streptococcus agalactiae, Streptococcus faecalis, and Streptococcus pneumoniae. The Pseudomonas genus was also represented by 3 species, namely Pseudomonas aeruginosa, Pseudomonas maltophilia and Pseudomonas putida. The physico-chemical parameters showed that apart from temperature and conductivity, which were in compliance with the standards, the other had values higher than these standards. This study shows that untreated hospital effluent contains most of the bacteria involved in community, nosocomial infections and would be a potential source of risk to the surrounding population.