Surveillance and Laboratory Support for Emerging Diarrhoea Pathogens

Diarrheal disease remains a major global health problem particularly in children under five years and the emergence of antibiotic-resistant strains of causative pathogens could slow control efforts particularly in settings where treatment options are limited. AS a department, we have conducted two major studies on bacterial derived diarrheal. The first study aimed at investigating Vibrio cholerae isolates from cholera outbreaks in southern Ghana using molecular epidemiology. Cholera remains a major global public health threat and continuous emergence of new V. cholerae strains is of major concern. Due to the annual cycles of cholera in Ghana, NMIMR in collaboration with National Public health Reference Laboratory conducted a molecular epidemiological study to detect virulence markers and antimicrobial resistance patterns of V. cholerae isolates obtained from the 2012–2015 cholera outbreaks in Ghana. The study sought to phenotypically characterize archived enterobacterial isolates from suspected cholera cases, determine the antibiotic sensitivity pattern of isolated V. cholerae using Kirby Bauer disc diffusion, identified major genomic virulent markers by PCR and strain clonality by multi-locus variable number tandem repeat analysis (MLVA).  We identified some antibiotics that are no longer effective in the treatment of the disease, new circulating strains (Inaba serotype and non-O1/O137 serogroups) and some diarrhea-causing bacteria other than V. cholerae that also play a role in the annual cholera outbreaks. We also found that the V. cholerae strains circulating in Ghana harbor several virulent genes and each year, a unique clone predominates the cholera outbreak. This research identified Ablekuma sub-district as the major hot spot for cholera.

Our second study was a multidisciplinary study involving diarrhoea surveillance conducted in Ghana aimed to determine the antimicrobial susceptibility profile of diarrhea-causing bacteria and viruses. For the bacteria arm, our objectives were; 1) To determine various microbial pathogens involved in diarrhoeal cases in Ga-West Municipal, 2) To determine the antibiotic sensitivity pattern and resistant conferring molecular markers to inform appropriate case management, and 3) To genotype pathogens identified for assessment of risk factors and prediction of possible outbreaks. We observed significant findings including the detection of several different bacteria etiology of diarrhoea aside V. cholerae which include, Salmonella, Shigella, Vibrio sp (parahaemolyicius, albensis), and Enterotoxigenic E. coli (ETEC). We also observed high resistance of isolates to commonly abused drugs such as tetracycline and noticed that multi-drug resistant Vibrio sp and extended spectrum beta-lactamase producing E. coli have the capability of destabilizing our health systems if drugs administered are not effective.