FUNCTIONS

The centre performs surveillance activities for a wide range of enteric bacteria, viruses and parasites. It functions as a reference laboratory for several enteric bacterial pathogens, including Salmonella species, Shigella species, Campylobacter species, Vibrio cholerae, Listeria monocytogenes and diarrhoeagenic Escherichia coli. Viruses associated with diarrhoea (rotavirus, norovirus, sapovirus, astrovirus and adenovirus) are monitored to track strain diversity and the emergence of any potential outbreak strains.

The centre coordinates PulseNet Africa, a regional network of PulseNet International, a global network concerned with global surveillance and molecular subtyping of bacterial enteric pathogens (http://www.pulsenetinternational.org/).

The CED actively supports enteric disease outbreak investigations countrywide. This includes a steadily increasing number of food- and water-borne disease outbreaks.

During the national listeriosis outbreak of 2017 to 2018 the centre played a leading role in outbreak investigation and response, providing critical specialised laboratory testing and epidemiological support to the National Department of Health (NDoH) during what became the largest listeriosis outbreak ever recorded. The CED collated and analysed data on laboratory-confirmed cases and issued publically available weekly situation updates and provided technical expertise to the NDoH to guide and support outbreak investigation activities. The centre was also instrumental in guiding and actively participating in the investigation activities, as well as the subsequent laboratory testing which ultimately confirmed the outbreak source. An integral component of the investigation was the use of whole genome sequencing (WGS) data for clinical, food and environmental isolates; through close collaboration with the Sequencing Core Facility of the NICD, WGS was successfully used in real-time to guide outbreak investigation activities and identify the source. The centre was actively engaged in media interviews during the course of the outbreak, providing a source of scientifically correct information and important health promotion messaging to the public. In addition, the centre assisted with phenotypic confirmatory testing and WGS of clinical isolates from other African countries that were suspected to be linked with the outbreak.

The CED laboratories provide specialised testing for enteric bacteria and viruses, including serotyping, pathotyping, biotyping and PCR where relevant. Molecular epidemiological testing, including PFGE, MLVA and more recently WGS, are utilised to characterise isolates and determine relatedness. This is of critical importance in outbreak investigations and outbreak source attribution

The CED contributes to the training of medical professionals, including medical scientists, medical technologists, epidemiologists, nurses, registrars, and public health officials.

The centre co-hosts WHO training workshops for the Southern African region, to build laboratory and epidemiologic capacity in other African countries for enteric and foodborne disease outbreak investigations. The centre actively participates in PulseNet training workshops for molecular subtyping and whole-genome sequencing of bacterial enteric pathogens.

The CED partners with the national Notifiable Medical Conditions (NMC) surveillance system, which is tasked with providing timely, accurate data of diseases that are of public health importance. These diseases may pose significant public health risks that can result in disease outbreaks or epidemics with high case fatality rates both nationally and internationally.

https://www.nicd.ac.za/wp-content/uploads/2018/11/NMC-information-pamphlet.pdf