Listeriosis Update

National Department of Health

20 February 2018
By Dr Lucia Anelich

The NICD has provided the latest update on the listeriosis outbreak in South Africa – attached to this note as at 20 February 2018. The outbreak is across all nine provinces. The cases have jumped from 872 on 15 February to 915 (43 more), with 172 deaths (8 more than on 15 February).

In summary to date for your convenience:

The strain that is still most frequently isolated belongs to sequence type ST6. This continues to indicate that these isolates originate from a single source, most likely a food product on the market or a series of food products produced in the same manufacturing environment. The source may even be products that are consistently contaminated from batch to batch by persistent L. monocytogenes in the environment of the facility, particularly if there is no environmental control programme with associated effective cleaning and disinfection in place.
Other statistics in summary (see more in NICD report):
Outcome data is available for 617 of the 915 cases. Of these 617 cases, 172 deaths have been reported (28% mortality rate) which drops the mortality rate slightly from 34% on 25 January, 30% on 06 February and is consistent with 27.5% mortality rate reported on 15 February 2018. This rate is currently (this will likely change as the disease progresses and more cases are traced) 2-7% higher than general mortality rates reported in other countries i.e. 20-25%. Neonates ≤ 28 days continue to be the most affected group.
The source of the outbreak remains unknown. Anelich Consulting opinion: “By all accounts, the outbreak has not yet peaked and more cases and deaths can be expected if the source is not found soon”.
The World Health Organization (WHO) had a team in South Africa a few weeks back to assist the National Authorities and the NICD with this outbreak. A few key facilities had been visited and whilst a “strong lead” was reported, there is still no source identified.
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Dr Anelich stated in previous communiques that this was the worst documented listeriosis outbreak in global history. It remains so. Her international colleagues in European countries, Canada, Australia and the USA concur.
This communique, further information and interviews conducted can be found on the Anelich Consulting website at and by clicking on links provided.