NICD updated this Listeria Outbreak at the end of July. Of note, the numbers of ill have continued to drop following the recall of Tiger Brands Enterprise Foods polony in March. However, it appears that some of the “recalled” product is still being consumed. NICD’s partial report is below.
1,060 laboratory-confirmed cases have been reported from 01 January 2017 to 17 July 2018. The number of new cases reported each week has decreased since the implicated products were recalled on 04 March 2018 with no new cases of listeriosis reported during the week prior to release of this sitrep (Figure 1). Neonates ≤28 days of age are the most affected age group (42%, 443/1 060), followed by adults aged 15 – 49 years of age (32%, 334/1 060) – Figure 2. Most cases have been reported from Gauteng Province (58%, 614/1 060), followed by Western Cape (13%, 136/1 060) and KwaZulu-Natal (8%, 83/1 060) provinces (Table 1). Final outcome (i.e. death or discharge) is known for 76% (806/1 060) of total cases to date; 27% (216/806) with known outcome died.
Following a recall of the implicated products, the number of cases has steadily decreased. However, it is anticipated that cases could still be reported for the following reasons:
- The incubation period of listeriosis can be up to 70 days.
- The implicated products have a long shelf life and it is possible that despite the recall some products have not been removed from retail or consumer’s homes.
- Cross-contamination at retail and in the home can occur.
Post recall (05 March 2018 to date), all new cases of laboratory-confirmed listeriosis are contacted by IMT members, and a comprehensive food history is obtained. Exposure to food products implicated in the listeria outbreak is determined.
Of 87 post-recall cases, 65 have been interviewed to date.
Of those interviewed, 38/65 (58%) of ill people or their proxy reported consuming polony prior to their illness onset; brands manufactured by Tiger Brands Enterprise Foods were most commonly reported to have been consumed where brand of polony was known.
Prior to 2017, an average of 60 to 80 laboratory-confirmed listeriosis cases per year (approximately 1 per week), were reported in South Africa. In July 2017, an increase in laboratory-confirmed cases of listeriosis was reported to National Institute for Communicable Diseases (NICD) which triggered further investigation. On 05 December 2017, the listeriosis outbreak was declared by the Minister of Health, Dr. Aaron Motsoaledi. The source of the outbreak was identified as ready-to-eat processed meat products manufactured at Tiger Brand’s Enterprise Foods’ Polokwane production facility. A recall of affected products was initiated on 04 March 2018.