The current issue of the Communicable disease threats report notes that, since 1 January 2017 and as of 25 January 2018, 820 laboratory-confirmed listeriosis cases have been reported in South Africa, with a particular increase notable from May 2017 onwards.
Most cases have been reported from Gauteng Province (59%, 486/820) followed by Western Cape (13%, 105/820) and KwaZuluNatal (7%, 59/820) provinces. Cases have been diagnosed in both public (66%, 542/820) and private (34%, 278/820) healthcare sectors. Where ages were reported (n=784), they ranged from birth to 93 years (median 18 years) and 42% (329/784) were neonates aged <=28 days. Of neonatal cases, 96% (317/329) had early-onset disease (birth to <= 6 days). Females account for 55% (431/783) of cases where gender is reported. Final outcome data is available for 29% (238/820) of cases, of which 34% (82/238) died.
Listeriosis can be a serious bacterial infection acquired via ingestion of contaminated food. The infection is primarily affecting pregnant women, neonates, elderly and immunocompromised people. In pregnant women, the infection can cause premature labour and stillbirth, and neonatal meningitis in a new-born. Milder forms of the disease result in gastroenteritis, which however can lead to a severe infection in those with a weakened immune system.
Prior to the current outbreak in South Africa, the first documented outbreaks occurred in 1977 (14 cases) and 2015 (seven cases), and since then only sporadic cases have been detected throughout the country. Since October 2017, an increase in the number of neonatal cases was observed. This increase and the associated deaths are of concern, as South Africa’s population also has high prevalence of HIV infection. In addition, poorly regulated street food vendors are common across South Africa. Many people lack access to electricity and thus refrigeration.
Based on whole genome sequencing (WGS) analysis, no associated cases were reported in EU/EEA countries. The risk of spread to Europe is considered to be very low. Travellers with immune disorders, severe chronic illnesses, pregnant women and older adults should nonetheless consult their doctors or seek advice from a travel clinic, particularly with regard to effective prevention measures, before travelling.
Source: Communicable disease threats report, 26 January 2018
Further information and advice for clinicians advising travellers can be accessed on the TRAVAX (for health professionals) and fitfortravel (for the general public) websites.