Issued by the National Institute for Communicable Diseases based on laboratory testing data (Based on laboratory testing data up until 11 May 2023)
Highlights
- The NICD has tested 5916 serum samples for measles since epidemiological week 40, 2022, of which 1004 (17%) were confirmed positive, all from outbreak-affected provinces. In the past weeks (week 18 up until week 19, 11/05/2023) there have been 7 laboratory-confirmed measles cases detected across the country, of which the majority were from Limpopo (7).
- The percentage of samples testing positive (PTP) increased from 10% of 96 samples tested in week 17 to 28% of 61 samples tested in week 18.
- A measles outbreak has been declared in all the provinces in South Africa except for the Eastern Cape. In week 18, seven (7) new cases were reported from Limpopo province. No new cases were reported in Mpumalanga, Northern Cape, Western Cape and KwaZulu-Natal provinces in the past four weeks.
- The measles strain detected in Limpopo province and North West province is genotype D8 which is similar to the strain in Zimbabwe in the 2022 outbreak.
- In the provinces where an outbreak has been declared, the most affected age groups are still the 5-9-year-olds (43%) with a considerable proportion of cases reported among the 1-4 (23%) and 10-14 age groups (20%).
Outbreak Overview
From epidemiological week 40, 2022 (ending 8 October 2022) to week 19, 2023 the NICD has tested 5916 serum samples for measles of which 1004 (17%) were confirmed measles cases. The number of samples submitted and the percentage of laboratory-confirmed measles-positive cases are shown in Figure 1. From epidemiological week 40 of 2022 to week 19 of 2023, 998 laboratory-confirmed cases were reported from eight provinces with declared measles outbreaks; Limpopo (432 cases), Mpumalanga (108 cases), North West (217 cases), Gauteng (170 cases), Free State (30 cases), Western Cape (14), KwaZulu-Natal (20) and Northern Cape (7) (Table 1). The geographical distribution of cases across South Africa from week 40 of 2022 until week 19 of 2023 is shown in Figure 2The number of blood samples and throat swabs submitted to the NICD for measles serology and PCR testing decreased from 90 in week 17 to 61 in week 18 (Figure 3).
Figure 1. Number of serum samples submitted to the NICD for measles, week 40 2022, until week 18, 2023, and the number (dark green) and % tested positive (red line), by epidemiological week using the date the specimen was collected. *Data from week 19 will be updated in next week’s situation report, when complete data from samples collected that week becomes available.
Figure 2. Distribution of laboratory-confirmed measles cases by testing site (red dots – the size of the dot indicates the number of cases from that facility) and district of South Africa (deepening colour of blue indicates the total number of cases by sub-district), from week 40 to week 19, 2023.
Figure 3. Number measles of tests conducted from week 40 2022, until week 19, 2023, by province and epidemiological week using the date the specimen was collected. *Data from week 18 represent partial data, and will be updated in next week’s situation report, when complete data from samples collected that week becomes available.
