Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020
As South Africa transitions from endemic to intermediate endemicity, hepatitis A surveillance needs strengthening to monitor trends in disease incidence and to identify outbreaks. We used passive laboratory-based surveillance data from the National Health Laboratory Services to calculate national he...
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MDPI AG
2021-12-01
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| Series: | Viruses |
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| Online Access: | https://www.mdpi.com/1999-4915/13/12/2470 |
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| author | Nishi Prabdial-Sing Villyen Motaze Jack Manamela Kerrigan McCarthy Melinda Suchard |
| author_facet | Nishi Prabdial-Sing Villyen Motaze Jack Manamela Kerrigan McCarthy Melinda Suchard |
| author_sort | Nishi Prabdial-Sing |
| collection | DOAJ |
| description | As South Africa transitions from endemic to intermediate endemicity, hepatitis A surveillance needs strengthening to monitor trends in disease incidence and to identify outbreaks. We used passive laboratory-based surveillance data from the National Health Laboratory Services to calculate national hepatitis A incidence and to establish thresholds for outbreaks. Incidence was calculated by age and geographic location. The static threshold used two or three standard deviations (SDs) above the mean hepatitis A incidence in 2017–2019, and a cumulative summation (CuSum2) threshold used three SDs above the mean of the preceding seven months. These thresholds were applied to hepatitis A data for 2020. From 2017 to 2020, the mean incidence of hepatitis A IgM was 4.06/100,000 and ranged from 4.23 to 4.85/100,000 per year. Hepatitis A incidence was highest in the Western Cape province (WCP) (7.00–10.92/100,000 per year). The highest incidence was in the 1–9-year-olds. The incidence of hepatitis A in 2020 exceeded the static threshold in two districts of the WCP: Cape Winelands in January and Overberg district in August. The provincial incidence did not exceed the static and CuSum2 thresholds. District-level analysis using either threshold was sensitive enough to monitor trends and to alert district health authorities, allowing early outbreak responses. |
| first_indexed | 2024-03-10T03:54:33Z |
| format | Article |
| id | doaj.art-de50bfaa11e74c888389f002702264b2 |
| institution | Directory Open Access Journal |
| issn | 1999-4915 |
| language | English |
| last_indexed | 2024-03-10T03:54:33Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Viruses |
| spelling | doaj.art-de50bfaa11e74c888389f002702264b22023-11-23T10:58:23ZengMDPI AGViruses1999-49152021-12-011312247010.3390/v13122470Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020Nishi Prabdial-Sing0Villyen Motaze1Jack Manamela2Kerrigan McCarthy3Melinda Suchard4Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg 2131, South AfricaDivision of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg 2131, South AfricaDivision of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg 2131, South AfricaDivision of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg 2131, South AfricaDivision of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg 2131, South AfricaAs South Africa transitions from endemic to intermediate endemicity, hepatitis A surveillance needs strengthening to monitor trends in disease incidence and to identify outbreaks. We used passive laboratory-based surveillance data from the National Health Laboratory Services to calculate national hepatitis A incidence and to establish thresholds for outbreaks. Incidence was calculated by age and geographic location. The static threshold used two or three standard deviations (SDs) above the mean hepatitis A incidence in 2017–2019, and a cumulative summation (CuSum2) threshold used three SDs above the mean of the preceding seven months. These thresholds were applied to hepatitis A data for 2020. From 2017 to 2020, the mean incidence of hepatitis A IgM was 4.06/100,000 and ranged from 4.23 to 4.85/100,000 per year. Hepatitis A incidence was highest in the Western Cape province (WCP) (7.00–10.92/100,000 per year). The highest incidence was in the 1–9-year-olds. The incidence of hepatitis A in 2020 exceeded the static threshold in two districts of the WCP: Cape Winelands in January and Overberg district in August. The provincial incidence did not exceed the static and CuSum2 thresholds. District-level analysis using either threshold was sensitive enough to monitor trends and to alert district health authorities, allowing early outbreak responses.https://www.mdpi.com/1999-4915/13/12/2470hepatitis Aincidencethresholdoutbreaksurveillance |
| spellingShingle | Nishi Prabdial-Sing Villyen Motaze Jack Manamela Kerrigan McCarthy Melinda Suchard Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020 Viruses hepatitis A incidence threshold outbreak surveillance |
| title | Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020 |
| title_full | Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020 |
| title_fullStr | Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020 |
| title_full_unstemmed | Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020 |
| title_short | Establishment of Outbreak Thresholds for Hepatitis A in South Africa Using Laboratory Surveillance, 2017–2020 |
| title_sort | establishment of outbreak thresholds for hepatitis a in south africa using laboratory surveillance 2017 2020 |
| topic | hepatitis A incidence threshold outbreak surveillance |
| url | https://www.mdpi.com/1999-4915/13/12/2470 |
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