A proposed surveillance approach for epizootic ulcerative syndrome (EUS) in South Africa
-
1
Dept. Agriculture Forestry and Fisheries, Directorate Aquaculture Research and Development, South Africa
Epizootic ulcerative syndrome (EUS), caused by the water mould Aphanomyces invadans (Oomycetes: Saprolegniales), is listed by the World Organisation for Animal Health (OIE) as an internationally significant and notifiable disease. More than 76 species of both farmed and wild freshwater fish have been documented as being susceptible to EUS and include members of the Cyprinidae, Clariidae, Cichlidae, Mormyridae and Centrarchidae.
In December 2010, the first suspected case presented itself in South Africa. Juvenile Bluegill Sunfish (Lepomis macrochirus) and Largemouth Bass (Micropterus salmoides) with fungal infections were sampled from the Palmiet River system near Grabouw, Western Cape. EUS was confirmed from these fish by skin scrapes showing typical Aphanomyces-like secondary zoosporangia and histopathology showing typical deeply penetrating fungal hyphae with a characteristic granulomatous tissue reaction. Definitive confirmation was obtained through the amplification of the internal transcribed spacer (ITS) region of the ribosomal DNA by PCR according to the specifications of the OIE and comparison of sequence data to existing sequences on the Genbank data base.
Subsequently EUS has been confirmed from 6 natural river systems from 4 provinces in South Africa. Due to the vast geographical area, the diversity of freshwater systems, shortage of human capacity and disease dynamics most confirmed, reported cases have been as a result of opportunistic or passsive surveillance based on gross clinical signs reported predominantly by recreational anglers. The potential for building on these angler based reports to inform, targeted surveillance or sampling for disease confirmation will be discussed.
Keywords:
EUS,
surveillance,
South Africa.,
Aphanomyces invadans,
citizen science
Conference:
AquaEpi I - 2016, Oslo, Norway, 20 Sep - 22 Sep, 2016.
Presentation Type:
Oral
Topic:
Aquatic Animal Epidemiology
Citation:
Christison
KW
(2016). A proposed surveillance approach for epizootic ulcerative syndrome (EUS) in South Africa.
Front. Vet. Sci.
Conference Abstract:
AquaEpi I - 2016.
doi: 10.3389/conf.FVETS.2016.02.00050
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
17 Aug 2016;
Published Online:
14 Sep 2016.
*
Correspondence:
Dr. Kevin W Christison, Dept. Agriculture Forestry and Fisheries, Directorate Aquaculture Research and Development, Cape Town, Western Cape, 8012, South Africa, KevinCH@daff.gov.za