Epizootic ulcerative syndrome,
Information received on 10/09/2020 from Dr Letlhogile Modisa, Director, Veterinary Services, Ministry of Agriculture, Gaborone, Botswana
Report type Follow-up report No. 1
Date of start of the event 31/07/2020
Date of confirmation of the event 31/07/2020
Report date 10/09/2020
Date submitted to OIE 10/09/2020
Reason for notification Recurrence of a listed disease
Date of previous occurrence 31/10/2010
Manifestation of disease Clinical disease
Causal agent Aphanomyces invadans
Nature of diagnosis Clinical
This event pertains to a defined zone within the country
Related reports Immediate notification (08/08/2020)
Follow-up report No. 1 (10/09/2020)
Follow-up report No. 2 (02/10/2020)
Outbreaks There are no new outbreaks in this report
Source of the outbreak(s) or origin of infection
  • Unknown or inconclusive
  • Horizontal spread through water
Epidemiological comments Further surveillance has been carried out since the last report. As of this week there is no more evidence of sick, dead or floating fishes noticed in the Chobe River system. Further surveys have been carried out in the Kwando/Linyanti river systems but no cases were detected in these areas. Preliminary laboratory investigations have not detected the causative agent but have isolated other infections as Actinomyces bacteria and Aspergillus fungus from the samples.
Control measures
Measures applied
  • Surveillance outside infected and/or protection zone
  • Surveillance within infected and/or protection zone
  • Emergency harvest
  • Killing for commercial use or own use
  • Vaccination permitted (if a vaccine exists)
  • No treatment of affected animals
Measures to be applied
  • No other measures
Diagnostic test results
Laboratory name and type Species Test Test date Result
Botswana National Veterinary Laboratory (National laboratory) Squicker (cynodontis species) histopathological examination Pending
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.