African horse sickness,
Thailand

Information received on 24/04/2020 from Dr Sorravis Thaneto, Director General, Livestock Development, Ministry of Agriculture and Cooperatives, BANGKOK, Thailand

Summary

Report type	Follow-up report No. 4
Date of start of the event	24/02/2020
Date of confirmation of the event	27/03/2020
Report date	24/04/2020
Date submitted to OIE	24/04/2020
Reason for notification	First occurrence of a listed disease in the country
Causal agent	African horse sickness virus
Serotype	1
Nature of diagnosis	Clinical, Laboratory (advanced)
This event pertains to	a defined zone within the country
Related reports	Immediate notification (27/03/2020) Follow-up report No. 1 (03/04/2020) Follow-up report No. 2 (10/04/2020) Follow-up report No. 3 (17/04/2020) Follow-up report No. 4 (24/04/2020) Follow-up report No. 5 (01/05/2020) Follow-up report No. 6 (08/05/2020) Follow-up report No. 7 (15/05/2020) Follow-up report No. 8 (22/05/2020) Follow-up report No. 9 (29/05/2020) Follow-up report No. 10 (05/06/2020) Follow-up report No. 11 (12/06/2020) Follow-up report No. 12 (19/06/2020) Follow-up report No. 13 (26/06/2020) Follow-up report No. 14 (03/07/2020) Follow-up report No. 15 (10/07/2020) Follow-up report No. 16 (17/07/2020) Follow-up report No. 17 (24/07/2020) Follow-up report No. 18 (31/07/2020) Follow-up report No. 19 (07/08/2020) Follow-up report No. 20 (14/08/2020) Follow-up report No. 21 (21/08/2020) Follow-up report No. 22 (28/08/2020) Follow-up report No. 23 (04/09/2020) Follow-up report No. 24 (11/09/2020) Follow-up report No. 25 (18/09/2020) Follow-up report No. 26 (25/09/2020) Follow-up report No. 27 (02/10/2020) Follow-up report No. 28 (14/10/2020) Follow-up report No. 29 (16/10/2020) Follow-up report No. 30 (26/10/2020) Follow-up report No. 31 (30/10/2020) Follow-up report No. 32 (06/11/2020) Follow-up report No. 33 (14/11/2020) Follow-up report No. 34 (23/11/2020) Follow-up report No. 35 (27/11/2020) Follow-up report No. 36 (04/12/2020) Follow-up report No. 37 (15/12/2020) Follow-up report No. 38 (21/12/2020) Follow-up report No. 39 (04/01/2021) Follow-up report No. 40 (07/01/2021) Follow-up report No. 41 (13/01/2021) Follow-up report No. 42 (21/01/2021)

New outbreaks (1)

Outbreak 1

Mueang Sa Kaeo, Sa Kaeo, Mueang Sa Kaeo, Sa Kaeo

Date of start of the outbreak

14/04/2020

Outbreak status

Resolved (25/05/2020)

Epidemiological unit

Farm

Affected animals

Species	Susceptible	Cases	Deaths	Killed and disposed of	Slaughtered
Equidae	22	4	3	0	0

Affected population

Species of horses of different ages and sexes.

Summary of outbreaks

Total outbreaks: 1

Total animals affected

Species	Susceptible	Cases	Deaths	Killed and disposed of	Slaughtered
Equidae	22	4	3	0	0

Outbreak statistics

Species	Apparent morbidity rate	Apparent mortality rate	Apparent case fatality rate	Proportion susceptible animals lost*
Equidae	18.18%	13.64%	75.00%	13.64%

*Removed from the susceptible population through death, destruction and/or slaughter

Epidemiology

Source of the outbreak(s) or origin of infection

Unknown or inconclusive

Epidemiological comments

Four samples (equine blood and serum) were sent to the Pirbright Institute (United Kingdom) for checking serotype on the 31st March 2020 and the results were positive for African Horse Sickness (AHS) disease and all four samples were diagnosed as serotype 1 of AHS virus. Those samples were sent by a private veterinarian. However, the Department of Livestock Development (DLD, competent authority of veterinary service in Thailand) will send more samples from other outbreak spots to check the serotype in two or more OIE Reference Laboratories for AHS soon. The Department of Livestock Development started vaccination against African Horse Sickness (Polyvalent live attenuated vaccine) on April 19, 2020. Horses within the Horse and Animal Breeding Station, Thai Red Cross Society, Cha-am District, Phetchaburi Province, supplying 560 horses used to produce immunoglobulins to treat rabies and snake venom, were the first one to be vaccinated with AHS vaccine in Thailand. The further AHS vaccination started from April 20, 2020 which will be conducted for horses at a distance of 50 kilometers from the disease sites in 7 provinces where an outbreak was discovered. The AHS working group conducted a preparatory meeting with targeted Regional, Provincial, and District Livestock offices and related parties before the vaccination. The meeting emphasized on the operation for effective vaccination to struggle against the AHS epidemic as quickly as possible.

Control measures

Measures applied

Movement control inside the country

Vaccination in response to the outbreak (s)

Administrative division	Species	Total Vaccinated	Details
Phetchaburi	Equidae	560

Surveillance outside containment and/or protection zone
Surveillance within containment and/or protection zone
Quarantine
Zoning
Disinfection
Control of vectors
Vector surveillance
Treatment of affected animals ( Anti-inflammation, antibiotics, antipyretic and supplement)

Measures to be applied

No other measures

Diagnostic test results

Laboratory name and type	Species	Test	Test date	Result
National Institute of Animal Health (National laboratory)	Equidae	polymerase chain reaction (PCR)	03/04/2020	Positive
National Institute of Animal Health (National laboratory)	Equidae	real-time reverse transcriptase/polymerase chain reaction (RRT-PCR)	13/04/2020	Positive
National Institute of Animal Health (National laboratory)	Equidae	real-time reverse transcriptase/polymerase chain reaction (RRT-PCR)	15/04/2020	Positive
National Institute of Animal Health (National laboratory)	Equidae	reverse transcription - polymerase chain reaction (RT-PCR)	07/04/2020	Positive
National Institute of Animal Health (National laboratory)	Equidae	serotyping	15/04/2020	Positive
The Pirbright Institute (OIE Reference Laboratory)	Equidae	reverse transcription - polymerase chain reaction (RT-PCR)	04/04/2020	Positive

Future Reporting

The event is continuing. Weekly follow-up reports will be submitted.

Map of outbreak locations