WHITE SPOT DISEASE IN BRAZIL
Follow-up report No. 1
See also: 21 January 2005
Translation of information received on 4 August 2005 from Dr Jorge Caetano Junior, Director, Department of Animal Protection (DDA), Ministry of Agriculture, Livestock and Food Supply, Brasilia:
End of previous report period: 20 January 2005 (see Disease Information , 18 , 30, dated 21 January 2005).
End of this report period: 4 August 2005.
Date of first confirmation of the event: 14 January 2005.
Date of start of the event: 10 December 2004.
Affected species: white shrimp( Litopenaeus vannamei ).
Clinical disease: yes.
Nature of diagnosis: advanced laboratory tests.
Details of new occurrence:
First administrative division: Ceará Lower administrative division: Aracati; Type of epide-miolo-gical unit: pond; Name of the location: Canavieira; Latitude: 4º 33' 41.76'' S; Longitude: 37º 46' 15.0'' W; Date of start of the occurrence: 7 February 2005
Species: cru; Morbidity rate:
Mortality rate: 40%.
Number of animals in the occurrence:- susceptible: 5,600,000; cases:
deaths: 2,240,000; destroyed:
Description of affected population in the new occurrence: marine-farmed shrimps (semi-closed farming system).
Diagnosis: samples were submitted to the OIE Reference Laboratory in order to confirm the positive results obtained at the National Reference Laboratory. Since then, the farm has been under surveillance and control. The finding is linked to the shrimp deaths observed by the farmer in February 2005.
Laboratories where diagnosis was made: Aquaculture Pathology Laboratory, University of Arizona, Tucson, United States of America (OIE Reference Laboratory for white spot disease); No. of animals examined: 3 samples (pools of pleopods); Diagnostic tests used: (a) 'nested' PCR(2) (primers 146F1/R1, F2/R2) / (b) 'nested' PCR (primers RR2-1/2, 3/4) / (c) 'nested' PCR (primers VP28-1/2, 3/4); Date : (a) (b) and (c) 1 Aug 2005; Results : (a), (b) and (c) positive
Source of occurrences: unknown or inconclusive.
- tracing forward;
- tracing back;
- surveillance within containment and/or buffer zone;
- surveillance outside containment and/or buffer zone;
- decontamination of premises/disinfection;
- within-country movement controls.
B. To be undertaken: official destruction of clinically diseased aquatic animals.
Treatment of infected animals: no.
Other details/comments: all the 11 crustacean farms in the perifocal area were placed under monitoring and surveillance.
(1) LANAGRO/RS: Laboratório Nacional Agropecuário / Rio Grande do Sul
(2) PCR: polymerase chain reaction