IMNV found in Asia-Pacific
Infectious Myonecrosis (IMN) is a new viral disease affecting shrimp that until recently had only been identified in northeast Brazil in cultured L. vannamei and had been considered exotic to the Asia-Pacific region. Considering the large scale trans-boundary movement and culture of Litopenaeus vannamei in the Asia-Pacific, the virus is considered important for the region and has been included in the NACA/FAO/OIE Quarterly Aquatic Animal Disease Report list for the purpose of surveillance and reporting since January 2006 as IMNV is not listed by the World Animal Health Organization (OIE).
ENACA reports that IMNV has been confirmed in Indonesia by the National Coordinator. Details are as follows:
1. Suspected IMNV was detected in Situbondo district, East Java Province in May 2006. Mortality rate: 7 – 15 shrimp per day.
2. Species: L. vannamei, 60 – 80 days old (sub adult).
3. Clinical signs: Red colour in the abdominal segment, myonecrosis with white discoloration of the affected muscle.
4. Diagnosis: conducted by Aquaculture Pathology Lab (Dr. Lightner, USA) - shrimp sample confirmed to be positively infected by IMNV.
5. Presently the Government of Indonesia is conducting surveillance for IMNV, in some areas of the East Java Province, Bali and West Nusa Tenggara.
In view of these recent findings and large scale unregulated movement and local propagation of P. vannamei, National Coordinators have been requested to take actions to increase surveillance and collect information on any possible occurrence of this disease in their countries.