1. Department of Oceanography, Pukyong National University, Busan 608-737, Korea.
2. College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.
3. College of Fisheries and Aquatic Sciences, Iloilo State College of Fisheries, Iloilo, Philippines.
4. KRF Zoonotic Disease Priority Research Institute, Seoul National University, Seoul 151-742, Korea.