Epidemiological and viral studies of rabies in Bali, Indonesia

Research (Published online: 20-12-2023)

8. Epidemiological and viral studies of rabies in Bali, Indonesia

Wayan Masa Tenaya, Nyoman Suartha, Nyoman Suarsana, Made Damriyasa, Ida Ayu Pasti Apsasi, Tri Komala Sari, Luh Putu Agustini, Yuli Miswati, and Kadek Karang Agustina

Veterinary World, 16(12): 2446-2450

Wayan Masa Tenaya: Department of Disease Prevention, Veterinary Public Health, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Nyoman Suartha: Department of Veterinary Clinic, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Nyoman Suarsana: Laboratory of Biochemistry, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Made Damriyasa: Laboratory of Clinical Pathology, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Ida Ayu Pasti Apsasi: Laboratory of Parasitology, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Tri Komala Sari: Laboratory of Virology, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Luh Putu Agustini: Laboratory of Virology, Veterinary Disease Investigation Center, Denpasar Bali, Jl. Raya Sesetan No. 266, Denpasar, Bali, 80223, Indonesia.

Yuli Miswati: Laboratory of Virology, Veterinary Disease Investigation Center, Bukittinggi Jl. Bukittinggi-Payakumbuh, Tabek Panjang, Sumatra Barat, Sumatra, 26192, Indonesia.

Kadek Karang Agustina: Department of Disease Prevention, Veterinary Public Health, Faculty of Veterinary Medicine, Udayana University, Denpasar Bali of Indonesia, Jl. PB Sudirman, Denpasar, Bali, 80234, Indonesia.

Background and Aim: Rabies has been endemic in Bali since 2009, and cases has recently increased. Unfortunately, there is a lack of available vaccines, which hinders the eradication program. This study aimed to investigate the epidemiological and virological aspects of rabies infection in Bali.

Materials and Methods: A total of 24 brain samples were collected from rabid dogs in all districts of Bali. The samples were tested using the direct fluorescent antibody (DFA) test and polymerase chain reaction (PCR) to confirm the presence of rabies virus in the samples. Samples with the highest virus content were propagated in vivo and then inoculated into BALB/c mice. The brains of dead mice were used to prepare an inoculate cultured in murine neuroblastoma cells. Supernatant-positive viruses representing each district were then reinoculated into eight groups of five BALB/c mice. A brain sample from each dead mouse was tested using DFA and PCR and detected under a fluorescence microscope.

Results: All rabies virus-positive samples collected from rabid dogs in all districts of Bali were positive. Rabies virus was detected by DFA test and PCR and was consistently confirmed in the in vivo and in vitro studies. BALB/c mice inoculated with the highest viral dilution (105 cells/mL) of culture supernatant showed typical signs of rabies, indicating that the virus could be properly investigated.

Conclusion: This study demonstrated a wide epidemiological distribution of rabies in Bali. The obtained virus can be adapted for in vitro and in vivo studies and can be used to develop a homologous vaccine.