Poster – Dog Ecology in Bali, Indonesia and Implications for Rabies Transmission
Judul: Dog Ecology in Bali, Indonesia and Implications for Rabies Transmission
Penulis: Jatikusumah. A1, Putra. A.A.G2, Estoepangestie. S3, Widaystuti. M.D.W.1, Sunandar1, Arief. R.A1, Basri. C1,4, Willyanto. I5, Basuno. E6, Rukmantara. T.A7, Mardiana. I.W8, Hampson. K9
1Center for Indonesian Veterinary Analytical Studies, Indonesia, 2Disease Investigation Centre Denpasar, Indonesia, 3Airlangga University, Indonesia, 4Bogor Agricultural University, Indonesia, 5InI Veterinary Service, Indonesia, 6Bali Provincial Livestock and Animal Health Office, Indonesia, 7International Livestock Research Institute, Kenya, 8University of Glasgow, United Kingdom, 9Boyd Orr Centre for Population and Ecosystem Health, Medical, Veterinary & Life Sciences, University of Glasgow Glasgow, QQ.
Over 130 human rabies deaths have occurred during an ongoing epidemic in Bali, Indonesia. The basic reproductive number estimated from this epidemic (1.2) is similar to estimates from elsewhere in the world, despite the extremely high densities of dogs in Bali (>100/km2). This lack of density-dependent transmission has important implications for rabies control but is difficult to explain. We investigated ecological factors affecting rabies transmission and spread in Bali. Household surveys (n=8588) confirmed the high dog densities and that most owned dogs are free-roaming, with only 8% and 17% and restrained in rural and suburban areas respectively, and these mostly restrained during the day only. We randomly selected and observed 69 free-roaming dogs continuously for 48 hours to quantify behaviour and movement during a period similar to the infectious period of rabies. Home ranges were small (90% kernel, median =0.6km2, mean =3km2), but some displacements exceeded 4km and most movements were constrained to roads. The skewed distribution of movements was similar to reports on the movement of rabid dogs whereby most transmission is localized (<1km), but a small number of dogs move disproportionately and carry the disease further (>3 km). Most observed activity and contact occurred between 6-10am and 4-8pm when dogs were less likely to be restrained. Despite the relatively small home ranges, the high dog densities and frequent opportunities for contact and heterogeneity in dog movement demonstrate potential for sustained transmission and suggest that sociality can help explain the lack of density-dependent transmission, with movement related to local population density. Close correlation between dog movement and road networks suggests that rabies likely spreads faster than naïve diffusion models would suggest. These findings should be used to inform epidemiological models and develop means for strategic measures to contain rabies spread.
Citation: Jatikusumah A, Putra AAG, Estoepangestie S, Widyastuti MDW, Sunandar, Arief RA, Basri C, Willyanto I, Mardiana I, Gilbert J and Hampson K. 2012. Dog Ecology in Bali, Indonesia and Implications for Rabies Transmission. Poster Presented 13th ISVEE Conference. Maastricht The Netherlands, 21-25 August 2012.