Designing programs for eliminating canine rabies from islands: Bali, Indonesia as a case study

<p>Background: Canine rabies is one of the most important and feared zoonotic diseases in the world. In some regions rabies elimination is being successfully coordinated, whereas in others rabies is endemic and continues to spread to uninfected areas. As epidemics emerge, both accepted and contentious control methods are used, as questions remain over the most effective strategy to eliminate rabies. The Indonesian island of Bali was rabies-free until 2008 when an epidemic in domestic dogs began, resulting in the deaths of over 100 people. Here we analyze data from the epidemic and compare the effectiveness of control methods at eliminating rabies.</p> <p>Methodology/Principal Findings: Using data from Bali, we estimated the basic reproductive number, R0, of rabies in dogs, to be ~1·2, almost identical to that obtained in ten–fold less dense dog populations and suggesting rabies will not be effectively controlled by reducing dog density. We then developed a model to compare options for mass dog vaccination. Comprehensive high coverage was the single most important factor for achieving elimination, with omission of even small areas (<0.5% of the dog population) jeopardizing success. Parameterizing the model with data from the 2010 and 2011 vaccination campaigns, we show that a comprehensive high coverage campaign in 2012 would likely result in elimination, saving ~550 human lives and ~$15 million in prophylaxis costs over the next ten years.</p> <p>Conclusions/Significance: The elimination of rabies from Bali will not be achieved through achievable reductions in dog density. To ensure elimination, concerted high coverage, repeated, mass dog vaccination campaigns are necessary and the cooperation of all regions of the island is critical. Momentum is building towards development of a strategy for the global elimination of canine rabies, and this study offers valuable new insights about the dynamics and control of this disease, with immediate practical relevance.</p&gt

Key epidemiological and operational variables determining the success of rabies vaccination programmes in terms of the predicted probability of eradication (grey y–axis and line) and time to eradication (black y–axis, medians and 95% PI), showing sensitivity to: (A) the basic reproductive number, <i>R</i>₀, (B) vaccination coverage (achieved at the time and location of the campaign (see Fig. 4)), (C) annual dog population turnover, with conversion into birth/death rate assuming constant population size (birth rates equal to death rates), and (D) duration of immunity provided by vaccine.

<p>Based on 1000 simulations generated using parameters in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t001" target="_blank">Table 1</a> (unless specified) and annual campaigns of the ‘random’ mass vaccination strategy (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t002" target="_blank">Table 2</a>).</p

Model description.

<p>(A) Secondary cases are drawn from the (i) offspring distribution, and become infectious at a date drawn from the (ii) generation interval distribution: here four secondary cases are generated by the index case (black dot) which become infectious on day 14, 21, 23, and 35. The occurrence of secondary cases depends on vaccination coverage in the grid cell at the time of transmission. (iii) With probability 1–<i>p</i> each offspring occurs at a location generated from the local dispersal kernel (solid black arrows). (iv) With probability <i>p</i>, each offspring occurs on any randomly chosen grid cell (broken black arrow). It took 2.2 years for rabies to be detected in all nine Regencies (grey band), consistent with <i>p</i> = 0.05–0.09 (black dots are medians with 95% PIs from 100 simulations). See <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t001" target="_blank">Table 1</a> for parameterization of distributions. (v) Human rabies deaths versus confirmed dog rabies cases, showing the best-fit relationship (black line, see <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#s3" target="_blank">Results</a> for equation) and 95% confidence intervals (grey area). (B) 95% PI envelope of simulated cases (grey area) with annual campaigns of the ‘random’ mass vaccination strategy (green line, <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t002" target="_blank">Table 2</a>), which is rolled out when cumulative cases reach 7,000 and from which point the time to eradication is measured.</p

Trajectories of vaccination coverage achieved at the island-wide level during modeled vaccination campaigns and in relation to levels of coverage required for herd immunity.

<p>Three types of coverage are referred to in the text: target coverage achieved in the subset of the population at the time and location of a local campaign (i.e. within a block); island-wide vaccination coverage (y-axis); and critical vaccination coverage (<i>P_crit</i>) which is required for herd immunity and is determined by <i>R</i>₀, the basic reproductive number of rabies in Bali, <i>P_crit</i> = 1-(1/<i>R</i>₀). <i>R</i>₀ estimated for Bali is 1·2, which corresponds to a <i>P_crit</i> of 17% (grey solid line). A 40% coverage campaign resulted in a trajectory that stayed above 17% (black solid line) and the probability of eradication was 1 (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-g003" target="_blank">Fig. 3B</a>), whereas 30% coverage resulted in a trajectory that dipped below 17% (black dashed line) and the probability of eradication was less than 1 (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-g003" target="_blank">Fig. 3B</a>). Annual campaigns were modeled, using parameters in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t001" target="_blank">Table 1</a> and the ‘random’ six-month strategy (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t002" target="_blank">Table 2</a>). Blocks are assumed to be vaccinated at the end of the month hence coverage increments jaggedly. Coverage declines between vaccinations due to waning of immunity and dog population turnover.</p

Modelled vaccination strategies.

<p> All campaigns were annual unless specified in the analyses.</p

Vaccination strategies.

<p>The probability of eradication following: (Ai) 1; (Aii) 2; (Aiii) 3 campaigns under a range of coverages (40, 60, 80%) and inter–campaign intervals (0, 6, 12 months); (Aiv) vaccination as implemented on Bali, and projected from January 2012 when rabies was still circulating. The time to eradication (medians with 95% PI) for a range of: (B) frequencies of human–mediated transport of dogs (<i>p</i> = 0, 0.02 or 0.05) and campaign strategies (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-t002" target="_blank">Table 2</a>). 95% PI of the one-month ‘sync’ strategy is highlighted (grey band) for comparison with the six–month strategies; (C) coverages when campaigns last 1 month or 6 months. (D) The probability of eradication with % island area left unvaccinated, made up of either randomly chosen 1 km squares (solid lines) or randomly chosen blocks, and when human-mediated movement of dogs was either infrequent (<i>p</i> = 0.02, grey) or frequent (<i>p</i> = 0.05, black).</p

Parameters values and distributions used to model rabid dog movement and transmission processes.

<p>Parameters values and distributions used to model rabid dog movement and transmission processes.</p

Rabies incidence and spread in Bali prior to island-wide mass vaccination.

<p>(A) Cases in humans and dogs and corresponding control efforts. (B) The month that rabies was first confirmed in each village. The black dot marks the village where the index case occurred. Regencies are outlined in black.</p

The vaccination campaigns on Bali and prospects for rabies eradication.

<p>Observed confirmed dog cases up to December 2011 (solid red line) overlay model confirmed cases (grey area, shaded according to confidence level) simulated from estimated vaccination coverage in the Bali dog population (solid blue line) and assuming 0.07 probability of confirming a case <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd.0002372-Townsend1" target="_blank">[6]</a>. For 3 scenarios, vaccination coverage was projected forward to December 2014 (broken blue lines), and implemented in the model to project upper percentile limits for confirmed cases (broken red lines) and the probability of island-wide eradication (see legend and <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002372#pntd-0002372-g003" target="_blank">Fig. 3Aiv</a>). The increase in cases in Dec 2011 may have been due to a substantial improvement in surveillance involving follow up of suspected animal bite cases by outbreak investigation teams.</p

PROCEEDING SEMINAR NASIONAL: SENI RUPA NUSANTARA BASIS KEUNGGULAN NASIONAL TAHUN 2016

Om Swastiastu, Seminar Nasional pada tanggal 28 Oktober 2016, diselenggarakan oleh Fakultas Seni Rupa dan Desain (FSRD), Institut Seni Indonesia (ISI) Denpasar dan diikuti oleh 17 pemakalah inti dan artikel pendamping yang dihimpun dalam buku Procceding Seminar Nasional 2016: “Seni Rupa Nusantara Basis Keunggulan Indonesia”. Makalah Seminar Nasional ini call for pa- per, sangat berarti bagi FSRD-ISI Denpasar dalam bentuk procceding yang ber ISBN 978-602- 9855-8-3. Seminar nasional ini juga menghadirkan keynote speaker Wali Kota Denpasar, I.B Rai Dharmawijaya Mantra, Pembicara sesi (I) Prof. Dr. Agus Burhan (Rektor ISI Yogyakarta), Pembicara sesi (II) Dr. Dody Wyancoko (Dosen ITB Bandung), dan Pembicara sesi (III) Dr. I Wayan Kun Adnyana ISI Denpasar. Seminar nasional akan diarahkan untuk mengembangkan “cara berpikir” dari berbagai aspek dalam studi seni rupa dan desain, termasuk media rekam untuk penciptaan suatu karya. Panitia penyelenggara mewakili institusi FSRD-ISI Denpasar yang menjadi tuan rumah seminar nasional, mengucapkan banyak terima kasih atas partisi- pasi para akademisi dan para pemerhati seni rupa Indonesia seperti: Seni Lukis, Seni Patung, Produk Kriya, Desain Interior, Desain Komunikasi Visual, Fotografi, Desain Mode, Film dan Televisi kemudian mempresentasikan dalam seminar nasional ini. Adapun bentuk sub tema: 1). Eksplorasi Seni Rupa Nusantara; 2). Keragaman Seni Rupa Nusantara, 3). Peluang studi dan penelitian; 4). Konsep dan filosofi Seni Rupa Nusantara. Dengan kerendahan hati panitia men- gucapkan selamat berseminar, terutama kepada peserta utusan dari; Universitas Negeri Malang (UNM), Institut Teknologi Bandung (ITB), Universitas Padjadjaran (UNPAD) Bandung, Uni- versitas Negeri Yogyakarta (UNY), Universita Mahasaraswati (UNMAS) Denpasar, Universitas Bunda Mulia Jakarta, dan Institut Seni Indonesia (ISI) Denpasar. Dengan penuh harapan, bahwa kegiatan seminar nasional ini dapat terselenggara den- gan sukses membawa pengalaman baru serta persahabatan abadi. Atas nama panitia, tidak lupa kami mengucapkan mohon maaf apabila ada pelayanan yang kurang memuaskan dan mungkin dilain waktu bisa lebih baik lagi penyelenggaraannya. Salam seni dan budaya. Om Santih Santih Santih O