Towards elimination of dog-mediated human rabies: experiences from implementing a large-scale demonstration project in Southern Tanzania

No abstract available

On Stirling functions of second kind

SIGLETIB Hannover: RN 5141(373) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Integrating contact tracing and whole-genome sequencing to track the elimination of dog-mediated rabies: An observational and genomic study

Background: Dog-mediated rabies is endemic across Africa causing thousands of human deaths annually. A One Health approach to rabies is advocated, comprising emergency post-exposure vaccination of bite victims and mass dog vaccination to break the transmission cycle. However, the impacts and cost-effectiveness of these components are difficult to disentangle. Methods: We combined contact tracing with whole-genome sequencing to track rabies transmission in the animal reservoir and spillover risk to humans from 2010 to 2020, investigating how the components of a One Health approach reduced the disease burden and eliminated rabies from Pemba Island, Tanzania. With the resulting high-resolution spatiotemporal and genomic data, we inferred transmission chains and estimated case detection. Using a decision tree model, we quantified the public health burden and evaluated the impact and cost-effectiveness of interventions over a 10-year time horizon. Results: We resolved five transmission chains co-circulating on Pemba from 2010 that were all eliminated by May 2014. During this period, rabid dogs, human rabies exposures and deaths all progressively declined following initiation and improved implementation of annual islandwide dog vaccination. We identified two introductions to Pemba in late 2016 that seeded re-emergence after dog vaccination had lapsed. The ensuing outbreak was eliminated in October 2018 through reinstated islandwide dog vaccination. While post-exposure vaccines were projected to be highly cost-effective ($256 per death averted), only dog vaccination interrupts transmission. A combined One Health approach of routine annual dog vaccination together with free post-exposure vaccines for bite victims, rapidly eliminates rabies, is highly cost-effective ($1657 per death averted) and by maintaining rabies freedom prevents over 30 families from suffering traumatic rabid dog bites annually on Pemba island. Conclusions: A One Health approach underpinned by dog vaccination is an efficient, cost-effective, equitable, and feasible approach to rabies elimination, but needs scaling up across connected populations to sustain the benefits of elimination, as seen on Pemba, and for similar progress to be achieved elsewhere. Funding: Wellcome [207569/Z/17/Z, 095787/Z/11/Z, 103270/Z/13/Z], the UBS Optimus Foundation, the Department of Health and Human Services of the National Institutes of Health [R01AI141712] and the DELTAS Africa Initiative [Afrique One-ASPIRE/DEL-15-008] comprising a donor consortium of the African Academy of Sciences (AAS), Alliance for Accelerating Excellence in Science in Africa (AESA), the New Partnership for Africa’s Development Planning and Coordinating (NEPAD) Agency, Wellcome [107753/A/15/Z], Royal Society of Tropical Medicine and Hygiene Small Grant 2017 [GR000892] and the UK government. The rabies elimination demonstration project from 2010-2015 was supported by the Bill & Melinda Gates Foundation [OPP49679]. Whole-genome sequencing was partially supported from APHA by funding from the UK Department for Environment, Food and Rural Affairs (Defra), Scottish government and Welsh government under projects SEV3500 and SE0421

Mobile phones as potential tools for surveillance in Tanzania.

<p>(A) Access and use of mobile phones versus computers by surveillance system users and 95% confidence intervals. The effects are shown of user (B) age and (C) self-reported use of text messaging (short message service or SMS), on the standardized time to complete surveillance forms on mobile phones, with boxes shaded in proportion to the sample size in the group (<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1002002#pmed.1002002.s002" target="_blank">S2 Data</a>). Time to completion in minutes was standardized by computing z-scores by sector, because forms used by health workers for recording bite patients were longer than forms used by livestock field officers to record mass dog vaccination campaigns (<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1002002#pmed.1002002.s005" target="_blank">S3 Table</a>, <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1002002#pmed.1002002.s008" target="_blank">S1 Text</a>). (D) Number and percentage of mobile phone form submissions where helpline support was used (<8% overall and <3% for the most commonly used form, that for bite patient records, data in <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1002002#pmed.1002002.s003" target="_blank">S1 Table</a>). Additional forms submitted by staff involved in system development and therefore familiar with the mobile phone application were excluded.</p

Example of mobile phone surveillance application.

<p>Mobile phone interface showing form being (A) completed for an example bite patient and (B) submitted.</p

The mobile-phone–based surveillance system.

<p>In the map, blue dots represent facilities that provide post-exposure prophylaxis (PEP) and report using the surveillance system (large dots represent hospitals, small dots represent health centres). The map is shaded by population density with wildlife-protected areas in white. The panels illustrate example surveillance data (<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1002002#pmed.1002002.s001" target="_blank">S1 Data</a>) from different districts that are annotated on the map by their initials. These data show monthly incidence of bite patients per 100,000 people on Pemba Island (P) and Ulanga (U), PEP use and shortages for Kibaha rural (KR) and Kisarawe (K), progress switching from intramuscular (IM) to intradermal (ID) administration of PEP for Morogoro rural (MR) and Rufiji (R), and numbers of dogs vaccinated each month for Nachingwea (N) and Masasi (M).</p