Prevention and response to rabies incursions in Low-and-Middle-Income Countries (LMICs)

Yuson, Mirava (2026) Prevention and response to rabies incursions in Low-and-Middle-Income Countries (LMICs). PhD thesis, University of Glasgow.

Abstract

Rabies is a viral, zoonotic disease that kills 59,000 people annually, mainly in low-andmiddle-income countries (LMICs) in Africa and Asia, through dog-to-human transmission. To eliminate dog-mediated human rabies deaths, the ‘Zero by 30’ global strategy developed by WHO and fellow international organisations recommend a sustained 70% vaccination coverage in dog populations. However, in rabies-endemic countries, rabies surveillance is severely limited due to lack of political will and insufficient resources for rabies detection, treatment and prevention. Rabies control measures including diagnostic tools, dog vaccines and post-exposure prophylaxis or PEP for humans, are undersupported in LMICs, therefore resulting in poor case detection and reporting, and high numbers of human deaths. Nevertheless, the path toward dog rabies elimination is straightforward, and has been achieved and sustained by many high-income countries (HICs), although incursions from LMICs are occasionally reported.

My objective was to explore different strategies aimed at controlling rabies incursions in LMICs. I used a transdisciplinary approach involving analysis of past incursions, realtime evaluation of an incursion as it unfolded into an outbreak, and assessment of a novel intervention that could potentially reduce rabies transmission. Beginning with an introductory chapter, this thesis focuses on what constitutes a rabies incursion and the current status of rabies surveillance and control measures worldwide. Next, in Chapter 2, I performed a systematic review of rabies incursions reported globally from 2001 to 2022 to highlight the catalytic role that incursions have played in global rabies (re-)emergence. My analysis identified incursions that resulted in outbreaks mainly in LMICs, and pinpointed common factors that contributed to different outcomes, from those that were contained to those causing fatal outbreaks and establishing endemic circulation. My findings illustrated the importance of preparedness and response capacity to minimize resurgence in nearby rabies-free zones, which is typically lacking in LMICs.

For the third chapter, I investigated the detection and response to a dog-mediated incursion in the previously rabies-free island province of Romblon, Philippines. A positive canine rabies case was initially detected in late 2022, and led to the detection of more than 40 positive samples within a year, as well as two laboratory-confirmed human rabies deaths. Lack of surveillance and suspension of mass dog vaccination activities due to COVID-19 restrictions contributed to the introduction of rabies into Tablas Island, which was human-mediated via boat travel. Contact tracing and dog vaccination were initiated but reach was limited. Integrated bite case management (IBCM) was essential for detection of this outbreak, and phylogenetic analysis of outbreak samples revealed possible introductions from rabies-endemic provinces within the Philippines.

My fourth and fifth chapters describe the implementation of long-lasting collars during a mass dog vaccination event in Puerto Galera municipality, Philippines. In the fourth chapter, I evaluated the feasibility of incorporating collars into vaccination campaigns by interviewing practitioners about their experiences with using collars. I also administered questionnaires to community members to gauge their behavior changes toward collared dogs, and conducted transect surveys to assess collar durability. While practitioners experienced minimal difficulty with learning and applying collars, questionnaire answers exposed a lack of understanding of rabies transmission among the local community. Most believed that dogs are susceptible to rabies even when vaccinated, and reported displaying indiscriminate behavior toward collared and non-collared dogs. Understanding of rabies among residents must therefore be improved for collars to induce a change in human behavior toward collared dogs. Collars were found to be vulnerable in coastal conditions as most were lost within months, necessitating a different material for improvement of collar durability. In Chapter 5, I used mark-resight survey results to estimate the free-roaming dog population and vaccination coverage in Puerto Galera, capitalizing on the deployment of collars. I determined that overall vaccination coverage was low, especially among freeroaming dogs, and that the dog population in Puerto Galera is severely underestimated. Targeting vaccination toward free-roaming dogs caused significantly increased coverage in an area where vaccination of free-roaming dogs was prioritized.

Summarized in my final chapter are the main conclusions to be drawn from this thesis: incursions in rabies-free zones in LMICs are frequent, underscoring the importance of targeting and sustaining rabies vaccination in rabies-endemic areas. Delayed incursion detection results from gaps in rabies surveillance, which can be enhanced with tools like IBCM, while genomic sequencing can determine incursion sources. LMICs such as the Philippines face unique cultural challenges to rabies elimination: knowledge gaps on rabies and traditional practices that have normalized free-roaming dogs are some of which have prevented rabies control interventions like collars from being more effective. My work shows that key priorities for LMICs like the Philippines should be sustaining control strategies (particularly dog vaccination and rabies surveillance) and improving rabies education, to accelerate progress toward the ‘Zero by 30’ goal.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Supported by funding from the Wellcome Trust.
• Subjects: S Agriculture > SF Animal culture > SF600 Veterinary Medicine
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Funder's Name: Wellcome Trust (WELLCOTR)
• Supervisor's Name: Hampson, Professor Katie and Chng, Dr. Nai Rui
• Date of Award: 2026
• Depositing User: Theses Team
• Unique ID: glathesis:2026-85685
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 15 Jan 2026 12:58
• Last Modified: 15 Jan 2026 13:08
• Thesis DOI: 10.5525/gla.thesis.85685
• URI: https://theses.gla.ac.uk/id/eprint/85685

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