Costs of rabies control: an economic calculation method applied to Flores Island

Assessment of the burden of rabies in one health approach control program in Ketapang District Indonesia: Using zDALY

Background

Ketapang District, located in West Kalimantan, is a region where rabies is endemic. The first human death from rabies was reported in 2014 and the problem persists to this day. In response, the government has implemented the one health approach to control rabies since 2017. This study aimed to assess the disease burden of rabies control using zDALY metrics.

Methods

The zoonotic burden for human and animal was measured by developing Zoonotic Disability-Adjusted Life Years (zDALY), which combines DALY and local values of animals and their products, considering animal morbidity and mortality due to the disease (Animal Loss Equivalent/ALE). Data were gathered through interviews with victims or their families, dog owners, and secondary data from the Animal Husbandry Service, and the District Health Office.

Results

Before implementing the one health approach, the zDALY value was 1,561.22 person-years (the zDALY rate: 109.53 years/100,000 people). After the intervention, the zDALY value was 1,808.86 person-years (the zDALY rate: 86.62 years/100,000 people).

Conclusions

This reduction in the zDaly rate indicates that rabies control through the one health approach in Ketapang District was effective in alleviating the disease burden caused by rabies.

Evaluation of Dynamics, Demography and Estimation of Free-Roaming Dog Population in Herat City, Afghanistan

FRDs pose a serious challenge in countries where dog-bite-related rabies is endemic. Understanding the size and core demographic characteristics of FRD populations is essential for the planning and implementation of effective dog-population and canine-rabies-control programmes. The photographic sight-resight method was used to estimate the FRD population and evaluate its demographic characteristics in Herat city. A total of 928 free-roaming dogs (FRD) were identified through 3172 sightings, and the total free-roaming population was estimated to amount to 1821 (95% CI: 1565-2077), which led to the estimation of 10 dogs/km² and the human-to-FRD ratio of 315:1. The male-to-female ratio was 2.85:1. The majority of them were healthy, with an ideal body score. Although the FRD density is considered low, it is still a concern and significant, since the majority of the people are unaware of the importance of canine populations in the transmission of zoonotic diseases such as rabies, and there were no specific measures for managing and controlling FRD populations. The information gained can be useful in animal health planning to design effective dog-population-control programmes, and for the planning of national rabies-prevention programmes.

Prophylactic treatment abandonment in people bitten by suspected rabid animals, El Salvador, 2013-2017

Introduction

Around the world 60,000 people die from rabies each year. The main form of exposure to rabies is by the bite of animals infected with the virus. More than 20,000 cases of rabies-transmitting animal bites are reported each year, in El Salvador, a country located in Central America. People exposed should be managed with rabies prophylaxis.

Objective

To determine the abandonment of post-exposure prophylaxis (PEP) cumulative incidence (CI) in humans bitten by suspected rabid animals in El Salvador from 2013 to 2017.

Methodology

This is an ecological study based on the cases of bites by suspected rabid animals reported between 2013 and 2017 in the public health system of El Salvador. Descriptive and correlation analysis was performed using Statistical Package for the Social Sciences (SPSS) version 24. The municipality CI, expressed per 100,000 inhabitants.

Results

The national CI of abandonment PEP in humans bitten by suspected rabid animals was 25.6 × 100,000 inhabitants. Simple bivariate correlation analysis shows that the departments with the highest CI of bites caused by cats, wild animals, and bites on the neck (R ² = 0.99 P < 0.05) are mostly associated with dropping out of the PEP.

Conclusion

In El Salvador, the abandonment CI of PEP is lower than other countries, however, bites by rabid suspected animal are frequent, this represents a public health problem due to the presence of the rabies virus in wild animals and the high lethality of the disease. Municipalities where head bites are common are the most related to the abandonment of PEP.

Immune Response After Rabies Vaccination in Owned Free-Roaming Domestic Dogs in Flores Island, Indonesia

Vaccination is the main tool to prevent the circulation of rabies in dog populations. The development of an immune response after vaccination differs between individual dogs and depends on many factors such as dog characteristics, management, or genetics. Here, we first investigated the level of, and associated factors for, the presence of binding antibodies in 130 healthy dogs from Flores Island, Indonesia. Secondly, we identified factors associated with the development of binding antibodies within 30 days after vaccination among a subsample of dogs that had a binding antibody titre <0.5 EU/ml at the day of vaccination (D0, N = 91). Blood samples were collected from the individual dogs immediately before vaccination at D0 and 30 days after vaccination (D30). The rabies antibody titres were determined using ELISAs. Information on potential risk factors such as the dog's age and sex, history of vaccination, type and frequency of feeding, and BCS (body condition score) were gathered during interviews at D0. Regression analyses were performed to identify the risk factors associated with the presence of binding antibody titre ≥0.5 EU/ml at D0 for the 130 dogs and the development of binding antibody titre ≥0.5EU/ml at D30 for the 91 dogs. The results showed that the proportion of dogs with antibody titre ≥0.5 EU/ml was 30% (39/130) at D0. The only factors found to be significantly influencing the presence of binding antibodies titres ≥0.5 EU/ml was previous vaccination within 1 year before D0 [46.8 vs. 14.7%, Odds ratio (OR) = 3.6, 95%CI 1.5–9.3; p-value = 0.006], although the same trend was found for dogs of higher age and better BCS. Eighty-six percent (79/91) of dogs whose rabies binding antibody level was <0.5 EU/ml at D0 had developed an adequate immune response (≥0.5 EU/ml) at D30. Almost a significantly higher proportion developed an adequate immune response in dogs of good BCS compared to those of poor BCS (95.3% vs. 79.2%, OR = 4.7, 95%CI 1.1–32.5; p-value = 0.057. Twelve (13.2%) dogs retain binding antibody level <0.5 EU/ml at D30, indicating poor immune response after vaccination. A majority of them did not receive vaccine before D0 according to the owner and had poor BCS (83.3%; 10/12). Our findings show the high effectiveness of rabies vaccine in under field conditions to develop measurable immunity and the importance of a good BCS, often achievable by good dog keeping conditions, for developing efficient immunity after parenteral vaccination in dogs.

The effects of geographical distributions of buildings and roads on the spatiotemporal spread of canine rabies: An individual-based modeling study

Rabies is a fatal disease that has been a serious health concern, especially in developing countries. Although rabies is preventable by vaccination, the spread still occurs sporadically in many countries, including Thailand. Geographical structures, habitats, and behaviors of host populations are essential factors that may result in an enormous impact on the mechanism of propagation and persistence of the disease. To investigate the role of geographical structures on the transmission dynamics of canine rabies, we developed a stochastic individual-based model that integrates the exact configuration of buildings and roads. In our model, the spatial distribution of dogs was estimated based on the distribution of buildings, with roads considered to facilitate dog movement. Two contrasting areas with high- and low-risk of rabies transmission in Thailand, namely, Hatyai and Tepha districts, were chosen as study sites. Our modeling results indicated that the distinct geographical structures of buildings and roads in Hatyai and Tepha could contribute to the difference in the rabies transmission dynamics in these two areas. The high density of buildings and roads in Hatyai could facilitate more rabies transmission. We also investigated the impacts of rabies intervention, including reducing the dog population, restricting owned dog movement, and dog vaccination on the spread of canine rabies in these two areas. We found that reducing the dog population alone might not be sufficient for preventing rabies transmission in the high-risk area. Owned dog confinement could reduce more the likelihood of rabies transmission. Finally, a higher vaccination coverage may be required for controlling rabies transmission in the high-risk area compared to the low-risk area.

Loss of binding antibodies against rabies in a vaccinated dog population in Flores Island, Indonesia

Effective parenteral vaccines are available to control rabies in dogs. While such vaccines are successfully used worldwide, the period between vaccine boosters required to guarantee protection of the population against rabies varies between vaccines and populations. In Flores Island, Indonesia, internationally and locally produced rabies vaccines are used during annual vaccination campaigns of predominantly free-roaming owned domestic dogs. The study objective was to identify the duration of the presence and factors associated with the loss of adequate level of binding antibodies (≥0.5 EU/ml) following rabies vaccination in a domestic dog population on Flores Island. A total of 171 dogs that developed an antibody titre higher or equal to 0.5 EU/ml 30 days after vaccination (D30), were repeatedly sampled at day 90, 180, 270, and 360 after vaccination. On the day of vaccination (D0), an interview was performed with dog owners to collect information on dog characteristics (age, sex, body condition score (BCS)), history of rabies vaccination, kind of daily food, frequency of feeding, and origin of the dog. Serum samples were collected and the level of antibodies was quantitatively assessed using ELISA tests. Dogs were categorized as having an adequate level of binding antibodies (≥0.5 EU/ml) or inadequate level of binding antibodies (<0.5 EU/ml) at each time points examined. A total of 115, 72, 23, and 31 dogs were sampled at D90, D180, D270, and D360, respectively, with the highest proportion of antibodies ≥ 0.5 EU/ml (58%, 95% CI, 49-67%) at D90, which reduced gradually until D360 (35%, 95% CI, 19-52%). Multivariable logistic regression models showed that loss of adequate level of binding antibodies is significantly associated with dogs having no history of vaccination or vaccination applied more than 12 months before D0, being less than 12 months of age, and having a poor BCS. These results highlight the importance of BCS regarding the immune response duration and provide insights into frequency of vaccination campaigns required for the internationally available vaccine used on Flores Island. For dogs without vaccination history or vaccination being applied more than 12 months before D0, a booster is recommended within 3 months (a largest drop of antibodies was detected within the first 90 days) after the first vaccination to guarantee measurable protection of the population that lasts at least for one year.

A Qualitative Risk Assessment of Rabies Reintroduction Into the Rabies Low-Risk Zone of Bhutan

In Bhutan, dog-mediated rabies has been successfully eliminated from most regions of the country but remains endemic in the Southern region and sporadic incursions are also reported in the East. Elimination of rabies from the southern part of Bhutan is challenged by the porous border with the neighboring states of India which facilitates free and unregulated movement of animals. Around 17 outbreaks of rabies are reported annually in dogs and other domestic animals, posing continuous public health risks and economic losses. Furthermore, due to anthropogenic factors, such as increasing human settlements along highways, increased animal transportation, and the complex and changing human-pet relationship, there is potential to reintroduce rabies from rabies high-risk zone to rabies low-risk zone. This study was undertaken to estimate the risk of rabies re-introduction to the rabies low-risk zone by performing a qualitative risk assessment. The assessment was conducted for three risk pathways (stray dog-pathway, pet dog-pathway and cattle-pathway) under two scenarios: (1) no risk mitigation measures in place and (2) current risk mitigation measures in place. The current control measures include Government led programs, such as mass dog vaccination and dog population management, regulation of the movment of animals through pre-travel check-up and health certification, regular awareness education and rabies surveillance in the rabies endemic areas. The probability of an event occurring was assigned using the data from the available literature. Where gaps in knowledge existed, expert opinion, elicited through modified Delphi method, was used. Under the scenario in which no risk mitigation measures were in place, the risk of rabies re-introduction was estimated to be medium for the stray-dog pathway with a low level of uncertainty, low for pet-dog pathway with a low level of uncertainty, and very low for the cattle-pathway with a medium level of uncertainty. When current risk-mitigation measures were included, the risk of rabies reintroduction was estimated to be very low for the stray-dog pathway with a medium level of uncertainty, low for the pet dog-pathway with a low level of uncertainty, and extremely low for the cattle-pathway with a medium level of uncertainty. The risk of rabies re-introduction through all the pathways was greater than negligible. These findings highlight the importance of maintaining and enhancing current risk mitigation measures to prevent re-introduction of rabies into rabies low-risk zone.

Costs and effectiveness of alternative dog vaccination strategies to improve dog population coverage in rural and urban settings during a rabies outbreak

Dog-rabies elimination programs have typically relied upon parenteral vaccination at central-point locations; however, dog-ownership practices, accessibility to hard-to-reach sub-populations, resource limitations, and logistics may impact a country's ability to reach the 70% coverage goal recommended by the World Organization for Animal Health (OIE) and World Health Organization (WHO). Here we report the cost-effectiveness of different dog-vaccination strategies during a dog-rabies outbreak in urban and peri-urban sections of Croix-des-Bouquets commune of the West Department, Haiti, in 2016. Three strategies, mobile static point (MSP), mobile static point with capture-vaccinate-release (MSP + CVR), and door-to-door vaccination with oral vaccination (DDV + ORV), were applied at five randomly assigned sites and assessed for free-roaming dog vaccination coverage and total population coverage. A total of 7065 dogs were vaccinated against rabies during the vaccination campaign. Overall, free-roaming dog vaccination coverage was estimated at 52% (47%-56%) for MSP, 53% (47%-60%) for DDV + ORV, and 65% (61%-69%) for MSP + CVR (differences with MSP and DDV + ORV significant at p < 0.01). Total dog vaccination coverage was 33% (95% CI: 26%-43%) for MSP, 49% (95% CI: 40%-61%) for MSP + CVR and 78% (77%-80%) for DDV + ORV (differences significant at p < 0.001). Overall, the least expensive campaign was MSP, with an estimated cost of about $2039 per day ($4078 total), and the most expensive was DDV + ORV with a cost of $3246 per day ($6492 total). Despite the relative high cost of an ORV bait, combining DDV and ORV was the most cost-effective strategy in our study ($1.97 per vaccinated dog), largely due to increased efficiency of the vaccinators to target less accessible dogs. Costs per vaccinated dog were $2.20 for MSP and $2.28 for MSP + CVR. We hope the results from this study will support the design and implementation of effective dog vaccination campaigns to achieve the goal of eliminating dog-mediated human rabies deaths by 2030.

Impact of One-Health framework on vaccination cost-effectiveness: A case study of rabies in Ethiopia

Livestock losses due to rabies and health and the corresponding benefits of controlling the disease are not often considered when the cost-effectiveness of rabies control is evaluated. In this research, assessed the benefits of applying a One Health perspective that includes these losses to the case of canine rabies vaccination in Ethiopia. We constructed a dynamic epidemiological model of rabies transmission. The model was fit to district-specific data on human rabies exposures and canine demography for two districts with distinct agro-ecologies. The epidemiological model was coupled with human and livestock economic outcomes to predict the health and economic impacts under a range of vaccination scenarios. The model indicates that human exposures, human deaths, and rabies-related livestock losses would decrease monotonically with increasing vaccination coverage. In the rural district, all vaccination scenarios were found to be cost-saving compared to the status quo of no vaccination, as more money could be saved by preventing livestock losses than would be required to fund the vaccination campaigns. Vaccination coverages of 70% and 80% were identified as most likely to provide the greatest net health benefits at the WHO cost-effectiveness threshold over a period of 5 years, in urban and rural districts respectively. Shorter time frames led to recommendations for higher coverage in both districts, as did even a minor threat of rabies re-introduction. Exclusion of rabies-related livestock losses reduced the optimal vaccination coverage for the rural district to 50%. This study demonstrated the importance of including all economic consequences of zoonotic disease into control decisions. Analyses that include cattle and other rabies-susceptible livestock are likely better suited to many rural communities in Africa wishing to maximize the benefits of canine vaccination.

Cost Savings of Using Updated Thai Red Cross Intradermal Regimen in a High-Throughput Anti-Rabies Clinic in New Delhi, India

Replacement of the Essen intramuscular (EIM) by the updated Thai Red Cross intradermal (UTRCID) regimen for rabies post-exposure prophylaxis (PEP), in high-throughput hospitals of India, has been advocated since 2006 thanks to its cost-effectiveness. However, several anti-rabies clinics in India and other parts of the world have not initiated this switchover of regimens because of the paucity of financial literature, generated in realistic settings, regarding the same. We calculated the procurement costs of various items required for providing rabies vaccinations via the EIM regimen and UTRCID regimen, on an annual basis, a year before and after the switchover. From a healthcare provider’s perspective, the cost of vaccination per patient was calculated to be 5.60 USD for the EIM regimen and 2.40 USD for the UTRCID regimen. The switchover to the UTRCID regimen from the EIM regimen reduced the financial burden of the rabies vaccination by almost 60%. Procurement of vaccine vials contributed to the majority of the cost (>94%) in both of the regimens. Procurement of syringes with fixed needles contributed negligibly (<6%) to the financial burden in both the regimens. A policy to progressively switch over to the UTRCID regimen from the EIM in all high-throughput anti-rabies centers of India would dramatically reduce the economic burden of running a successful anti-rabies program.

Benefit-cost analysis of the policy of mandatory annual rabies vaccination of domestic dogs in rabies-free Japan

Japan is one of the few rabies-free countries/territories which implement the policy of mandatory vaccination of domestic dogs. In order to assess the economic efficiency of such policy in reducing the economic burden of a future canine rabies outbreak in Japan, a benefit-cost analysis (BCA) was performed using probabilistic decision tree modelling. Input data derived from simulation results of published mathematical model, field investigation conducted by the authors at prefectural governments, literature review, international or Japanese database and empirical data of rabies outbreaks in other countries/territories. The current study revealed that the annual costs of implementing the current vaccination policy would be US$160,472,075 (90% prediction interval [PI]: $149,268,935-171,669,974). The economic burden of a potential single canine rabies outbreak in Japan were estimated to be US$1,682,707 (90% PI: $1,180,289-2,249,283) under the current vaccination policy, while it would be US$5,019,093 (90% PI: $3,986,882-6,133,687) under hypothetical abolition of vaccination policy, which is 3-fold higher. Under a damage-avoided approach, the annual benefits of implementing the current vaccination policy in expected value were estimated to be US$85.75 (90% PI: $55.73-116.89). The benefit-cost ratio (BCR) was estimated to be 5.35 X 10(-7) (90% PI: 3.46 X 10(-7)-7.37 X 10(-7)), indicating that the implementation of the current policy is very economically inefficient for the purpose of reducing the economic burden of a potential canine rabies outbreak. In worse-case scenario analysis, the BCR would become above 1 (indicating economic efficiency) if the risk of rabies introduction increased to 0.04 corresponding to a level of risk where rabies would enter Japan in 26 years while the economic burden of a rabies outbreak under the abolition of vaccination policy increased to $7.53 billion. Best-case analysis further revealed that under relatively extreme circumstances the economic efficiency of the current policy could be improved by decreasing the vaccination price charged to dog owners, relaxing the frequency of vaccination to every two to three years and implementing the policy on a smaller scale, e.g. only in targeted prefectures instead of the whole Japan.

Cost-effectiveness of mass dog rabies vaccination strategies to reduce human health burden in Flores Island, Indonesia

The cost-effectiveness of different mass dog rabies vaccination strategies, defined as the costs per year of life lost (YLL) averted was evaluated for a period of 10 years by means of a dynamic simulation study for a typical village on Flores Island. In the base strategy (no dog vaccination and no post-exposure treatment (PET) of human bite cases), the model showed that the introduction of the virus by one infectious dog into an isolated village with 1500 inhabitants and 400 dogs resulted in 881 YLLs during a 10-year simulation period, which is equivalent to 30 human rabies cases. An annual dog vaccination campaign with a coverage of 70% using a short-acting vaccine saved 832 YLLs, while the cumulative costs for the public sector were US$3646 or US$4.38 per YLL averted. Switching to a long-acting vaccine, the annual vaccination strategies with a coverage of 50% (AV_156_50) or 70% (AV_156_70) reduced the baseline YLLs from 881 to respectively 78 and 26 YLLs with cumulative costs of US$3716 and US$2264 or US$4.63 and US$2.65 per YLL averted, respectively. In general, dog vaccination was more cost-effective than PET alone (US$2.65-4.63 per YLL averted versus US$23.29 per YLL averted). Although a combination of PET with AV_156_70 was less cost-effective compared to AV_156_70 alone, this strategy was able to prevent all human deaths due to rabies. A combination of PET with annual vaccination using a short-acting vaccine at a coverage of 50% was far from being cost-effective, suggesting that the currently applied rabies control in Flores Island is not an efficient investment in reducing human rabies burden. An increased investment in either an increase in the current coverage or in a switch from the short-acting vaccine to the long-acting vaccine type would certainly pay off.

Spatial Association of Canine Rabies Outbreak and Ecological Urban Corridors, Arequipa, Peru

In the city of Arequipa, Peru, a rabid dog was detected in March 2015, marking the reintroduction of the rabies virus in the area; more rabid dogs have been detected since then. The presence of free-roaming dogs in Arequipa seems to be higher in dry water channels, which are widespread in the city. We created a geographic information system (GIS) with surveillance data on the location of rabid dogs detected during the first year of the outbreak, as well as the water channels. We conducted a spatial analysis using Monte Carlo simulations to determine if detected rabid dogs were closer to the water channels than expected. Thirty rabid dogs were detected during the first year of the outbreak, and they were statistically associated with the water channels (average distance to closest water channel = 334 m; p-value = 0.027). Water channels might play a role in the ecology of free-roaming dog populations, functioning as ecological corridors. Landscape ecology could assist in understanding the impact of these urban structures on control activities and the persistence of transmission.

The Role of Dog Population Management in Rabies Elimination-A Review of Current Approaches and Future Opportunities

Free-roaming dogs and rabies transmission are integrally linked across many low-income countries, and large unmanaged dog populations can be daunting to rabies control program planners. Dog population management (DPM) is a multifaceted concept that aims to improve the health and well-being of free-roaming dogs, reduce problems they may cause, and may also aim to reduce dog population size. In theory, DPM can facilitate more effective rabies control. Community engagement focused on promoting responsible dog ownership and better veterinary care could improve the health of individual animals and dog vaccination coverage, thus reducing rabies transmission. Humane DPM tools, such as sterilization, could theoretically reduce dog population turnover and size, allowing rabies vaccination coverage to be maintained more easily. However, it is important to understand local dog populations and community attitudes toward them in order to determine whether and how DPM might contribute to rabies control and which DPM tools would be most successful. In practice, there is very limited evidence of DPM tools achieving reductions in the size or turnover of dog populations in canine rabies-endemic areas. Different DPM tools are frequently used together and combined with rabies vaccinations, but full impact assessments of DPM programs are not usually available, and therefore, evaluation of tools is difficult. Surgical sterilization is the most frequently documented tool and has successfully reduced dog population size and turnover in a few low-income settings. However, DPM programs are mostly conducted in urban settings and are usually not government funded, raising concerns about their applicability in rural settings and sustainability over time. Technical demands, costs, and the time necessary to achieve population-level impacts are major barriers. Given their potential value, we urgently need more evidence of the effectiveness of DPM tools in the context of canine rabies control. Cheaper, less labor-intensive tools for dog sterilization will be extremely valuable in realizing the potential benefits of reduced population turnover and size. No one DPM tool will fit all situations, but if DPM objectives are achieved dog populations may be stabilized or even reduced, facilitating higher dog vaccination coverages that will benefit rabies elimination efforts.

Cost Description and Comparative Cost Efficiency of Post-Exposure Prophylaxis and Canine Mass Vaccination against Rabies in N'Djamena, Chad

Rabies claims approximately 59,000 human lives annually and is a potential risk to 3.3 billion people in over 100 countries worldwide. Despite being fatal in almost 100% of cases, human rabies can be prevented by vaccinating dogs, the most common vector, and the timely administration of post-exposure prophylaxis (PEP) to exposed victims. For the control and prevention of human rabies in N'Djamena, the capital city of Chad, a free mass vaccination campaign for dogs was organized in 2012 and 2013. The campaigns were monitored by parallel studies on the incidence of canine rabies based on diagnostic testing of suspect animals and the incidence of human bite exposure recorded at selected health facilities. Based on the cost description of the campaign and the need for PEP registered in health centers, three cost scenarios were compared: cumulative cost-efficiency of (1) PEP alone, (2) dog mass vaccination and PEP, (3) dog mass vaccination, PEP, and maximal communication between human health and veterinary workers (One Health communication). Assuming ideal One Health communication, the cumulative prospective cost of dog vaccination and PEP break even with the cumulative prospective cost of PEP alone in the 10th year from the start of the calculation (2012). The cost efficiency expressed in cost per human exposure averted is much higher with canine vaccination and One Health communication than with PEP alone. As shown in other studies, our cost-effectiveness analysis highlights that canine vaccination is financially the best option for animal rabies control and rabies prevention in humans. This study also provides evidence of the beneficial effect of One Health communication. Only with close communication between the human and animal health sectors will the decrease in animal rabies incidence be translated into a decline for PEP. An efficiently applied One Health concept would largely reduce the cost of PEP in resource poor countries and should be implemented for zoonosis control in general.

Rationale and support for a One Health program for canine vaccination as the most cost-effective means of controlling zoonotic rabies in endemic settings

Although dog vaccination has been demonstrated to reduce and eliminate rabies in humans, during meetings there are often calls for further pilot studies. The assembled data proves that a widespread approach is now required. While zoonotic rabies has a minimal presence in developed nations, it is endemic throughout most of Asia and Africa, where it is considered to be a neglected tropical disease. In these areas, rabies causes an estimated annual mortality of at least 55,000 human deaths. Worldwide rabid dogs are the source of the vast majority of human rabies exposures. The World Health Organization (WHO), the Food and Agriculture Organization (FAO) of the United Nations and the World Organization for Animal Health (OIE) advocate a collaborative One Health approach involving human public health and veterinary agencies, with mass canine vaccination programs in endemic areas being the mainstay of strategies to eliminate dog-mediated human rabies. While post-exposure prophylaxis (PEP) is effective in preventing deaths in people exposed to rabies, it is comparatively expensive and has little impact on the canine reservoir that is the primary source of zoonotic rabies. Indiscriminate culling of the dog population is expensive and there is little evidence that it is effective in controlling rabies in non-island locations. Mass canine vaccination programs using a One Health framework that achieves a minimum 70% vaccination coverage during annual campaigns have proven to be cost-effective in controlling zoonotic rabies in endemic, resource-poor regions. Case studies, such as in Tanzania and Bhutan, illustrate how an approach based on mass canine rabies vaccination has effectively reduced both canine and human rabies to minimal levels. The multiple benefits of mass canine rabies vaccination in these cases included eliminating rabies in the domestic dog reservoirs, eliminating human rabies cases, and decreasing the rabies economic burden by reducing expenditures on PEP.

Cost-Effectiveness of Mass Dog Vaccination Campaigns against Rabies in Flores Island, Indonesia

A dynamic deterministic simulation model was developed to determine the cost-effectiveness of different mass dog vaccination strategies against rabies in a dog population representative of a typical village on Flores Island. Cost-effectiveness was measured as public cost per averted dog-rabies case. Simulations started with the introduction of one infectious dog into a susceptible dog population of 399 dogs and subsequently ran for a period of 10 years. The base scenario represented a situation without any control intervention. Evaluated vaccination strategies were as follows: annual vaccination campaigns with short-acting vaccine (immunity duration of 52 weeks) (AV_52), annual campaigns with long-acting vaccine (immunity duration of 156 weeks) (AV_156), biannual campaigns with short-acting vaccine (BV_52) and once-in-2-years campaigns with long-acting vaccine (O2V_156). The effectiveness of the vaccination strategies was simulated for vaccination coverages of 50% and 70%. Cumulative results were reported for the 10-year simulation period. The base scenario resulted in three epidemic waves, with a total of 1274 dog-rabies cases. The public cost of applying AV_52 at a coverage of 50% was US$5342 for a village. This strategy was unfavourable compared to other strategies, as it was costly and ineffective in controlling the epidemic. The costs of AV_52 at a coverage of 70% and AV_156 at a coverage of 70% were, respectively, US$3646 and US$3716, equivalent to US$3.00 and US$3.17 per averted dog-rabies case. Increasing the coverage of AV_156 from 50% to 70% reduced the number of cases by 7% and reduced the cost by US$1452, resulting in a cost-effectiveness ratio of US$1.81 per averted dog-rabies case. This simulation model provides an effective tool to explore the public cost-effectiveness of mass dog vaccination strategies in Flores Island. Insights obtained from the simulation results are useful for animal health authorities to support decision-making in rabies-endemic areas, such as Flores Island.

Willingness to Pay for Dog Rabies Vaccine and Registration in Ilocos Norte, Philippines (2012)

BACKGROUND

The Philippines is one of the developing countries highly affected by rabies. Dog vaccination campaigns implemented through collaborative effort between the government and NGOs have played an important role in successfully reducing the burden of disease within the country. Nevertheless, rabies vaccination of the domestic animal population requires continuous commitment not only from governments and NGOs, but also from local communities that are directly affected by such efforts. To create such long-term sustained programs, the introduction of affordable dog vaccination and registration fees is essential and has been shown to be an important strategy in Bohol, Philippines. The aim of this study, therefore, was to estimate the average amount of money that individuals were willing to pay for dog vaccination and registration in Ilocos Norte, Philippines. This study also investigated some of the determinants of individuals' willingness to pay (WTP).

METHODS

A cross-sectional questionnaire was administered to 300 households in 17 municipalities (out of a total of 21) selected through a multi-stage cluster survey technique. At the time of the survey, Ilocos Norte had a population of approximately 568,017 and was predominantly rural. The Contingent Valuation Method was used to elicit WTP for dog rabies vaccination and registration. A 'bidding game' elicitation strategy that aims to find the maximum amount of money individuals were willing to pay was also employed. Data were collected using paper-based questionnaires. Linear regression was used to examine factors influencing participants' WTP for dog rabies vaccination and registration.

KEY RESULTS

On average, Ilocos Norte residents were willing to pay 69.65 Philippine Pesos (PHP) (equivalent to 1.67 USD in 2012) for dog vaccination and 29.13PHP (0.70 USD) for dog registration. Eighty-six per cent of respondents were willing to pay the stated amount to vaccinate each of their dogs, annually. This study also found that WTP was influenced by demographic and knowledge factors. Among these, we found that age, income, participants' willingness to commit to pay each year, municipality of residency, knowledge of the signs of rabies in dogs, and number of dogs owed significantly predicted WTP.

Global epidemiology of canine rabies: past, present, and future prospects

The rabies virus, a public health scourge from ancient times, is currently responsible for an estimated 59,000 human deaths a year, almost all transmitted via dog bites. It causes considerable economic impacts on developing countries, primarily in Africa and Asia, which can least afford these losses. However, despite its almost 100% case fatality rate, canine rabies is a completely preventable disease, and historic examples of canine rabies elimination in the developed world attest to this. Over the last decade, programs based on eliminating the source of the disease from dogs have shown success in reducing the public health burden of canine rabies in developing countries, notably across Latin America, and this has contributed to the growing evidence base necessary to change attitudes toward the feasibility of global canine rabies elimination. More recently, assessments of the current economic burden of canine rabies and the potential cost savings achievable through mass dog vaccinations have been added to this evidence base. Tools and support are available from the international community to help countries move progressively toward canine rabies elimination, and there is optimism that global freedom from canine rabies can be achieved within the next few decades.

Development of a Novel Rabies Simulation Model for Application in a Non-endemic Environment

Domestic dog rabies is an endemic disease in large parts of the developing world and also epidemic in previously free regions. For example, it continues to spread in eastern Indonesia and currently threatens adjacent rabies-free regions with high densities of free-roaming dogs, including remote northern Australia. Mathematical and simulation disease models are useful tools to provide insights on the most effective control strategies and to inform policy decisions. Existing rabies models typically focus on long-term control programs in endemic countries. However, simulation models describing the dog rabies incursion scenario in regions where rabies is still exotic are lacking. We here describe such a stochastic, spatially explicit rabies simulation model that is based on individual dog information collected in two remote regions in northern Australia. Illustrative simulations produced plausible results with epidemic characteristics expected for rabies outbreaks in disease free regions (mean R₀ 1.7, epidemic peak 97 days post-incursion, vaccination as the most effective response strategy). Systematic sensitivity analysis identified that model outcomes were most sensitive to seven of the 30 model parameters tested. This model is suitable for exploring rabies spread and control before an incursion in populations of largely free-roaming dogs that live close together with their owners. It can be used for ad-hoc contingency or response planning prior to and shortly after incursion of dog rabies in previously free regions. One challenge that remains is model parameterisation, particularly how dogs’ roaming and contacts and biting behaviours change following a rabies incursion in a previously rabies free population.

Rabies in domestic dog populations still causes >50,000 human deaths worldwide each year. While its eradication by vaccination of the reservoir population (dogs and wildlife) was successful in many parts of the world, it is still present in the developing world and continues to spread to new regions. Theoretical rabies models supporting control plans do exist for rabies endemic regions; however these models usually provide information for long-term programs. Here, we describe a novel rabies simulation model for application in rabies-free regions experiencing an incursion. The model simulates a rabies outbreak in the free-ranging dog population in remote indigenous communities in northern Australia. Vaccination, dog density reduction and dog confinement are implemented as control strategies. Model outputs suggest that the outbreak lasts for an average of 7 months and typically spreads through all communities of the region. Dog vaccination was found to be the most effective response strategy. The model produces plausible results and can be used to provide information for ad-hoc response planning before and shortly after rabies incursion.

Uptake of rabies control measures by dog owners in Flores Island, Indonesia

BACKGROUND

Rabies has been a serious public health threat in Flores Island, Indonesia since it was introduced in 1997. To control the disease, annual dog vaccination campaigns have been implemented to vaccinate all dogs free of charge. Nevertheless, the uptake rate of the vaccination campaigns has been low. The objective of this paper is to identify risk factors associated with the uptake of rabies control measures by individual dog owners in Flores Island.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 450 dog owners from 44 randomly selected villages in the Sikka and Manggarai regencies were interviewed regarding their socio-demographic factors, knowledge of rabies, and their uptake of rabies control measures. The majority of dog owners surveyed (>90%) knew that rabies is a fatal disease and that it can be prevented. Moreover, 68% of the dog owners had a high level of knowledge about available rabies control measures. Fifty-two percent of the dog owners had had at least one of their dogs vaccinated during the 2012 vaccination campaign. Vaccination uptake was significantly higher for dog owners who resided in Sikka, kept female dogs for breeding, had an income of more than one million Rupiah, and had easy access to their village. The most important reasons not to join the vaccination campaign were lack of information about the vaccination campaign schedule (40%) and difficulty to catch the dog during the vaccination campaign (37%).

CONCLUSIONS/SIGNIFICANCE

Dog owners in Flores Island had a high level of knowledge of rabies and its control, but this was not associated with uptake of the 2012 vaccination campaign. Geographical accessibility was one of the important factors influencing the vaccination uptake among dog owners. Targeted distribution of information on vaccination schedules and methods to catch and restrain dogs in those villages with poor accessibility may increase vaccination uptake in the future.

Review on dog rabies vaccination coverage in Africa: a question of dog accessibility or cost recovery?

Background

Rabies still poses a significant human health problem throughout most of Africa, where the majority of the human cases results from dog bites. Mass dog vaccination is considered to be the most effective method to prevent rabies in humans. Our objective was to systematically review research articles on dog rabies parenteral vaccination coverage in Africa in relation to dog accessibility and vaccination cost recovery arrangement (i.e.free of charge or owner charged).

Methodology/Principal Findings

A systematic literature search was made in the databases of CAB abstracts (EBSCOhost and OvidSP), Scopus, Web of Science, PubMed, Medline (EBSCOhost and OvidSP) and AJOL (African Journal Online) for peer reviewed articles on 1) rabies control, 2) dog rabies vaccination coverage and 3) dog demography in Africa. Identified articles were subsequently screened and selected using predefined selection criteria like year of publication (viz. ≥ 1990), type of study (cross sectional), objective(s) of the study (i.e. vaccination coverage rates, dog demographics and financial arrangements of vaccination costs), language of publication (English) and geographical focus (Africa). The selection process resulted in sixteen peer reviewed articles which were used to review dog demography and dog ownership status, and dog rabies vaccination coverage throughout Africa. The main review findings indicate that 1) the majority (up to 98.1%) of dogs in African countries are owned (and as such accessible), 2) puppies younger than 3 months of age constitute a considerable proportion (up to 30%) of the dog population and 3) male dogs are dominating in numbers (up to 3.6 times the female dog population). Dog rabies parenteral vaccination coverage was compared between “free of charge” and “owner charged” vaccination schemes by the technique of Meta-analysis. Results indicate that the rabies vaccination coverage following a free of charge vaccination scheme (68%) is closer to the World Health Organization recommended coverage rate (70%) than the achieved coverage rate in owner-charged dog rabies vaccination schemes (18%).

Conclusions/Significance

Most dogs in Africa are owned and accessible for parenteral vaccination against rabies if the campaign is performed “free of charge”.

Rabies is one of the most fatal diseases in both humans and animals. A bite by a rabid dog is the main cause of human rabies in Africa. Parenteral mass dog vaccination is the most cost-effective tool to prevent rabies in humans. Our main objective was to review research articles on the parenteral dog rabies vaccination coverage in Africa. We aimed to review published research articles on percentage of dogs owned and percentage of dogs vaccinated against rabies, and on the relation between vaccination coverage and cost recovery. We followed the standard procedures of a systematic literature review resulting in a final review of 16 scientific articles. Our review results indicate that only a small percentage of African dogs is ownerless. Puppies younger than 3 months of age constitute a considerable proportion of the African dog population. There are considerably more male dogs than female dogs present within the dog population. The dog rabies parenteral vaccination coverage following a “free of charge” vaccination scheme (68%) is closer to World Health Organization recommended threshold coverage rate (70%) compared to the coverage rate achieved in “owner-charged” dog rabies vaccination schemes (18%). In conclusion, most dogs in Africa are owned and accessible for vaccination once the necessary financial arrangements have been made.