Comparing Sight-Resight Methods for Dog Populations: Analysis of 2015 and 2016 Rabies Vaccination Campaign Data from Haiti

INTRODUCTION: Sight-resight studies are performed to estimate population sizes, in this case dog populations in rabies endemic areas. AIM: This study compares one- and two-day sight-resight methods with two-day as the standard to explore the feasibility and accuracy of the one-day method in different vaccination campaign strategies and dog population characteristics. METHODS: 2015 household survey data and sight-resight data are analyzed to find the percentage of free roaming and confined dogs in the community and use those to adjust the population estimate formulas. 2016 sight-resight data are analyzed as a two-day campaign and as if it had been a one-day campaign. In a sensitivity analysis, confidence intervals are explored in relation to vaccination coverage. RESULTS: Before missed mark and proportion free-roaming corrections, the one-day method results in slightly underestimated population estimates to the two-day method when the vaccination campaign is central point, overestimated when door-to-door, and far underestimated when capture, vaccinate, release. After corrections door-to-door estimates were accurate whereas central point and capture, vaccinate, release estimates substantially underestimated population sizes. DISCUSSION: Results suggest that the one-day mark-resight method could be used to conserve resources depending on the vaccination method and estimated coverage

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

Every Dog Has Its Data:Evaluation of a Technology-Aided Canine Rabies Vaccination Campaign to Implement a Microplanning Approach

Background: Robust dog vaccination coverage is the primary way to eliminate canine rabies. Haiti conducts annual canine mass vaccination campaigns, but still has the most human deaths in the Latin American and Caribbean region. We conducted an evaluation of dog vaccination methods in Haiti to determine if more intensive, data-driven vaccination methods, using smartphones for data reporting and geo-communication, could increase vaccination coverage to a level capable of disrupting rabies virus transmission.Methods: Two cities were designated into “Traditional” and “Technology-aided” vaccination areas. Traditional areas utilized historical methods of vaccination staff management, whereas Technology-aided areas used smartphone-supported spatial coordination and management of vaccination teams. Smartphones enabled real time two-way geo-communication between campaign managers and vaccinators. Campaign managers provided geographic instruction to vaccinators by assigning mapped daily vaccination boundaries displayed on phone handsets, whilst vaccinators uploaded spatial data of dogs vaccinated for review by the campaign manager to inform assignment of subsequent vaccination zones. The methods were evaluated for vaccination effort, coverage, and cost.Results: A total of 11,420 dogs were vaccinated during the 14-day campaign. The technology-aided approach achieved 80% estimated vaccination coverage as compared to 44% in traditional areas. Daily vaccination rate was higher in Traditional areas (41.7 vaccinations per team-day) compared to in technology-aided areas (26.8) but resulted in significantly lower vaccination coverages. The cost per dog vaccinated increased exponentially with the associated vaccination coverage, with a cost of $1.86 to achieve 25$2.51 for 50% coverage, and $3.19 for 70% coverage.Conclusions: Traditional vaccination methods failed to achieve sufficiently high vaccination coverages needed to interrupt sustained rabies virus transmission, whilst the technology-aided approach increased coverage above this critical threshold. Over successive campaigns, this difference is likely to represent the success or failure of the intervention in eliminating the rabies virus. Technology-aided vaccination should be considered in resource limited settings where rabies has not been controlled by Traditional vaccination methods. The use of technology to direct health care workers based on near-real-time spatial data from the field has myriad potential applications in other vaccination and public health initiatives

Characterizing Ebola Transmission Patterns Based on Internet News Reports

Background. Detailed information on patient exposure, contact patterns, and discharge status is rarely available in real time from traditional surveillance systems in the context of an emerging infectious disease outbreak. Here, we validate the systematic collection of Internet news reports to characterize epidemiological patterns of Ebola virus disease (EVD) infections during the West African 2014–2015 outbreak. Methods. Based on 58 news reports, we analyzed 79 EVD clusters (286 cases) ranging in size from 1 to 33 cases between January 2014 and February 2015 in Guinea, Sierra Leone, and Liberia. Results. The majority of reported exposures stemmed from contact with family members (57.3%) followed by hospitals (18.2%) and funerals (12.7%). Our data indicate that funeral exposure was significantly more frequent in Sierra Leone (27.3%) followed by Guinea (18.2%) and Liberia (1.8%; χ(2) test; P < .0001). Funeral exposure was the dominant route of transmission until April 2014 (60%) and was replaced with hospital exposure in June 2014–July 2014 (70%), both of which declined after interventions were put in place. The mean reproduction number of the outbreak was 2.3 (95% confidence interval [CI], 1.8, 2.7). The case fatality rate was estimated at 74.4% (95% CI, 68.3, 79.8). Conclusions. Overall, our findings based on news reports are in close agreement with those derived from traditional epidemiological surveillance data and with those reported for prior outbreaks. Our findings support the use of real-time information from trustworthy news reports to provide timely estimates of key epidemiological parameters that may be hard to ascertain otherwise

Determining the post-elimination level of vaccination needed to prevent re-establishment of dog rabies.

BackgroundOnce a canine rabies-free status has been achieved, there is little guidance available on vaccination standards to maintain that status. In areas with risk of reintroduction, it may be practical to continue vaccinating portions of susceptible dogs to prevent re-establishment of canine rabies.MethodsWe used a modified version of RabiesEcon, a deterministic mathematical model, to evaluate the potential impacts and cost-effectiveness of preventing the reintroduction of canine rabies through proactive dog vaccination. We analyzed four scenarios to simulate varying risk levels involving the reintroduction of canine rabies into an area where it is no longer present. In a sensitivity analysis, we examined the influences of reintroduction frequency and intensity, the density of susceptible dog population, dog birth rate, dog life expectancy, vaccine efficacy, rate of loss of vaccine immunity, and the basic reproduction number (R0).ResultsTo prevent the re-establishment of canine rabies, it is necessary to vaccinate 38% to 56% of free-roaming dogs that have no immunity to rabies. These coverage levels were most sensitive to adjustments in R0 followed by the vaccine efficacy and the rate of loss of vaccine immunity. Among the various preventive vaccination strategies, it was most cost-effective to continue dog vaccination at the minimum coverage required, with the average cost per human death averted ranging from $257 to$398 USD.ConclusionsWithout strong surveillance systems, rabies-free countries are vulnerable to becoming endemic when incursions happen. To prevent this, it may be necessary to vaccinate at least 38% to 56% of the susceptible dog population depending on the risk of reintroduction and transmission dynamics

Rabies post-exposure healthcare-seeking behaviors and perceptions: Results from a knowledge, attitudes, and practices survey, Uganda, 2013.

BackgroundRabies is a viral disease of animals and people causing fatal encephalomyelitis if left untreated. Although effective pre- and post-exposure vaccines exist, they are not widely available in many endemic countries within Africa. Since many individuals in these countries remain at risk of infection, post-exposure healthcare-seeking behaviors are crucial in preventing infection and warrant examination.MethodologyA rabies knowledge, attitudes, and practices survey was conducted at 24 geographically diverse sites in Uganda during 2013 to capture information on knowledge concerning the disease, response to potential exposure events, and vaccination practices. Characteristics of the surveyed population and of the canine-bite victim sub-population were described. Post-exposure healthcare-seeking behaviors of canine-bite victims were examined and compared to the related healthcare-seeking attitudes of non-bite victim respondents. Wealth scores were calculated for each household, rabies knowledge was scored for each non-bitten survey respondent, and rabies exposure risk was scored for each bite victim. Logistic regression was used to determine the independent associations between different variables and healthcare-seeking behaviors among canine-bite victims as well as attitudes of non-bitten study respondents.ResultsA total of 798 households were interviewed, capturing 100 canine-bite victims and a bite incidence of 2.3 per 100 person-years. Over half of bite victims actively sought medical treatment (56%), though very few received rabies post-exposure prophylaxis (3%). Bite victims who did not know or report the closest location where PEP could be received were less likely to seek medical care (p = 0.05). Respondents who did not report having been bitten by a dog with higher knowledge scores were more likely to respond that they would both seek medical care (p = 0.00) and receive PEP (p = 0.06) after a potential rabies exposure event.ConclusionsThere was varying discordance between what respondents who did not report having been bitten by a dog said they would do if bitten by a dog when compared to the behaviors exhibited by canine-bite victims captured in the KAP survey. Bite victims seldom elected to wash their wound or receive PEP. Having lower rabies knowledge was a barrier to theoretically seeking care and receiving PEP among not bitten respondents, indicating a need for effective and robust educational programs in the country

Initial pen and field assessment of baits to use in oral rabies vaccination of Formosan ferret-badgers in response to the re-emergence of rabies in Taiwan

<div><p>Background</p><p>Taiwan had been considered rabies free since 1961, until a newly established wildlife disease surveillance program identified rabies virus transmission within the Formosan ferret-badger (<i>Melogale moschata subaurantiaca</i>) in 2013. Ferret-badgers occur throughout southern China and Southeast Asia, but their ecological niche is not well described.</p><p>Methodology/Principle findings</p><p>As an initial feasibility assessment for potential rabies control measures, field camera trapping and pen assessment of 6 oral rabies vaccine (ORV) baits were conducted in Taiwan in 2013. 46 camera nights were recorded; 6 Formosan ferret-badgers and 14 non-target mammals were sighted. No baits were consumed by ferret-badgers and 8 were consumed by non-target mammals. Penned ferret-badgers ingested 5 of the 18 offered baits. When pen and field trials were combined, and analyzed for palatability, ferret-badgers consumed 1 of 9 marshmallow baits (11.1%), 1 of 21 fishmeal baits (4.8%), 0 of 3 liver baits, and 3 of 3 fruit-flavored baits. It took an average of 261 minutes before ferret-badgers made oral contact with the non-fruit flavored baits, and 34 minutes for first contact with the fruit-based bait. Overall, ferret-badgers sought out the fruit baits 8 times faster, spent a greater proportion of time eating fruit baits, and were 7.5 times more likely to have ruptured the vaccine container of the fruit-based bait.</p><p>Conclusions/Significance</p><p>Ferret-badgers are now recognized as rabies reservoir species in China and Taiwan, through two independent ‘dog to ferret-badger’ host-shift events. Species of ferret-badgers can be found throughout Indochina, where they may be an unrecognized rabies reservoir. Findings from this initial study underscore the need for further captive and field investigations of fruit-based attractants or baits developed for small meso-carnivores. Non-target mammals’ competition for baits, ants, bait design, and dense tropical landscape represent potential challenges to effective ORV programs that will need to be considered in future studies.</p></div

Ferret-badger photographed at field camera site.

<p>Ferret-badger photographed at field camera site.</p