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Wildlife rabies has been well controlled in Israel due to regular oral rabies vaccine (ORV) campaigns targeting the primary rabies reservoirs, red foxes (Vulpes vulpes) and golden jackals (Canis aureus). During 2017, a rabies outbreak was detected in golden jackals in the Jezreel and Hama'ayanot Valleys covering approximately 500 km2 area in Israel's Northern District. From October 2017 to March 2018, 68 of 93 (73%) reported rabies cases were golden jackals and the majority were juveniles of less than 1 year of age. Unusually high jackal population densities in the region (>80 animals/km2), with a large proportion of juveniles born after the autumn ORV campaign, fueled the outbreak to a peak of 19 reported cases during January 2018. Two high-density ORV campaigns (one during October 2017 and another during March 2018) targeted jackal habitat with bait densities up to 200 baits/km2. In addition to routine November and January baiting cycles, additional ORV baits were deployed during the summer months (July-October) to increase bait uptake by the unvaccinated juveniles. Due to an abundance of aquaculture in the area, bait acceptance studies were performed to confirm sufficient vaccine uptake. As high ambient temperatures conditions are common in the outbreak area, thermostability studies were conducted prior to these campaigns to determine whether the vaccinia-vectored recombinant oral vaccine was suitable for use under extreme weather conditions. Geographically and demographically targeted ORV distribution, paired with population control through focused culling, followed by enhanced rabies surveillance and rapid laboratory testing of suspect wildlife cases, contributed to rapid outbreak control by late March 2018. [ABSTRACT FROM AUTHOR]

Raccoon rabies virus (RRV) has been managed using multiple vaccination strategies, including oral rabies vaccination and trap-vaccinate-release (TVR). Identifying a rabies vaccination strategy for an area is a nontrivial task. Vaccination strategies differ in the amount of effort and monetary costs required to achieve a particular level of vaccine seroprevalence (efficiency). Simulating host movement relative to different vaccination strategies in silico can provide a useful tool for exploring the efficiency of different vaccination strategies. We refined a previously developed individual-based model of raccoon movement to evaluate vaccination strategies for urban Hamilton, Ontario, Canada. We combined different oral rabies vaccination baiting (hand baiting, helicopter, and bait stations) with TVR strategies and used GPS data to parameterize and simulate raccoon movement in Hamilton. We developed a total of 560 vaccination strategies, in consultation with the Ontario Ministry of Natural Resources and Forestry, for RRV control in Hamilton. We documented the monetary costs of each vaccination strategy and estimated the population seroprevalence. Intervention costs and seroprevalence estimates were used to calculate the efficiency of each strategy to meet targets set for the purpose of RRV control. Estimated seroprevalence across different strategies varied widely, ranging from less than 5% to more than 70%. Increasing bait densities (distributed using by hand or helicopter) led to negligible increase in seroprevalence. Helicopter baiting was the most efficient and TVR was the least efficient, but helicopter-based strategies led to lower levels of seroprevalence (6–12%) than did TVR-based strategies (17–70%). Our simulations indicated that a mixed strategy including at least some TVR may be the most efficient strategy for a local urban RRV control program when seroprevalence levels >30% may be required. Our simulations provide information regarding the efficiency of different vaccination strategies for raccoon populations, to guide local RRV control in urban settings. [ABSTRACT FROM AUTHOR]

The small Indian mongoose is an invasive pest species and rabies reservoir in Puerto Rico and other islands in the Caribbean. In the United States and Europe, rabies in wild carnivores is largely controlled through oral rabies vaccination (ORV), but no ORV program for mongooses exists. The oral rabies vaccine currently licensed for use in wild carnivores in the United States has not been reported as immunogenic for mongooses. A mongoose-specific bait has been developed but field-based bait flavor preference trials have not been performed in Puerto Rico. We evaluated removal of egg-flavored (treatment) vs. unflavored (control), water-filled placebo ORV baits in a subtropical dry forest in southwestern Puerto Rico from 2014-2015. During six trials at four plots we distributed 350 baits (175 treatment and 175 control) and monitored baits for five days or until at least 50% of baits had been removed or were rendered unavailable to mongooses due to inundation by fire ants. The estimated overall probability of bait removal within five days was 85% (95% CI 75-91%) and 45% (95% CI 35-55%) for treatment and control baits, respectively. Removal rate estimates in the spring were 95% (95% CI 86-98%) and 63% (95% CI 49-76%) for treatment and control baits, respectively. Removal rate estimates in autumn were 68% (95% CI 58-77%) and 30% (95% CI 22-39%) for treatment and controls, respectively. Model estimates suggest that treatment and season were more influential on bait removal rates than diel period or experimental day, although bait removal rates were higher at night than during the day, suggesting non-target bait removal by nocturnal rodents. Our results suggest that egg-flavored baits were preferred by mongooses over unflavored baits. During operational ORV bait application, non-target bait removal should be taken into consideration when calculating bait application rates.

Black rats are among the world’s most invasive rodent species and are responsible for considerable agricultural losses and risks to human health through zoonotic disease. In Puerto Rico, rats may also compete with the primary rabies reservoir (the small Indian mongoose) for baits during oral rabies vaccination (ORV) programs. We evaluated black rat population density and home range size on the Cabo Rojo National Wildlife Refuge, southwestern Puerto Rico. We fitted 10 rats with VHF transmitters and tracked them using radio telemetry for approximately 4 weeks. We entered locations into ArcGIS and obtained minimum convex polygon (MCP) home range estimates. We established two plots of 55 snap traps and performed removal for 5 consecutive days during January and July, to correspond roughly with wet and dry seasons for this region. To calculate abundance, we entered snap trap data using a removal model approach in Program MARK. We calculated the effective trapping area by creating a buffer around the trapping area based on the square root of mean home range estimate. We divided the abundance calculated in MARK by the effective trapping area to calculate the estimated population density. Mean MCP home range estimate was 0.28 ha (SE: 0.05, range: 0.07-0.50 ha). Population density estimates were 114.7 (SE: 201.80) and 19.3 (SE: 6.85) per ha for January and July, respectively. To reduce the potential for rat consumption of ORV baits, wildlife managers should consider conducting ORV activities in Puerto Rico during periods of lower rat abundance or density.

Over the last few decades, Oral Rabies Vaccinations (ORV) has eliminated sylvatic rabies from most of Central andWestern Europe. Despite this success, they will probably be needed in the near future, due to the expansion of native and invasive reservoirs. It is unclear if they still work, at this time when many countries have an abundant wild boar population and complex assemblages of mammals. The ORV boasts a non-invasive and socially acceptable approach, but it presents some critical issues that we have analyzed in our study. Between November 2011 and March 2015, a total of 249 Rabigen® SAG2 VIRBAC baits were positioned on the ground at 5 sites in the study area. Baits were monitored by weekly inspections of camera traps. Overall, 63.4% of baits were found to have been worn after one week, mostly due to rainy weather, and had to be replaced. Remaining baits lasted on the field 3.66±1.07 days and 54.4% of them were consumed by wild boar (Sus scrofa). Our data highlight how a potential reservoir species such as the grey wolf did not ingest the vaccine baits while only few were taken by red fox, due to numerous competitors, especially wild boar. Findings raise doubts about the effectiveness of ORV in areas of Europe characterized by the presence of non-target species, particularly wild boar. The rising number in wild boar populations around Europe could seriously reduce baits presence in the environment, limiting their effectiveness. Future ORV campaigns against re-emerging rabies in Europe should either account for bait loss, or experiment with targeted forms of bait distribution, that prevent their uptake by non-target species. [ABSTRACT FROM AUTHOR]

Targeted surveillance for raccoon rabies virus was conducted between February and May 2017, near Waweig, New Brunswick, Canada, in response to detection of a rabid striped skunk (Mephitis mephitis) on 8 February 2017. A total of six skunks, 11 raccoons (Procyon lotor), and two porcupines (Erethizon dorsatum) were live-trapped, euthanized, and tested for rabies virus antigens using the direct rapid immunohistochemical test. Of these, only two skunks tested positive for rabies. All three rabid skunks came from the same location, an abandoned barn used as a denning site. Four of five skunks removed from this barn were males. Feeding, aggression, extreme response to noise and light stimuli, and exposure to porcupine quills were observed in two rabid skunks. No additional cases of rabies in wildlife were detected in the area since 8 March 2017. A targeted surveillance approach that removed potentially infected wildlife followed by localized oral rabies vaccine distribution was implemented in this locality. [ABSTRACT FROM AUTHOR]

During 2016-2017, three rabid terrestrial animals were discovered in the raccoon rabies virus-free zone of Long Island, New York, USA. Whole-genome sequencing and phylogenetic analyses revealed the likely origins of the viruses, enabling the rabies outbreak response (often costly and time-consuming) to be done less expensively and more efficiently. [ABSTRACT FROM AUTHOR]

The small Indian mongoose (Herpestes auropunctatus) is a rabies reservoir in areas of the Caribbean including Puerto Rico, but no rabies vaccination program targeting this host exists. We used two derivatives of iophenoxic acid (IPA) to evaluate placebo oral rabies vaccine bait uptake by mongooses in southwestern Puerto Rico. We hand-distributed baits at an application rate of 200 baits/km2 at three, 400 ha, sites during autumn 2016 and spring 2017. Each site contained 90–100 cage traps in a 100 ha central trapping area. We used ethyl-IPA as a biological marker during the autumn and methyl-IPA during the spring. We live captured mongooses for 10 consecutive days, beginning 1 wk following bait application. We obtained a serum sample from captured mongooses and analyzed the sera for ethyl- and methyl-IPA by liquid chromatography-mass spectrometry. During autumn 2016, 63% (55/87) mongooses sampled were positive for ethyl-IPA. In spring 2017, 69% (85/123) of mongooses were positive for methyl-IPA. Pooling seasons, accounting for recaptures between years, and disregarding marker type, 74% (133/179) unique mongooses were positive for IPA biomarker, indicating bait consumption during either the autumn, spring, or both trials. We conclude that distributing baits at an application rate of 200 baits/km2 is sufficient to reach over 60% of the target mongoose population in dry forest habitats of Puerto Rico. [ABSTRACT FROM AUTHOR]

USDA APHIS Wildlife Services has been a primary cooperator in the Cape Cod Oral Rabies Vaccination Program (CCORVP) in southeastern Massachusetts since 2001. The CCORVP (1994 - present) was originally designed to reduce the incidence of terrestrial rabies adjacent to the Cape Cod Canal in order to prevent its spread on to peninsular Cape Cod. However, since the barrier breach in 2004, CCORVP is now focused on rabies control in this coastal resort area southeast of Boston, MA. An integral component of wildlife rabies management is oral vaccination with vaccine-laden baits. Consequently, maximizing bait uptake rates is critical to achieving sufficient population immunity to reduce rabies prevalence and achieve control. To that end, knowledge of raccoon food habits, especially at ORV bait delivery times (spring and fall on Cape Cod) is crucial. We undertook a study of raccoon food selection in southeastern Massachusetts to assess the presence of and interest in competing food resources. We collected intact stomachs from raccoons found dead or euthanized for rabies testing within the CCORVP zone during 2006 (n = 33) and 2007 (n = 109) for analysis. Stomach contents were dominated by vegetation (80%), followed by invertebrates (43%), non-food items (41%), vertebrates (35%), and hair (primarily raccoon based on appearance) (15%). Food item occurrence appears to be related to age. We present findings, potential management implications, and suggestions for assessing food use related to rabies control in other locations.

Rabies remains a globally significant zoonotic disease, but rabies control is achievable under certain circumstances. Canine rabies has been eliminated from the U.S.; however, approximately 55,000 humans die annually worldwide from the disease. In the U.S., economic losses continue to be substantial and the risk to humans and domestic animals has not been eliminated. As an example of the complexity of rabies management, we describe a local rabies control program and efforts to restore Cape Cod, MA to terrestrial rabies-free status, after a 2004 oral rabies vaccination (ORV) barrier breach following 10 years of rabies-free status. The emergence of raccoon rabies in southeastern New England in 1992 prompted the U.S. Centers for Disease Control and Prevention, the Tufts Cummings School of Veterinary Medicine, and the Massachusetts Department of Public Health to begin an ORV program to reduce the occurrence of carnivore rabies in an area directly adjacent to the Cape Cod Canal. In 2001, USDA APHIS Wildlife Services began full-time collaboration on the Cape Cod Oral Rabies Vaccination Program (CCORVP) as part of national wildlife rabies control efforts. The primary objective of the CCORVP was to use ORV in tandem with the physical barrier created by the Canal to prevent the spread of rabies to peninsular Cape Cod, a heavily-populated tourist destination southeast of Boston. After an increase in rabies cases within the traditional Cape Cod ORV zone, ORV bait distribution efforts were modified to reduce the risk of rabies spread onto the Cape. In spite of these modifications, raccoon rabies was detected for the first time on peninsular Cape Cod in March 2004. A trap-vaccinate-release campaign, removal of suspect raccoons and skunks, and expanded ORV efforts were unsuccessful in preventing the spread of the virus. Rabies surveillance became the priority of the Cape Cod Rabies Task Force. In 2006, rabies was finally detected at the eastern extremity of the peninsula. In this paper, we summarize ORV efforts, explore possible causes for the spread of raccoon rabies onto the Cape, summarize several small-scale Cape Cod rabies research projects, and suggest a 5-year plan for future Cape Cod rabies controls efforts.

This paper describes issues and concepts relevant to economic modeling of oral rabies vaccination (ORV) campaigns for managing wildlife rabies. Economic models of ORV are mathematical expressions used to predict and draw inferences about the costs and savings likely to be recouped by these rabies management efforts. Costs that are prevented due to ORV campaigns convert to savings. Comparison of campaign duration, bait cost, bait density, and bait distribution data for North American ORV campaigns showed that: 1) campaigns are lengthy, 2) those involving raccoons entail greater bait densities (i.e., related bait costs) and per unit area bait-distribution costs than those involving foxes and coyotes, and 3) all entail “enhanced” surveillance and establishment of maintenance barriers (i.e., deter translocation or reintroduction of new cases) upon completion. Key modeling issues were: model parameterization, ORV cost variables (i.e., bait costs, bait densities, and unit area distribution costs), time horizon, contingency costs, and ORV host specificity.

A study was initiated in 2005 to examine the ecology of gray fox in Texas, to assist the oral rabies vaccination program. The study’s objectives are to examine space use and long-distance movements of radio-collared foxes, and to provide landscape-level ecological assessment of fox dispersal and the factors that influence it. Concurrently, GIS habitat layers being built will assist in understanding fox movement and gene flow.

Knowledge of the rate and extent of spread of epizootic diseases is critical to facilitate effective management. Terrestrial rabies was first detected in spring 2004 on Cape Cod Massachusetts, compromising a long-standing ORV zone established from the west side of the Cape Cod Canal to serve as a barrier to raccoon rabies spread onto the Cape. In March 2004, USDA Wildlife Services and local and state cooperators implemented a surveillance program to track the spread of rabies on Cape Cod for planning contingency action strategies aimed at containment and elimination. During 13 months of enhanced rabies surveillance, 198 (167 raccoons and 29 skunks) out of 942 specimens tested positive for rabies. We discuss management implications of these results to the Cape Cod Oral Rabies Vaccination program and to other integrated rabies control programs.

Knowledge of wildlife population abundance and activity patterns is integral to sound management decisions. Traditional methods of determining population abundance include mark-recapture, catch/unit effort, aerial and ground counts, and harvest-based or removal efforts. Capture methods are labor intensive and expensive. Census methods are potentially expensive and are often impractical for many wildlife species. Harvest-derived population estimates are not useful where harvest is limited. Tracking or scent stations have been used to index wildlife activity and abundance, but the use of traditional scented-tracking stations may lead to biased population activity or abundance estimates. We built on previous evaluations of passive and scented tracking stations to determine their potential utility for providing raccoon and other carnivore population information to support decisions for wildlife rabies control in coastal pine-oak communities. Methods were evaluated through several small-scale studies conducted in southeastern Massachusetts. Passive tracking stations appear more sensitive to raccoon activity than scented tracking stations (1.38% of scented stations visited vs. 3.38% of passive stations) under apparently low raccoon population densities. Despite concerns over the utility of track-based indices, we recommend the use of passive tracking stations to index raccoon activity over scented tracking stations.

Persistence of unique rabies virus variants in a diverse array of terrestrial carnivores and insectivorous bats makes rabies control in the U.S. a complex task. The public health system in the U.S. is effective in keeping human deaths near zero each year in the face of enzootic wildlife rabies, but the annual cost of coexistence with the disease is high, exceeding $300 million. In addition, each year tens of thousands of people are impacted by anxiety, fear, and trauma associated with potential or actual rabies exposure to themselves and their domestic animals. Exclusion, proper storage and disposal of garbage, and removal of problem animals are often effective alternatives to address wildlife rabies threats at specific sites; however, oral rabies vaccination (ORV) is the only currently available technique that shows promise for wildlife rabies control on a broad geographic and species scale. In this paper, we discuss progress toward using ORV to contain specific terrestrial rabies virus variants in the U.S. and planning towards coordinated national efforts to explore the elimination of terrestrial variants of rabies virus in the U.S.

The statistics of rabies cases in Volyn, Lviv, and Zakarpattia oblasts of Ukraine from 2012 to 2016 were analyzed to establish spatial–temporal distribution of rabies endemic outbreaks and to identify causes of widespread infections among wild and domestic animals. The occurrence of rabies outbreaks in wild and domestic animals in Ukraine was also assessed to determine the effectiveness of oral rabies vaccination (ORV) efforts. According to our analysis, parenteral vaccination of domestic animals and ORV campaigns in foxes have proved unsuccessful in providing a sustainable, long-term reduction in endemic rabies outbreaks. ORV campaigns in foxes were deemed ineffective based on our studies of the endemic rabies outbreaks in Volyn, Lviv, and Zakarpattia oblasts in 2012–2016. The current rabies prevention system (parenteral vaccination) failed to offer protection to domestic animals based on our review of the occurrence of endemic rabies outbreaks in dogs and cats. ORV campaign shortcomings and their causes must be identified in order to provide maximum rabies vaccine coverage for dogs and cats. Altogether, the results presented here provide information that can assist public health agencies to devise more effective disease control plans to curtail the spread of rabies in domestic animals and wildlife in Ukraine.

Oral rabies vaccination is the principal strategy used to control rabies in wildlife. No oral rabies vaccine is licensed for small Indian mongooses (Herpestes auropunctatus). The Ontario Rabies Vaccine Bait (ONRAB) is a human adenovirus type-5 rabies glycoprotein recombinant vaccine licensed for rabies control in striped skunks (Mephitis mephitis) in Canada and is under experimental evaluation in the US. We evaluated varying doses of ONRAB vaccine by direct instillation into the oral cavity with three groups of 10 mongooses: Group 1 received 109.5 TCID50, group 2 received 108.8 TCID50, and group 3 received 108.5 TCID50 of vaccine. Six control mongooses were sham-vaccinated with culture media. We collected a serum sample prior to vaccination and on days 14 and 30 postvaccination (PV). We quantified the level of rabies virus neutralizing antibodies (RVNA) from mongoose sera and compared titers among vaccinated groups and time points PV, where values greater than or equal to 0.1 IU/mL were considered positive. On day 14 PV, 87% (26 of 30, 95% confidence interval 70–95%) of vaccinates had seroconverted, whereas all vaccinates demonstrated RVNA by day 30 PV. There was a marginal effect of vaccine dose on group means of log-transformed RVNA titers at day 14 PV (F=2.5, P=0.099), but not day 30 PV. Sham-vaccinated animals were seronegative during all time points. [ABSTRACT FROM AUTHOR]

Oral rabies vaccination (ORV) campaigns have been conducted annually in the US over the past two decades to prevent raccoon (Procyon lotor) rabies, which is enzootic along the eastern region of the country from southeastern Canada to Alabama. Because raccoon rabies has been eliminated from neighboring Canadian provinces, continued detection of the variant in the US is of concern due to the potential for infected raccoons to cross the border via the St. Lawrence River. Ontario Rabies Vaccine Baits (ONRAB) containing a live, recombinant human adenovirus expressing the rabies virus glycoprotein have been under experimental use in the US since 2011. We distributed ONRAB in St. Lawrence County, New York, from 2013 to 2015 as part of field trials to evaluate serologic responses in raccoons. Prior to ONRAB distribution, rabies virus neutralizing antibody (RVNA) seroprevalence in raccoons was 45.2% (183 of 405) and increased to 57.7% (165 of 286) after 3 yr of ONRAB baiting. Postbait RVNA seroprevalence increased each year, with a lower response observed in juvenile compared with adult raccoons. The pre-ONRAB seroprevalence detected in 2013 was relatively high and was likely impacted both by elevated rabies activity in the county and the use of ORV with a different vaccine bait for 14 consecutive years prior to our study. Tetracycline biomarker prevalence increased from 1.4% prior to ONRAB baiting to 51.3% from 2013 to 2015, demonstrating bait palatability to raccoons. These data complemented related field trials conducted in West Virginia and the northeastern US. [ABSTRACT FROM AUTHOR]

Understanding howthe spatial deployment of interventions affects elimination time horizons and potential for disease re-emergence has broad application to control programmes targeting human, animal and plant pathogens. We previously developed an epidemiological model that captures the main features of rabies spread and the impacts of vaccination based on detailed records of fox rabies in eastern Germany during the implementation of an oral rabies vaccination (ORV) programme. Here, we use simulations from this fitted model to determine the best vaccination strategy, in terms of spatial placement and timing ofORVefforts, for three epidemiological scenarios representative of current situations in Europe. We found that consecutive and comprehensive twice-yearly vaccinations across all regions rapidly controlled and eliminated rabies and that the autumn campaigns had the greater impact on increasing the probability of elimination. This appears to result fromthe need to maintain sufficient herd immunity in the face of large birth pulses, as autumn vaccinations reach susceptible juveniles and therefore a larger proportion of the population than spring vaccinations. Incomplete vaccination compromised time to elimination requiring the same or more vaccination effort to meet similar timelines. Our results have important practical implications that could inform policies for rabies containment and elimination in Europe and elsewhere. [ABSTRACT FROM AUTHOR]

From 2014 to 2016, we examined the effect of distributing oral rabies vaccine baits at high density (150 baits/km2) in an area of Virginia, US that was naïve to oral rabies vaccination prior to the study. We also compared the effect of baiting at high density in a naïve area to baiting at standard density (75 baits/km2) in an area that had been baited annually for 12 yr. Our results suggested that rabies virus seroconversion in raccoons (Procyon lotor) gradually increased each year under the highdensity bait treatment. However, we did not detect a difference in seroconversion between bait density treatments. Virginia opossums (Didelphis virginiana) were abundant in the study area and were a potentially important nontarget species that competed for oral rabies vaccine baits, but the ratio of opossums to raccoons in this study did not affect rabies virus neutralizing antibody response of the raccoon populations. [ABSTRACT FROM AUTHOR]

Beginning in October 1988, Texas experienced an expanding epizootic of canine rabies, in South Texas, which now involves 21 counties where a total of 678 confirmed cases (50% in coyotes, the majority of the rest in domestic dogs, with 76 "spill-over" cases found in 7 other species). Some 2,000 persons have received post-exposure rabies treatment, and there have been 2 human fatalities. The Texas Department of Health has led the initiation of an experimental program to use an oral rabies vaccine, Raboral V-RG, over the next 4-5 years with the goal of pushing the epizootic southward and eliminating it from Texas. Success in reducing rabies during 1995, when 830,000 baits were distributed over 15,000 acres, is described. Data on bait uptake and immune status of coyotes are presented.

Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA.

In the US, rabies virus (RV) has been enzootic in raccoons (Procyon lotor) since the late 1940s. Oral rabies vaccination (ORV) was implemented in the 1990s to halt the spread of raccoon RV and continues to be used as a wildlife management tool. Our objective was to evaluate a recombinant human adenovirus–rabies virus glycoprotein vaccine in northern New York, Vermont, and New Hampshire over a 3-yr period, using changes in RV neutralizing antibody (RVNA) seroprevalence in raccoon populations as an immunologic index of ORV impact. Vaccine baits were distributed at 75 baits/km2 and 750-m flight-line spacing in the study area. Animal sampling occurred during 10-d intervals pre- and post-ORV during 2012–14 within eight study cells: four northern cells had a history of ORV with a different vaccine for 3 or more years prior and four southern cells were ORV naive. Baseline raccoon RVNA seroprevalence was 27.3% (n=1,079, 95% confidence interval [CI]: 24.8–30.1) before ORV in 2012. Raccoon RVNA seroprevalence averaged 68.5% (n=1,551, 95% CI: 66.2–70.8) post-ORV during the 3-yr study. The RVNA seroprevalence levels in this study were considered to be adequate for stopping raccoon RV transmission and supported and expanded the results from a West Virginia field trial, as well as earlier evaluations along the Canada–US border. [ABSTRACT FROM AUTHOR]

Endemic animal rabies causes >99% of all human rabies cases; elimination of animal rabies reduces the rate of human infections. The most recent animal rabies cases in the Gangwon and Gyeonggi provinces of Korea occurred in November 2012 and February 2013, respectively. Here we explore ways to ensure that Korea remains animal rabies non-occurrence. The government must prevent rabies recurrence by vaccinating dogs, distributing bait vaccine in regions with a high rabies risk, performing laboratory-based surveillance, preventing the flow of rabiessuspect animals from neighboring countries, and enhancing border quarantine. As has already been shown in several developed countries, careful and ongoing rabies control will allow Korea to remain animal rabies-free. [ABSTRACT FROM AUTHOR]

Background: 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 (Melogale moschata subaurantiaca) in 2013. Ferret-badgers occur throughout southern China and Southeast Asia, but their ecological niche is not well described. Methodology/Principle findings: 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. Conclusions/Significance: 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. [ABSTRACT FROM AUTHOR]

We evaluated the efficacy of an oral rabies vaccination (ORV) program conducted in Erie County, New York, from July through September, 2002–2005. Ingress of the raccoon (Procyon lotor) rabies variant first occurred along the southern border of Erie County, New York, during 1992 and began to spread northward at a velocity of 31 km/year. Fixed-wing aircraft dropped ORV baits in rural landscapes; helicopters, hand baiting, and bait stations distributed baits in suburban landscapes (x̄ bait densities ranged 59–118 baits/km2). Our study objectives were to quantify rabies case densities, evaluate efficacy of intervention efforts, and determine biological, census, geographical, and weather variables potentially affecting oral rabies vaccination of raccoons in Erie County. Overall, 16% and 9% of the raccoons in Erie County tested positive for virus-neutralizing antibodies (VNA) at the 0.125 and 0.5 international units (IU)/ml levels, respectively. We found no differences between baiting strategies and frequencies of antibody-positive raccoons. However, adult males generally consumed baits most often, and the probability of seropositivity increased with raccoon age. Seroprevalence of VNA differed among raccoon sex and age classes, and vaccination year. A post-hoc kernel density estimation of rabies-positive raccoons and skunks (Mephitis mephitis) from 1992– 2006 (n = 364) revealed clustering in northeastern Erie County. Our results should help ORV managers maximize limited resources.

The Centers for Disease Control (CDC) and USDA Wildlife Services (WS) have been involved in an oral rabies vaccination (ORV) program for raccoons (Procyon lotor) that has slowed the westward spread of raccoon rabies. The objective of this study was to forecast the spread of the disease if an ORV zone was not maintained. A group decision-making process was designed to address the forecasting problem and was implemented using a group of 15 experts and 4 support personnel at a meeting at the USDA National Wildlife Research Center. Ten expansion regions were constructed that described the spread of disease at 2-year intervals. This forecast may provide for more accurate cost-benefit analysis of the ORV barrier.

Progressive elimination of rabies in wildlife has been a general strategy in Canada and the United States; common campaign tactics are trap–vaccinate–release (TVR), point infection control (PIC), and oral rabies vaccination (ORV). TVR and PIC are labor intensive and the most expensive tactics per unit area (≈$616/km2 [in 2008 Can$, converted from the reported $450/km2 in 1991 Can$] and ≈$612/km2 [$500/km2 in 1999 Can$], respectively), but these tactics have proven crucial to elimination of raccoon rabies in Canada and to maintenance of ORV zones for preventing the spread of raccoon rabies in the United States. Economic assessments have shown that during rabies epizootics, costs of human postexposure prophylaxis, pet vaccination, public health, and animal control spike. Modeling studies, involving diverse assumptions, have shown that ORV programs can be cost-efficient and yield benefit:cost ratios >1.0.

Efforts to eliminate the raccoon variant of the rabies virus (raccoon rabies) in the eastern United States by USDA, APHIS, Wildlife Services and cooperators have included the distribution of oral rabies vaccine baits from polyvinyl chloride (PVC) bait stations in west-central Florida from 2009 to 2015. Achieving sufficient vaccine bait uptake among urban raccoons is problematic, given limitations on aerial and vehicle-based bait distribution for safety and other reasons. One or three bait stations/km2 were deployed across four 9-km2 sites within rural and urban sites in Pasco and Pinellas Counties, Florida. Based on tetracycline biomarker analysis, bait uptake was only significantly different among the urban (Pinellas County) high and low bait station densities in 2012 (p = 0.0133). Significant differences in RVNA were found between the two bait station densities for both urban 2011 and 2012 samples (p = 0.0054 and p = 0.0031). Landscape differences in terms of urban structure and human population density may modify raccoon travel routes and behavior enough for these differences to emerge in highly urbanized Pinellas County, but not in rural Pasco County. The results suggest that, in urban settings, bait stations deployed at densities of >1/km2 are likely to achieve higher seroprevalence as an index of population immunity critical to successful raccoon rabies control.

Bait stations for distribution of oral rabies vaccine baits are designed for rabies management in highly-developed areas where traditional distribution of oral rabies vaccine baits may be difficult. As part of national efforts to contain and eliminate the raccoon (Procyon lotor) variant of the rabies virus (raccoon rabies) in the eastern United States, the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services program, distributed vaccine baits by bait stations experimentally and operationally in Massachusetts during 2006-present, and in Florida during 2009–2015. In Massachusetts, a rabies virus-neutralizing antibody (RVNA) response of 42.1% for raccoons captured in areas baited with high density bait stations during 2011–2015 was achieved, compared with 46.2% in areas baited by hand, suggesting the continuation of this as a strategy for the oral rabies vaccination (ORV) program there, and for similar locations. Non-target competition for vaccine baits is problematic, regardless of distribution method. In Massachusetts, bait station visitation rates for targeted raccoons and non-target opossums (Didelphis virginiana) were similar (1.18:1) during 2006–2009 (p > 0.05). Bait station modifications for reducing non-target uptake were tested, and in Massachusetts, reduced non-target bait access was achieved with two design alternatives (p < 0.001). However, no difference was noted between the control and these two alternative designs in Florida. Due to ongoing trials of new vaccines and baits, the bait station performance of an adenovirus rabies glycoprotein recombinant vaccine bait, ONRAB® bait (Artemis Technologies, Guelph, ON, Canada) and a vaccinia-rabies glycoprotein recombinant vaccine bait, RABORAL V-RG®bait (Merial Limited, Athens, GA, USA), was compared. While uptake of the ONRAB bait was greater in Massachusetts (p < 0.001) in this limited trial, both types performed equally well in Florida. Since bait station tampering or theft as well as potential human bait contacts has been problematic, performance of camouflaged versus unpainted white bait stations was analyzed in terms of internal temperatures and maintaining a stable bait storage environment. In Massachusetts, camouflaged bait station interiors did not reach higher average temperatures than plain white bait stations in partially- or fully-shaded locations, while in Florida, camouflaged bait stations were significantly warmer in light exposure categories (p < 0.05). As ORV operations expand into more heavily-urbanized areas, bait stations will be increasingly important for vaccine bait distribution, and continued refinements in the strategy will be key to that success.

Enhanced rabies surveillance (ERS) is essential for sound oral rabies vaccination (ORV) decisions to prevent the spread of specific rabies virus variants in meso-carnivores and to achieve disease elimination. Use of a direct rapid immunohistochemistry test (dRIT) in North America for timely, accurate rabies diagnosis in the field has facilitated greater ERS emphasis since 2005. ERS used in tandem with exposure-based public health surveillance provides a comprehensive understanding of the geographic distribution of rabies as an aid to formulate effective management strategies for raccoons and other meso-carnivores. In 2015, best management practices were implemented for improving, reinvigorating, and standardizing ERS. A point system for weighing ERS sample categories was evaluated, to determine whether sampling emphasis should be focused upon ill or strange-acting animals, the highest quality category. During 2016, 70.7% of rabid animals detected through ERS in raccoon rabies management states were obtained from strange-acting animals, followed by animals found dead (14.1%), road kills (9.1%), and nuisance-collected specimens (6.1%). Sample category weights may be adjusted based on additional evaluation to ensure continued emphasis on the highest value samples. High quality ERS, in conjunction with serologic evidence of population-based immunity, form the backbone for ORV decisions in the elimination of raccoon rabies.

The article provides information on a study which examined the safety and immunogenicity of a live, recombinant human adenovirus rabies virus glycoprotein vaccine in wild raccoons and skunks in rural West Virginia. Topics covered include a description of the study area, a discussion of the animal capture, handling and sampling performed and results of the rabies neutralizing antibodies (RVNA) determination.

The Centers for Disease Control (CDC) and USDA Wildlife Services (WS) have been involved in an oral rabies vaccination (ORV) program for raccoons (Procyon lotor) that has slowed the westward spread of raccoon rabies. The objective of this study was to forecast the spread of the disease if an ORV zone was not maintained. A group decision-making process was designed to address the forecasting problem and was implemented using a group of 15 experts and 4 support personnel at a meeting at the USDA National Wildlife Research Center. Ten expansion regions were constructed that described the spread of disease at 2-year intervals. This forecast may provide for more accurate cost-benefit analysis of the ORV barrier. [ABSTRACT FROM AUTHOR]

Despite perceived challenges to controlling an infectious disease in wildlife, oral rabies vaccination (ORV) of foxes has proved a remarkably successful tool and a prime example of a sophisticated strategy to eliminate disease from wildlife reservoirs. During the past three decades, the implementation of ORV programmes in 24 countries has led to the elimination of fox-mediated rabies from vast areas of Western and Central Europe. In this study, we evaluated the efficiency of 22 European ORV programmes between 1978 and 2010. During this period an area of almost 1.9 million km2 was targeted at least once with vaccine baits, with control taking between 5 and 26 years depending upon the country. We examined factors influencing effort required both to control and eliminate fox rabies as well as cost-related issues of these programmes. The proportion of land area ever affected by rabies and an index capturing the size and overlap of successive ORV campaigns were identified as factors having statistically significant effects on the number of campaigns required to both control and eliminate rabies. Repeat comprehensive campaigns that are wholly overlapping much more rapidly eliminate infection and are less costly in the long term. Disproportionally greater effort is required in the final phase of an ORV programme, with a median of 11 additional campaigns required to eliminate disease once incidence has been reduced by 90 per cent. If successive ORV campaigns span the entire affected area, rabies will be eliminated more rapidly than if campaigns are implemented in a less comprehensive manner, therefore reducing ORV expenditure in the longer term. These findings should help improve the planning and implementation of ORV programmes, and facilitate future decision-making by veterinary authorities and policy-makers. [ABSTRACT FROM AUTHOR]

The article presents a study which examined the variations in tetracycline biomarking used in the oral rabies vaccination (ORV) of Ohio raccoons. Its aim is to see whether tetracycline, a traditional index to bait uptake in ORV, serves well in this capacity. It conducted a tissue analysis of hunter-harvested Ohio raccoons where ORV had been conducted in 1998, 1999 and 2001 which showed that tetracycline marking was significantly different among all tissue types.

The article offers information on a study conducted by researchers Julien Mainguy from Ministere des ressources naturelles et de la Faune, Christine Fehlner-Gardiner from Centre of Expertise for Rabies and Dennis Slate from the U.S. Department of Agriculture to compare the performance of oral vaccine baits (OCBs) against rabies for raccoons from Quebec and Vermont. It examines the use of raccoon sera in the comparison of the OCBs Raboral V-RG and Onrab.

The article explores rabies antibody prevalence in wild-caught raccoons and striped skunks, Mephitis mephitis, and pinpoint factors influencing the probability of being antibody positive at the individual level in these species. Oral rabies vaccination campaigns have been conducted in which ONRAB vaccination baits were distributed in 2007-2009 in Quebec. The yearly percentages of antibody-positive raccoons and skunks varied between 35% and 56% and 11% and 17%, respectively.

In west-central Texas, USA, abatement efforts for the gray fox (Urocyon cinereoargenteus) rabies epizootic illustrate the difficulties inherent in large-scale management of wildlife disease. The rabies epizootic has been managed through a cooperative oral rabies vaccination program (ORV) since 1996. Millions of edible baits containing a rabies vaccine have been distributed annually in a 16-km to 24-km zone around the perimeter of the epizootic, which encompasses a geographic area .4 3 105 km2. The ORV program successfully halted expansion of the epizootic into metropolitan areas but has not achieved the ultimate goal of eradication. Rabies activity in gray fox continues to occur periodically outside the ORV zone, preventing ORV zone contraction and dissipation of the epizootic. We employed a landscape-genetic approach to assess gray fox population structure and dispersal in the affected area, with the aim of assisting rabies management efforts. No unique genetic clusters or population boundaries were detected. Instead, foxes were weakly structured over the entire region in an isolation by distance pattern. Local subpopulations appeared to be genetically non-independent over distances .30 km, implying that long-distance movements or dispersal may have been common in the region. We concluded that gray foxes in west-central Texas have a high potential for long-distance rabies virus trafficking. Thus, a 16-km to 24-km ORV zone may be too narrow to contain the fox rabies epizootic. Continued expansion of the ORV zone, although costly, may be critical to the long-term goal of eliminating the Texas fox rabies virus variant from the United States. [ABSTRACT FROM AUTHOR]

Hand-baiting and helicopter distribution are commonly used to distribute vaccine-laden baits to help control raccoon (Procyon lotor) rabies in suburban landscapes. These techniques can be labor intensive and costly. We designed and tested a polyvinyl chloride bait station as an alternative method to dispense the baits to raccoons. Our goal was to build an inexpensive, portable, and weather-resistant bait station that minimized nontarget species visitation. We tested the bait station over a 2-year period. We used infrared-triggered cameras (IRCs) to quantify animal visitation to bait stations. During the study IRCs provided 522 photographs of animals present at bait stations; 90.3% of all animals photographed were raccoons. In 2003 and 2004, approximately 4,651 (93 baits/km²) and 2,960 (59 baits/km²) baits were removed from the bait stations, respectively. We believe the bait stations could potentially replace or supplement hand-baiting and helicopter distribution as a cost-effective method for dispensing rabies vaccine to raccoons in suburban landscapes. [ABSTRACT FROM AUTHOR]

The case of an immunocompetent 3 and half-year-old girl who developed encephalitis and herpes zoster ophthalmicus 20 months after immunization with varicella-zoster virus vaccine is reported from Children's Hospital, Athens, Greece, and University College, London, UK.

Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA. [ABSTRACT FROM AUTHOR]