Divergent Rabies Virus Variant of Probable Bat Origin in 2 Gray Foxes, New Mexico, USA.

In the Western Hemisphere, bat-associated rabies viruses (RABVs) have established independent transmission cycles in multiple mammal hosts, forming genetically distinct lineages. In New Mexico, USA, skunks, bats, and gray foxes are rabies reservoir hosts and represent a public health risk because of encounters with humans. During 2015 and 2019, two previously undescribed RABVs were detected in 2 gray foxes (Urocyon cinereoargenteus) in Lincoln County, New Mexico. Phylogenetic analysis of the nucleoprotein gene indicated that the isolates are a novel RABV variant. These 2 cases probably represent repeated spillover events from an unknown bat reservoir to gray foxes. Molecular analysis of rabies cases across New Mexico identified that other cross-species transmission events were the result of viral variants previously known to be enzootic to New Mexico. Despite a robust rabies public health surveillance system in the United States, advances in testing and surveillance techniques continue to identify previously unrecognized zoonotic pathogens.

Translocation of a Stray Cat Infected with Rabies from North Carolina to a Terrestrial Rabies-Free County in Ohio, 2017.

On July 24, 2017, the Ohio Department of Health (ODH) was notified of a positive rabies test result from a domestic cat in Summit County, a county considered free from terrestrial rabies. Oral rabies vaccination (ORV) of raccoons, in the form of consumable bait, is conducted each year along the Ohio-Pennsylvania border to prevent the westward expansion of the raccoon rabies virus variant (RVV). In the United States, several distinct rabies virus variants exist; raccoon RVV is enzootic along the eastern parts of the United States (from Florida to Maine), including several counties in northeast Ohio (1). Animal rabies vaccination is protective against all rabies virus variants. The rabid cat (cat A) was located west of the ORV barrier, raising concern that it had acquired the infection from a raccoon and suggesting a possible breach in the ORV barrier (Figure 1). ODH initiated an investigation to identify persons and animals exposed to the rabid cat during its viral shedding period and collaborated with CDC to determine the likely origin of the virus (Figure 2). Public health investigators later discovered that the cat originated in North Carolina. Phylogenetic analysis confirmed that the virus was most similar to the raccoon RVV that circulates in North Carolina (Figure 3); therefore, this ORV breach was likely the result of human-mediated movement of a rabid animal rather than natural expansion of the raccoon rabies virus enzootic area. This report summarizes the investigation and highlights the importance of owner compliance regarding rabies vaccination.

Rabies in a Dog Imported from Egypt - Connecticut, 2017.

In 2007, the United States successfully eliminated canine rabies virus variant. Globally, however, dogs remain the principal source of human rabies infections. Since 2007, three cases of canine rabies virus variant were reported in dogs imported into the United States, one each from India (2007), Iraq (2008), and Egypt (2015) (1-3). On December 20, 2017, a dog imported into the United States from Egypt was identified with rabies, representing the second case from Egypt in 3 years. An Egyptian-based animal rescue organization delivered four dogs from Cairo, Egypt, to a flight parent (a person solicited through social media, often not affiliated with the rescue organization, and usually compensated with an airline ticket), who transported the dogs to the United States. The flight parent arrived at John F. Kennedy International Airport (JFK) in New York City and, via transporters (persons who shuttle dogs from one state to another), transferred the dogs to foster families; the dogs ultimately were adopted in three states. The Connecticut Department of Public Health Laboratory (CDPHL) confirmed the presence of a canine rabies virus variant in one of the dogs, a male aged 6 months that was adopted by a Connecticut family. An investigation revealed the possibility of falsified rabies vaccination documentation presented on entry at JFK, allowing the unvaccinated dog entry to the United States. This report highlights the continuing risk posed by the importation of dogs inadequately vaccinated against rabies from high-risk countries and the difficulties in verifying any imported dog's health status and rabies vaccination history.

Human Rabies - Wyoming and Utah, 2015.

In September 2015, a Wyoming woman was admitted to a local hospital with a 5-day history of progressive weakness, ataxia, dysarthria, and dysphagia. Because of respiratory failure, she was transferred to a referral hospital in Utah, where she developed progressive encephalitis. On day 8 of hospitalization, the patient's family told clinicians they recalled that, 1 month before admission, the woman had found a bat on her neck upon waking, but had not sought medical care. The patient's husband subsequently had contacted county invasive species authorities about the incident, but he was not advised to seek health care for evaluation of his wife's risk for rabies. On October 2, CDC confirmed the patient was infected with a rabies virus variant that was enzootic to the silver-haired bat (Lasionycteris noctivagans). The patient died on October 3. Public understanding of rabies risk from bat contact needs to be improved; cooperation among public health and other agencies can aid in referring persons with possible bat exposure for assessment of rabies risk.

Rabies in a Dog Imported from Egypt with a Falsified Rabies Vaccination Certificate--Virginia, 2015.

Canine rabies virus variant has been eliminated in the United States and multiple other countries. Globally, however, dogs remain the principal source for human rabies infections. The World Health Organization recommends that when dogs cross international borders, national importing authorities should require an international veterinary certificate attesting that the animal did not show signs of rabies at the time of shipment, was permanently identified, vaccinated, or revaccinated, and had been subjected to a serologic test for rabies before shipment. On June 8, 2015, an adult female dog that had recently been picked up from the streets of Cairo, Egypt, and shipped by a U.S. animal rescue organization to the United States was confirmed to have rabies by the Virginia Department of General Services Division of Consolidated Laboratory Services (DCLS). This dog was part of a large shipment of dogs and cats from Egypt that rescue organizations had distributed to multiple states for adoption. During the investigation, public health officials learned that the rabies vaccination certificate used for entry of the rabid dog into the United States had intentionally been falsified to avoid exclusion of the dog from entry under CDC's current dog importation regulations. This report underscores the ongoing risk posed by U.S. importation of domestic animals that have not been adequately vaccinated against rabies.

Reemergence of a Big Brown Bat Lyssavirus rabies Variant in Striped Skunks in Flagstaff, Arizona, USA, 2021-2023.

Background: Throughout the Americas, Lyssavirus rabies (RV) perpetuates as multiple variants among bat and mesocarnivore species. Interspecific RV spillover occurs on occasion, but clusters and viral host shifts are rare. The spillover and host shift of a big brown bat (Eptesicus fuscus) RV variant Ef-W1 into mesocarnivores was reported previously on several occasions during 2001-2009 in Flagstaff, Arizona, USA, and controlled through rabies vaccination of target wildlife. During autumn 2021, a new cluster of Ef-W1 RV cases infecting striped skunks (Mephitis mephitis) was detected from United States Department of Agriculture enhanced rabies surveillance in Flagstaff. The number of Ef-W1 RV spillover cases within a short timeframe suggested the potential for transmission between skunks and an emerging host shift. Materials and Methods: Whole and partial RV genomic sequencing was performed to evaluate the phylogenetic relationships of the 2021-2023 Ef-W1 cases infecting striped skunks with earlier outbreaks. Additionally, real-time reverse-transcriptase PCR (rtRT-PCR) was used to opportunistically compare viral RNA loads in brain and salivary gland tissues of naturally infected skunks. Results: Genomic RV sequencing revealed that the origin of the 2021-2023 epizootic of Ef-W1 RV was distinct from the multiple outbreaks detected from 2001-2009. Naturally infected skunks with the Ef-W1 RV showed greater viral RNA loads in the brain, but equivalent viral RNA loads in the mandibular salivary glands, compared to an opportunistic sample of skunks naturally infected with a South-Central skunk RV from northern Colorado, USA. Conclusion: Considering a high risk for onward transmission and spread of the Ef-W1 RV in Flagstaff, public outreach, enhanced rabies surveillance, and control efforts, focused on education, sample characterization, and vaccination, have been ongoing since 2021 to mitigate and prevent the spread and establishment of Ef-W1 RV in mesocarnivores.

Comparing the genetic typing methods for effective surveillance and rabies control in Georgia.

A full nucleoprotein gene sequencing of 68 isolates collected from passive rabies surveillance system in Georgia between 2015 and 2016 identified two distinct dog rabies phylogroups, GEO_V1 and GEO_V2, which both belonged to the cosmopolitan dog clade. GEO_V1 was found throughout the country and was further divided into four sub-phylogroups that overlapped geographically; GEO_V2 was found in the southeast region and was closely related to dog rabies in Azerbaijan. A sequence analysis of the full N gene, partial nucleoprotein gene of N-terminal and C-terminal, and the amplicon sequences of pan-lyssavirus RT-qPCR LN34 showed that all four sequencing approaches provided clear genetic typing results of canine rabies and could further differentiate GEO_V1 and GEO_V2. The phylogenetic analysis results vary and were affected by the length of the sequences used. Amplicon sequencing of the LN34 assay positive samples provided a rapid and cost-effective method for rabies genetic typing, which is important for improving rabies surveillance and canine rabies eradication globally.

Ecological and anthropogenic drivers of rabies exposure in vampire bats: implications for transmission and control.

Despite extensive culling of common vampire bats in Latin America, lethal human rabies outbreaks transmitted by this species are increasingly recognized, and livestock rabies occurs with striking frequency. To identify the individual and population-level factors driving rabies virus (RV) transmission in vampire bats, we conducted a longitudinal capture-recapture study in 20 vampire bat colonies spanning four regions of Peru. Serology demonstrated the circulation of RV in vampire bats from all regions in all years. Seroprevalence ranged from 3 to 28 per cent and was highest in juvenile and sub-adult bats. RV exposure was independent of bat colony size, consistent with an absence of population density thresholds for viral invasion and extinction. Culling campaigns implemented during our study failed to reduce seroprevalence and were perhaps counterproductive for disease control owing to the targeted removal of adults, but potentially greater importance of juvenile and sub-adult bats for transmission. These findings provide new insights into the mechanisms of RV maintenance in vampire bats and highlight the need for ecologically informed approaches to rabies prevention in Latin America.