Showing papers by "Charles E. Rupprecht published in 2013"

New world bats harbor diverse influenza A viruses.

Abstract: Aquatic birds harbor diverse influenza A viruses and are a major viral reservoir in nature. The recent discovery of influenza viruses of a new H17N10 subtype in Central American fruit bats suggests that other New World species may similarly carry divergent influenza viruses. Using consensus degenerate RT-PCR, we identified a novel influenza A virus, designated as H18N11, in a flat-faced fruit bat (Artibeus planirostris) from Peru. Serologic studies with the recombinant H18 protein indicated that several Peruvian bat species were infected by this virus. Phylogenetic analyses demonstrate that, in some gene segments, New World bats harbor more influenza virus genetic diversity than all other mammalian and avian species combined, indicative of a long-standing host-virus association. Structural and functional analyses of the hemagglutinin and neuraminidase indicate that sialic acid is not a ligand for virus attachment nor a substrate for release, suggesting a unique mode of influenza A virus attachment and activation of membrane fusion for entry into host cells. Taken together, these findings indicate that bats constitute a potentially important and likely ancient reservoir for a diverse pool of influenza viruses.

Case Definitions, Diagnostic Algorithms, and Priorities in Encephalitis: Consensus Statement of the International Encephalitis Consortium

Abstract: Background Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research. Methods In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study. Results We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed. Conclusions We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

Abstract: Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors that promote zoonotic viral richness. More zoonotic viruses are hosted by species whose distributions overlap with a greater number of other species in the same taxonomic order (sympatry). Specifically in bats, there was evidence for increased zoonotic viral richness in species with smaller litters (one young), greater longevity and more litters per year. Furthermore, our results point to a new hypothesis to explain in part why bats host more zoonotic viruses per species: the stronger effect of sympatry in bats and more viruses shared between bat species suggests that interspecific transmission is more prevalent among bats than among rodents. Although bats host more zoonotic viruses per species, the total number of zoonotic viruses identified in bats (61) was lower than in rodents (68), a result of there being approximately twice the number of rodent species as bat species. Therefore, rodents should still be a serious concern as reservoirs of emerging viruses. These findings shed light on disease emergence and perpetuation mechanisms and may help lead to a predictive framework for identifying future emerging infectious virus reservoirs.

Bats are a major natural reservoir for hepaciviruses and pegiviruses

Abstract: Although there are over 1,150 bat species worldwide, the diversity of viruses harbored by bats has only recently come into focus as a result of expanded wildlife surveillance. Such surveys are of importance in determining the potential for novel viruses to emerge in humans, and for optimal management of bats and their habitats. To enhance our knowledge of the viral diversity present in bats, we initially surveyed 415 sera from African and Central American bats. Unbiased high-throughput sequencing revealed the presence of a highly diverse group of bat-derived viruses related to hepaciviruses and pegiviruses within the family Flaviridae. Subsequent PCR screening of 1,258 bat specimens collected worldwide indicated the presence of these viruses also in North America and Asia. A total of 83 bat-derived viruses were identified, representing an infection rate of nearly 5%. Evolutionary analyses revealed that all known hepaciviruses and pegiviruses, including those previously documented in humans and other primates, fall within the phylogenetic diversity of the bat-derived viruses described here. The prevalence, unprecedented viral biodiversity, phylogenetic divergence, and worldwide distribution of the bat-derived viruses suggest that bats are a major and ancient natural reservoir for both hepaciviruses and pegiviruses and provide insights into the evolutionary history of hepatitis C virus and the human GB viruses.

Discovery of diverse polyomaviruses in bats and the evolutionary history of the Polyomaviridae.

Abstract: Polyomaviruses (PyVs) have been identified in a wide range of avian and mammalian species. However, little is known about their occurrence, genetic diversity and evolutionary history in bats, even though bats are important reservoirs for many emerging viral pathogens. This study screened 380 specimens from 35 bat species from Kenya and Guatemala for the presence of PyVs by semi-nested pan-PyV PCR assays. PyV DNA was detected in 24 of the 380 bat specimens. Phylogenetic analysis revealed that the bat PyV sequences formed 12 distinct lineages. Full-genome sequences were obtained for seven representative lineages and possessed similar genomic features to known PyVs. Strikingly, this evolutionary analysis revealed that the bat PyVs were paraphyletic, suggestive of multiple species jumps between bats and other mammalian species, such that the theory of virus–host co-divergence for mammalian PyVs as a whole could be rejected. In addition, evidence was found for strong heterogeneity in evolutionary rate and potential recombination in a number of PyV complete genomes, which complicates both phylogenetic analysis and virus classification. In summary, this study revealed that bats are important reservoirs of PyVs and that these viruses have a complex evolutionary history.

Host–rabies virus protein–protein interactions as druggable antiviral targets

Abstract: We present an unconventional approach to antiviral drug discovery, which is used to identify potent small molecules against rabies virus. First, we conceptualized viral capsid assembly as occurring via a host-catalyzed biochemical pathway, in contrast to the classical view of capsid formation by self-assembly. This suggested opportunities for antiviral intervention by targeting previously unappreciated catalytic host proteins, which were pursued. Second, we hypothesized these host proteins to be components of heterogeneous, labile, and dynamic multi-subunit assembly machines, not easily isolated by specific target protein-focused methods. This suggested the need to identify active compounds before knowing the precise protein target. A cell-free translation-based small molecule screen was established to recreate the hypothesized interactions involving newly synthesized capsid proteins as host assembly machine substrates. Hits from the screen were validated by efficacy against infectious rabies virus in mammalian cell culture. Used as affinity ligands, advanced analogs were shown to bind a set of proteins that effectively reconstituted drug sensitivity in the cell-free screen and included a small but discrete subfraction of cellular ATP-binding cassette family E1 (ABCE1), a host protein previously found essential for HIV capsid formation. Taken together, these studies advance an alternate view of capsid formation (as a host-catalyzed biochemical pathway), a different paradigm for drug discovery (whole pathway screening without knowledge of the target), and suggest the existence of labile assembly machines that can be rendered accessible as next-generation drug targets by the means described.

Metabolomics of cerebrospinal fluid from humans treated for rabies.

Abstract: Rabies is a rapidly progressive lyssavirus encephalitis that is statistically 100% fatal. There are no clinically effective antiviral drugs for rabies. An immunologically naive teenager survived rabies in 2004 through improvised supportive care; since then, 5 additional survivors have been associated with use of the so-called Milwaukee Protocol (MP). The MP applies critical care focused on the altered metabolic and physiologic states associated with rabies. The aim of this study was to examine the metabolic profile of cerebrospinal fluid (CSF) from rabies patients during clinical progression of rabies encephalitis in survivors and nonsurvivors and to compare these samples with control CSF samples. Unsupervised clustering algorithms distinguished three stages of rabies disease and identified several metabolites that differentiated rabies survivors from those who subsequently died, in particular, metabolites related to energy metabolism and cell volume control. Moreover, for those patients who survived, the...

The Global Availability of Rabies Immune Globulin and Rabies Vaccine in Clinics Providing Indirect Care to Travelers

Abstract: We assessed rabies vaccine (RV) and immune globulin (RIG) availability on the local market by querying US Embassy medical staff worldwide. Of 112 responses, 23% were from West, Central, and East Africa. RV and RIG availability varied by region. Possible rabies exposures accounted for 2% of all travelers' health inquiries.

Conservation of Binding Epitopes for Monoclonal Antibodies on the Rabies Virus Glycoprotein

Abstract: The global need for rabies immune globulin (RIG) for post-exposure prophylaxis (PEP) is significant. The cost of RIG, either of equine or human origin, is prohibitive for most patients in developing countries. Limitations of supply may occur worldwide. Several virus-neutralizing monoclonal antibodies (MAbs), binding to the rabies virus glycoprotein have been proposed as a replacement of conventional RIG in human PEP due to the ability of largescale production at a reduced cost. In the present study we analyzed 1,042 rabies virus glycoprotein sequences, generated de novo and retrieved from GenBank, to determine the conservation of binding epitopes for several well characterized rabies virus-neutralizing MAbs. Our analysis demonstrated that the use of a single MAb for rabies PEP is inappropriate, because certain viral sequences had critical amino acid substitutions in binding epitopes for each MAb. Rather, a cocktail of MAbs, targeting non-overlapping epitopes, offers a reliable alternative, as no sequences from our study harbored critical substitutions in binding sites for two or more MAbs simultaneously.

The Phylogeography and Spatiotemporal Spread of South-Central Skunk Rabies Virus

Abstract: The south-central skunk rabies virus (SCSK) is the most broadly distributed terrestrial viral lineage in North America. Skunk rabies has not been efficiently targeted by oral vaccination campaigns and represents a natural system of pathogen invasion, yielding insights to rabies emergence. In the present study we reconstructed spatiotemporal spread of SCSK in the whole territory of its circulation using a combination of Bayesian methods. The analysis based on 241 glycoprotein gene sequences demonstrated that SCSK is much more divergent phylogenetically than was appreciated previously. According to our analyses the SCSK originated in the territory of Texas ~170 years ago, and spread geographically during the following decades. The wavefront velocity in the northward direction was significantly greater than in the eastward and westward directions. Rivers (except the Mississippi River and Rio Grande River) did not constitute significant barriers for epizootic spread, in contrast to deserts and mountains. The mean dispersal rate of skunk rabies was lower than that of the raccoon and fox rabies. Viral lineages circulate in their areas with limited evidence of geographic spread during decades. However, spatiotemporal reconstruction shows that after a long period of stability the dispersal rate and wavefront velocity of SCSK are increasing. Our results indicate that there is a need to develop control measures for SCSK, and suggest how such measure can be implemented most efficiently. Our approach can be extrapolated to other rabies reservoirs and used as a tool for investigation of epizootic patterns and planning interventions towards disease elimination.

A reassessment of the evolutionary timescale of bat rabies viruses based upon glycoprotein gene sequences

Abstract: Rabies, an acute progressive encephalomyelitis caused by viruses in the genus Lyssavirus, is one of the oldest known infectious diseases. Although dogs and other carnivores represent the greatest threat to public health as rabies reservoirs, it is commonly accepted that bats are the primary evolutionary hosts of lyssaviruses. Despite early historical documentation of rabies, molecular clock analyses indicate a quite young age of lyssaviruses, which is confusing. For example, the results obtained for partial and complete nucleoprotein gene sequences of rabies viruses (RABV), or for a limited number of glycoprotein gene sequences, indicated that the time of the most recent common ancestor (TMRCA) for current bat RABV diversity in the Americas lies in the seventeenth to eighteenth centuries and might be directly or indirectly associated with the European colonization. Conversely, several other reports demonstrated high genetic similarity between lyssavirus isolates, including RABV, obtained within a time interval of 25–50 years. In the present study, we attempted to re-estimate the age of several North American bat RABV lineages based on the largest set of complete and partial glycoprotein gene sequences compiled to date (n = 201) employing a codon substitution model. Although our results overlap with previous estimates in marginal areas of the 95 % high probability density (HPD), they suggest a longer evolutionary history of American bat RABV lineages (TMRCA at least 732 years, with a 95 % HPD 436–1107 years).

Anthropogenic Roost Switching and Rabies Virus Dynamics in House-Roosting Big Brown Bats

Abstract: Big brown bats (Eptesicus fuscus) are the most commonly encountered rabid bat in North America and represent an important source of wildlife rabies epizootics. Urban and suburban colonies of E. fuscus are often evicted from their roosts in houses, with poorly understood consequences for bat dispersal, population dynamics, and rabies virus transmission. We combined radiotelemetry and mark-recapture of E. fuscus with enhanced surveillance to understand the frequency of rabies virus exposure in house-roosting bats and to assess the potential for behavioral responses of eviction to exacerbate viral transmission. Serology demonstrated the circulation of rabies virus in nearly all sites, with an overall seroprevalence of 12%, but no bats were excreting rabies virus at the time of capture. Bats that were excluded from roosts relocated to houses <1 km from the original roost. However, behavioral responses to eviction differed, with bats switching repeatedly among new roosts in 1 site, but fusing with a n...

Isolation and molecular characterization of Fikirini rhabdovirus, a novel virus from a Kenyan bat.

Abstract: Zoonotic and vector-borne pathogens have comprised a significant component of emerging human infections in recent decades, and bats are increasingly recognized as reservoirs for many of these disease agents. To identify novel pathogens associated with bats, we screened tissues of bats collected in Kenya. Virus isolates were identified by next generation sequencing of viral nucleic acid preparations from the infected cell culture supernatant and characterized. Here we report the identification of Fikirini rhabdovirus, a novel rhabdovirus isolated from a bat, Hipposideros vittatus, captured along the Kenyan coast.

Multidisciplinary approach to epizootiology and pathogenesis of bat rabies viruses in the United States.

Abstract: Summary Zoonotic disease surveillance is typically initiated after an animal pathogen has caused disease in humans. Early detection of potentially high-risk pathogens within animal hosts may facilitate medical interventions to cope with an emerging disease. To effectively spillover to a novel host, a pathogen may undergo genetic changes resulting in varying transmission potential in the new host and potentially to humans. Rabies virus (RABV) is one model pathogen to consider for studying the dynamics of emerging infectious diseases under both laboratory and field conditions. The evolutionary history of RABV is characterized by regularly documented spillover infections and a series of notable host shifts. Within this context, enhanced field surveillance to improve detection of spillover infections will require validated techniques to non-invasively differentiate infected from non-infected individuals. In this study, we evaluate the use of infrared thermography to detect thermal changes associated with experimental RABV infection in big brown bats (Eptesicus fuscus) in a captive colony. Our results indicated that 62% of rabid bats had detectable facial temperature decreases ()4.6� C, SD ± 2.5) compared with pre-inoculation baseline values. These data suggest potential utility for discriminating rabid bats in natural field settings. In addition, focusing upon RABV circulating in the United States between 2008 and 2011, we confirmed spillover events of bat RABV among carnivores and identified cross-species transmission events caused by four lineages of RABV associated with insectivorous bats. Additionally, our analysis of RABV glycoprotein sequences identified substitutions in antigenic sites that may affect neutralizing activity associated with monoclonal antibodies proposed for use in human post-exposure prophylaxis. This study provides a glimpse into RABV pathobiology and spillover dynamics among and between bats and a variety of mesocarnivores.

Evaluation of knowledge, attitudes, and practices of deer owners following identification of a cluster of captive deer with rabies in Pennsylvania in July 2010

Abstract: Objective—To evaluate knowledge, attitudes, and practices of deer owners following identification of a cluster of captive deer with rabies as an aid for the development of rabies prevention educational materials. Design—Cross-sectional study. Population—Captive-deer owners who were members of the Pennsylvania Deer Farmers Association. Procedures—Information was obtained via a mailed, self-administered questionnaire. Results—The questionnaire response rate was 59% (249/425). One hundred three of 206 (50%) respondents had incomplete knowledge of rabies virus vectors, transmission, severity, and prevention measures. Birds or snakes were incorrectly identified as rabies vectors by 96 of 213 (45%) respondents, and most (≥ 94%) respondents identified rabies virus reservoirs as vectors. Ninety of 231 (39%) respondents identified death as an outcome of rabies, and 184 of 235 (78%) respondents would seek emergency treatment if they suspected exposure. Only 62 of 235 (26%) respondents would wash a wound immediately...

Prevalence of neutralizing antibodies to rabies virus in serum of seven species of insectivorous bats from colorado and new mexico, united states

Abstract: We determined the presence of rabies-virus-neutralizing antibodies (RVNA) in serum of 721 insectivorous bats of seven species captured, sampled, and released in Colorado and New Mexico, United States in 2003-2005. A subsample of 160 bats was tested for rabies-virus RNA in saliva. We sampled little brown bats (Myotis lucifugus) at two maternity roosts in Larimer County, Colorado; big brown bats (Eptesicus fuscus) at three maternity roosts in Morgan County, Colorado; and big brown bats at five maternity roosts in Larimer County. We also sampled hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans) captured while drinking or foraging over water in Bernalillo County, New Mexico and at various locations in Larimer County. Big brown bats, little brown bats, long-legged myotis (Myotis volans), long-eared myotis (Myotis evotis), and fringed myotis (Myotis thysanodes) were also sampled over water in Larimer County. All species except long-eared myotis included individuals with RVNA, with prevalences ranging from 7% in adult female silver-haired bats to 32% in adult female hoary bats. None of the bats had detectable rabies-virus RNA in oropharyngeal swabs, including 51 bats of 5 species that had RVNA in serum. Antibody-positive bats were present in nine of the 10 maternity colonies sampled. These data suggest that wild bats are commonly exposed to rabies virus and develop a humoral immune response suggesting some degree of viral replication, but many infections fail to progress to clinical disease.

Human Rabies — South Carolina, 2011

Abstract: On December 3, 2011, a South Carolina woman visited a local emergency department (ED) with an overnight history of shortness of breath, diaphoresis, chills, and intermittent paresthesia. The patient was transferred to a referral hospital, where she became comatose and developed multiorgan failure. The patient did not report a history of an animal bite. However, family members subsequently revealed that bats had been observed in the patient's home during the previous summer. Family members also reported that the patient had sought information on bat removal from a local county service, but was not advised of the risk for rabies associated with bat exposures and was not referred for public health consultation. CDC confirmed infection with a rabies virus variant associated with Mexican free-tailed bats (Tadarida brasiliensis) on December 14, after which the patient received hospice care. She died on December 19. This report summarizes the patient's clinical course and the associated public health investigation. This case highlights the importance of strong partnerships among public health officials and diverse non-health-care partners to ensure appropriate referral of persons exposed to bats in their homes for prompt and appropriate risk assessment, postexposure prophylaxis (PEP) recommendations, and information on safe, effective, and humane bat exclusion methods.

Costs of raccoon rabies incidents in cattle herds in Hampshire County, West Virginia, and Guernsey County, Ohio.

Abstract: Objective—To determine direct and indirect costs associated with raccoon rabies incidents involving cattle herds in Hampshire County, WV, in 2008 and Guernsey County, Ohio, in 2010. Design—Ex post cost analysis. Animals—1 cattle herd in Hampshire County, WV, in 2008 and 1 cattle herd in Guernsey County, Ohio, in 2010. Procedures—Data were collected for each incident through telephone and email interviews with 16 federal, state, and county agency personnel involved in the case investigations and coordinated responses for rabies in the cattle herds. To characterize the economic impact associated with rabies in the 2 cattle herds, cost analysis was conducted with 7 cost variables (salary and benefits for personnel involved in the response, human postexposure prophylaxis, indirect patient costs, rabies diagnostic testing, cattle carcass disposal, market value of euthanized cattle, and enhanced rabies surveillance). Estimates of direct costs were determined on the basis of agency records and other relevant dat...

Human Contacts with Oral Rabies Vaccine Baits Distributed for Wildlife Rabies Management — Ohio, 2012

Abstract: Baits laden with oral rabies vaccines are important for the management of wildlife rabies in the United States. In August 2012, the Wildlife Services program of the U.S. Department of Agriculture's Animal and Plant Health Inspection Service began a field trial involving limited distribution of a new oral rabies vaccine bait in five states, including Ohio. The vaccine consisted of live recombinant human adenovirus type 5 vector, expressing rabies virus glycoprotein (AdRG1.3) (Onrab). A previously used oral rabies vaccine consisting of a live recombinant vaccinia vector, expressing rabies virus glycoprotein (V-RG) (Raboral V-RG), was distributed in other areas of Ohio. To monitor human contacts and potential vaccine virus exposure, surveillance was conducted by the Ohio Department of Health, local Ohio health agencies, and CDC. During August 23-September 7, 2012, a total of 776,921 baits were distributed in Ohio over 4,379 square miles (11,341 square kilometers). During August 24-September 12, a total of 89 baits were reported found by the general public, with 55 human contacts with baits identified (some contacts involved more than one bait). In 27 of the 55 human contacts, the bait was not intact, and a barrier (e.g., gloves) had not been used to handle the bait, leaving persons at risk for vaccine exposure and vaccine virus infection. However, no adverse events were reported. Continued surveillance of human contacts with oral rabies vaccine baits and public warnings to avoid contact with baits are needed because of the potential for vaccine virus infection.

Chapter 13 – Rabies Vaccines

Abstract: Rabies vaccine is the most valuable tool to prevent rabies in humans and animals. Vaccines provide the best service to public health when used in concert with effective risk management assessment systems that include enhanced surveillance, reliable de-centralized diagnostic laboratories and continued education for health professionals. All modern human rabies vaccines are inactivated, but both inactivated and modified-live or recombinant rabies cell culture rabies vaccines are produced for use in animals.

Modeling enzootic raccoon rabies from land use patterns - Georgia (USA) 2006-2010.

Abstract: We analyzed how land-use patterns and changes in urbanization influence reported rabid raccoons in Georgia from 2006 - 2010. Using Geographical Information Systems and rabies surveillance data, multivariate analysis was conducted on 15 land-use variables that included natural topography, agricultural development, and urbanization to model positive raccoon rabies cases while controlling for potential raccoon submission bias associated with higher human population densities. Low intensity residential development was positively associated with reported rabid raccoons while a negative association was found with evergreen forest. Evergreen forests may offer a barrier effect where resources are low and raccoon populations are not supported. Areas with pure stands of upland evergreen forest might be utilized in baiting strategies for oral rabies vaccination programs where fewer or no baits may be needed. Their use as a barrier should be considered carefully in a cost-effective strategy for oral rabies vaccination (ORV) programs to contain the western spread of this important zoonotic disease.

Food Animal Economics

Abstract: From the USDA, APHIS, Wildlife Services, National Rabies Manage-ment Program, 59 Chenell Dr, Ste 2, Concord, NH 03301 (Chipman, Algeo, Slate); USDA, APHIS, Wildlife Services, National Wildlife Re-search Center, 4101 LaPorte Ave, Fort Collins, CO 80521 (Cozzens, Shwiff); School of Business, University at Albany, Albany, NY 12222 (Biswas); West Virginia Department of Agriculture, PO Box 239, Moorefield, WV 26835 (Plumley); College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210 (O’Quin); and the Rabies Program, NCEZID/DHCPP/Poxvirus and Rabies Branch, CDC, Mail Stop G-33, 1600 Clifton Rd NE, Atlanta, GA 30333 (Rupprecht). Dr. Rupprecht’s present address is the Global Alliance for Rabies Control, 529 Humboldt St, Ste 1, Manhattan, KS 66502.The authors thank Rachel Radcliff, Christopher Croson, Sam Mills, Kevin Sullivan, Judith Cox, Terry Mayhew, Vickie Medlin, Dr. Kathy Smith, Todd Smith, Andy Montoney, John Seman, Josh Hoblet, Dr. Tony Forshey, Andrea Geilinger, Rose Ball, Dr. Skip Oertli, Jesse Blanton, Dr. Bruce Wagner, Dr. Chuck Fossler, and Dr. Jason Lombard for providing data and technical assistance.Address correspondence to Mr. Chipman (richard.b.chipman@aphis.usda.gov).