The spread of rabies into Europe and the probable origin of this disease in antiquity

Assessing rabies knowledge gaps in human and animal healthcare professionals practicing in Washington, DC-A one health approach

Once a person is exposed to the rabies virus, it is universally fatal unless postexposure prophylaxis (PEP) is administered promptly. In the United States, determining whether PEP recommeded is often a collaborative effort where health departments work with both animal and human healthcare professionals to enact animal quarantines (or rabies testing), recommending PEP when appropriate. A failure in the knowledge base of either profession can result in incorrect PEP recommendations and an increased risk of adverse outcomes. To assess rabies knowledge in licensed physicians and veterinarians practicing in Washington, DC, we conducted a survey from December 2, 2016, to January 2, 2017, assessing their knowledge of the clinical signs, epidemiology and the primary vectors of rabies. These responses were compared between the two groups. Physician-specific or veterinary-specific questions regarding the correct PEP schedule and administration site or animal quarantine recommendations, respectively, were also included. Nine hundred and fifty-two physicians and 125 veterinarians responded. Veterinarians were more likely to select the correct vectors and clinical signs in animals than physicians. Physicians more likely selected the correct transmission routes. Less than half of physicians identified the correct PEP schedule (39.4%) and administration site (49.0%). Half of veterinarians (50.0%) correctly identified quarantine length for wildlife-exposed vaccinated dogs compared to only 19.4% for unvaccinated dogs. Several knowledge gaps were identified amongst physicians and veterinarians. Due to the fatal nature of rabies, it is important that all healthcare providers have an understanding of current recommendations. Health departments can work to correct these gaps and serve as a bridge between human and animal healthcare professionals.

Formation of the Asian Rabies Control Network (ARACON): A common approach towards a global good

The drive towards the worldwide elimination of dog-mediated human rabies by 2030 is the first step towards the ultimate goal of dog rabies elimination - as dogs account for more than 99% of human rabies cases globally - and has gained considerable momentum since this resolution was taken at a global meeting in Geneva in December 2015. For dog rabies-endemic countries and regions, dedicated regional networks may offer unique opportunities to take advantage of this global momentum. Towards this goal, the Pan-African Rabies Control Network (PARACON) was created in 2015, and the past year has seen the formation of the Asian Rabies Control Network (ARACON). ARACON provides opportunities for member countries to share lessons learnt and challenges faced, while also introducing them to programmatic support tools such as the Stepwise Approach towards Rabies Elimination (SARE) assessment and the Rabies Epidemiological Bulletin (REB). During the inaugural ARACON meeting, member countries evaluated their progress and developed country-specific Practical Workplans based on their SARE outcomes. The results from the national-level SARE assessments were considered at the regional level and, after discussion among countries, consensual agreement was reached that the target date of regional freedom from dog-mediated human rabies by 2020 was not feasible, and a new regional target of 2030 was set. With this new regional target, ongoing support will continue to be provided to countries through regional structures such as ARACON. However, the responsibility remains with the countries to use the available tools and resources to progress towards the new regional goal of dog-mediated human rabies elimination by 2030.

The Health Impact of Rabies in Haiti and Recent Developments on the Path Toward Elimination, 2010-2015

Haiti, a Caribbean country of 10.5 million people, is estimated to have the highest burden of canine-mediated human rabies deaths in the Western Hemisphere, and one of the highest rates of human rabies deaths in the world. Haiti is also the poorest country in the Western Hemisphere and has numerous economic and health priorities that compete for rabies-control resources. As a result, primary rabies-control actions, including canine vaccination programs, surveillance systems for human and animal rabies, and appropriate postbite treatment, have not been fully implemented at a national scale. After the 2010 earthquake that further hindered the development of public health program infrastructure and services, the U.S. Centers for Disease Control and Prevention worked with the Ministry of Public Health and Population and key health development partners (including the Pan-American Health Organization) to provide technical expertise and funding for general disease surveillance systems, laboratory capacity, and selected disease control programs; including rabies. In 2011, a cross-ministerial rabies consortium was convened with participation from multiple international rabies experts to develop a strategy for successful rabies control in Haiti. The consortium focused on seven pillars: 1) enhancement of laboratory diagnostic capacity, 2) development of comprehensive animal surveillance system, 3) development of comprehensive human rabies surveillance system, 4) educational outreach, 5) sustainable human rabies biologics supply, 6) achievement of sustained canine vaccination rates of ≥ 70%, and 7) finalization of a national rabies control strategy. From 2010 until 2015, Haiti has seen improvements in the program infrastructure for canine rabies control. The greatest improvements were seen in the area of animal rabies surveillance, in support of which an internationally recognized rabies laboratory was developed thereby leading to an 18-fold increase in the detection of rabid animals. Canine rabies vaccination practices also improved, from a 2010 level of approximately 12% to a 2015 dog population coverage level estimated to be 45%. Rabies vaccine coverage is still below the goal of 70%, however, the positive trend is encouraging. Gaps exist in the capacity to conduct national surveillance for human rabies cases and access to human rabies vaccine is lacking in many parts of the country. However, control has improved over the past 5 years as a result of the efforts of Haiti’s health and agriculture sectors with assistance from multiple international organizations. Haiti is well situated to eliminate canine-mediated human rabies deaths in the near future and should serve as a great example to many developing countries struggling with similar barriers and limitations.

Insights and efforts to control rabies in Zambia: Evaluation of determinants and barriers to dog vaccination in Nyimba district

BACKGROUND

The current rabies control strategy in Zambia is based on dog vaccination, dog population control and dog movement restrictions. In Nyimba district of Zambia, dog vaccination coverage is low but the incidence of dog bites is high which places the community at risk of rabies infection. The renewed global interest eliminating rabies in developing countries has spurred interest to identify determinants and barriers of dog vaccination in an effort to reduce the overall disease burden.

METHODOLOGY

A mixed methods cross sectional design was used in the study. This consisted of three parts: Evaluation of medical records regarding dog bite injuries, implementation and analysis of a household survey and in-depth review of key informant interviews. Data was collected into a Microsoft Excel database and subsequently transferred to STATA for descriptive, inferential and thematic analysis.

RESULTS

Dog vaccination coverage overall was 8.7% (57/655), with 3.4% (22/655) in urban areas, 1.8% (12/655) in peri-urban and 3.5 (23/655) in the rural regions. Financially stable households were more likely to have their dogs vaccinated. Only 10.3% (31/300) of the respondents had vaccinated their dogs and these had a reliable source of income as 6% (18/300) were peasant farmers, 2% (6/300) were dependants whose guardians were financially stable and 2.3% (7/300) were in steady employment. Important barriers to dog vaccination included cost, limited awareness of vaccination program and access.

CONCLUSION

Current rabies control strategies in Nyimba district, Zambia, appear quite limited. Improvements in the regional dog vaccination program may provide benefits. Enhancement of educational efforts targeting behavioural factors may also prove useful. Finally, the cost of dog vaccination can be reduced with scaled up production of a local vaccine.

Subversion of the Immune Response by Rabies Virus

Rabies has affected mankind for several centuries and is one of the oldest known zoonoses. It is peculiar how little is known regarding the means by which rabies virus (RABV) evades the immune response and kills its host. This review investigates the complex interplay between RABV and the immune system, including the various means by which RABV evades, or advantageously utilizes, the host immune response in order to ensure successful replication and spread to another host. Different factors that influence immune responses—including age, sex, cerebral lateralization and temperature—are discussed, with specific reference to RABV and the effects on host morbidity and mortality. We also investigate the role of apoptosis and discuss whether it is a detrimental or beneficial mechanism of the host’s response to infection. The various RABV proteins and their roles in immune evasion are examined in depth with reference to important domains and the downstream effects of these interactions. Lastly, an overview of the means by which RABV evades important immune responses is provided. The research discussed in this review will be important in determining the roles of the immune response during RABV infections as well as to highlight important therapeutic target regions and potential strategies for rabies treatment.

Study of rabies virus by Differential Scanning Calorimetry

Differential Scanning Calorimetry (DSC) has been used in the past to study the thermal unfolding of many different viruses. Here we present the first DSC analysis of rabies virus. We show that non-inactivated, purified rabies virus unfolds cooperatively in two events centered at approximately 62 and 73 °C. Beta-propiolactone (BPL) treatment does not alter significantly viral unfolding behavior, indicating that viral inactivation does not alter protein structure significantly. The first unfolding event was absent in bromelain treated samples, causing an elimination of the G-protein ectodomain, suggesting that this event corresponds to G-protein unfolding. This hypothesis was confirmed by the observation that this first event was shifted to higher temperatures in the presence of three monoclonal, G-protein specific antibodies. We show that dithiothreitol treatment of the virus abolishes the first unfolding event, indicating that the reduction of G-protein disulfide bonds causes dramatic alterations to protein structure. Inactivated virus samples heated up to 70 °C also showed abolished recognition of conformational G-protein specific antibodies by Surface Plasmon Resonance analysis. The sharpness of unfolding transitions and the low standard deviations of the Tm values as derived from multiple analysis offers the possibility of using this analytical tool for efficient monitoring of the vaccine production process and lot to lot consistency.

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Differential Scanning Calorimetry analysis of rabies virus.

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Rabies virus unfolds in two thermal events.

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The first event corresponds to G-protein.

Three dimensional morphology of rabies virus studied by cryo-electron tomography

The rabies virus (RABV) continues to be a worldwide health problem. RABV contains a single-stranded RNA genome that associates with the nucleoprotein N. The resulting ribonucleoprotein complex is surrounded by matrix protein M, lipid bilayer and glycoprotein G. RABV was reported to organize in bullet-like virions, but the role of each viral component in adopting this morphology is unclear. We present here a cryo-electron tomography study of RABV showing additional morphologies consisting in bullet-like virions containing a tubular, lipidic appendage having G-protein at its apex. In addition, there was evidence for an important fraction of pleomorphic particles. These pleomorphic forms differed in the amount of membrane-associated M-, M/N-protein providing interesting insight into its role in viral morphogenesis. In the absence of membrane-associated M-, M/N-protein viral morphology was almost spherical. Other images, showing straight membrane portions, correlate with the M-protein recruitment at the membrane independently of the presence of the G-protein. The viral membrane was found to contain a negative net charge indicating that M-, M/N-protein-membrane charge attraction drives this interaction.