Rabies - the need for a 'one medicine' approach

Single visit rabies pre-exposure prophylaxis: A literature review

BACKGROUND

The current WHO-recommended rabies pre-exposure prophylaxis (PrEP) are two-visit vaccination schedules, but there are studies suggesting that single visit schedules might be sufficient to prime the immunity.

METHODS

A literature review was conducted to retrieve and summarize published data on single visit rabies PrEP. PubMed database was screened for articles published between January 1st, 2003 and December 31st, 2022. The bibliographies of the articles chosen to undergo full text review and of the current major WHO publications on rabies were searched to find additional references, regardless of publication date. The primary outcome was the percentage of subjects having received rabies PrEP on single visit schedules who achieved antibody levels ≥0.5 IU/mL one week after post-exposure prophylaxis (PEP), regardless of the PEP regimen.

RESULTS

11 studies were selected for inclusion, totalling 935 subjects, of which 696 received a simulated PEP schedule. Of these 696, a serological test result on day 7 was available for 408 of them, and 406 subjects (99.51%) seroconverted after PEP without any difference regarding time delay between PrEP and PEP or the vaccination schedule used for PEP.

CONCLUSION

Single visit PrEP schedules seem to confer sufficient protection in most healthy individuals without immunocompromised status if a booster PEP is administered after a suspected rabies exposure. Further studies in real-life settings and in different age categories are needed to confirm this finding, which may increase the availability of vaccines and thus the accessibility of PrEP for vulnerable populations.

Knowledge, attitudes, and practices toward rabies in three provinces of Indonesia

Background and Aim:

Rabies is an important viral zoonotic disease that is mostly transmitted through the bite of a rabid dog. Despite serious efforts regarding its control, rabies is still endemic in many provinces of Indonesia. The study aims to assess the knowledge, attitudes, and practices (KAP) related to rabies in urban and rural areas in three provinces of Indonesia.

Materials and Method:

s: A total of 432 respondents of different age groups, educational levels, geographical areas, and occupations participated in this study. Data were collected using a pre-designed questionnaire with online and offline modes to assess the KAP of rabies among the respondents. A series of Chi-square tests and frequency distribution analyses were performed to determine associations between response variables.

Results:

Of the 432 participants, 56.9% were aware of the clinical signs of rabies. Excepting for people at high risk of contracting the disease (e.g., veterinarians), most respondents (83.1%) were not vaccinated against rabies. Surprisingly, 79.4 % of those who were bitten by an infected dog did not seek medical care from the doctor and approximately 71.8% had poor knowledge of rabies control and vaccine campaigns. Of all respondents, 64% (p<0.05, odds ratio=1.63) were vaccinated after an infected dog bite. Similarly, 32% (p<0.05, odds ratio=1.59) were aware of surveys and vaccinations in their areas. In contrast, 20.7% (p<0.05, odds ratio=0.593) reported that rabid dogs were killed in their areas. The majority (89.60%) of the respondents were aware of the fact that rabies can cause death. Most of the respondents (93%) knew that rabies is caused by an infected dog bite. The overall levels of KAP among the respondents were good.

Conclusion:

The findings of the current study generally show that participants had good knowledge about clinical signs based on their frequency percentage, but lacked knowledge regarding medical treatment and surveys for awareness and vaccination of rabies. Overall, a significant (p<0.05, odds ratio>1) relationship was found among the KAP of participants. This depicts that the majority of the population is aware of rabies and factors involved in its transmission.

Barriers and opportunities for canine rabies vaccination campaigns in Addis Ababa, Ethiopia

BACKGROUND

Canine rabies is endemic in Ethiopia and presents a significant burden for both animal and human health. We investigate barriers to dog vaccination in Addis Ababa, Ethiopia. These results can be utilized to improve and target future rabies control efforts.

METHODOLOGY/PRINCIPLE FINDINGS

During May of 2017, dog owners were surveyed during a free canine rabies vaccination programs that utilized both door-to-door (DtD) and central point (CP) vaccination methods. Surveys collected information on preferences for rabies vaccine delivery and were administered in Amharic. A total of 1057 surveys were completed. Of those surveyed, 62.4 % indicated that their dogs had been vaccinated against rabies within the last year. Commonly reported barriers to vaccination were a lack of awareness that dogs required rabies vaccines (18.1 %) and lack of knowledge about where to find vaccine (15.0 %). The median price owners were willing to pay for vaccination was 25 birr ($0.91 USD) and the median distance willing to travel was 1.0 km; however, 48.9 % of those surveyed during DtD were unwilling to travel at all. We identified 3 classes of respondents who were grouped due to their responses by latent class analysis: 'the Unaware', 'the Vaccinators', and 'the Multiple Barriers'.

CONCLUSIONS/SIGNIFICANCE

Although many respondents were willing to pay for rabies vaccine (94.0 %); the preferred cost (median) was less than the actual cost of providing the vaccine. This supports the need for reduced-cost or free vaccine to achieve and sustain the 70 % vaccine coverage target threshold for canine rabies elimination. Additionally, a significant portion (41.5 %) of those surveyed indicated that they were unwilling to travel in order to have their dog vaccinated. The latent class analysis provides useful guidance on how to reach target vaccination. Owners from 'the Unaware' group made up 18.1 % of respondents and their high rate of allowing their dogs to roam identifies them as a prime target for canine health and behavior education. 'The Multiple Barriers' owners reported lower degrees of dog roaming and were substantially more likely to be found by DtD campaigns, possibly because they have limited ability/interest in handling their dogs. These results demonstrate the importance of incorporating DtD vaccination as well as subsidies to maximize vaccine coverage in Addis Ababa.

Rabies: Knowledge, Attitude and Practices in and Around South Gondar, North West Ethiopia

A cross-sectional study was conducted from February 2017 to April 2017 to assess knowledge, attitude and practices of the community towards rabies in south Gondar zone, Ethiopia. A structured closed ended questionnaire was used to collect the data through face to face interviews among 384 respondents. The data were then analyzed using SPSS statistical software version 20. Almost all (91.5%) surveyed individuals were aware of rabies. Bite was known as mode of rabies transmission by majority of the respondents (71.1%) with considerable means of transmission through wound contact with saliva of diseased animals. Sudden change of behavior was described as a major clinical sign of rabies in animals by the majority of the respondents. Nearly half of the respondents (48.2%) believed that consumption of rabid animal's meat can be a medicine for human rabies and majority of the respondents (66.7%) indicated crossing a river before 40 days after dog bite increases severity of the disease. More than eighty percent of the respondents prefer traditional medicines for treating rabies in humans. In total, 51% of the respondents had poor Knowledge, Attitudes and Practices (KAP) level about the disease rabies. Educational status (χ2 = 21.152), Monthly income (χ2 = 23.059), Sex (χ2 = 11.249), source of information (χ2 = 8.594) and Residence (χ2 = 4.109) were significantly associated with KAP scores (p < 0.05). Education and awareness creation should be given to increase communities KAP about the disease with special focus to traditional healers.

Rabies - epidemiology, pathogenesis, public health concerns and advances in diagnosis and control: a comprehensive review

Rabies is a zoonotic, fatal and progressive neurological infection caused by rabies virus of the genus Lyssavirus and family Rhabdoviridae. It affects all warm-blooded animals and the disease is prevalent throughout the world and endemic in many countries except in Islands like Australia and Antarctica. Over 60,000 peoples die every year due to rabies, while approximately 15 million people receive rabies post-exposure prophylaxis (PEP) annually. Bite of rabid animals and saliva of infected host are mainly responsible for transmission and wildlife like raccoons, skunks, bats and foxes are main reservoirs for rabies. The incubation period is highly variable from 2 weeks to 6 years (avg. 2-3 months). Though severe neurologic signs and fatal outcome, neuropathological lesions are relatively mild. Rabies virus exploits various mechanisms to evade the host immune responses. Being a major zoonosis, precise and rapid diagnosis is important for early treatment and effective prevention and control measures. Traditional rapid Seller's staining and histopathological methods are still in use for diagnosis of rabies. Direct immunofluoroscent test (dFAT) is gold standard test and most commonly recommended for diagnosis of rabies in fresh brain tissues of dogs by both OIE and WHO. Mouse inoculation test (MIT) and polymerase chain reaction (PCR) are superior and used for routine diagnosis. Vaccination with live attenuated or inactivated viruses, DNA and recombinant vaccines can be done in endemic areas. This review describes in detail about epidemiology, transmission, pathogenesis, advances in diagnosis, vaccination and therapeutic approaches along with appropriate prevention and control strategies.

Rabies

Rabies is a life-threatening neglected tropical disease: tens of thousands of cases are reported annually in endemic countries (mainly in Africa and Asia), although the actual numbers are most likely underestimated. Rabies is a zoonotic disease that is caused by infection with viruses of the Lyssavirus genus, which are transmitted via the saliva of an infected animal. Dogs are the most important reservoir for rabies viruses, and dog bites account for >99% of human cases. The virus first infects peripheral motor neurons, and symptoms occur after the virus reaches the central nervous system. Once clinical disease develops, it is almost certainly fatal. Primary prevention involves dog vaccination campaigns to reduce the virus reservoir. If exposure occurs, timely post-exposure prophylaxis can prevent the progression to clinical disease and involves appropriate wound care, the administration of rabies immunoglobulin and vaccination. A multifaceted approach for human rabies eradication that involves government support, disease awareness, vaccination of at-risk human populations and, most importantly, dog rabies control is necessary to achieve the WHO goal of reducing the number of cases of dog-mediated human rabies to zero by 2030.

Current status of rabies and prospects for elimination

Rabies is one of the most deadly infectious diseases, with a case-fatality rate approaching 100%. The disease is established on all continents apart from Antarctica; most cases are reported in Africa and Asia, with thousands of deaths recorded annually. However, the estimated annual figure of almost 60,000 human rabies fatalities is probably an underestimate. Almost all cases of human rabies result from bites from infected dogs. Therefore, the most cost-effective approach to elimination of the global burden of human rabies is to control canine rabies rather than expansion of the availability of human prophylaxis. Mass vaccination campaigns with parenteral vaccines, and advances in oral vaccines for wildlife, have allowed the elimination of rabies in terrestrial carnivores in several countries worldwide. The subsequent reduction in cases of human rabies in such regions advocates the multidisciplinary One Health approach to rabies control through the mass vaccination of dogs and control of canine populations.

Knowledge, attitudes, and practices regarding rabies in Filipinos following implementation of the Bohol Rabies Prevention and Elimination Programme

Knowledge, attitudes, and practices (KAP) regarding rabies in Bohol, Philippines were assessed following introduction of the Bohol Rabies Prevention and Elimination Programme. A cross-sectional questionnaire was administered to 460 households chosen utilizing the WHO's Expanded Programme on Immunization coverage cluster survey technique with population proportionate to size. Scores for KAP were evaluated using linear regression. The majority of households had heard of rabies (94%); however, specific knowledge of rabies was limited. Only 18% knew to report a suspected rabid dog to the authorities. In multivariate analyses, having known someone with rabies had the greatest effect on knowledge scores. Employment (professional or non-professional) had the greatest effect on attitudes scores, and only the knowledge score was significantly associated with higher practices scores. Several factors, notably, personal experience with rabies, affect KAP in Bohol. The programme should continue to focus on education and include personal accounts to underscore why rabies prevention and control is so important.

Epidemiological characteristics of human and animal rabies in Azerbaijan

The Caucasus is a region of geopolitical importance, in the gateway between Europe and Asia. This geographical location makes the region equally important in the epidemiology and control of transboundary infectious diseases such as rabies. Azerbaijan is the largest country in the Caucasus, and although rabies is notifiable and considered endemic, there is little information on the burden of human and animal rabies. Here, we describe a cross-disciplinary international collaboration aimed at improving rabies control in Azerbaijan. Partial nucleoprotein gene sequences were obtained from animal rabies cases for comparison with those from surrounding areas. Reported human and animal rabies cases between 2000 and 2010 were also reviewed and analysed by region and year. Comparison of rabies virus strains circulating in Azerbaijan demonstrates more than one lineage of rabies virus circulating concurrently in Azerbaijan and illustrates the need for further sample collection and characterization. Officially reported rabies data showed an increase in human and animal rabies cases, and an increase in animal bites requiring provision of post-exposure prophylaxis, since 2006. This is despite apparently consistent levels of dog vaccination and culling of stray dogs.

Diagnosis, management and post-mortem findings of a human case of rabies imported into the United Kingdom from India: a case report

BACKGROUND

Human rabies infection continues to be a significant public health burden globally, and is occasionally imported to high income settings where the Milwaukee Protocol for intensive care management has recently been employed, with limited success in improving survival. Access to molecular diagnostics, pre- and post-mortem, and documentation of pathophysiological responses while using the Milwaukee protocol, can add useful insights for the future of rabies management.

CASE PRESENTATION

A 58-year-old British Asian woman was referred to a regional general hospital in the UK with hydrophobia, anxiety and confusion nine weeks after receiving a dog bite in North West India. Nuchal skin biopsy, saliva, and a skin biopsy from the site of the dog bite wound, taken on the day of admission, all demonstrated the presence of rabies virus RNA. Within 48 hours sequence analysis of viral RNA confirmed the diagnosis and demonstrated that the virus was a strain closely related to canine rabies viruses circulating in South Asia. Her condition deteriorated rapidly with increased agitation and autonomic dysfunction. She was heavily sedated and intubated on the day after admission, treated according to a modified Milwaukee protocol, and remained stable until she developed heart block and profound acidosis and died on the eighth day. Analysis of autopsy samples showed a complete absence of rabies neutralizing antibody in cerebrospinal fluid and serum, and corresponding high levels of virus antigen and nucleic acid in brain and cerebrospinal fluid. Quantitative PCR showed virus was also distributed widely in peripheral tissues despite mild or undetectable histopathological changes. Vagus nerve branches in the heart showed neuritis, a probable Negri body but no demonstrable rabies antigen.

CONCLUSION

Rapid molecular diagnosis and strain typing is helpful in the management of human rabies infection. Post-mortem findings such as vagal neuritis highlight clinically important effects on the cardiovascular system which are typical for the clinical course of rabies in humans. Management guided by the Milwaukee protocol is feasible within well-resourced intensive care units, but its role in improving outcome for canine-derived rabies remains theoretical.

Diagnosis, management and post-mortem findings of a human case of rabies imported into the United Kingdom from India: a case report

BACKGROUND

Human rabies infection continues to be a significant public health burden globally, and is occasionally imported to high income settings where the Milwaukee Protocol for intensive care management has recently been employed, with limited success in improving survival. Access to molecular diagnostics, pre- and post-mortem, and documentation of pathophysiological responses while using the Milwaukee protocol, can add useful insights for the future of rabies management.

CASE PRESENTATION

A 58-year-old British Asian woman was referred to a regional general hospital in the UK with hydrophobia, anxiety and confusion nine weeks after receiving a dog bite in North West India. Nuchal skin biopsy, saliva, and a skin biopsy from the site of the dog bite wound, taken on the day of admission, all demonstrated the presence of rabies virus RNA. Within 48 hours sequence analysis of viral RNA confirmed the diagnosis and demonstrated that the virus was a strain closely related to canine rabies viruses circulating in South Asia. Her condition deteriorated rapidly with increased agitation and autonomic dysfunction. She was heavily sedated and intubated on the day after admission, treated according to a modified Milwaukee protocol, and remained stable until she developed heart block and profound acidosis and died on the eighth day. Analysis of autopsy samples showed a complete absence of rabies neutralizing antibody in cerebrospinal fluid and serum, and corresponding high levels of virus antigen and nucleic acid in brain and cerebrospinal fluid. Quantitative PCR showed virus was also distributed widely in peripheral tissues despite mild or undetectable histopathological changes. Vagus nerve branches in the heart showed neuritis, a probable Negri body but no demonstrable rabies antigen.

CONCLUSION

Rapid molecular diagnosis and strain typing is helpful in the management of human rabies infection. Post-mortem findings such as vagal neuritis highlight clinically important effects on the cardiovascular system which are typical for the clinical course of rabies in humans. Management guided by the Milwaukee protocol is feasible within well-resourced intensive care units, but its role in improving outcome for canine-derived rabies remains theoretical.

Deciphering serology to understand the ecology of infectious diseases in wildlife

The ecology of infectious disease in wildlife has become a pivotal theme in animal and public health. Studies of infectious disease ecology rely on robust surveillance of pathogens in reservoir hosts, often based on serology, which is the detection of specific antibodies in the blood and is used to infer infection history. However, serological data can be inaccurate for inference to infection history for a variety of reasons. Two major aspects in any serological test can substantially impact results and interpretation of antibody prevalence data: cross-reactivity and cut-off thresholds used to discriminate positive and negative reactions. Given the ubiquitous use of serology as a tool for surveillance and epidemiological modeling of wildlife diseases, it is imperative to consider the strengths and limitations of serological test methodologies and interpretation of results, particularly when using data that may affect management and policy for the prevention and control of infectious diseases in wildlife. Greater consideration of population age structure and cohort representation, serological test suitability and standardized sample collection protocols can ensure that reliable data are obtained for downstream modeling applications to characterize, and evaluate interventions for, wildlife disease systems.

Control and prevention of canine rabies: the need for building laboratory-based surveillance capacity

Dogs are the source of more than 99% of human rabies virus infections in endemic regions. Without postexposure prophylaxis, almost all cases are fatal, making rabies the most lethal infectious disease. Tens of thousands of deaths are reported annually, but the official figures are believed to be gross underestimates. Controlling canine rabies, especially in free-ranging dogs, is the first priority to reduce the burden of human disease. Because of their limited medical infrastructure, most endemic countries lack the laboratory facilities needed to diagnose human cases of viral encephalitis. Moreover, the veterinary sectors are often unable to undertake systematic surveillance and reporting of rabies in animals. Without an adequate and functioning risk assessment system that is primed for use, rabies will remain a 'neglected' and omnipresent disease, especially in poverty-stricken regions of the world. Fortunately, experience with the elimination of canine rabies from many industrialized countries has shown that these barriers are not insurmountable. Successful rabies prevention and control strategies that prove the absence of the disease depend on laboratory-based surveillance, rapid data reporting and an adequate system of risk assessment. Future control and prevention programmes should therefore coordinate the development of these key factors, creating synergies to eliminate rabies at its animal source. This article forms part of a symposium in Antiviral Research on the global elimination of canine rabies.

Passive immunity in the prevention of rabies

Prevention of clinical disease in those exposed to viral infection is an important goal of human medicine. Using rabies virus infection as an example, we discuss the advances in passive immunoprophylaxis, most notably the shift from the recommended polyclonal human or equine immunoglobulins to monoclonal antibody therapies. The first rabies-specific monoclonal antibodies are undergoing clinical trials, so passive immunisation might finally become an accessible, affordable, and routinely used part of global health practices for rabies. Coupled with an adequate supply of modern tissue-culture vaccines, replacing the less efficient and unsafe nerve-tissue-derived rabies vaccines, the burden of this disease could be substantially reduced.

Renewed global partnerships and redesigned roadmaps for rabies prevention and control

Canine rabies, responsible for most human rabies deaths, is a serious global public health concern. This zoonosis is entirely preventable, but by focusing solely upon rabies prevention in humans, this “incurable wound” persists at high costs. Although preventing human deaths through canine rabies elimination is feasible, dog rabies control is often neglected, because dogs are not considered typical economic commodities by the animal health sector. Here, we demonstrate that the responsibility of managing rabies falls upon multiple sectors, that a truly integrated approach is the key to rabies elimination, and that considerable progress has been made to this effect. Achievements include the construction of global rabies networks and organizational partnerships; development of road maps, operational toolkits, and a blueprint for rabies prevention and control; and opportunities for scaling up and replication of successful programs. Progress must continue towards overcoming the remaining challenges preventing the ultimate goal of rabies elimination.