Rabies in the Americas: 1998-2014

Long-term spatio-temporal trends in global rabies burden and its association with animal rabies vaccination during 1990-2019

Rabies remains a major public health issue. Yet, trends in rabies burden associated with age, period, and cohort effects remain unknown, and the association between animal rabies vaccination and rabies burden is unclear. We aimed to understand the long-term spatio-temporal trends in global rabies burden, the impacts of age, periods, and birth cohorts, and the association between animal rabies vaccination and burden. Rabies burden data were extracted from Global Burden of Disease Study 2019. We used joinpoint regression to assess temporal trends in rabies burden and age-period-cohort model to evaluate age, period, and cohort effects on rabies incidence and mortality. Animal rabies vaccination data were obtained from World Animal Health Information System. The association between the ratio of vaccinated animals and age-standardized incidence rate was explored. From 1990 to 2019, the global rabies incident cases, deaths, and disability-adjusted life years (DALYs) decreased by 43.12%, 47.20%, and 54.59%, respectively. Age-standardized rates of incidence, mortality, and DALYs declined in all socio-demographic index (SDI) regions, yet consistently remained the highest in low SDI region. The highest rabies incidence rate and mortality rate were observed in children aged 0-9 years. Population living during 1990-1994 had the highest rabies incidence and mortality risks. Countries and territories with high rabies age-standardized incidence rate generally had low ratios of vaccinated animals. Globally, rabies burden decreased over past 30 years, yet disparities in rabies burden regarding gender, age, period, cohort and SDI region existed. Targeted strategies are needed, especially in low SDI region and among children aged 0-9 years.

Future climate change and the distributional shift of the common vampire bat, Desmodus rotundus

Interactions among humans, livestock, and wildlife within disturbed ecosystems, such as those impacted by climate change, can facilitate pathogen spillover transmission and increase disease emergence risks. The study of future climate change impacts on the distribution of free-ranging bats is therefore relevant for forecasting potential disease burden. This study used current and future climate data and historic occurrence locations of the vampire bat species Desmodus rotundus, a reservoir of the rabies virus to assess the potential impacts of climate change on disease reservoir distribution. Analyses included a comprehensive comparison of different climate change periods, carbon emission scenarios, and global circulation models (GCMs) on final model outputs. Models revealed that, although climatic scenarios and GCMs used have a significant influence on model outputs, there was a consistent signal of range expansion across the future climates analyzed. Areas suitable for D. rotundus range expansion include the southern United States and south-central portions of Argentina and Chile. Certain areas in the Amazon Rainforest, which currently rests at the geographic center of D. rotundus' range, may become climatically unsuitable for this species within the context of niche conservatism. While the impacts of rabies virus transmitted by D. rotundus on livestock are well known, an expansion of D. rotundus into novel areas may impact new mammalian species and livestock with unexpected consequences. Some areas in the Americas may benefit from an assessment of their preparedness to deal with an expected D. rotundus range expansion.

Climate change linked to vampire bat expansion and rabies virus spillover

Bat-borne pathogens are a threat to global health and in recent history have had major impacts on human morbidity and mortality. Examples include diseases such as rabies, Nipah virus encephalitis, and severe acute respiratory syndrome (SARS). Climate change may exacerbate the emergence of bat-borne pathogens by affecting the ecology of bats in tropical ecosystems. Here, we report the impacts of climate change on the distributional ecology of the common vampire bat Desmodus rotundus across the last century. Our retrospective analysis revealed a positive relationship between changes in climate and the northern expansion of the distribution of D. rotundus in North America. Furthermore, we also found a reduction in the standard deviation of temperatures at D. rotundus capture locations during the last century, expressed as more consistent, less-seasonal climate in recent years. These results elucidate an association between D. rotundus range expansion and a continental-level rise in rabies virus spill-over transmission from D. rotundus to cattle in the last 50 years of the 120-year study period. This correlative study, based on field observations, offers empirical evidence supporting previous statistical and mathematical simulation-based studies reporting a likely increase of bat-borne diseases in response to climate change. We conclude that the D. rotundus rabies system exemplifies the consequences of climate change augmentation at the wildlife-livestock-human interface, demonstrating how global change acts upon these complex and interconnected systems to drive increased disease emergence.

Outcomes of a Short-Duration, Large-Scale Canine Rabies Vaccination Campaign in Central Cambodia

BACKGROUND

WHO and WOAH advocate for annual high-coverage canine rabies vaccination campaigns as the most sustainable approach to eliminate the risk of dog rabies transmission to humans. It is estimated that Cambodia has one of the highest human rabies deaths per capita of any country (5.8 human deaths per 100,000 people), highlighting the urgent need to implement an effective canine rabies vaccination program. To this end, a coalition of government and non-government organizations conducted a pioneering short-duration dog rabies vaccination campaign over 10 days across Phnom Penh and Kandal Provinces in May 2023.

METHODS

Over 10 working days, 120 vaccination teams, each consisting of two vaccinators and one tuk-tuk driver, traveled door-to-door to deliver parenteral rabies vaccines to all dogs that could be held by the teams or members of the community. Spatial team management and data collection were conducted through the WVS Data Collection Application.

RESULTS

A total of 74,983 dogs were vaccinated, giving a mean vaccination rate of 62.5 dogs per team per day. An additional 2145 cats were vaccinated. Of all dogs encountered by the teams, 84.0% could be vaccinated, with 99.1% of those being identified as owned. Post-vaccination surveys of 4356 households estimated a mean vaccination coverage of 70.7% in owned dogs across the districts of Phnom Penh Province.

CONCLUSION

Short-duration, large-scale canine rabies vaccination campaigns can achieve high vaccination coverage using a door-to-door approach in urban centers of Cambodia. Data gathered through the campaign yielded insights to support the refinement and planning of a wider rabies control strategy and is anticipated to drive further support for subsequent campaigns in Cambodia.

Spatial clusters, temporal behavior, and risk factors analysis of rabies in livestock in Ecuador

Rabies, a globally distributed and highly lethal zoonotic neglected tropical disease, has a significant impact in South America. In Ecuador, animal rabies cases are primarily linked to livestock, and hematophagous bats play a crucial role in disease transmission. This study aims to identify temporal trends, spatial patterns, and risk factors for animal rabies in Ecuador between 2014 and 2019. Epidemiological survey reports from the official Animal Rabies Surveillance Program of the Phyto and Zoosanitary Regulation and Control Agency of Ecuador (AGROCALIDAD) were used. The Animal Rabies Surveillance Program from AGROCALIDAD consists of an official passive surveillance program that receives reports from farmers or individuals (both trained or untrained) who have observed animals with neurological clinical signs and lesions compatible with bat bites, or who have seen or captured bats on their farms or houses. Once this report is made, AGROCALIDAD personnel is sent for field inspection, having to confirm the suspicion of rabies based on farm conditions and compatibility of signs. AGROCALIDAD personnel collect samples from all suspicious animals, which are further processed and analyzed using the Direct Fluorescent Antibody (DFA) test for rabies confirmatory diagnosis. In this case, study data comprised 846 bovine farms (with intra-farm sample sizes ranging from 1 to 16 samples) located in different ecoregions of Ecuador; out of these, 397 (46.93%) farms tested positive for animal rabies, revealing six statistically significant spatial clusters. Among these clusters, three high-risk areas were identified in the southeast of Ecuador. Seasonality was confirmed by the Ljung-Box test for both the number of cases (p < 0.001) and the positivity rate (p < 0.001). The Pacific Coastal lowlands and Sierra regions showed a lower risk of positivity compared to Amazonia (OR = 0.529; 95% CI = 0.318 - 0.883; p = 0.015 and OR = 0.633; 95% CI = 0.410 - 0.977; p = 0.039, respectively). The breeding of non-bovine animal species demonstrated a lower risk of positivity to animal rabies when compared to bovine (OR = 0.145; 95% CI = 0.062 - 0.339; p < 0.001). Similarly, older animals exhibited a lower risk (OR = 0.974; 95% CI = 0.967 - 0.981; p < 0.001). Rainfall during the rainy season was also found to decrease the risk of positivity to animal rabies (OR = 0.996; 95% CI = 0.995 - 0.998; p < 0.001). This study underscores the significance of strengthening the national surveillance program for the prevention and control of animal rabies in Ecuador and other countries facing similar epidemiological, social, and geographical circumstances.

A Global Perspective on Oral Vaccination of Wildlife against Rabies

The long-term mitigation of human-domestic animal-wildlife conflicts is complex and difficult. Over the last 50 yr, the primary biomedical concepts and actualized collaborative global field applications of oral rabies vaccination to wildlife serve as one dramatic example that revolutionized the field of infectious disease management of free-ranging animals. Oral vaccination of wildlife occurred in diverse locales within Africa, Eurasia, the Middle East, and North America. Although rabies is not a candidate for eradication, over a billion doses of vaccine-laden baits distributed strategically by hand, at baiting stations, or via aircraft, resulted in widespread disease prevention, control, or local disease elimination among mesocarnivores. Pure, potent, safe, and efficacious vaccines consisted of either modified-live, highly attenuated, or recombinant viruses contained within attractive, edible baits. Since the late 1970s, major free-ranging target species have included coyotes (Canis latrans), foxes (Urocyon cinereoargenteus; Vulpes vulpes), jackals (Canis aureus; Lupulella mesomelas), raccoons (Procyon lotor), raccoon dogs (Nyctereutes procyonoides), and skunks (Mephitis mephitis). Operational progress has occurred in all but the latter species. Programmatic evaluations of oral rabies vaccination success have included: demonstration of biomarkers incorporated within vaccine-laden baits in target species as representative of bait contact; serological measurement of the induction of specific rabies virus neutralizing antibodies, indicative of an immune response to vaccine; and most importantly, the decreasing detection of rabies virus antigens in the brains of collected animals via enhanced laboratory-based surveillance, as evidence of management impact. Although often conceived mistakenly as a panacea, such cost-effective technology applied to free-ranging wildlife represents a real-world, One Health application benefiting agriculture, conservation biology, and public health. Based upon lessons learned with oral rabies vaccination of mesocarnivores, opportunities for future extension to other taxa and additional diseases will have far-reaching, transdisciplinary benefits.

Empowering Riverine Communities in the Amazon: Strategies for Preventing Rabies

Rabies, caused by the Lyssavirus genus, is a highly lethal zoonotic disease transmitted by animals such as bats and domestic and wild carnivores to humans, claiming nearly 100% of lives. In Brazil, recent evidence suggests an increasing role of bats in human deaths from rabies, particularly in the Amazon region. This neglected tropical disease disproportionately affects impoverished and vulnerable populations in rural areas, where approximately 80% of human cases are concentrated. This article presents research conducted in riverine communities of the Tapajós/Arapiuns Extractive Reserve in Brazil to combat rabies in September 2022. The study adopted a participatory and collaborative approach, involving community members, healthcare professionals, and educators. Prioritizing proactive interventions, the health team administered prophylactic vaccinations to 30 individuals residing in communities exposed to the Lyssavirus. Educational activities focused on dispelling myths and raising awareness about preventive measures, with 100% of individuals reporting prior doubts about the disease, emphasizing the essential nature of the clarification, especially regarding preventive aspects. This study underscores the importance of community involvement, personalized interventions, and ongoing education to effectively combat rabies. By reinforcing public health policies and promoting health education, we can empower communities to take proactive measures in rabies prevention, leading to a reduction in incidence and an improvement in quality of life.

Fifty Years of the National Rabies Control Program in Brazil under the One Health Perspective

In 1973, the National Rabies Program was created in Brazil through an agreement between the Ministry of Health and Agriculture. Since its beginning, it developed integrated action through access to free post-exposure prophylaxis (PEP) for people at risk, dog vaccination campaigns, a joint surveillance system, and awareness. This study aims to describe human rabies in Brazil under the One Health perspective in recent decades, including achievements in the control of dog-mediated cases and challenges in human cases transmitted by wild animals. This paper also explores possible drivers of human rabies in the Northeast Region with half of the cases. The first part of this study was descriptive, presenting data and examples by periods. Statistical analysis was performed in the last period (2010-2022) to explore possible drivers. Dog-mediated human cases decreased from 147 to 0, and dog cases decreased from 4500 to 7. A major challenge is now human cases transmitted by wild animals (bats, non-human primates, and wild canids). Most current human cases occur in municipalities with a tropical and subtropical moist broadleaf forest biome and a Gini index higher than 0.5. In the multivariable analysis, an association with temperature was estimated (OR = 1.739; CI95% = 1.181-2.744), and primary healthcare coverage (OR = 0.947; CI95% = 0.915-0.987) was identified as a protector. It is possible to significantly reduce the number of dog-mediated human rabies cases through the efforts presented. However, Brazil has wildlife variants of the rabies virus circulating. The association of human cases with higher temperatures in the Northeast is a concern with climate change. To reduce human cases transmitted by wild animals, it is important to continue distributing free PEP, especially in remote at-risk areas in the Amazon Region, and to increase awareness.

Neuroimmunology of rabies: New insights into an ancient disease

Rabies is an ancient neuroinvasive viral (genus Lyssavirus, family Rhabdoviridae) disease affecting approximately 59,000 people worldwide. The central nervous system (CNS) is targeted, and rabies has a case fatality rate of almost 100% in humans and animals. Rabies is entirely preventable through proper vaccination, and thus, the highest incidence is typically observed in developing countries, mainly in Africa and Asia. However, there are still cases in European countries and the United States. Recently, demographic, increasing income levels, and the coronavirus disease 2019 (COVID-19) pandemic have caused a massive raising in the animal population, enhancing the need for preventive measures (e.g., vaccination, surveillance, and animal control programs), postexposure prophylaxis, and a better understanding of rabies pathophysiology to identify therapeutic targets, since there is no effective treatment after the onset of clinical manifestations. Here, we review the neuroimmune biology and mechanisms of rabies. Its pathogenesis involves a complex and poorly understood modulation of immune and brain functions associated with metabolic, synaptic, and neuronal impairments, resulting in fatal outcomes without significant histopathological lesions in the CNS. In this context, the neuroimmunological and neurochemical aspects of excitatory/inhibitory signaling (e.g., GABA/glutamate crosstalk) are likely related to the clinical manifestations of rabies infection. Uncovering new links between immunopathological mechanisms and neurochemical imbalance will be essential to identify novel potential therapeutic targets to reduce rabies morbidity and mortality.

Emergency response using oral rabies vaccination of dogs -field data from Namibia demonstrate high efficiency

Dog-mediated rabies is responsible for tens of thousands of human deaths annually, and in resource-constrained settings, vaccinating dogs to control the disease at source remains challenging for various reasons. Currently, rabies elimination efforts rely on mass dog vaccination by the parenteral route. While oral rabies vaccination (ORV) of dogs is primarily considered a tool to increase herd immunity, particularly by targeting free-roaming and stray dogs, here, we are showcasing an ORV-only approach as an emergency response model. Using a third-generation vaccine and a standardized egg-flavored bait, we assessed the effectiveness and vaccination under field conditions in the Zambezi region of Namibia. During this trial, with four teams and within four working days, 3097 dogs were offered a bait, of which 88,0% were considered vaccinated. Teams managed to vaccinate, on average, over 20 dogs/h, despite using a door-to-door vaccination approach. The favorable results both in terms of bait acceptance and successful vaccination as well as field applicability and effectiveness further support the great potential of ORV in dog rabies control programmes.

Addressing vaccine-preventable encephalitis in vulnerable populations

PURPOSE OF REVIEW

Vaccinations have been pivotal in lowering the global disease burden of vaccine-preventable encephalitides, including Japanese encephalitis, tick-borne encephalitis, measles encephalitis, and rabies encephalitis, among others.

RECENT FINDINGS

Populations vulnerable to vaccine-preventable infections that may lead to encephalitis include those living in endemic and rural areas, military members, migrants, refugees, international travelers, younger and older persons, pregnant women, the immunocompromised, outdoor, healthcare and laboratory workers, and the homeless. There is scope for improving the availability and distribution of vaccinations, vaccine equity, surveillance of vaccine-preventable encephalitides, and public education and information.

SUMMARY

Addressing these gaps in vaccination strategies will allow for improved vaccination coverage and lead to better health outcomes for those most at risk for vaccine-preventable encephalitis.

Rabies in a postpandemic world: resilient reservoirs, redoubtable riposte, recurrent roadblocks, and resolute recidivism

Rabies is an ancient disease. Two centuries since Pasteur, fundamental progress occurred in virology, vaccinology, and diagnostics-and an understanding of pathobiology and epizootiology of rabies in testament to One Health-before common terminological coinage. Prevention, control, selective elimination, and even the unthinkable-occasional treatment-of this zoonosis dawned by the twenty-first century. However, in contrast to smallpox and rinderpest, eradication is a wishful misnomer applied to rabies, particularly post-COVID-19 pandemic. Reasons are minion. Polyhostality encompasses bats and mesocarnivores, but other mammals represent a diverse spectrum of potential hosts. While rabies virus is the classical member of the genus, other species of lyssaviruses also cause the disease. Some reservoirs remain cryptic. Although global, this viral encephalitis is untreatable and often ignored. As with other neglected diseases, laboratory-based surveillance falls short of the notifiable ideal, especially in lower- and middle-income countries. Calculation of actual burden defaults to a flux within broad health economic models. Competing priorities, lack of defined, long-term international donors, and shrinking local champions challenge human prophylaxis and mass dog vaccination toward targets of 2030 for even canine rabies impacts. For prevention, all licensed vaccines are delivered to the individual, whether parenteral or oral-essentially 'one and done'. Exploiting mammalian social behaviors, future 'spreadable vaccines' might increase the proportion of immunized hosts per unit effort. However, the release of replication-competent, genetically modified organisms selectively engineered to spread intentionally throughout a population raises significant biological, ethical, and regulatory issues in need of broader, transdisciplinary discourse. How this rather curious idea will evolve toward actual unconventional prevention, control, or elimination in the near term remains debatable. In the interim, more precise terminology and realistic expectations serve as the norm for diverse, collective constituents to maintain progress in the field.

The Amazonian Tropical Bites Research Initiative, a hope for resolving zoonotic neglected tropical diseases in the One Health era

BACKGROUND

Neglected tropical diseases (NTDs) disproportionately affect populations living in resource-limited settings. In the Amazon basin, substantial numbers of NTDs are zoonotic, transmitted by vertebrate (dogs, bats, snakes) and invertebrate species (sand flies and triatomine insects). However, no dedicated consortia exist to find commonalities in the risk factors for or mitigations against bite-associated NTDs such as rabies, snake envenoming, Chagas disease and leishmaniasis in the region. The rapid expansion of COVID-19 has further reduced resources for NTDs, exacerbated health inequality and reiterated the need to raise awareness of NTDs related to bites.

METHODS

The nine countries that make up the Amazon basin have been considered (Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Surinam and Venezuela) in the formation of a new network.

RESULTS

The Amazonian Tropical Bites Research Initiative (ATBRI) has been created, with the aim of creating transdisciplinary solutions to the problem of animal bites leading to disease in Amazonian communities. The ATBRI seeks to unify the currently disjointed approach to the control of bite-related neglected zoonoses across Latin America.

CONCLUSIONS

The coordination of different sectors and inclusion of all stakeholders will advance this field and generate evidence for policy-making, promoting governance and linkage across a One Health arena.

Rabies in Bats (Chiroptera, Mammalia) in Brazil: Prevalence and Potential Risk Factors Based on Twenty Years of Research in the Northwestern Region of São Paulo, Brazil

The number of rabies cases in bats has increased recently in Brazil and in the state of São Paulo, representing a new epidemiological scenario for this zoonosis. This study aimed to analyze the prevalence of rabies in bats according to food habits, taxonomic classification, sex and season of the year to identify possible risk factors for rabies occurrence in bats. A retrospective analysis of 6389 records of bat samples, from different municipalities of São Paulo, submitted to rabies diagnosis and taxonomic identification was carried out at the Rabies Diagnostic and Chiroptera Laboratories of Unesp Araçatuba, São Paulo, Brazil, from 1998 to 2017. Seventy-six (1.1%) positive rabies cases were detected in bats from ten species and seven genera of three families. The number of rabies-positive cases was higher in the dry season, with a significant association. The prevalence was higher in the Vespertilionidae family (37), especially Myotis nigricans (19) and Eptesicus furinalis (14). Frugivorous bats had a greater association with positivity for rabies, whereas the variable "sex" had no association. We recommend that the surveillance and control of rabies should be undertaken primarily during the dry season, especially in the Vespertilionidae family species and other species with a frugivorous food habit.

Oral rabies vaccination of dogs-Experiences from a field trial in Namibia

Dog-mediated rabies is responsible for tens of thousands of human deaths annually, and in resource-constrained settings, vaccinating dogs to control the disease at source remains challenging. Currently, rabies elimination efforts rely on mass dog vaccination by the parenteral route. To increase the herd immunity, free-roaming and stray dogs need to be specifically addressed in the vaccination campaigns, with oral rabies vaccination (ORV) of dogs being a possible solution. Using a third-generation vaccine and a standardized egg-flavoured bait, bait uptake and vaccination was assessed under field conditions in Namibia. During this trial, both veterinary staff as well as dog owners expressed their appreciation to this approach of vaccination. Of 1,115 dogs offered a bait, 90% (n = 1,006, 95%CI:91-94) consumed the bait and 72.9% (n = 813, 95%CI:70.2-75.4) of dogs were assessed as being vaccinated by direct observation, while for 11.7% (n = 130, 95%CI:9.9-17.7) the status was recorded as "unkown" and 15.4% (n = 172, 95%CI: 13.4-17.7) were considered as being not vaccinated. Smaller dogs and dogs offered a bait with multiple other dogs had significantly higher vaccination rates, while other factors, e.g. sex, confinement status and time had no influence. The favorable results of this first large-scale field trial further support the strategic integration of ORV into dog rabies control programmes. Given the acceptance of the egg-flavored bait under various settings worldwide, ORV of dogs could become a game-changer in countries, where control strategies using parenteral vaccination alone failed to reach sufficient vaccination coverage in the dog population.

Of love and other demons: depicting human rabies in Colombia

Human rabies has been described by various cultures in many countries around the world. Gabriel García Márquez's novel Of love and other demons recounts the story of a girl who, in colonial Colombia in the 18^th century, was bitten by a rabid dog. This paper aims to review the general status of the disease in Colombia and interweave it with García Márquez's book. Developed countries have successfully controlled dog-mediated rabies virus transmission, whereas in some countries in Latin America wildlife and canine rabies are still an issue. Our approach suggests that although the measures that have been taken to mitigate dog-transmitted rabies have worked well in most parts of the world, greater efforts are required to control sylvatic rabies transmitted by bats or other mammals, as occurs in Colombia. Since developing countries are the most affected by the disease at present, transdisciplinary commitment between human and veterinary sectors is necessary to fight against rabies virus transmission.

Rabies in the Tropics

Purpose of Review

Rabies is an ancient yet still neglected tropical disease (NTD). This review focuses upon highlights of recent research and peer-reviewed communications on the underestimated tropical burden of disease and its management due to the complicated dynamics of virulent viral species, diverse mammalian reservoirs, and tens of millions of exposed humans and animals - and how laboratory-based surveillance at each level informs upon pathogen spread and risks of transmission, for targeted prevention and control.

Recent Findings

While both human and rabies animal cases in enzootic areas over the past 5 years were reported to PAHO/WHO and OIE by member countries, still there is a huge gap between these "official" data and the need for enhanced surveillance efforts to meet global program goals.

Summary

A review of the complex aspects of rabies perpetuation in human, domestic animal, and wildlife communities, coupled with a high fatality rate despite the existence of efficacious biologics (but no therapeutics), warrants the need for a One Health approach toward detection via improved laboratory-based surveillance, with focal management at the viral source. More effective methods to prevent the spread of rabies from enzootic to free zones are needed.

Review of Oral Rabies Vaccination of Dogs and Its Application in India

Oral rabies vaccines (ORVs) have been in use to successfully control rabies in wildlife since 1978 across Europe and the USA. This review focuses on the potential and need for the use of ORVs in free-roaming dogs to control dog-transmitted rabies in India. Iterative work to improve ORVs over the past four decades has resulted in vaccines that have high safety profiles whilst generating a consistent protective immune response to the rabies virus. The available evidence for safety and efficacy of modern ORVs in dogs and the broad and outspoken support from prominent global public health institutions for their use provides confidence to national authorities considering their use in rabies-endemic regions. India is estimated to have the largest rabies burden of any country and, whilst considerable progress has been made to increase access to human rabies prophylaxis, examples of high-output mass dog vaccination campaigns to eliminate the virus at the source remain limited. Efficiently accessing a large proportion of the dog population through parenteral methods is a considerable challenge due to the large, evasive stray dog population in many settings. Existing parenteral approaches require large skilled dog-catching teams to reach these dogs, which present financial, operational and logistical limitations to achieve 70% dog vaccination coverage in urban settings in a short duration. ORV presents the potential to accelerate the development of approaches to eliminate rabies across large areas of the South Asia region. Here we review the use of ORVs in wildlife and dogs, with specific consideration of the India setting. We also present the results of a risk analysis for a hypothetical campaign using ORV for the vaccination of dogs in an Indian state.

Epidemiological and numerical simulation of rabies spreading from canines to various human populations in mainland China

BACKGROUND

The mortality of humans due to rabies in China has been declining in recent years, but it is still a significant public health problem. According to the global framework, China strives to achieve the goal of eliminating human rabies before 2030.

METHODS

We reviewed the epidemiology of human deaths from rabies in mainland China from 2004 to 2018. We identified high risk regions, age and occupational groups, and used a continuous deterministic susceptibility-exposure-infection-recovery (SEIR) model with periodic transmission rate to explore seasonal rabies prevalence in different human populations. The SEIR model was used to simulate the data of human deaths from rabies reported by the Chinese Center for Disease Control and Prevention (China CDC). We calculated the relative transmission intensity of rabies from canines to different human groups, and they provided a reliable epidemiological basis for further control and prevention of human rabies.

RESULTS

Results showed that human deaths from rabies exhibited regional differences and seasonal characteristics in mainland China. The annual human death from rabies in different regions, age groups and occupational groups decreased steadily across time. Nevertheless, the decreasing rates and the calculated R0s of canines of various human groups were different. The transmission intensity of rabies from canines to human populations was the highest in the central regions of China, in people over 45 years old, and in farmers.

CONCLUSIONS

Although the annual cases of human deaths from rabies have decreased steadily since 2007, the proportion of human deaths from rabies varies with region, age, gender, and occupation. Further enhancement of public awareness and immunization status in high-risk population groups and blocking the transmission routes of rabies from canines to humans are necessary. The concept of One Health should be abided and human, animal, and environmental health should be considered simultaneously to achieve the goal of eradicating human rabies before 2030.

Rabies in Costa Rica - Next Steps Towards Controlling Bat-Borne Rabies After its Elimination in Dogs

Rabies is an acute, progressive encephalitis caused by a lyssavirus, with the highest case fatality of any conventional infectious disease. More than 17 different lyssaviruses have been described, but rabies virus is the most widely distributed and important member of the genus. Globally, tens of thousands of human fatalities still occur each year. Although all mammals are susceptible, most human fatalities are caused by the bites of rabid dogs, within lesser developed countries. A global plan envisions the elimination of human rabies cases caused via dogs by the year 2030. The combination of prophylaxis of exposed humans and mass vaccination of dogs is an essential strategy for such success. Regionally, the Americas are well on the way to meet this goal. As one example of achievement, Costa Rica, a small country within Central America, reported the last autochthonous case of human rabies transmitted by a dog at the end of the 1970s. Today, rabies virus transmitted by the common vampire bat, Desmodus rotundus, as well as other wildlife, remains a major concern for humans, livestock, and other animals throughout the region. This review summarizes the historical occurrence of dog rabies and its elimination in Costa Rica, describes the current occurrence of the disease with a particular focus upon affected livestock, discusses the ecology of the vampire bat as the primary reservoir relevant to management, details the clinical characteristics of recent human rabies cases, and provides suggestions for resolution of global challenges posed by this zoonosis within a One Health context.

The impact of the COVID-19 pandemic on rabies reemergence in Latin America: The case of Arequipa, Peru

In Latin America, there has been tremendous progress towards eliminating canine rabies. Major components of rabies elimination programs leading to these successes have been constant and regular surveillance for rabid dogs and uninterrupted yearly mass dog vaccination campaigns. Unfortunately, vital measures to control COVID-19 have had the negative trade-off of jeopardizing these rabies elimination and prevention activities. We aimed to assess the effect of interrupting canine rabies surveillance and mass dog vaccination campaigns on rabies trends. We built a deterministic compartment model of dog rabies dynamics to create a conceptual framework for how different disruptions may affect rabies virus transmission. We parameterized the model for conditions found in Arequipa, Peru, a city with active rabies virus transmission. We examined our results over a range of plausible values for R0 (1.36-2.0). Also, we prospectively evaluated surveillance data during the pandemic to detect temporal changes. Our model suggests that a decrease in canine vaccination coverage as well as decreased surveillance could lead to a sharp rise in canine rabies within months. These results were consistent over all plausible values of R0. Surveillance data from late 2020 and early 2021 confirms that in Arequipa, Peru, rabies cases are on an increasing trajectory. The rising rabies trends in Arequipa, if indicative to the region as whole, suggest that the achievements made in Latin America towards the elimination of dog-mediated human rabies may be in jeopardy.

Evaluation of the Worldwide Occurrence of Rabies in Dogs and Cats Using a Simple and Homogenous Framework for Quantitative Risk Assessments of Rabies Reintroduction in Disease-Free Areas through Pet Movements

Dog and cat rabies cases imported from rabies enzootic countries represent a major threat for areas that have acquired rabies-free status and quantitative risk analyses (QRAs) are developed in order to assess this risk of rabies reintroduction through dog and cat movements. Herein we describe a framework to evaluate dog and cat rabies incidence levels in exporting countries along with the associated uncertainty for such QRAs. For enzootic dog rabies areas (EDRAs), we extended and adapted a previously published method to specify the relationship between dog rabies vaccination coverage and canine rabies incidence; the relationship between dog and cat rabies incidences; and then to predict annual dog and cat rabies incidences. In non-enzootic dog rabies areas (nEDRAs), we provided annual incidence based on declared dog and cat rabies cases. For EDRAs, we predicted an annual incidence potentially greater than 1.5% in dogs and about ten times lower in cats with a high burden in Africa and Asia but much lower in Latin America. In nEDRAs, the occurrence of rabies was lower and of similar magnitude in dogs and cats. However, wildlife could still potentially infect dogs and cats through spillover events. This framework can directly be incorporated in QRAs of rabies reintroduction.

Experimental Lagos bat virus infection in straw-colored fruit bats: A suitable model for bat rabies in a natural reservoir species

Rabies is a fatal neurologic disease caused by lyssavirus infection. Bats are important natural reservoir hosts of various lyssaviruses that can be transmitted to people. The epidemiology and pathogenesis of rabies in bats are poorly understood, making it difficult to prevent zoonotic transmission. To further our understanding of lyssavirus pathogenesis in a natural bat host, an experimental model using straw-colored fruit bats (Eidolon helvum) and Lagos bat virus, an endemic lyssavirus in this species, was developed. To determine the lowest viral dose resulting in 100% productive infection, bats in five groups (four bats per group) were inoculated intramuscularly with one of five doses, ranging from 100.1 to 104.1 median tissue culture infectious dose (TCID50). More bats died due to the development of rabies after the middle dose (102.1 TCID50, 4/4 bats) than after lower (101.1, 2/4; 101.1, 2/4) or higher (103.1, 2/4; 104.1, 2/4) doses of virus. In the two highest dose groups, 4/8 bats developed rabies. Of those bats that remained healthy 3/4 bats seroconverted, suggesting that high antigen loads can trigger a strong immune response that abrogates a productive infection. In contrast, in the two lowest dose groups, 3/8 bats developed rabies, 1/8 remained healthy and seroconverted and 4/8 bats remained healthy and did not seroconvert, suggesting these doses are too low to reliably induce infection. The main lesion in all clinically affected bats was meningoencephalitis associated with lyssavirus-positive neurons. Lyssavirus antigen was detected in tongue epithelium (5/11 infected bats) rather than in salivary gland epithelium (0/11), suggesting viral excretion via the tongue. Thus, intramuscular inoculation of 102.1 TCID50 of Lagos bat virus into straw-colored fruit bats is a suitable model for lyssavirus associated bat rabies in a natural reservoir host, and can help with the investigation of lyssavirus infection dynamics in bats.

Update on lyssaviruses and rabies: will past progress play as prologue in the near term towards future elimination?

Rabies is an ancient, much-feared, and neglected infectious disease. Caused by pathogens in the family Rhabdoviridae, genus Lyssavirus, and distributed globally, this viral zoonosis results in tens of thousands of human fatalities and millions of exposures annually. All mammals are believed susceptible, but only certain taxa act as reservoirs. Dependence upon direct routing to, replication within, and passage from the central nervous system serves as a basic viral strategy for perpetuation. By a combination of stealth and subversion, lyssaviruses are quintessential neurotropic agents and cause an acute, progressive encephalitis. No treatment exists, so prevention is the key. Although not a disease considered for eradication, something of a modern rebirth has been occurring within the field as of late with regard to detection, prevention, and management as well as applied research. For example, within the past decade, new lyssaviruses have been characterized; sensitive and specific diagnostics have been optimized; pure, potent, safe, and efficacious human biologics have improved human prophylaxis; regional efforts have controlled canine rabies by mass immunization; wildlife rabies has been controlled by oral rabies vaccination over large geographic areas in Europe and North America; and debate has resumed over the controversial topic of therapy. Based upon such progress to date, there are certain expectations for the next 10 years. These include pathogen discovery, to uncover additional lyssaviruses in the Old World; laboratory-based surveillance enhancement by simplified, rapid testing; anti-viral drug appearance, based upon an improved appreciation of viral pathobiology and host response; and improvements to canine rabies elimination regionally throughout Africa, Asia, and the Americas by application of the best technical, organizational, economic, and socio-political practices. Significantly, anticipated Gavi support will enable improved access of human rabies vaccines in lesser developed countries at a national level, with integrated bite management, dose-sparing regimens, and a 1 week vaccination schedule.

Virome of crab-eating (Cerdocyon thous) and pampas foxes (Lycalopex gymnocercus) from southern Brazil and Uruguay

Crab-eating (Cerdocyon thous) and Pampas foxes (Lycalopex gymnocercus) are wild canids distributed in South America. Domestic dogs (Canis lupus familiaris) and wild canids may share viral pathogens, including rabies virus (RABV), canine distemper virus (CDV), and canine parvovirus 2 (CPV-2). To characterize the virome of these wild canid species, the present work evaluated the spleen and mesenteric lymph node virome of 17 crab-eating and five Pampas foxes using high-throughput sequencing (HTS). Organ samples were pooled and sequenced using an Illumina MiSeq platform. Additional PCR analyses were performed to identify the frequencies and host origin for each virus detected by HTS. Sequences more closely related to the Paramyxoviridae, Parvoviridae and Anelloviridae families were detected, as well as circular Rep-encoding single-stranded (CRESS) DNA viruses. CDV was found only in crab-eating foxes, whereas CPV-2 was found in both canid species; both viruses were closely related to sequences reported in domestic dogs from southern Brazil. Moreover, the present work reported the detection of canine bocavirus (CBoV) strains that were genetically divergent from CBoV-1 and 2 lineages. Finally, we also characterized CRESS DNA viruses and anelloviruses with marked diversity. The results of this study contribute to the body of knowledge regarding wild canid viruses that can potentially be shared with domestic canids or other species.

Towards the elimination of dog-mediated rabies: development and application of an evidence-based management tool

BACKGROUND

International organizations advocate for the elimination of dog-mediated rabies, but there is only limited guidance on interpreting surveillance data for managing elimination programmes. With the regional programme in Latin America approaching elimination of dog-mediated rabies, we aimed to develop a tool to evaluate the programme's performance and generate locally-tailored rabies control programme management guidance to overcome remaining obstacles.

METHODS

We developed and validated a robust algorithm to classify progress towards rabies elimination within sub-national administrative units, which we applied to surveillance data from Brazil and Mexico. The method combines criteria that are easy to understand, including logistic regression analysis of case detection time series, assessment of rabies virus variants, and of incursion risk. Subjecting the algorithm to robustness testing, we further employed simulated data sub-sampled at differing levels of case detection to assess the algorithm's performance and sensitivity to surveillance quality.

RESULTS

Our tool demonstrated clear epidemiological transitions in Mexico and Brazil: most states progressed rapidly towards elimination, but a few regressed due to incursions and control lapses. In 2015, dog-mediated rabies continued to circulate in the poorest states, with foci remaining in only 1 of 32 states in Mexico, and 2 of 27 in Brazil, posing incursion risks to the wider region. The classification tool was robust in determining epidemiological status irrespective of most levels of surveillance quality. In endemic settings, surveillance would need to detect less than 2.5% of all circulating cases to result in misclassification, whereas in settings where incursions become the main source of cases the threshold detection level for correct classification should not be less than 5%.

CONCLUSION

Our tool provides guidance on how to progress effectively towards elimination targets and tailor strategies to local epidemiological situations, while revealing insights into rabies dynamics. Post-campaign assessments of dog vaccination coverage in endemic states, and enhanced surveillance to verify and maintain freedom in states threatened by incursions were identified as priorities to catalyze progress towards elimination. Our finding suggests genomic surveillance should become increasingly valuable during the endgame for discriminating circulating variants and pinpointing sources of incursions.

The impact of the COVID-19 pandemic on rabies reemergence in Latin America: the case of Arequipa, Peru

Over the past decades, there has been tremendous progress towards eliminating canine rabies in Latin America. Major components of rabies prevention programs in Latin America leading to these successes have been constant and intense surveillance for rabid dogs and uninterrupted yearly mass dog vaccination campaigns. However, vital measures to control COVID-19 in Latin America have had the negative trade-off of jeopardizing these rabies elimination and prevention activities. In this paper, we aimed to assess the effect of interrupting canine rabies surveillance and mass dog vaccination campaigns on rabies trends. We built a deterministic compartment model of dog rabies dynamics parameterized for conditions found in Arequipa, Peru, where there is an ongoing dog rabies epidemic. Our model suggests that a decrease in canine vaccination coverage as well as decreased surveillance leading to an increased length of survival of infected dogs could lead to a sharp rise in canine rabies and, subsequently, human rabies risk. We examined our results over the best estimate of the basic reproductive number in Arequipa (R0 = 1.44) and a range of plausible values for R0 (1.36 - 2). The rising trend was consistent. It is very possible that COVID-19 will continue to challenge our public health departments in the short- and medium-term. Innovative strategies to conduct dog vaccination and rabies surveillance during these trying times should be considered to safeguard the achievements made in Latin America towards the elimination of dog-mediated human rabies.

Using Surveillance of Animal Bite Patients to Decipher Potential Risks of Rabies Exposure From Domestic Animals and Wildlife in Brazil

Direct contact with domestic animals and wildlife is linked to zoonotic spillover risk. Patients presenting with animal-bite injuries provide a potentially valuable source of surveillance data on rabies viruses that are transmitted primarily by animal bites. Here, we used passive surveillance data of bite patients to identify areas with high potential risk of rabies transmission to humans across Brazil, a highly diverse and populous country, where rabies circulates in a range of species. We analyzed one decade of bite patient data from the national health information system (SINAN) comprising over 500,000 patients attending public health facilities after being bitten by a domestic or wild animal. Our analyses show that, between 2008 and 2016, patients were mostly bitten by domestic dogs (average annual dog bite patients: 502,043 [436,391-544,564], annual incidence per state: 258 dog bites/100,000 persons) and cats (76,512 [56,588-97,580] cat bites, 41 cat bites/100,000/year), but bites from bats (4,172 [3,351-5,365] bat bites, 2.3/100,000/year), primates (3,320 [3,013-3,710] primate bites, 2.0/100,000/year), herbivores (1,908 [1,492-2,298] herbivore bites, 0.9/100,000/year) and foxes (883 [609-1,086] fox bites, 0.6/100,000/year) were also considerable. Incidence of bites due to dogs and herbivores remained relatively stable over the last decade. In contrast bites by cats and bats increased while bites by primates and foxes decreased. Bites by wild animals occurred in all states but were more frequent in the North and Northeast of Brazil, with over 3-fold differences in incidence between states across all animal groups. Most bites reported from domestic animals and wildlife occurred in urban settings (71%), except for bites from foxes, which were higher in rural settings (57%). Based upon the Ministry of Health guidelines, only half of patients received the correct Post-Exposure Prophylaxis following a bite by a suspect rabid animal. We identified areas and species of high-risk for potential zoonotic transmission of rabies in Brazil and reveal that, despite increasing human encroachment into natural ecosystems, only patients reporting bites by bats increased. Our study calls for future research to identity the socio-ecological factors underlying bites and the preventive measures needed to reduce their incidence and potential risk of rabies transmission.

WHO Rabies Modelling Consortium. Zero human deaths from dog-mediated rabies by 2030: perspectives from quantitative and mathematical modelling

Dog-mediated rabies continues to kill tens of thousands of people every year in low- and middle-income countries despite being an entirely vaccine-preventable disease. WHO and partners have launched a global campaign to reach zero human deaths from dog-mediated rabies by 2030. The primary tools for reaching this target are mass dog vaccination to interrupt transmission in domestic dog populations that maintain infection, appropriate post-exposure prophylaxis (PEP) for rabies-exposed persons to prevent the fatal onset of disease, together with education to support their effective uptake. Models have been developed to assess the feasibility, impact and cost-effectiveness of these measures. From these models, we argue that the 2030 target of zero human rabies deaths is achievable, but will require concerted effort, engagement and investment. A proposed Gavi investment in human rabies vaccines has potential to drive progress towards the 2030 target; however, concomitant investment is needed to scale up mass dog vaccination or this target will be missed. Predicted economic benefits of mass dog vaccination vary according to national PEP provisioning and healthcare access. Integrated Bite Case Management can enhance surveillance and rationalize PEP use, but needs adapting to and integrating within local health systems and international reporting systems to improve PEP accountability, monitor impacts and support verification of disease freedom. Modelling approaches need refining to project realistic and geographically specific timelines for achieving targets. Model iterations informed by data on the implementation of interventions can be used to evaluate progress and guide future strategies. Critically such models are needed to advocate for investment, since the greatest risk to the ‘Zero by 30’ strategy is the limited long-term cross-sectoral or targeted financing to support countries to deliver and sustain mass dog vaccination.

Barriers to attendance of canine rabies vaccination campaigns in Haiti, 2017

We conducted a cross-sectional survey to better understand the barriers to attendance at canine rabies vaccination campaigns in Haiti. A structured community-based questionnaire was conducted over a 15-day period during May-June 2017, focused on socio-economic status correlated with participation at canine rabies vaccination campaigns. Questions phrased as a bidding game were asked to determine individuals' willingness to pay (WTP) for dog rabies vaccination and willingness to walk (WTW) to fixed-point vaccination campaigns. The Kaplan-Meier estimator was applied to determine relationships between survey variables. Logistic regression was used to examine factors associated with participants' WTP and WTW. A total of 748 households from eight communities were surveyed. Respondents were predominantly female (54.4%) and had a median age of 45 years. The total number of owned dogs reported from households was 926, yielding a human-to-dog ratio in dog-owning households of 5.2:1. The majority of dogs (87.2%) were acquired for security, and 49% were allowed to roam freely; 42.0% of dog owners reported that they were unable to manage (or restrain) their dogs using a leash. Seventy per cent of dog owners were willing to pay up to 15.9 gourdes (0.25 USD) and/or walk up to 75 m to vaccinate their dogs. Households that owned free-roaming dogs, owned dogs for the purpose of companionship and owned dogs that they were unable to walk on a leash were associated with a higher WTP for vaccination. Living in Artibonite Department, having a middle or higher household income, and owning a dog for security purpose were associated with a higher WTW for vaccination. Low leash use and propensity for dogs to roam freely are barriers to successful fixed-point vaccination methods in Haiti, and alternative methods such as door to door (DD), capture-vaccinate-release (CVR) or oral vaccination should be explored. There may be some prospect for fee-for-service vaccination in Haiti; however, this programme should be introduced as a supplement, rather than a replacement for free rabies vaccination programmes so that mass dog vaccination is not discouraged.

Modern biologics for rabies prophylaxis and the elimination of human cases mediated by dogs

Introduction: Rabies is a major viral zoonosis and neglected tropical disease, with a global distribution. Humans, domestic animals, and wild mammals are susceptible to infection. Etiological agents reside in the Order Mononegavirales, Family Rhabdoviridae, Genus Lyssavirus. This acute, progressive encephalitis causes the highest case fatality of any conventional infectious disease. Tens of millions of humans become exposed annually to the bites of infected mammals, predominantly in Asia and Africa. Despite the existence of effective vaccines and immune globulins, tens of thousands of people, typically children in the developing world, succumb. Areas covered: Concentrating upon both historical and major published references from the peer-reviewed literature over the past 5 years, we describe current biologics for rabies prevention, newly recommended principles for prophylaxis, and relevant future products in the developmental pipeline. Expert opinion: Modern human rabies biologics are pure, potent, safe, and efficacious, when used in a timely and appropriate manner. Few individuals survive after clinical signs. Anti-viral compounds are not licensed. Experimental therapy, while obviously desirable, is highly controversial. Education on bite prevention and integrated risk management are critical. Access to affordable care, dose-sparing, and shortened regimens of human rabies biologics remain key.

Reviewing Solutions of Scale for Canine Rabies Elimination in India

Canine rabies elimination can be achieved through mass vaccination of the dog population, as advocated by the WHO, OIE and FAO under the 'United Against Rabies' initiative. Many countries in which canine rabies is endemic are exploring methods to access dogs for vaccination, campaign structures and approaches to resource mobilization. Reviewing aspects that fostered success in rabies elimination campaigns elsewhere, as well as examples of largescale resource mobilization, such as that seen in the global initiative to eliminate poliomyelitis, may help to guide the planning of sustainable, scalable methods for mass dog vaccination. Elimination of rabies from the majority of Latin America took over 30 years, with years of operational trial and error before a particular approach gained the broad support of decision makers, governments and funders to enable widespread implementation. The endeavour to eliminate polio now enters its final stages; however, there are many transferrable lessons to adopt from the past 32 years of global scale-up. Additionally, there is a need to support operational research, which explores the practicalities of mass dog vaccination roll-out and what are likely to be feasible solutions at scale. This article reviews the processes that supported the scale-up of these interventions, discusses pragmatic considerations of campaign duration and work-force size and finally provides an examples hypothetical resource requirements for implementing mass dog vaccination at scale in Indian cities, with a view to supporting the planning of pilot campaigns from which expanded efforts can grow.

WHO Rabies Modelling Consortium. Zero human deaths from dog-mediated rabies by 2030: perspectives from quantitative and mathematical modelling

Dog-mediated rabies continues to kill tens of thousands of people every year in low- and middle-income countries despite being an entirely vaccine-preventable disease. WHO and partners have launched a global campaign to reach zero human deaths from dog-mediated rabies by 2030. The primary tools for reaching this target are mass dog vaccination to interrupt transmission in domestic dog populations that maintain infection, appropriate post-exposure prophylaxis (PEP) for rabies-exposed persons to prevent the fatal onset of disease, together with education to support their effective uptake. Models have been developed to assess the feasibility, impact and cost-effectiveness of these measures. From these models, we argue that the 2030 target of zero human rabies deaths is achievable, but will require concerted effort, engagement and investment. A proposed Gavi investment in human rabies vaccines has potential to drive progress towards the 2030 target; however, concomitant investment is needed to scale up mass dog vaccination or this target will be missed. Predicted economic benefits of mass dog vaccination vary according to national PEP provisioning and healthcare access. Integrated Bite Case Management can enhance surveillance and rationalize PEP use, but needs adapting to and integrating within local health systems and international reporting systems to improve PEP accountability, monitor impacts and support verification of disease freedom. Modelling approaches need refining to project realistic and geographically specific timelines for achieving targets. Model iterations informed by data on the implementation of interventions can be used to evaluate progress and guide future strategies. Critically such models are needed to advocate for investment, since the greatest risk to the 'Zero by 30' strategy is the limited long-term cross-sectoral or targeted financing to support countries to deliver and sustain mass dog vaccination.

Increased detection of rabies virus in bats in Ceará State (Northeast Brazil) after implementation of a passive surveillance programme

The intensification of dog, cat and livestock vaccination campaigns significantly reduced rabies cases in humans and domestic animals in Ceará State, Brazil. However, sylvatic animals-bats (order Chiroptera), wild canids, raccoons and non-human primates- remain as reservoirs for the virus. Our hypothesis is that surveillance and monitoring of rabies virus in bats, especially passive surveillance, is of fundamental importance, besides the implementation of health education and strengthening of surveillance actions in humans exposed to aggressions. Thus, we assessed the occurrence of rabies virus in animals focusing on bats, before and after launching of the Sylvatic Rabies Surveillance Program in 2010. Surveillance data from the 184 municipalities of Ceará State were analysed, collected during the periods 2003-2010 (active surveillance) and 2011-2016 (passive surveillance), respectively. A total of 13,543 mammalian samples were received for rabies diagnosis from 2003 to 2016. Of these, 10,960 were from dogs or cats (80.9%), 1,180 from bats (8.7%), 806 from other sylvatic animals (foxes, marmosets, raccoons; 6.0%) and 597 from herbivores (cattle, goats, sheep, equines, pigs; 4.4%). A total of 588 (4.3%) samples were positive for rabies. About 8.4% (99/1,180) of the bat samples were infected with rabies virus, 92 (92.9%) of these were from non-haematophagous bat species and 7 (7.1%) from haematophagous species. The number of bat samples received and infection rates increased considerably, after a shift from active surveillance (9/355 [2.5%] samples positive), to passive surveillance (90/825 [10.9%] samples positive). Surveillance of rabies virus in bats is fundamental for human and domestic animal health in Ceará State. Bats have to be considered as targets in surveillance and control programmes. Virus lineages should be characterized to increase knowledge on transmission dynamics of sylvatic rabies virus to domestic animals and the human population, and to provide additional evidence for planning and implementation of improved control measures.

Rabies surveillance in wild mammals in South of Brazil

The sylvatic cycle of rabies, caused by the Rabies lyssavirus (RABV), is maintained in the American Continent by aerial and terrestrial wild mammals. In this study, we combined passive surveillance of rescued wild animals with active serological surveillance in targeting areas at Rio Grande do Sul State and Santa Catarina State, south of Brazil, where bites of humans by wild animals have been reported. Circulation of RABV in Brazilian bats has been extensively demonstrated; however, the observation of such infections in unvaccinated terrestrial mammals is restricted to some regions of the Brazilian territory. The occurrence of rabies infection in unvaccinated animals has been identified by the detection of RABV antigens in brain tissues of dead animals or anti-rabies antibodies in live animals. Such strategies allow the surveillance of rabies and the assessment of spillover risks from infected animals to humans. Our aim included the identification of species of wild mammals that are involved in the sylvatic cycle of rabies virus in Southern Brazil and to assess the risk of rabies infection in patients bitten by wild animals in the state. To assess the anti-rabies seropositivity, sera were submitted to the Rapid Fluorescent Focus Inhibition Test (RFFIT). Among the 100 mammals tested, five animals were seropositive (5%) including three (one primate and two wild canids) with rabies virus neutralizing antibodies titres >0.5 IU/ml. Our results highlight the exposure to RABV of both primates and wild canids in Southern Brazil and suggest the occurrence of RABV exposure without the development of further symptoms. Further research should clarify the dynamics of rabies in wild canids and whether primates are accidental hosts or reservoirs for RABV at this region.

Healthcare demand in response to rabies elimination campaigns in Latin America

The World Health Organization, the World Organization for Animal Health, and the Food and Agriculture Organization have resolved to eliminate human rabies deaths due to dog bites by 2030, and the Vaccine Alliance (Gavi) has added human rabies vaccines to their investments for 2021–2025. Implementing these goals cost-effectively and sustainably requires understanding the complex connections between dog rabies vaccination and human risk and response. The objective of this paper is to estimate how dog rabies vaccinations affect human rabies deaths, mediated through dog rabies cases, dog bite reporting, and post-exposure human rabies vaccination. To approach this objective, we apply multivariate regression analysis over five rabies-related outcomes: (a) dog vaccinations, (b) dog rabies cases, (c) reported human exposures, (d) human post-exposure prophylaxis (PEP) use, and (e) human rabies cases. Analysis uses aggregate annual data over 1995–2005 for seven Latin American countries that experienced dramatic declines in canine and human rabies. Among other results, we estimate the following. (i) A 10% increase in dog vaccinations decreases dog rabies cases by 2.3%. (ii) Reported exposures decline as concurrent dog rabies cases decline, but these declines are more than offset by increases in reported exposures per dog rabies case, which may result from higher rabies awareness due to anti-rabies campaigns. (iii) A 10% increase in PEP use decreases human deaths by 7%, but a 10% increase in dog vaccination induces a 2.8% decrease in PEP use. The net effect is that a 10% increase in dog vaccination reduces human deaths by 12.4% overall, although marginal effectiveness declines as dog rabies incidence declines. (iv) Increases in income and public health expenditures increase PEP demand. The findings highlight the importance of mass dog vaccination, heightened awareness, treatment access, and clinical algorithms to reduce both false negatives leading to death and false positives leading to costly unnecessary PEP prescriptions.

Several global health organizations have prioritized investment for global elimination of human death from canine rabies. Cost-effective deployment requires understanding complex connections between rabies risk and healthcare seeking behavior. During 1995–2005, there was a rapid decline in dog and human rabies cases in several Latin American countries following concerted investment in mass dog vaccinations and human post-exposure vaccination. Using data from this period, we econometrically estimate relationships between dog vaccinations, dog rabies cases, human exposure reports, human post-exposure prophylaxis (PEP) use, and human rabies deaths. We estimate quantitatively how dog vaccinations indirectly reduce human rabies deaths, mediated through dog rabies cases, dog bite reporting, and PEP use. We find that reported human exposures decline as dog rabies cases decline, but these declines are offset by increases in reported exposures per dog rabies case, which may be driven by increased rabies awareness through anti-rabies campaigns. Furthermore, while PEP demand declines as dog rabies cases decline, increases in income and public health expenditures concurrently increase demand for PEP. These findings provide better understanding of the underlying factors driving PEP demand and exposure (under)reporting to inform cost-effective policy design to reduce unnecessary PEP prescription and false negatives leading to human death.

A Novel Integrated and Labile eHealth System for Monitoring Dog Rabies Vaccination Campaigns

The elimination of canine rabies through the implementation of high coverage mass dog vaccination campaigns is a complex task, particularly in the resource-limited countries of the rabies endemic world. Here we demonstrated the feasibility of applying targeted rabies vaccination campaigns to deliver more impactful intervention campaigns in resource-limited settings using evidence and lessons learnt from other diseases. With the use of strategic rabies intervention programs, we demonstrate the noteworthy reduction of rabies cases in two very different African settings. The strategic intervention was most significantly aided by the use of a custom-developed vaccination tracking device (the Global Alliance for Rabies Control (GARC) Data Logger) and an integrated rabies surveillance system (the Rabies Epidemiological Bulletin). Our first case study, an island-wide strategic dog vaccination on Tanzania's Unguja island, reduced the incidence of rabies by 71% in the first 16 months of implementation. In the second case study, a similar approach was applied in the metropolitan capital city of Zimbabwe and the incidence of rabies declined by 13% during the first 13 months of implementation. The methodologies and results presented here suggest that, in resource-limited settings, an optimal approach towards the elimination of dog rabies would revolve around strategic interventions, subject to the use of appropriate planning, surveillance, and vaccination tools.

An evaluation of Brazil's surveillance and prophylaxis of canine rabies between 2008 and 2017

An effective surveillance system is critical for the elimination of canine rabies in Latin America. Brazil has made substantial progress towards canine rabies elimination, but outbreaks still occurred in the last decade in two states. Brazil uses a health information system (SINAN) to record patients seeking post-exposure prophylaxis (PEP) following contact with an animal suspected of having rabies. This study evaluated: (i) whether SINAN can be reliably used for rabies surveillance; (ii) if patients in Brazil are receiving appropriate PEP and (iii) the benefits of implementing the latest World Health Organization (WHO) recommendations on PEP. Analysing SINAN records from 2008 to 2017 reveals an average of 506,148 bite-injury patients/year [range: 437k-545k] in the country, equivalent to an incidence of 255 bite-injuries/100,000 people/year [range: 231–280]. The number of reports of bites from suspect rabid dogs generally increased over time. In most states, records from SINAN indicating a suspect rabid dog do not correlate with confirmed dog rabies cases reported to the Regional Information System for Epidemiological Surveillance of Rabies (SIRVERA) maintained by the Pan American Health Organization (PAHO). Analyses showed that in 2017, only 45% of patients received appropriate PEP as indicated by the Brazilian Ministry of Health guidance. Implementation of the latest WHO guidance using an abridged intradermal post-exposure vaccination regimen including one precautionary dose for dog bites prior to observation would reduce the volume of vaccine required by up to 64%, with potential for annual savings of over USD 6 million from reduced vaccine use. Our results highlight the need to improve the implementation of SINAN, including training of health workers responsible for delivering PEP using an Integrated Bite Case Management approach so that SINAN can serve as a reliable surveillance tool for canine rabies elimination.

Dog-mediated rabies has declined to only a few cases in Latin America over the last decade. Brazil has the largest human and dog population of Latin America. Despite the decline of canine rabies, the country’s public health system still spends millions of dollars annually on half a million patients seeking health care for dog bites. In this study, we analysed a decade of national surveillance data on dog bites. These data suggest that health workers report dog rabies in many states where the disease is likely to be absent, with false positive cases frequently reported into the surveillance system. In addition, only half of patients appear to receive the appropriate rabies post-exposure prophylaxis as recommended by the Ministry of Health. We estimated that Brazil could save up to USD 6 million per annum on vaccine by reducing the number of doses administered during prophylaxis and adopting the intradermal vaccine delivery technique following the latest WHO recommendations. Our study highlights an urgent need for updating health care workers on canine rabies knowledge, prophylaxis and assessment of dog bites to improve prophylaxis provision and surveillance of dog rabies.

Current status of human rabies prevention: remaining barriers to global biologics accessibility and disease elimination

Introduction: Rabies is a serious, neglected tropical disease. Zoonotic agents are RNA viruses (Genus Lyssavirus, Family Rhabdoviridae), global in distribution. As an acute, progressive, incurable encephalitis, rabies has the highest case fatality of any infectious disease. Warm-blooded vertebrates are susceptible hosts. Major mammalian reservoirs include mesocarnivores and bats. Given wildlife perpetuation, rabies is not eradicable, but is preventable and controllable, especially under newly available international guidelines. Areas covered: Literature review over the past 5 years reveals development of sensitive, specific diagnostic tests and safe and highly effective human and veterinary vaccines. Yet, tens of thousands of human fatalities occur annually, usually in Africa and Asia, primarily after canine exposure. Human and domestic animal vaccination, before or after exposure, is the single greatest preventative strategy following a rabid animal bite. Expert opinion: Significant progress occurred during the twenty-first century regarding vaccine development, doses, and schedules. Remaining barriers to widespread rabies vaccination include an inter-related set of economic, cultural, social, educational, ecological and technological factors. A basic understanding of local and regional root causes of cases historically allows for broader accessibility to vaccination in a trans-disciplinary fashion to meet the global elimination of human rabies caused via dogs (GEHRD) by 2030.

Size, spatial and household distribution, and rabies vaccination coverage of the Brazilian owned-dog population

Dog rabies and human rabies transmitted by dogs can be prevented through adequate dog vaccination coverage. For surveillance purposes, this coverage must be calculated using accurate population size estimates to avoid misleading conclusions. We used data from a Brazilian national survey comprising 64,348 households, to calculate point estimates and confidence intervals of the size, household density, and rabies vaccination coverage of the owned-dog population in Brazilian federative units. We also evaluated the precision of owned-dog population size estimates, based on the extrapolation among different areas, of the mean number of dogs per household and the human/dog ratio. The estimated owned-dog population size in Brazil was 52,198,324 (95% CI = 51,028,583-53,368,066) and the dog vaccination coverage was 80.09% (95% CI = 79.09%-81.09%). Both estimates had marked variation across Brazilian federative units and urban/rural strata. Only two of the 27 federative units had a confidence interval in rural vaccination coverage above 70% and six did not pass this threshold in their urban stratum. For the first time, we reported probabilistic estimates for an entire country and its main administrative areas. The estimated coverage for the country was high because the most populated federative unit also had high coverage. The mean number of dogs per household and the human/dog ratio were useful as survey estimates to characterize owned-dog density. However, the simple extrapolation of these parameters resulted in estimates of owned-dog population sizes with large errors (up to 254%) that must be interpreted with caution to avoid misleading conclusions. To evaluate the dog population size, we recommend the use of probabilistic sampling designs instead of simple human/dog ratio extrapolations, and the inclusion of animal-related questions in censuses and national surveys to obtain reliable estimates to support improvements in animal and human health.

Unbiased assessment of disease surveillance utilities: A prospect theory application

Objectives

We contribute a new methodological approach to the ongoing efforts towards evaluating public health surveillance. Specifically, we apply a descriptive framework, grounded in prospect theory (PT), for the evaluation of decisions on disease surveillance deployment. We focus on two attributes of any surveillance system: timeliness, and false positive rate (FPR).

Methods

In a sample of 69 health professionals from a number of health related networks polled online, we elicited PT preferences, specifically respondents’ attitudes towards gains, losses and probabilities (i.e., if they overweight or underweight extreme probabilities) by means of a series of lotteries for either timeliness or FPR. Moreover, we estimated willingness to pay (WTP) for improvements in the two surveillance attributes. For contextualization, we apply our framework to rabies surveillance.

Results

Our data reveal considerable probability weighting, both for gains and losses. In other words, respondents underestimate their chances of getting a good outcome in uncertain situations, and they overestimate their chances of bad outcomes. Moreover, there is convex utility for losses and loss aversion, that is, losses loom larger than gains of the same absolute magnitude to the respondents. We find no differences between the estimated parameters for timeliness and FPR. The median WTP is $7,250 per day gained in detection time and $30 per 1/10,000 reduction in FPR.

Conclusion

Our results indicate that the biases described by PT are present among public health professionals, which highlights the need to incorporate a PT framework when eliciting their preferences for surveillance systems.

In this paper we contribute a new methodological approach to the ongoing efforts towards evaluating public health surveillance. Specifically, we apply a descriptive framework for the evaluation of decisions on disease surveillance deployment. We focus on two attributes of any surveillance system: timeliness and false positive rates. In a sample of 69 health professionals from a number of health related networks polled online, we elicited preferences, specifically respondents’ attitudes towards gains, losses and probabilities (i.e., if they overweight or underweight extreme probabilities) by means of a series of lotteries. For contextualization, we apply our framework to rabies surveillance. Our data reveal that respondents underestimate their chances of getting a good outcome in uncertain situations, and they overestimate their chances of bad outcomes. Moreover, losses loom larger than gains of the same absolute magnitude to the respondents. We find no differences between the estimated parameters for timeliness and false positive rates. Our results indicate that the biases described are present among public health professionals, and highlight the need to adjust for them when eliciting their preferences for surveillance systems.

Oral bait handout as a method to access roaming dogs for rabies vaccination in Goa, India: A proof of principle study

Rabies has profound public health, social and economic impacts on developing countries, with an estimated 59,000 annual human rabies deaths globally. Mass dog vaccination is effective at eliminating the disease but remains challenging to achieve in India due to the high proportion of roaming dogs that cannot be readily handled for parenteral vaccination. Two methods for the vaccination of dogs that could not be handled for injection were compared in Goa, India; the oral bait handout (OBH) method, where teams of two travelled by scooter offering dogs an empty oral bait construct, and the catch-vaccinate-release (CVR) method, where teams of seven travel by supply vehicle and use nets to catch dogs for parenteral vaccination. Both groups parenterally vaccinated any dogs that could be held for vaccination. The OBH method was more efficient on human resources, accessing 35 dogs per person per day, compared to 9 dogs per person per day through CVR. OBH accessed 80% of sighted dogs, compared to 63% by CVR teams, with OBH accessing a significantly higher proportion of inaccessible dogs in all land types. All staff reported that they believed OBH would be more successful in accessing dogs for vaccination. Fixed operational team cost of CVR was four times higher than OBH, at 127 USD per day, compared to 34 USD per day. Mean per dog vaccination cost of CVR was 2.53 USD, whilst OBH was 2.29 USD. Extrapolation to a two week India national campaign estimated that 1.1 million staff would be required using CVR, but 293,000 staff would be needed for OBH. OBH was operationally feasible, economical and effective at accessing the free roaming dog population. This study provides evidence for the continued expansion of research into the use of OBH as a supplementary activity to parenteral mass dog vaccination activities in India.

Knowledge, attitudes, and practices regarding rabies in Grenada

Objective

While Grenada attained a zero-human-rabies case status since 1970, the authors conducted the first study to assess knowledge, attitudes, and practices that may contribute to this status as well as to receive feedback on the rabies control program in Grenada.

Methodology

A cross-sectional survey was conducted in July, 2017 with 996 households on the mainland. A questionnaire was administered to collect information on knowledge of rabies and prevention, vaccination practices, perception of institutional responsibilities for rabies control, and evaluation of the anti-rabies program.

Results

Of the 996 households, 617 (62%) had owners of animals that can be infected with rabies and were included in the analysis. Respondents were very aware of rabies as a disease that can infect animals and humans. The rate of participation in the vaccination program was 51.6% for pets and 38.0% for livestock. About 40% of respondents were knowledgeable about the extent of protection from the rabies vaccine. Respondents did not demonstrate exceptionally high levels of knowledge about animals that were likely to be infected with rabies, neither the anti-rabies programs that were conducted in Grenada. The three most frequent recommendations made to improve the rabies-control programs were: increase education programs, control the mongoose population, and expand the vaccination period each year.

Conclusions

Conducting a comprehensive national rabies education program, expanding the vaccination program, and increasing the rate of animal vaccination are important steps that need to be taken to maintain the current zero-human-case status.

About 62% of households in Grenada owned animals that are susceptible to rabies. Pets, particularly dogs, were more commonly owned than livestock. Males were more likely to correctly identify animals that are susceptible to rabies. The level of participation in the animal vaccination program was low, especially among owners of livestock. A lack of knowledge about the free anti-rabies vaccination service and the length of time that it took to vaccinate animals were the most common problems associated with the low vaccination rate. Increasing education programs, controlling the mongoose population, and increasing the vaccination times per year were the most frequent recommendations to improve the Ministry of Health rabies control programs. The anti-rabies program remains a critical step to maintain the current zero-human-case status in Grenada. There is a need to also expand the vaccination program and increase the rate of animal vaccination.

2018 international meeting of the Global Virus Network

The Global Virus Network (GVN) was established in 2011 to strengthen research and responses to emerging viral causes of human disease and to prepare against new viral pandemics. There are now 45 GVN Centers of Excellence and 7 Affiliate laboratories in 29 countries. The 10th International GVN meeting was held from November 28–30, 2018 in Veyrier du Lac, France and was co-hosted by the two GVN Centers of Excellence, the Mérieux Foundation and the University of Veterinary Medicine Hannover (TiHo). The theme of this 10th International GVN meeting was “Eradication and control of (re-) emerging viruses”. This report highlights the recent accomplishments of GVN researchers in several important areas of medical virology, including strategies for the eradication of smallpox, measles, polio, SARS and vector-borne or zoonotic infections, emergence and intervention strategies for retroviruses and arboviruses, preparedness for outbreaks of Filo- and other hemophilic viruses, pathogenesis, impact and prevention of respiratory viruses, as well as, viruses affecting the central and peripheral nervous system. Also threats in crisis settings like refugee camps were presented.

Priorities in applied research to ensure programmatic success in the global elimination of canine rabies

The elimination of human rabies mediated by dogs is attainable in concept, based upon current sensitive and specific diagnostic methods, existing safe and effective human and veterinary vaccines and a sound virological, pathological and epidemiological understanding of the disease. Globally, all developed countries achieved this goal. Regionally, major progress occurred throughout the Americas. However, less advancement is evident in Africa and Asia. Our objective was to concentrate upon those salient improvements to extant tools and methods over the next five years which could assist and simplify the task for both those developing countries that have already begun the process, as well as other localities in the earlier stages of consideration. We considered several categories of applied research which could be accomplished in the short term, based upon the available scientific evidence and recent recommendations from subject matter experts and key opinion leaders, focused upon perceived major limitations to prior program success. Areas of concentration included: laboratory-based surveillance, pathogen detection and characterization; human rabies prophylaxis; veterinary biologics; implementation of canine vaccination; and oral vaccination of free-ranging community dogs. Further real-time application in these core areas with proven techniques and technology would simplify attaining not only the global goal focused subtly upon human mortality, but the actual elimination of canine rabies as well.

Recent advances in the development of monoclonal antibodies for rabies post exposure prophylaxis: A review of the current status of the clinical development pipeline

Despite successful control in many parts of the world, rabies virus continues to result in tens of thousands of deaths each year. Death from rabies can be prevented by timely and appropriate post exposure prophylaxis including wound cleaning and administration of vaccine and rabies immunoglobulin. Currently, rabies immunoglobulin is derived from the blood plasma of horses or humans and has several limitations relating to supply, cost and quality. Monoclonal antibodies produced through recombinant DNA technologies could potentially overcome these limitations. The first anti-rabies monoclonal antibody has recently gained regulatory approval in India and there are several other candidates being evaluated in clinical trials. Given the advances in the field, rabies monoclonal antibodies have been recently considered by the World Health Organization's Strategic Advisory Group of Experts on Immunization and included in updated WHO immunization policy recommendations for rabies published in April 2018. This article reviews the current landscape of the clinical trial development of anti-rabies monoclonal antibodies and the historical clinical trial pathways followed for blood-derived rabies immunoglobulin before discussing challenges in the clinical evaluation, regulatory approval, uptake and monitoring of these products.