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.

Modelling modifiable factors associated with the probability of human rabies deaths among self-reported victims of dog bites in Abuja, Nigeria

Canine-mediated rabies kills tens of thousands of people annually in lesser-developed communities of Asia, Africa, and the Americas, primarily through bites from infected dogs. Multiple rabies outbreaks have been associated with human deaths in Nigeria. However, the lack of quality data on human rabies hinders advocacy and resource allocation for effective prevention and control. We obtained 20 years of dog bite surveillance data across 19 major hospitals in Abuja, incorporating modifiable and environmental covariates. To overcome the challenge of missing information, we used a Bayesian approach with expert-solicited prior information to jointly model missing covariate data and the additive effects of the covariates on the predicted probability of human death after rabies virus exposure. Only 1155 cases of dog bites were recorded throughout the study period, out of which 4.2% (N = 49) died of rabies. The odds for risk of human death were predicted to decrease among individuals who were bitten by owned dogs compared to those bitten by free-roaming dogs. Similarly, there was a predicted decrease in the probability of human death among victims bitten by vaccinated dogs compared to those bitten by unvaccinated dogs. The odds for the risk of human death after bitten individuals received rabies prophylaxis were predicted to decrease compared to no prophylaxis. We demonstrate the practical application of a regularised Bayesian approach to model sparse dog bite surveillance data to uncover risk factors for human rabies, with broader applications in other endemic rabies settings with similar profiles. The low reporting observed in this study underscores the need for community engagement and investment in surveillance to increase data availability. Better data on bite cases will help to estimate the burden of rabies in Nigeria and would be important to plan effective prevention and control of this disease.

COVID-19 Vaccine Hesitancy and Determinants of Acceptance among Healthcare Workers, Academics and Tertiary Students in Nigeria

The COVID-19 pandemic has resulted in millions of human deaths, prompting the rapid development and regulatory approval of several vaccines. Although Nigeria implemented a COVID-19 vaccination program on 15 March 2021, low vaccine acceptance remains a major challenge. To provide insight on factors associated with COVID-19 vaccine hesitancy (VH), we conducted a national survey among healthcare workers, academics, and tertiary students, between 1 September 2021 and 31 December 2021. We fitted a logistic regression model to the data and examined factors associated with VH to support targeted health awareness campaigns to address public concerns and improve vaccination rates on par with global efforts. A total of 1525 respondents took part in the survey, composed of healthcare-workers (24.5%, 373/1525), academics (26.9%, 410/1525), and students (48.7%, 742/1525). Only 29% (446/1525) of the respondents were vaccinated at the time of this study. Of the 446 vaccinated respondents, 35.7% (159/446), 61.4% (274/446) and 2.9% (13/446) had one, two and three or more doses, respectively. Reasons for VH included: difficulty in the vaccination request/registration protocols (21.3%, 633/1079); bad feelings towards the vaccines due to negative social media reports/rumours (21.3%, 633/1079); personal ideology/religious beliefs against vaccination (16.7%, 495/1079); and poor confidence that preventive measures were enough to protect against COVID-19 (11%, 323/1079). Some health concerns that deterred unvaccinated respondents were: innate immunity issues (27.7%, 345/1079); allergic reaction concerns (24.6%, 307/1079); and blood clot problems in women (21.4%, 266/1079). In the multivariable model, location of respondents/geopolitical zones, level of education, testing for COVID-19, occupation/job description and religion were significantly associated with VH. Findings from this study underscore the need for targeted awareness creation to increase COVID-19 vaccination coverage in Nigeria and elsewhere. Besides professionals, similar studies are recommended in the general population to develop appropriate public health interventions to improve COVID-19 vaccine uptake.

COVID-19 pandemic and its impacts on the environment: A global perspective

Many researchers worldwide have focused on the health impact of the coronavirus disease 2019 (COVID-19) pandemic without paying much emphasis to the environmental impacts associated with the pandemic. Evidence suggests that prior to the pandemic there was an alarming increase in environmental pollution due to rising industrialization, in particular in urban areas. Following the COVID-19 pandemic, satellite data over Asia and Europe showed a substantial decrease in air pollution, in particular nitrogen dioxide. However, the increase in industrial and household wastes may pose a significant challenge to environmental management. The improper management of these wastes poses an unforeseen "knock-on" effect on human health and the environment. It is imperative to establish an effective and safe procedure, for handling and disposing of the consequential wastes accumulating during the pandemic. The review aims to highlight both the beneficial and detrimental effects of COVID-19 pandemic on the natural environment and to discuss the possible strategies to improve the quality of the global environment during the period of the pandemic and beyond.

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.

Spatiotemporal heterogeneity and determinants of canine rabies evidence at Local Government Area Level in Nigeria: Implications for rabies prevention and control

Canine rabies poses a significant risk to humans and animals in Nigeria. However, the lack of reliable tools to evaluate the performance of existing canine rabies control programs to inform public health policy decisions poses a severe obstacle. We obtained canine rabies surveillance data from the National Veterinary Research Institute (NVRI) and supplemented these data with rabies diagnoses reported in the published studies from Nigeria. To uncover contextual factors (i.e., environmental and sociodemographic) associated with canine rabies evidence at the Local Government Area (LGA) level, we classified LGAs in Nigeria into four categories based on evidence availability (i.e., LGAs with NVRI data or published studies, both, or no evidence). We described the geographical and temporal variation in coverage. We fitted a multinomial regression model to examine the association between LGA level canine rabies evidence and potential sociodemographic and ecological determinants of canine rabies evidence. The effective annual testing during the 19 years was less than one dog/100,000 Nigerian resident-year. Our results showed that 58% of Nigerian LGAs (450/774) had not been targeted by the existing national rabies surveillance or studies on rabies, including ten states capitals with high human populations. While 16% (122/774) of Nigerian LGAs concentrated in Taraba, Adamawa, and Abia had canine rabies evidence from published studies, none of these LGAs was represented in the NVRI rabies surveillance data. We also observed an increasing trend in rabies evidence over time towards the eastern part of Nigeria. Our multinomial regression model indicated that education level, poverty, population density, land use and temperature were significantly associated with canine rabies evidence at the LGA level. This study underscores the value of combining canine rabies evidence from different sources to better understand the current disease situation for targeted intervention.

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This study shows the value of combining different evidence sources to advocate for public health interventions.

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Educational level, poverty, population density, land use and temperature were determinants of evidence of canine rabies.

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Such evidence demonstrates the need to expand Nigeria's rabies laboratory-based surveillance to support rabies prevention.

Rabies epidemiology, prevention and control in Nigeria: Scoping progress towards elimination

Background

Human rabies remains a significant public health problem in Africa with outbreaks reported in most countries. In Nigeria–the most populous country in Africa–rabies causes a significant public health burden partly due to perennial obstacles to implementing a national prevention and control program.

Methods

We conducted a scoping review using standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify and select published articles from Nigeria during 1978–2020 reporting on rabies virus infections (human, canine, livestock, and wildlife), canine bites, knowledge, attitudes and practices (KAP) surveys on rabies and canine ecology studies. We extracted information on study location, year and additional details of each study such as rabies prevalence, general characteristics of offending dogs, dog vaccination status and health-seeking behaviours.

Findings

Between 1978 and 2020, 90 published articles met our inclusion criteria. The prevalence of rabies virus antigen detection varied between 3% and 28%, with more studies in the north. Most bites were unprovoked from dog bite studies (36.4%-97%), by dogs with low vaccination rates (12–38%). A more significant proportion of biting dogs were owned (31–90%). Laboratory confirmation for biting was available for only a small proportion of studies (6%; n = 2/32). Of the dogs surveyed during ecology studies, indigenous dogs accounted for the majority (62–98%), used mostly for security purposes (52–98%), with the vaccination rate between 15% and 38% in most states. Studies conducted in areas distant from rabies diagnostic facilities accounted for more human rabies cases and fewer dog rabies cases.

Conclusion

Significant improvements are necessary to achieve the elimination of human rabies mediated via dogs by 2030.

Rabies remains one of the deadliest zoonoses known to humanity since antiquity, resulting in tens of thousands of human deaths each year, mostly in African and Asian countries. Mass dog vaccination, enhanced surveillance, improved access to Pre-exposure prophylaxis(PrE) and (Post-exposure prophylaxis(PEP) to at-risk groups, enforcement of responsible dog ownership and public education are keystones to rabies prevention and control. Since the first reported case in Nigeria during 1912, rabies has continued to take its toll on human and animal lives. However, gross underreporting due to a frail health care infrastructure, deficient reporting systems, and misdiagnosis with neurological diseases further complicated by socio-cultural practices have resulted in a lack of empirical data to support rabies prioritization, per the global target of 2030. We used the standard PRISMA guidelines to select Nigerian rabies studies between 1978 and 2020. Rabies risk, coupled with welfare concerns identified in this study, demonstrates the need for continued advocacy towards legislation prohibiting the dog trade in Nigeria and elsewhere. The high-risk community groups identified in this review (i.e., children, butchers, and adult males) need to be educated on response to dog bite exposure to reduce the impact of this invariable fatal but preventable disease. Moreover, there is a need for mandatory dog vaccination and implementation of a national rabies program to attain the World Health Organization (WHO) recommended vaccination coverage of at least 70%. We unravel the need to establish rabies diagnostic centres in the country’s six geopolitical zones. Local inclusion of dog bite occurrence by Disease Surveillance and Notification Officers (DSNOs), with related community surveillance tools, can help in rabies/dog surveillance. In addition, there is a need for investment into pathogen discovery by enhancing laboratory-based surveillance for wildlife rabies, understanding its potential role in Nigeria and the need for quantitative research to understand the various risk factors for disease perpetuation.

Bat and Lyssavirus Exposure among Humans in Area that Celebrates Bat Festival, Nigeria, 2010 and 2013

Using questionnaires and serologic testing, we evaluated bat and lyssavirus exposure among persons in an area of Nigeria that celebrates a bat festival. Bats from festival caves underwent serologic testing for phylogroup II lyssaviruses (Lagos bat virus, Shimoni bat virus, Mokola virus). The enrolled households consisted of 2,112 persons, among whom 213 (10%) were reported to have ever had bat contact (having touched a bat, having been bitten by a bat, or having been scratched by a bat) and 52 (2%) to have ever been bitten by a bat. Of 203 participants with bat contact, 3 (1%) had received rabies vaccination. No participant had neutralizing antibodies to phylogroup II lyssaviruses, but >50% of bats had neutralizing antibodies to these lyssaviruses. Even though we found no evidence of phylogroup II lyssavirus exposure among humans, persons interacting with bats in the area could benefit from practicing bat-related health precautions.

Profiling the public health risk of canine rabies transmission in Kogi state, Nigeria

Recently reports have emerged of rabies outbreaks in townships close to the city of Lokoja, the capital city of Kogi State in Nigeria. Areas in Lokoja are known to have high rates of dog bites and dogs are frequently butchered for human consumption, both of which may constitute risk factors for rabies transmission. However, data on the relative importance of these factors on canine rabies exposure in the densely populated capital of Kogi State is scarce. To understand the risk for public health two separate observational cross-sectional studies were conducted in Lokoja. Firstly, a retrospective study was performed to investigate the human profile of dog bite injuries and quantify the vaccination coverage of offending dogs. Information on dog bite cases and vaccination records covering of 11 years (2003-2013) were obtained from the largest public veterinary clinic (i.e. State Veterinary Clinic) and a private veterinary clinic in Lokoja. Then, an investigation of the presence of rabies antigen in the brain tissues of dogs slaughtered for human consumption in Lokoja was performed. A total of 208 canine brain samples from five slaughter points within the army barracks (the main venue in Lokoja where dogs are slaughtered for human consumption) were examined by fluorescent antibody technique. Out of 95 human dog bite cases, 46 (48.4%) were in persons between 10 and 19 years of age and 57 (60%) were males. There was a statistically significant association between gender of victims and their age, with a greater proportion of bites in males <10 years of age compared to other age groups (P < .001). Our results indicated a higher frequency of dog bites on the legs (51%) than other parts of the body; vaccination rates of offending dogs were lower compared to the general population of dogs presenting to clinics in Lokoja (25% vs 31%, respectively). Rabies antigen was detected in 11/203 (5.3%) brain samples from dogs slaughtered for human consumption. Paediatric dog bites and dog slaughtering practices represent a significant public health risk to residents of Lokoja in the context of rabies exposure. In order to minimize the risk of rabies outbreaks in children and people butchering, handling and consuming dog meat, dog vaccination and health promotion and education should be prioritized to these high risk groups.

Two fatal cases of rabies in humans who did not receive rabies postexposure prophylaxis in Nigeria

These two cases highlight some of the many challenges encountered when handling dog bite and rabies exposure. They also provide examples of the many barriers, and while highlighting only two individuals, they are likely representative of large numbers of the over 59 000 people that die every year from this preventable disease.

Canine babesiosis in a male Boerboel: Hematobiochemical and anatomic pathological changes in the cardiorespiratory and reproductive organs

A 9-month old male Boerboel was presented at the University of Abuja Small Animal Clinic with a primary complaint of inappetence and micturition with brownish-yellow urine. Physical examination revealed pale mucous membranes, enlarged pre-scapular lymph nodes, bilateral ocular discharges, pyrexia (41.2 °C), depression and the presence of ticks of the genus Rhipicephalus sanguineus on the body of the animal. History revealed that the dog was recently vaccinated against canine distemper, hepatitis, leptospirosis, parainfluenza, parvovirus (DHLPP) and rabies six days prior to the onset of clinical signs, and had been anorexic. Following clinical examination, blood and faecal samples were collected for biochemical and parasitological analyses, and the results revealed the presence of intraerythrocytic Babesia parasites, normocytic and normochromic anaemia with extensive cellular damage. However, during the course of the investigation, the dog died. With appropriate consent, a post-mortem examination was carried out. Diffuse oedema with interstitial pneumonia in the lung, focal haemorrhage with cellular infiltration in the heart and progressive necrosis of epithelial cells within the seminiferous tubules of the testicles were observed. Many of the observed clinicopathological alterations were consistent with complicated babesiosis. However, in the current case, some unique systemic complications such as testicular degeneration, which has not been previously observed in the Boerboel are discussed.

Dog ecology and its implications for rabies control in Gwagwalada, Federal Capital Territory, Abuja, Nigeria

The objectives of this study were to determine the characteristics of a dog population, including their accessibility to vaccination and health care, in urban and semiurban areas of Gwagwalada, Abuja, Nigeria. Direct street counts and a house-to-house survey of city streets were performed. A total of 451 households were surveyed comprising 43.7% urban and 53.3% semiurban areas. A total of 848 owned dogs were identified, along with 3,115 corresponding humans. With a dog-to-human ratio of 1:3.7, the dog population in the study area was estimated as 103,758. A total of 396 dogs were counted on the streets with the greater proportion (74%) in semiurban areas. Most dogs in semiurban areas (77.3%) had no certificate confirming vaccination against rabies, compared to 47.2% in urban areas (p = .004). The majority of dogs in the urban (60.9%) and semiurban (82.0%) were free roaming. In the multivariable model, age, presence of a collar, region, sex, use and having ever visited a veterinarian were significantly associated with rabies vaccination. The majority (125/197, 63.5%) of respondents with higher education were willing to pay more for the healthcare needs of their dogs as opposed to those with a lower level of education (93/251, 37.1%, p = .001). The study revealed a high dog population density, vaccination coverage below WHO recommendation of 70% and generally reduced healthcare-seeking behaviour among dog owners in Gwagwalada, Abuja, Nigeria.