Current status of rabies and prospects for elimination

Magnetic resonance imaging in rabies encephalitis, a case report, and review of the literature

Rabies is an acute fatal disease of the central nervous system. Neuroimaging plays an important role, especially in establishing an early diagnosis and distinguishing it from other types of encephalitis. This case report aims to give a brief review of this condition and report the less common MRI findings of the disease. We herein report a case of a 61-year-old male bitten by a stray dog who presented with fever, vomiting, headache, sialorrhea, dysarthria, dysphagia, and upper limb weakness which progressed to lower limbs on the next day. T2W and FLAIR images demonstrated subtle bilateral hyperintense signal in the deep gray matter with more apparent increased signal intensity in the white matter of the frontal and parietal lobes which shows mild diffusion restriction but no postcontrast enhancement. The diagnosis of rabies encephalitis was made based on a typical history of exposure, a compatible clinical presentation, and MRI findings. Rabies diagnosis is essentially clinical. It is definitively confirmed by the isolation of the virus from biological samples such as saliva, CSF, hair, or detection of rabies antigens or antibodies. Magnetic resonance imaging (MRI) brain used as one of the modalities of investigation for distinguishing it from other encephalitis. Rabies per se does not have any characteristic features on the MRI brain.

Spatial accessibility and inequality analysis of rabies-exposed patients to rabies post-exposure prophylaxis clinics in Guangzhou City, China

BACKGROUND

The incidence of rabies exposure is high and increasing in China, leading to an urgent demand of rabies post-exposure prophylaxis (PEP) clinics for the injured. However, the spatial accessibility and inequality of rabies-exposed patients to rabies PEP clinics is less known in China.

METHODS

Based on rabies exposure data, PEP clinic data, and resident travel origin-destination (OD) matrix data in Guangzhou City, China, we first described the incidence of rabies exposure in Guangzhou from 2020 to 2022. Then, the Gaussian two-step floating catchment area method (2SFCA) was used to analyze the spatial accessibility of rabies-exposed patients to rabies PEP clinics in Guangzhou, and the Gini coefficient and Moran's I statistics were utilized to evaluate the inequality and clustering of accessibility scores.

RESULTS

From 2020 to 2022, a total of 524,160 cases of rabies exposure were reported in Guangzhou, and the incidence showed a significant increasing trend, with an average annual incidence of 932.0/100,000. Spatial accessibility analysis revealed that the overall spatial accessibility scores for three scenarios (threshold of driving duration [d0] = 30 min, 45 min, and 60 min) were 0.30 (95% CI: 0.07, 0.87), 0.28 (95% CI: 0.11, 0.53) and 0.28 (95% CI: 0.14, 0.44), respectively. Conghua, Huangpu, Zengcheng and Nansha districts had the higher accessibility scores, while Haizhu, Liwan, and Yuexiu districts exhibited lower spatial accessibility scores. The Gini coefficient and Moran's I statistics showed that there were certain inequality and clustering in the accessibility to rabies PEP clinics in Guangzhou.

CONCLUSIONS

This study clarifies the heterogeneity of spatial accessibility to rabies PEP clinics, and provide valuable insights for resource allocation to achieve the WHO target of zero human dog-mediated rabies deaths by 2030.

Knowledge, attitudes, and practices of healthcare professionals regarding rabies in tertiary care hospitals: A cross-sectional study in Peshawar, Pakistan

BACKGROUND

Rabies, caused by the rhabdovirus, is a fatal zoonotic disease with over 59,000 annual deaths globally. Asia and Africa account for 95%, with India leading, followed by China. In Pakistan, where it's endemic, over 50,000 cases are reported yearly. Controlling rabid dog populations through vaccination is crucial in curbing mortality. This research aimed to evaluate healthcare professionals' knowledge, attitudes, and practices concerning rabies in Peshawar, Pakistan.

METHODS

The study was conducted at different tertiary care hospitals in Peshawar, Pakistan from 16 August 2021 to 15 February 2022. Cross-sectional research was conducted to gather data from a total of 100 healthcare workers representing different sections within the healthcare field, including Medical Officers, House Officers, Faculty Staff, Nurses, and Paramedics. Data on knowledge, attitudes, and practices about rabies were collected using a standardized questionnaire. The data analysis included using descriptive statistics and chi-square testing to ascertain potential correlations.

RESULTS

Among the healthcare professionals, 68 (68%) were males, and 32 (32%) were females. Profession-wise, the included professionals were Nurses 31 (31%), Medical Officers 27 (27%), House officers 26 (26%), paramedical staff 13 (13%), and faculty staff 3 (3%). 91 (91%) and 9 (9%) healthcare professionals responded that dogs and cats are responsible for rabies transmission, respectively. Moreover, 82 (82%) individuals responded that animal bite plays a vital role in the transmission of rabies, whilst 76 (76%) individuals responded that rabies transferred from human to human. 82 (82%) individuals replied that the anti-rabies vaccine (ARV) is the treatment of choice for rabies. Furthermore, 78 (78%) individuals responded that ARV is safe in pregnancy and lactation. Moreover, after being asked about the perception of the health care professionals about the failure in controlling rabies, their responses were unavailability of ARV/RIG 41 (41%), lack of control of stray dogs 34 (34%), lack of awareness 20 (20%). The study revealed statistically significant correlations between healthcare occupations and variables: knowledge of animals responsible for transmitting rabies (p = 0.024) and awareness of human-to-human transmission (p = 0.007). Significant disparities were noted in understanding rabies transmission through contaminated water (p = 0.002). There were variations in attitudes and practices seen across different positions, particularly about views about home treatments (p = 0.033) and the perceived effectiveness of cleansing bite wounds (p = 0.010). Disparities in perceptions of rabies treatment and the accessibility of anti-rabies vaccines and immunoglobulin were observed, with variations based on individual roles.

CONCLUSION

The present research elucidates variations in rabies knowledge, attitudes, and practices among healthcare workers, specifically concerning their respective roles. Tailored training programs and standardized practices play a crucial role in mitigating these discrepancies, fostering a greater understanding of rabies, and enhancing the quality of patient treatment. It is recommended that future studies undertake an assessment of the efficacy of therapies and advocate for the adoption of collaborative One Health strategies in the realm of rabies management.

Construction of Vero cell-adapted rabies vaccine strain by five amino acid substitutions in HEP-Flury strain

Rabies virus (RABV) causes fatal neurological disease. Pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) using inactivated-virus vaccines are the most effective measures to prevent rabies. In Japan, HEP-Flury, the viral strain, used as a human rabies vaccine, has historically been propagated in primary fibroblast cells derived from chicken embryos. In the present study, to reduce the cost and labor of vaccine production, we sought to adapt the original HEP-Flury (HEP) to Vero cells. HEP was repeatedly passaged in Vero cells to generate ten- (HEP-10V) and thirty-passaged (HEP-30V) strains. Both HEP-10V and HEP-30V grew significantly better than HEP in Vero cells, with virulence and antigenicity similar to HEP. Comparison of the complete genomes with HEP revealed three non-synonymous mutations in HEP-10V and four additional non-synonymous mutations in HEP-30V. Comparison among 18 recombinant HEP strains constructed by reverse genetics and vesicular stomatitis viruses pseudotyped with RABV glycoproteins indicated that the substitution P(L115H) in the phosphoprotein and G(S15R) in the glycoprotein improved viral propagation in HEP-10V, while in HEP-30V, G(V164E), G(L183P), and G(A286V) in the glycoprotein enhanced entry into Vero cells. The obtained recombinant RABV strain, rHEP-PG4 strain, with these five substitutions, is a strong candidate for production of human rabies vaccine.

Rabies Virus Infection Causes Pyroptosis of Neuronal Cells

Rabies virus (RABV) is a neurotropic virus that causes fatal neurological disease, raising serious public health issues and attracting extensive attention in society. To elucidate the molecular mechanism of RABV-induced neuronal damage, we used hematoxylin-eosin staining, transmission electron microscopy, transcriptomics analysis, and immune response factor testing to investigate RABV-infected neurons. We successfully isolated the neurons from murine brains. The specificity of the isolated neurons was identified by a monoclonal antibody, and the viability of the neurons was 83.53-95.0%. We confirmed that RABV infection induced serious damage to the neurons according to histochemistry and transmission electron microscope (TEM) scanning. In addition, the transcriptomics analysis suggested that multiple genes related to the pyroptosis pathway were significantly upregulated, including gasdermin D (Gsdmd), Nlrp3, caspase-1, and IL-1β, as well as the chemokine genes Ccl2, Ccl3, Ccl4, Ccl5, Ccl7, Ccl12, and Cxcl10. We next verified this finding in the brains of mice infected with the rRC-HL, GX074, and challenge virus standard strain-24 (CVS-24) strains of RABV. Importantly, we found that the expression level of the Gsdmd protein was significantly upregulated in the neurons infected with different RABV strains and ranged from 691.1 to 5764.96 pg/mL, while the basal level of mock-infected neurons was less than 100 pg/mL. Taken together, our findings suggest that Gsdmd-induced pyroptosis is involved in the neuron damage caused by RABV infection.

Assessment of respondents' knowledge, attitudes, and practices toward rabies and associated risk factors in Shone Town, Southern Ethiopia

IMPORTANCE

Rabies is a neglected tropical viral disease most often transmitted through the bite of an infected animal.

OBJECTIVE

This study assessed the level of knowledge, attitudes, and practices of the Shone Town community toward rabies.

METHODS

A survey-based cross-sectional study was conducted in Shone town, Ethiopia, from November 2022 to April 2023. Woreda was selected purposefully, while Kebeles and the study populations were selected by simple random sampling. Four hundred and sixteen respondents were interviewed using a semi-structured questionnaire.

RESULTS

All respondents had heard about rabies from different sources, with the majority hearing from informal sources (62%). Approximately 51.9%, 0.7%, and 47.4% of individuals were aware of saliva contact, rabid animal bites, and both as means of transmission, respectively. The survey showed that 64.4% of participants knew the 100% fatal nature of rabies once the clinical signs developed, and 35.6% did not. Approximately 51.4% of respondents agreed that killing stray dogs was an effective method for rabies prevention. In this study, 72.6% of the respondents had contact with pets, and 36.8% of the interviewees had vaccinated their dogs. Only the educational level (p = 0.03) was associated with knowledge of the transmission route. Age (p = 0.04) and educational level (p = 0.01) had a statistically significant association with knowledge of the risk of not vaccinating dogs.

CONCLUSIONS AND RELEVANCE

A lack of formal education in the communities, low levels of education, and the majority of respondents acquiring their knowledge from unofficial sources are important contributors to the low levels of awareness.

Transcriptome analysis of salivary glands of rabies-virus-infected mice

Rabies is a fatal zoonotic disease that poses a threat to public health. Rabies virus (RABV) is excreted in the saliva of infected animals, and is primarily transmitted by bite. The role of the salivary glands in virus propagation is significant, but has been less studied in the pathogenic mechanisms of RABV. To identify functionally important genes in the salivary glands, we used RNA sequencing (RNA-seq) to establish and analyze mRNA expression profiles in parotid tissue infected with two RABV strains, CVS-11 and PB4. The biological functions of differentially expressed genes (DEGs) were determined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, which revealed 3,764 DEGs (678 up-regulated and 3,086 down-regulated) in the CVS-11 infected group and 4,557 DEGs (874 up-regulated and 3,683 down-regulated) in the PB4 infected group. Various biological processes are involved, including the salivary secretion pathway and the phosphatidylinositol 3-kinase-Akt (PI3K-Akt) signaling pathway. This study provides the first mapping of the transcriptome changes in response to RABV infection in parotid tissue, offering new insights into the study of RABV-affected salivary gland function and RABV pathogenic mechanisms in parotid tissue. The salivary gland-enriched transcripts may be potential targets of interest for rabies disease control.

Establishment of serological neutralizing tests using pseudotyped viruses for comprehensive detection of antibodies against all 18 lyssaviruses

Rabies is a fatal zoonotic, neurological disease caused by rabies lyssavirus (RABV) and other lyssaviruses. In this study, we established novel serological neutralizing tests (NT) based on vesicular stomatitis virus pseudotypes possessing all 18 known lyssavirus glycoproteins. Applying this system to comparative NT against rabbit sera immunized with current RABV vaccines, we showed that the current RABV vaccines fail to elicit sufficient neutralizing antibodies against lyssaviruses other than to those in phylogroup I. Furthermore, comparative NT against rabbit antisera for 18 lyssavirus glycoproteins showed glycoproteins of some lyssaviruses elicited neutralizing antibodies against a broad range of lyssaviruses. This novel testing system will be useful to comprehensively detect antibodies against lyssaviruses and evaluate their cross-reactivities for developing a future broad-protective vaccine.

Evaluation of the effect of sample suspension concentration and viral load on the outcome of the rabies tissue culture infection test

In this study, we examined various brain suspension concentrations and viral loads in Neuro-2a cell cultures using 20 rabies-positive bovine samples. The reproducibility of results varied: 65% showed consistent outcomes across all concentrations, while 35% disagreed in at least one. Viral titers ranged from less than 25 × 101 to 25 × 103.50 TCID50/mL, with 20% below 25 × 101 TCID50/mL. Concentrations between 5% and 20% yielded over 90% agreement in positive results, but at 30%, agreement dropped from 85% to 50%. Cell confluence was successfully maintained at 5%, 10%, and 20%, while concentrations of 30% and above led to confluence loss. Low viral loads also negatively impacted reproducibility. These results suggest that sample concentration has a direct influence on preservation of cell confluence and that low viral loads may influence the reproducibility of the rabies tissue culture infection test (RTCIT).

Genetic analyses of rabies virus glycoprotein and nucleoprotein gene sequences reveal the emergence of multiple lineages in animals in Arkhangai province, a central region of Mongolia

Genetic characterizations of rabies viruses circulating in carnivore and non-carnivore animals were investigated for the first time in Arkhangai province, a central region of Mongolia. Also, glycoprotein gene of the rabies virus was sequenced for the first time in Mongolia. The nucleotide sequences of the glycoprotein and nucleoprotein genes were analysed, revealing the presence of multiple lineages in this area. Of particular concern are the lineages identified in carnivores, which might emerge to spread throughout Mongolia, further facilitating transboundary transmission to neighbouring countries, including China and Russia.

Exploring the spatial pattern of animal bites in Iran (2021-2022)

OBJECTIVE

Knowledge of the spatial pattern of animal bites can be helpful for targeted resource allocation and to develop and deliver effective intervention programs. The aim of this study was to explore the spatial pattern of the animal bites in Iran during 2021-2022.

METHODS

Animal bite cases from all provinces and counties in Iran were obtained from a nationally based registry. Global Moran's I was applied to check spatial autocorrelation. The spatially adjusted standardized incidence ratios (SIRs) were estimated using the Besag, York, and Mollie (BYM) model. Spatial clusters were identified by local indicators of spatial association (LISA) and purely spatial scan statistic.

RESULTS

A total of 260,470 animal bites were registered during the study period. There was a positive spatial autocorrelation (global Moran's I=0.27, p-value=0.001). The majority of SIRs greater than 1.00 was found in counties in the northern belt of Iran (e.g., observed greater than expected animal bites). LISA found that approximately 7% of counties in the north and northeast, 18% in the west and south, and 3% in the central part of Iran were significant hot spots, cold spots, and spatial outliers (p-value≤0.05). Spatial scan statistic detected primary hot spot cluster in the counties in the Mazandaran and Alborz provinces (Relative Risk=2.56, p-value<0.001), while primary cold spot cluster involved counties in Kurdistan and Kermanshah province (0.37, <0.001).

CONCLUSION

Animal bites were unevenly distributed in Iran. Further prevention and control programs as well as appropriately resource allocation are needed in order to reduce the observed animal bites spatial disparity.

Evaluating the benefit of serology during potential Australian bat lyssavirus and rabies post-exposure prophylaxis

Post-exposure prophylaxis (PEP) for potential lyssavirus exposures consists of wound management, rabies vaccination and may include rabies immunoglobulin (RIG). Rabies serology is sometimes indicated if there is risk of PEP failure.

OBJECTIVES

Evaluate the benefit of serology by indication.

METHODS

Chart review of potential lyssavirus exposures managed at a Public Health Unit (June 2015 - December 2022) where serology was requested was conducted. The proportion of non-therapeutic titres was compared by sex, age, Indigenous status, serology indication, and whether RIG was given.

RESULTS

46 notifications with serology were included. Males (5/19) and people over 40 (3/16) were more likely to demonstrate a non-therapeutic response. 2/3 of cases where vaccine doses were not given in the deltoid were non-therapeutic. The rate of non-therapeutic titres was similar for RIG given into the ipsilateral arm (2/11) and given excess RIG for weight (1/4). Although this small sample was inconclusive in isolation, it was also noted that all cases who did not receive RIG had therapeutic serology, whereas 6/35 of those receiving RIG had non-therapeutic serology.

CONCLUSIONS

This study supports broader literature questioning the utility of systemic RIG administration as likely limited and potentially detrimental considering the increased risk of immune interference.

IMPLICATIONS FOR PUBLIC HEALTH

Highlights a need to review Australian national guidelines to align with World Health Organization advice recommending local RIG administration only.

A single immunization with core-shell structured lipopolyplex mRNA vaccine against rabies induces potent humoral immunity in mice and dogs

The persistence and clinical consequences of rabies virus (RABV) infection have prompted global efforts to develop a safe and effective vaccines against rabies. mRNA vaccines represent a promising option against emerging and re-emerging infectious diseases, gaining particular interest since the outbreak of COVID-19. Herein, we report the development of a highly efficacious rabies mRNA vaccine composed of sequence-modified mRNA encoding RABV glycoprotein (RABV-G) packaged in core-shell structured lipopolyplex (LPP) nanoparticles, named LPP-mRNA-G. The bilayer structure of LPP improves protection and delivery of RABV-G mRNA and allows gradual release of mRNA molecules as the polymer degrades. The unique core-shell structured nanoparticle of LPP-mRNA-G facilitates vaccine uptake and demonstrates a desirable biodistribution pattern with low liver targeting upon intramuscular immunization. Single administration of low-dose LPP-mRNA-G in mice elicited potent humoral immune response and provided complete protection against intracerebral challenge with lethal RABV. Similarly, single immunization of low-dose LPP-mRNA-G induced high levels of virus-neutralizing antibody titers in dogs. Collectively, our data demonstrate the potential of LPP-mRNA-G as a promising next-generation rabies vaccine used in human and companion animals.

Tracking lethal threat: in-depth review of rabies

An infectious disease known as rabies (family Rhabdoviridae, genus Lyssavirus) causes severe damage to mammals' central nervous systems (CNS). This illness has been around for a very long time. The majority of human cases of rabies take place in underdeveloped regions of Africa and Asia. Following viral transmission, the Rhabdovirus enters the peripheral nervous system and proceeds to the CNS, where it targets the encephalon and produces encephalomyelitis. Postbite prophylaxis requires laboratory confirmation of rabies in both people and animals. All warm-blooded animals can transmit the Lyssavirus infection, while the virus can also develop in the cells of cold-blooded animals. In the 21st century, more than 3 billion people are in danger of contracting the rabies virus in more than 100 different nations, resulting in an annual death toll of 50,000-59,000. There are three important elements in handling rabies disease in post exposure prophylaxis (PEP), namely wound care, administration of anti-rabies serum, and anti-rabies vaccine. Social costs include death, lost productivity as a result of early death, illness as a result of vaccination side effects, and the psychological toll that exposure to these deadly diseases has on people. Humans are most frequently exposed to canine rabies, especially youngsters and the poor, and there are few resources available to treat or prevent exposure, making prevention of human rabies challenging.

An mRNA vaccine against rabies provides strong and durable protection in mice

Introduction

Rabies is a serious public health problem worldwide for which an effective treatment method is lacking but can be prevented by vaccines. Current vaccines are produced in cell or egg cultures, which are both costly and time consuming.

Methods

Here, a non-replicating mRNA vaccine (RV021) encoding the rabies virus glycoprotein was developed in vitro, and its immunogenicity and protective efficacy against live virus was evaluated in mice.

Results

A two-dose vaccination with 1 μg of RV021 at 7-day intervals induced a protective level of neutralizing antibody that was maintained for at least 260 days. RV021 induced a robust cellular immune response that was significantly superior to that of an inactivated vaccine. Two doses of 1 μg RV021 provided full protection against challenge with CVS of 30~60-fold lethal dose, 50%. Vaccine potency testing (according to the National Institutes of Health) in vivo revealed that the potency of RV021 at 15 μg/dose was 7.5 IU/dose, which is substantially higher than the standard for lot release of rabies vaccines for current human use.

Conclusion

The mRNA vaccine RV021 induces a strong protective immune response in mice, providing a new and promising strategy for human rabies prevention and control.

Evolution and distribution of rabies viruses from a panorama view

Rabies kills more than 59,000 people annually, mainly in developing countries. Previous studies on the evolution and distribution of rabies viruses (RABVs) were scattered. Here, we explore the evolution and distribution of this deadly virus from a novel panorama view. Multiple bioinformatic software tools were employed to analyze the phylogenetic diversity, evolution, spatiotemporal, and distribution of RABVs. The analyses were based on 1,202 qualified full-length genomes of RABVs and numerous literatures. Of the 10 distinct phylogenetic clades of RABV that we identified, more frequent intra- and inter-clade recombination occurs in the sequences of Asian-SEA, Arctic, and Cosmopolitan clades isolated from China, while according to existing sequence information, RABV might originate from bats (posterior probability, PP = 0.75, PP = 0.60 inferred from N and L genes, separately) in North America (PP = 0.57, PP = 0.62 inferred from N and L genes, separately). Due to the difference in evolutionary rate of N (2.22 × 10-4 subs/site/year, 95% HPD 1.99-2.47 × 10-4 subs/site/year) and L genes (1.67 × 10-4 subs/site/year, 95% HPD 1.59-1.74 × 10-4 subs/site/year), the root age was 1,406.6 (95% HPD 1,291.2-1,518.2) and 1,122.7 (95% HPD 1,052.4-1,193.9) inferred from N and L genes, separately. Among other findings, Mephitidae plays an important role in the interspecific transmission and communication of RABV, which we found tends to spread to populations genetically proximate to the host. We also identified amino acids under positive selection in different genes of different clades as well as single nucleotide variation sites important for different lineages. IMPORTANCE Rabies virus is widely distributed all over the world, and wild animals are its largest potential reservoir. Our study offers a panorama view about evolution and distribution of rabies viruses and emphasizes the need to monitor the transmission dynamics of animal rabies.

How knowledgeable are people in Nepal about rabies?

Eliminating dog-mediated human rabies cases by 2030 is a collective global pledge. Rabies is a vaccine-preventable, zoonotic, and fatal viral disease tormenting human beings and animals for at least four thousand years. An average annual fatality of 59,000 people has been reported from rabies in more than 150 countries, including Nepal. Understanding people's knowledge towards rabies is paramount to preventing this disease. A cross-sectional study was conducted in three districts, namely, Siraha, Parsa, and Parasi in Nepal, from October to December 2021 to assess the level of public awareness of rabies. Information was obtained using a structured questionnaire among 308 household heads. Study findings show that some of the respondents were unfamiliar with the term 'rabies'. They knew major carriers or sources of rabies, but the majority of them (87.3%) did not know its causative agent. They had some idea of how rabies is transmitted from animals to humans, but they lacked a clear understanding of the fate of the animals and humans once affected cases are symptomatic. Only 35.1% of respondents knew that rabies pathogens attack and multiply in the brain tissues. Rabies vaccination in pets is critical for rabies eradication, yet only 26.3% of respondents were aware of the vaccination schedule. Nearly 90% of respondents thought post-exposure prophylaxis (PEP) to be effective immediately after a suspected animal bite. The findings show that there was a significant relationship between independent variables viz. pet ownership (X2 = 20.273, p < 0.001), level of education (X2 = 39.215, p < 0.001), household income (X2 = 13.574, p < 0.001), family size (X2 = 15.053, p < 0.001), main occupation (X2 = 11.618, p = 0.020), age (X2 = 6.982, p = 0.008) with dependent variable i. e., knowledge category (good and poor knowledge). Education to invoke awareness among rural people about rabies, its transmission and prevention, including making anti-rabies vaccines freely available, should be the priority for municipalities, public health and veterinary health authorities in the study districts and throughout the country.

Immunogenicity and Antigenicity of the Ectodomain of Rabies Virus Glycoprotein Stably Expressed in HEK293T Cells

Rabies continues to be a huge threat to public health. The rabies virus envelope glycoprotein (RABV G) is a major rabies virus antigen and contains neutralizing epitopes, which are primary candidates for subunit vaccines and diagnostic antigens. However, the production and purification of rRABV G while retaining its antigenic and immunogenic remains to be a challenge. Here, we aimed to establish a platform for rRABV G production and purification, and determine the immunogenicity and antigenicity of rRABV G. The cDNA fragment encoding the soluble form of RABV G was synthesized and cloned into a lentiviral expressing vector. Recombinant lentiviral vector LV-CMV-RABV G-eGFP was packaged, titered, and then transduced into HEK 293T cells. The cell culture supernatant was purified using nickel affinity chromatography and subsequently confirmed through Western Blot analysis and indirect enzyme-linked immunosorbent assay (ELISA). The ELISA utilized human sera obtained from individuals who had been vaccinated with the human commercial Purified Vero Cells Rabies Vaccine (PVRV). Notably, we observed a neutralizing antibody response in immunized pigs rather than in mice. This discrepancy could potentially be attributed to factors such as the instability of the rRABV G protein, variations in host responses, and variances in the adjuvant used. Taking all these findings into account, the rRABV G protein generated in this study exhibits promise as a potential vaccine candidate for the prevention of rabies.

The occurrence and extent of anxiety and distress among Dutch travellers after encountering an animal associated injury

BACKGROUND

Prompt administration of post-exposure prophylaxis (PEP) is crucial to prevent a fatal rabies infection after an animal associated injury (AAI), preferably within 24 h. PEP, especially in case of a type III injury for which rabies immune globulin (RIG) is needed, is difficult to obtain abroad. This, along with the fear of potentially having contracted a lethal disease, might be an important source for anxiety and distress. We investigated the occurrence and extent of self-reported anxiety and distress at different timepoints among Dutch travellers after encountering an AAI, and the involved factors.

METHODS

A retrospective quantitative observational study was conducted including insured Dutch travellers who actively contacted Eurocross Assistance after encountering an AAI abroad. An online questionnaire was designed to measure anxiety and distress levels, using the HADS (Hospital Anxiety and Depression Scale) and distress thermometer at three time points: departure from home (T1), post-AAI (T2), and treatment administration (T3). Statistical analyses included T-tests, Chi-square tests, and ANCOVA analyses.

RESULTS

We showed a significant increase in mean anxiety and distress scores at T2, and a significant decrease at T3. Women were more often anxious and distressed. Between T1 and T2, PrEP, and being aware of the risks were positively associated with anxiety levels, and PrEP and WHO region Africa with distress levels. Between T2 and T3, anxiety levels remained higher for monkey-induced injury, thoracic injuries, and WHO region Southeast Asia. PEP-delay between 24-48 h resulted in decreased distress levels at this time period, while type II injury elevated distress levels.

CONCLUSIONS

This study showed significant anxiety and distress levels after an AAI among the vast majority of travellers, which is detrimental to their health-related quality of life (HR-QOL). This highlights the importance of proper pre-travel information. In the context of rabies prevention, these results suggest that pre-travel advice and policy makers should also take aspects of HR-QOL into consideration.

Improved Transdermal Delivery of Rabies Vaccine using Iontophoresis Coupled Microneedle Approach

AIM

This study was aimed to develop rabies vaccine incorporated microneedle (MN) patches and evaluate the immunogenicity of prepared formulations in combination with iontophoresis.

METHODS

Patches comprising of polyvinyl pyrrolidone, hyaluronic acid and polyethylene glycol 400 were engineered by vacuum micromolding technique. Physical evaluation of patches included determination of folding endurance, % swelling and morphological features. In vitro release study was performed in skin simulant agarose gel using model drug (methylene blue) loaded patches. In vitro insertion ability was assessed using stratum corneum simulant parafilm. In vivo insertion study was performed in rats. Immunogenicity was evaluated in dogs by determining immunoglobulin G (IgG) and rabies virus neutralizing antibodies (RVNA) titer.

RESULTS

Patches displayed uniformly distributed microprojections with pointed tips and smooth surface,  ~ 70% swelling, remained intact for  ~ 200 foldings and successfully penetrated the parafilm. The area covered by model drug across agarose gel was almost double following treatment with MN-iontophoresis combination (MNdi) compared to MN alone (MNdo). Histological examination of rat skin treated with vaccine laden MN (MNvo) and MN-iontophoresis combination (MNvi) confirmed the formation of grooves in epidermis without any damage to the deep vasculature. A ~ 73% and  ~ 206% increase (compared to untreated counterpart) was observed in the IgG titer of MNvo and MNvi treated dogs, respectively. The RVNA titer was increased by  ~ 1.2 and  ~ 2.2 times (compared to threshold value) after MNvo and MNvi treatment, respectively.

CONCLUSION

MN-iontophoresis combination provided relatively potent immunogenic response over the conventional intramuscular injection, hence, can be used for administering vaccines transcutaneously.

Short-Chain Fatty Acids Alleviate Vancomycin-Caused Humoral Immunity Attenuation in Rabies-Vaccinated Mice by Promoting the Generation of Plasma Cells via Akt-mTOR Pathway

Mounting evidence suggests that gut microbial composition and its metabolites, including short-chain fatty acids (SCFAs), have beneficial effects in regulating host immunogenicity to vaccines. However, it remains unknown whether and how SCFAs improve the immunogenicity of the rabies vaccine. In this study, we investigated the effect of SCFAs on the immune response to rabies vaccine in vancomycin (Vanco)-treated mice and found that oral gavage with butyrate-producing bacteria (C. butyricum) and butyrate supplementation elevated RABV-specific IgM, IgG, and virus-neutralizing antibodies (VNAs) in Vanco-treated mice. Supplementation with butyrate expanded antigen-specific CD4+ T cells and IFN-γ-secreting cells, augmented germinal center (GC) B cell recruitment, promoted plasma cells (PCs) and RABV-specific antibody-secreting cells (ASCs) generation in Vanco-treated mice. Mechanistically, butyrate enhanced mitochondrial function and activated the Akt-mTOR pathway in primary B cells isolated from Vanco-treated mice, ultimately promoting B lymphocyte-induced maturation protein-1 (Blimp-1) expression and CD138+ PCs generation. These results highlight the important role of butyrate in alleviating Vanco-caused humoral immunity attenuation in rabies-vaccinated mice and maintaining host immune homeostasis. IMPORTANCE The gut microbiome plays many crucial roles in the maintenance of immune homeostasis. Alteration of the gut microbiome and metabolites has been shown to impact vaccine efficacy. SCFAs can act as an energy source for B-cells, thereby promoting both mucosal and systemic immunity in the host by inhibiting HDACs and activation of GPR receptors. This study investigates the impact of orally administered butyrate, an SCFA, on the immunogenicity of rabies vaccines in Vanco-treated mice. The results showed that butyrate ameliorated humoral immunity by facilitating the generation of plasma cells via the Akt-mTOR in Vanco-treated mice. These findings unveil the impact of SCFAs on the immune response of the rabies vaccine and confirm the crucial role of butyrate in regulating immunogenicity to rabies vaccines in antibiotic-treated mice. This study provides a fresh insight into the relationship of microbial metabolites and rabies vaccination.

Open source board based acoustofluidic transwells for reversible disruption of the blood-brain barrier for therapeutic delivery

BACKGROUND

Blood-brain barrier (BBB) is a crucial but dynamic structure that functions as a gatekeeper for the central nervous system (CNS). Managing sufficient substances across the BBB is a major challenge, especially in the development of therapeutics for CNS disorders.

METHODS

To achieve an efficient, fast and safe strategy for BBB opening, an acoustofluidic transwell (AFT) was developed for reversible disruption of the BBB. The proposed AFT was consisted of a transwell insert where the BBB model was established, and a surface acoustic wave (SAW) transducer realized using open-source electronics based on printed circuit board techniques.

RESULTS

In the AFT device, the SAW produced acousto-mechanical stimulations to the BBB model resulting in decreased transendothelial electrical resistance in a dose dependent manner, indicating the disruption of the BBB. Moreover, SAW stimulation enhanced transendothelial permeability to sodium fluorescein and FITC-dextran with various molecular weight in the AFT device. Further study indicated BBB opening was mainly attributed to the apparent stretching of intercellular spaces. An in vivo study using a zebrafish model demonstrated SAW exposure promoted penetration of sodium fluorescein to the CNS.

CONCLUSIONS

In summary, AFT effectively disrupts the BBB under the SAW stimulation, which is promising as a new drug delivery methodology for neurodegenerative diseases.

Single visit rabies pre-exposure prophylaxis: A literature review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Incidence and mortality trends of neglected tropical diseases and malaria in China and ASEAN countries from 1990 to 2019 and its association with the socio-demographic index

BACKGROUND

People in China and the countries in the Association of Southeast Asian Nations (ASEAN) are affected by neglected tropical diseases and malaria (NTDM). In this study, we aimed to assess the current status and trends of NTDM burden from 1990 to 2019 in China and ASEAN countries, and also explore the association of NTDM burden with socio-demographic index (SDI).

METHODS

The data from the Global Burden of Diseases Study 2019 (GBD 2019) results were used. Absolute incidence and death number, and age-standardized incidence and mortality rate (ASIR and ASMR) of NTDM in China and ASEAN were extracted. The estimated annual percentage change (EAPC) and join-point regression in the rates quantified the trends. Nonlinear regression (second order polynomial) was used to explore the association between SDI and ASRs.

RESULTS

The ASIR of NTDM increased in China, Philippines, Singapore and Brunei, at a speed of an average 4.15% (95% CI 3.83-4.47%), 2.15% (1.68-2.63%), 1.03% (0.63-1.43%), and 0.88% (0.60-1.17%) per year. Uptrends of ASIR of NTDM in recent years were found in China (2014-2017, APC = 10.4%), Laos (2005-2013, APC = 3.9%), Malaysia (2010-2015, APC = 4.3%), Philippines (2015-2019, APC = 4.2%), Thailand (2015-2019, APC = 2.4%), and Vietnam (2014-2017, APC = 3.2%, all P < 0.05). Children < 5 had relatively low incidences but unexpectedly high mortality rates of NTDM in most ASEAN countries. Both incidence and mortality rates of NTDM were higher in older people. ASIR and ASMR of NTDM had a U-shaped association with SDI.

CONCLUSIONS

The burden of NTDM in China and ASEAN countries was still huge and affects vulnerable and impoverished populations' livelihoods, including children under the age of 5 and people aged 60 and older. Facing with the large burden and complex situation of NTDM in China and ASEAN countries, regional cooperating strategies are needed to reduce the burden of NTDM, so as to achieve the goal of elimination in the world.

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.

Transcriptomic Analysis of mRNA Expression Profiles in the Microglia of Mouse Brains Infected with Rabies Viruses of Varying Virulence

Rabies is a lethal encephalitis caused by the rabies virus (RABV) with a fatality rate near 100% after the onset of clinical symptoms in humans and animals. Microglia are resident immune cells in the central nervous system. Few studies have been conducted on the functional role of microglia in RABV infection. Here, we performed a transcriptomic analysis of mRNA expression profiles in the microglia of mouse brains intracerebrally infected with RABV. We successfully isolated single microglial cells from the mouse brains. The survival rate of dissociated microglial cells was 81.91%-96.7%, and the purity was 88.3%. Transcriptomic analysis revealed 22,079 differentially expressed mRNAs identified in the microglia of mouse brains infected with RABV strains (rRC-HL, GX074, and CVS-24) of varying virulence at 4 and 7 days post-infection (dpi) compared to the control group. The numbers of DEGs versus the control at 4 and 7 dpi in mice infected with rRC-HL, GX074, and CVS-24 were 3622 and 4590, 265 and 4901, and 4079 and 6337. The GO enrichment analysis showed that response to stress, response to external stimulus, regulation of response to stimulus, and immune system process were abundant during RABV infection. The KEGG analysis indicated that the Tlr, Tnf, RIG-I, NOD, NF-κB, MAPK, and Jak-STAT signaling pathways were involved in RABV infection at both 4 and 7 dpi. However, some phagocytosis and cell signal transduction processes, such as endocytosis, p53, phospholipase D, and oxidative phosphorylation signaling pathways, were only expressed at 7 dpi. The involvement of the Tnf and Tlr signaling pathways prompted us to construct a protein-protein interaction (PPI) network of these pathways. The PPI revealed 8 DEGs, including Mmp9, Jun, Pik3r1, and Mapk12. Notably, Il-1b interacted with Tnf and Il-6 with combined scores of 0.973 and 0.981, respectively. RABV causes significant changes in mRNA expression profiles in the microglia in mice. 22,079 differentially expressed mRNAs were identified in the microglia of mice infected with RABV strains of varying virulence at 4 and 7 dpi. The DEGs were evaluated using GO, KEGG, and PPI network analysis. Many immune pathways were up-regulated in RABV-infected groups. The findings will help elucidate the microglial molecular mechanisms of cellular metabolism dysregulated by RABV and may provide important information for investigating RABV pathogenesis and therapeutic methods.

Evaluation of country infrastructure as an indirect measure of dog-mediated human rabies deaths

Background

Rabies is a neglected disease, primarily due to poor detection stemming from limited surveillance and diagnostic capabilities in most countries. As a result, there is limited ability to monitor and evaluate country, regional, and global progress towards the WHO goal of eliminating human rabies deaths by 2030. There is a need for a low-cost, readily reproducible method of estimating rabies burden and elimination capacity in endemic countries.

Methods

Publicly available economic, environmental, political, social, public health, and One Health indicators were evaluated to identify variables with strong correlation to country-level rabies burden estimates. A novel index was developed to estimate infrastructural rabies elimination capacity and annual case-burden for dog-mediated rabies virus variant (DMRVV) endemic countries.

Findings

Five country-level indicators with superior explanatory value represent the novel "STOP-R index:" (1) literacy rate, (2) infant mortality rate, (3) electricity access, (4) political stability, and (5) presence/severity of natural hazards. Based on the STOP-R index, 40,111 (95% CI 25,854-74,344) global human rabies deaths are estimated to occur in 2022 among DMRVV-endemic countries and are projected to decrease to 32,349 (95% CI 21,110-57,019) in 2030.

Interpretation

The STOP-R index offers a unique means of addressing the data gap and monitoring progress towards eliminating dog-mediated human rabies deaths. Results presented here suggest that factors external to rabies programs influence the successes of rabies elimination, and it is now possible to identify countries exceeding or lagging in expected rabies control and elimination progress based on country infrastructure.

Diagnostic sensitivity and specificity of immunohistochemistry for the detection of rabies virus in domestic and wild animals in South Africa

We estimated the diagnostic sensitivity (DSe) and specificity (DSp) of an immunohistochemistry (IHC) protocol compared to the direct fluorescent antibody test (DFAT), which is the gold standard test for rabies diagnosis. We obtained brain samples from 199 domestic and wild animal cases (100 DFAT-negative, 99 DFAT-positive), by convenience sampling from 2 government-accredited rabies virus (RABV) testing laboratories in South Africa, between February 2015 and August 2017. Tissues that had been stored at 4-8°C for several days to weeks at the 2 accredited laboratories were formalin-fixed and paraffin-embedded. Nighty-eight cases tested IHC-positive using a polyclonal anti-RABV nucleoprotein antibody and a polymer detection system. The overall DSe and DSp for the RABV IHC test were 98% (95% CI: 93-100%) and 99% (95% CI: 95-100%), respectively. Domestic dogs accounted for 41 of 98 RABV IHC-positive cases, with the remainder in 4 domestic cats, 25 livestock, and 28 wildlife. Herpestidae species, including 7 meerkats and 9 other mongoose species, were the most frequently infected wild carnivores, followed by 11 jackals. Three cases in domestic dogs had discordant test results; 2 cases were IHC-/DFAT+ and 1 case was IHC+/DFAT-. Considering the implications of a false-negative rabies diagnosis, participating in regular inter-laboratory comparisons is vital, and a secondary or confirmatory method, such as IHC, should be performed on all submitted specimens, particularly negative cases with human contact history.

Interleukin-1β suppresses rabies virus infection by activating cGAS-STING pathway and compromising the blood-brain barrier integrity in mice

Rabies, caused by rabies virus (RABV), is an ancient zoonotic disease that severely threatens the public health throughout the world. Previous study indicated that interleukin-1β (IL-1β) plays an important role in RABV infection. However, the mechanism how IL-1β affects RABV pathogenicity is still unknown yet. In this study, we confirmed that IL-1β was able to reduce viral titers of RABV in different cells, and the recombinant RABV expressing IL-1β, designated as rCVS-IL1β, could be suppressed in different cells due to the expression of IL-1β. Furthermore, the survival rates of mice infected with rCVS-IL1β by intramuscular route was significantly higher than those of mice infected with parent virus rCVS, which is associated with the less viral loads for entry into the central nervous system (CNS). We further characterized that the cGAS-STING pathway was activated in rCVS-IL1β infected bone marrow derived dendritic cells (BMDC), which could contribute to the decreased viral loads of RABV after intramuscular infection. Moreover, we also observed that the expression of IL-1β by rCVS-IL1β could compromise the blood-brain barrier (BBB) integrity by degrading the tight junction proteins, which allowing peripheral inflammatory cytokines, chemokines, and CD4+T cells to enter into the brain for the clearance of RABV in the CNS. Together, our study suggests that IL-1β could attenuate RABV pathogenicity through activating cGAS-STING pathway in to decrease the viral entry into the CNS and enhance the BBB permeability to promote RABV clearance in the CNS as well, which provides new insight into developing effective therapeutics for rabies.

Update on laboratory data of animal rabies at the Centre Pasteur of Cameroon from 2014 to 2021

Rabies is a worldwide zoonotic disease mainly transmitted to humans by an infected dog bite. Despite the endemicity of rabies in dogs and few documented cases in Cameroon, there is still not enough data on frequency of rabies cases in animals. The present study aims to update data on the circulation of rabies in animals screened at the Centre Pasteur of Cameroon (CPC) between 2014 and 2021. The detection of rabies in animals was based on passive surveillance. Animal rabies cases were confirmed on brain biopsies using fluorescent antibody test and SYBR green based real-time RT-PCR for negative results confirmation. The total nucleoprotein (N) gene of animal-derived RABV isolated were amplified by hemi nested RT-PCR and subjected to phylogenetic analyses. From 2014 to 2021, a total of 92 animals including 86 dogs (93.5%), 3 cats, 2 pigs and 1 chiropteran were screened for rabies at the CPC. From the 86 dog sampled, 62.3% (54/86) were tested positive for rabies and 1 out of 3 cat samples was also tested positive. The PEP demand was very high (59,371) during the study period. Phylogenetic analyses assigned all 15 studied isolates successfully sequenced to the Africa-1a lineage belonging to the Cosmopolitan clade. The study highlights the frequent circulation of rabies in Cameroon and the role of dogs and cat as main reservoir and vector of rabies.

Evaluation of Dynamics, Demography and Estimation of Free-Roaming Dog Population in Herat City, Afghanistan

FRDs pose a serious challenge in countries where dog-bite-related rabies is endemic. Understanding the size and core demographic characteristics of FRD populations is essential for the planning and implementation of effective dog-population and canine-rabies-control programmes. The photographic sight-resight method was used to estimate the FRD population and evaluate its demographic characteristics in Herat city. A total of 928 free-roaming dogs (FRD) were identified through 3172 sightings, and the total free-roaming population was estimated to amount to 1821 (95% CI: 1565-2077), which led to the estimation of 10 dogs/km² and the human-to-FRD ratio of 315:1. The male-to-female ratio was 2.85:1. The majority of them were healthy, with an ideal body score. Although the FRD density is considered low, it is still a concern and significant, since the majority of the people are unaware of the importance of canine populations in the transmission of zoonotic diseases such as rabies, and there were no specific measures for managing and controlling FRD populations. The information gained can be useful in animal health planning to design effective dog-population-control programmes, and for the planning of national rabies-prevention programmes.

Strategies to inTerrupt RAbies Transmission for the Elimination Goal by 2030 In China (STRATEGIC): a modelling study

BACKGROUND

A global plan has been set to end human deaths from dog-mediated rabies by 2030 ("Zero-by-30"), but whether it could be achieved in some countries, such as China, remains unclear. Although elimination strategies through post-exposure prophylaxis (PEP) use, dog vaccination, and patient risk assessments with integrated bite case management (IBCM) were proposed to be cost-effective, evidence is still lacking in China. We aim to evaluate the future burdens of dog-mediated human rabies deaths in the next decade and provide quantitative evidence on the cost-effectiveness of different rabies-control strategies in China.

METHODS

Based on data from China's national human rabies surveillance system, we used decision-analytic modelling to estimate dog-mediated human rabies death trends in China till 2035. We simulated and compared the expected consequences and costs of different combination strategies of the status quo, improved access to PEP, mass dog vaccination, and use of IBCM.

RESULTS

The predicted human rabies deaths in 2030 in China will be 308 (95%UI: 214-411) and remain stable in the next decade under the status quo. The strategy of improved PEP access alone could only decrease deaths to 212 (95%UI: 147-284) in 2028, remaining unchanged till 2035. In contrast, scaling up dog vaccination to coverage of 70% could eliminate rabies deaths by 2033 and prevent approximately 3,265 (95%UI: 2,477-3,687) extra deaths compared to the status quo during 2024-2035. Moreover, with the addition of IBCM, the "One Health" approach through mass dog vaccination could avoid unnecessary PEP use and substantially reduce total cost from 12.53 (95%UI: 11.71-13.34) to 8.73 (95%UI: 8.09-9.85) billion US dollars. Even if increasing the total costs of IBCM from 100 thousand to 652.10 million US dollars during 2024-2035, the combined strategy of mass dog vaccination and use of IBCM will still dominate, suggesting the robustness of our results.

CONCLUSIONS

The combined strategy of mass dog vaccination and IBCM requires collaboration between health and livestock/veterinary sectors, and it could eliminate Chinese rabies deaths as early as 2033, with more deaths averted and less cost, indicating that adding IBCM could reduce unnecessary use of PEP and make the "One Health" rabies-control strategy most cost-effective.

One Health responses to prevent the occurrence of rabies due to attacks by a rabid stray dog

BACKGROUND

The number of human rabies cases caused by pet dogs in Guangzhou has been decreasing after years of comprehensive interventions. Consequently, attacks by stray dogs become a major issue in rabies control.

OBJECTIVES

To share our experience of successfully dealing with rabies to provide some inspiration for prevention and control in countries and regions affected by it.

METHODS

A multidisciplinary One Health response was initiated to control this outbreak. Rabies virus was detected by PCR in the brain tissue of the associated stray dog. The sequences were aligned with reference sequences downloaded from GenBank using ClustalX. The maximum likelihood method implemented in MEGA 5.0 software package was used in a phylogenetic analysis of the aligned sequences.

RESULTS

Twelve patients with exposure to the stray dog were identified in the field investigation. Rabies vaccines and immunoglobulin were administered to all patients within 48 h. After 1 year of follow-up, no exposed patients showed symptoms. Maximum likelihood analysis of the nucleotide sequences obtained from the PCR products indicated that the rabies virus in the dog was closely related to isolates from neighbouring provinces of Guangdong as well as those from surrounding countries of China.

CONCLUSIONS

Multidisciplinary One Health intervention is effective not only in the control of rabies but also in rapid emergency responses to attacks by rabid stray dogs.

An evaluation of the impact of anti-rabies programs in Nigeria

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 uncoordinated efforts and the ineffectiveness of available anti-rabies programs. We aim to address the current efforts, and challenges associated with the available anti-rabies programs in Nigeria and provide recommendations to tackle these challenges.

Results

The anti-rabies programs available in Nigeria are highlighted. They are sponsored by different bodies such as government parastatals, veterinary teaching hospitals, professional associations, nongovernmental associations, and students. These programs provide support to eradicate rabies but are not devoid of challenges. Recommendations are provided to the Nigerian government, bodies anchoring the anti-rabies programs, and health professionals to tackle the challenges hindering the effective impact of the programs.

Conclusion

Anti-rabies programs in Nigeria are supported by individual and collaborative bodies. It is pertinent to hold on to these programs and create a comprehensive national program to achieve effective rabies eradication in Nigeria.

Comparing Control Intervention Scenarios for Raccoon Rabies in Southern Ontario between 2015 and 2025

The largest outbreak of raccoon rabies in Canada was first reported in Hamilton, Ontario, in 2015 following a probable translocation event from the United States. We used a spatially-explicit agent-based model to evaluate the effectiveness of provincial control programs in an urban-centric outbreak if control interventions were used until 2025, 2020, or never used. Calibration tests suggested that a seroprevalence of protective rabies antibodies 2.1 times higher than that inferred from seroprevalence in program assessments was required in simulations to replicate observed raccoon rabies cases. Our simulation results showed that if control interventions with an adjusted seroprevalence were used until 2025 or 2020, the probability of rabies elimination due to control intervention use was 49.2% and 42.1%, respectively. However, if controls were never used, the probability that initial rabies cases failed to establish a sustained outbreak was only 18.2%. In simulations where rabies was not successfully eliminated, using control interventions until 2025 resulted in 67% fewer new infections compared to only applying controls until 2020 and in 90% fewer new infections compared to no control intervention use. However, the model likely underestimated rabies elimination rates since we did not adjust for adaptive control strategies in response to changes in rabies distributions and case numbers, as well as extending control interventions past 2025. Our agent-based model offers a cost-effective strategy to evaluate approaches to rabies control applications.

Susceptibilities of CNS Cells towards Rabies Virus Infection Is Linked to Cellular Innate Immune Responses

Rabies is caused by neurotropic rabies virus (RABV), contributing to 60,000 human deaths annually. Even though rabies leads to major public health concerns worldwide, we still do not fully understand factors determining RABV tropism and why glial cells are unable to clear RABV from the infected brain. Here, we compare susceptibilities and immune responses of CNS cell types to infection with two RABV strains, Tha and its attenuated variant Th2P-4M, mutated on phospho- (P-protein) and matrix protein (M-protein). We demonstrate that RABV replicates in human stem cell-derived neurons and astrocytes but fails to infect human iPSC-derived microglia. Additionally, we observed major differences in transcription profiles and quantification of intracellular protein levels between antiviral immune responses mediated by neurons, astrocytes (IFNB1, CCL5, CXCL10, IL1B, IL6, and LIF), and microglia (CCL5, CXCL10, ISG15, MX1, and IL6) upon Tha infection. We also show that P- and M-proteins of Tha mediate evasion of NF-κB- and JAK-STAT-controlled antiviral host responses in neuronal cell types in contrast to glial cells, potentially explaining the strong neuron-specific tropism of RABV. Further, Tha-infected astrocytes and microglia protect neurons from Tha infection via a filtrable and transferable agent. Overall, our study provides novel insights into RABV tropism, showing the interest in studying the interplay of CNS cell types during RABV infection.

A Descriptive Analysis of Human Rabies in Mainland China, 2005-2020

Epidemiological characteristics of human rabies in mainland China, 2005-2020 were analyzed to evaluate the effect of rabies control in China in recent years. A total of 24,319 human rabies cases were recorded in 2097 counties in 321 cities of 31 provinces in mainland China. Only 202 cases, located in 143 counties, were recorded in 2020, compared with 3305 cases in 992 counties in 2007; however, rabies was still relatively severe in Hunan Province even in 2020. Peak periods occurred in July-November; August was often the month with the most cases. Guizhou, Hunan, Guangdong, and Guangxi Provinces, in the central and southern regions, accounted for 50.0% of the cases in 2005-2020. Cases occurred almost exclusively in rural areas with 96.7% versus 3.3% in urban areas. A paradoxical relative expansion from southern, eastern, and central towards southwestern, northwestern, northern, and northeastern regions was observed along with the overall reduction of cases. Some regions witnessed complete elimination. The male-to-female ratio was 2.33:1; 66.8% of all cases were reported in the 0-10 (13.8%) and 41-70 (53.0%) age groups. Farmers (68.3%), followed by students (12.2), and diaspora children (6.5%) were most frequently involved. Our results provide objective information for the improvement of rabies prevention and control efforts. This will aid policymakers in China and elsewhere achieve the "Zero human deaths from dog-mediated rabies by 2030" global goal.

Taiwan Bat Lyssavirus: In Vitro and In Vivo Assessment of the Ability of Rabies Vaccine-Derived Antibodies to Neutralise a Novel Lyssavirus

Rabies is a neglected tropical disease. The prototype virus, the rabies virus, still causes tens of thousands of human fatalities annually. Rabies is one member of the genus Lyssavirus. The burden of other lyssaviruses is unclear. The continued emergence of novel lyssaviruses means that assessment of vaccine efficacy against these viruses is critical, as standard rabies vaccines are not efficacious against all lyssaviruses. Taiwan bat lyssavirus (TWBLV) was first reported in 2018 following isolation from Japanese house bats. Since the initial detection and genetic characterisation, no attempts have been made to antigenically define this virus. Due to the inaccessibility of the wildtype isolate, the successful generation of a live recombinant virus, cSN-TWBLV, is described, where the full-length genome clone of the RABV vaccine strain, SAD-B19, was constructed with the glycoprotein of TWBLV. In vitro and in vivo characterization of cSN-TWBLV was undertaken and demonstrated evidence for cross-neutralisation of cSN-TWBLV with phylogroup I -specific sera and rabies virus standard sera. For neutralisation equivalent to 0.5 IU/mL of WHO and World Organisation of Animal Health (WOAH) sera against CVS, 0.5 IU/mL of WOAH sera and 2.5 IU/mL of WHO sera were required to neutralise cSN-TWBLV. In addition, specific sera for ARAV and EBLV-1 exhibited the highest neutralising antibody titres against cSN-TWBLV, compared to other phylogroup I-specific sera.

Identifying high-risk areas for dog-mediated rabies using Bayesian spatial regression

Despite ongoing control efforts, rabies remains an endemic zoonotic disease in many countries. Determining high-risk areas and the space-time patterns of rabies spread, as it relates to epidemiologically important factors, can support policymakers and program managers alike to develop evidence-based targeted surveillance and control programs. In this One Health approach which selected Thailand as the example site, the location-based risk of contracting dog-mediated rabies by both human and animal populations was quantified using a Bayesian spatial regression model. Specifically, a conditional autoregressive (CAR) Bayesian zero-inflated Poisson (ZIP) regression was fitted to the reported human and animal rabies case counts of each district, from the 2012–2017 period. The human population was used as an offset. The epidemiologically important factors hypothesized as risk modifiers and therefore tested as predictors included: number of dog bites/attacks, the population of dogs and cats, number of Buddhist temples, garbage dumps, animal vaccination, post-exposure prophylaxis, poverty, and shared administrative borders. Disparate sources of data were used to improve the estimated associations and predictions. Model performance was assessed using cross-validation. Results suggested that accounting for the association between human and animal rabies with number of dog bites/attacks, number of owned and un-owned dogs; shared country borders, number of Buddhist temples, poverty levels, and accounting for spatial dependence between districts, may help to predict the risk districts for dog-mediated rabies in Thailand. The fitted values of the spatial regression were mapped to illustrate the risk of dog-mediated rabies. The cross-validation indicated an adequate performance of the spatial regression model (AUC = 0.81), suggesting that had this spatial regression approach been used to identify districts at risk in 2015, the cases reported in 2016/17 would have been predicted with model sensitivity and specificity of 0.71 and 0.80, respectively. While active surveillance is ideal, this approach of using multiple data sources to improve risk estimation may inform current rabies surveillance and control efforts including determining rabies-free zones, and the roll-out of human post-exposure prophylaxis and anti-rabies vaccines for animals in determining high-risk areas.

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Bayesian spatial regression was used to quantify location-based risk of dog-mediated rabies

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Available and publicly accessible data from disparate sources were gathered

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Risk was estimated using the association between

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Risk estimates were compared over time to determine the prediction ability

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Study suggests while active surveillance is ideal, using multiple data sources may improve risk estimation

Rabies Encephalitis and the Use of Optic Nerve Sheath Diameter to Detect Elevated Intracranial Pressure

Rabies is a rare but rapidly progressive and almost universally fatal disease. A previously healthy 59-year-old male presented with rabies encephalitis. We measured his optic nerve sheath diameter (ONSD) daily in both eyes using ultrasonography to indirectly monitor for elevated intracranial pressure (ICP). We performed CT and MRI brain on days when his ONSD changed significantly. An increase in ONSD temporally correlated with radiologic findings of cerebral edema and acute subarachnoid hemorrhage (SAH). ONSD measurement is a fast, inexpensive, and widely-available imaging modality that may serve as a surrogate marker for elevated ICP. It may be especially useful in patients who are difficult to be transported to radiology due to the unstable nature of their disease.

Spatial and temporal dynamic analysis of rabies: A review of current methodologies

Rabies continues to be one of the deadliest, high risk diseases worldwide, posing a severe threat to public health. The lack of human-to-human transmission means that the spread of rabies is not significantly affected by the distribution of humans or migra- tion. Thus, the spatiotemporal dynamic of cases in both wild and domestic animals is an important issue that can result in human cases. This paper gives an overview of the methodologies for the spatial and temporal dynamic analysis of this disease. It introduces the most representative research progress of spatial aggregation, dynamic transmission, spatiotemporal distribution, epidemiologi- cal analysis and application of modelling in the study of rabies transmission in recent years. This overview should be useful for investigating the spatial and temporal dynamics of rabies, as it could help understanding the spread of cases as well as contribute to the development of better prevention and control strategies in ecology and epidemiology.

Substitution of S179P in the Lyssavirus Phosphoprotein Impairs Its Interferon Antagonistic Function

Interferon (IFN) and the IFN-induced cellular antiviral response constitute the first line of defense against viral invasion. Evading host innate immunity, especially IFN signaling, is the key step required for lyssaviruses to establish infection.

General insights on obstacles to dog vaccination in Chad on community and institutional level

Domestic dogs are responsible for 95% of all human rabies cases worldwide and continue to be the main reservoir for this fatal virus in African and Asian countries. Interrupting the spread of the disease in the domestic dog population is therefore necessary for long-term, sustainable rabies control. Chad has been recognized as a rabies-endemic country since 1961, but no national control strategy is in place to date and dog vaccination coverage is very low. This qualitative, descriptive study aims to describe the main barriers to dog vaccination on both the community and the institutional level from a socio-anthropological point of view in Chad. The study was embedded in an overall project conducted from 2016 to 2018, to determine rabies burden and vaccine demand in West and Central Africa, funded by GAVI, the vaccine alliance. Data collection was conducted on the occasion of the project's closing workshops with stakeholders organized between August to September 2018 in the four (4) project areas: Logone Occidental, Ouaddaï, Hadjer Lamis and Chari Baguirmi. We conducted interviews and focus group discussions (FGD) among veterinary officers and dog owners. Participants were selected purposively based on their place of residence (dog owners) or work place (veterinary officers) and their previous contact with the project through reporting (dog owner) or management (veterinary officers) of a suspect dog rabies case. In each region, one FGD was organized with dog owners, and one FGD with heads of veterinary posts. At the end of the FGDs, a few participants were randomly selected for interviews. In addition, in each region an interview was conducted with the head of the livestock sector, the chief district medical officers and the head of a civil society association. The identified barriers to dog vaccination access are grouped into three main aspects: the economic, the socio-cultural and the institutional level. Economic constraints encountered relate to the cost of the vaccine itself and the expenses for transporting the dogs to the vaccination site. The cultural belief that the vaccine will have an impact on the therapeutic properties of dog meat for consumers (observed in Southern Chad), and the fact that dogs are considered impure animals in Muslim faith, which prohibits handling of dogs, are obstacles identified on the sociocultural level. At the institutional level, the unavailability of vaccines in veterinary services, the lack of communication about the law on dog vaccination, the absence of rabies in the training curricula of veterinary agents, and the lack of intersectoral collaboration limit vaccination coverage. In order to improve vaccination coverage and rabies surveillance with a view to eradicate rabies by 2030, communication strategies that are adapted to the context and that take cultural obstacles into account must be put in place in a synergy of interdisciplinary action. In addition, factors such as affordability, geographical access and availability of dog rabies vaccines needs to be addressed throughout the country. Although our study design did not allow a detailed analysis of obstacles related to socio-economic level, gender and age the broad insights gained can provide general guidance for future interventions in Chad and similar countries.

Compliance to post-exposure prophylaxis among animal bite patients - A hospital-based epidemiological study

Background and Objectives

Although rabies is a 100% fatal disease, it is preventable with appropriate and timely post-exposure prophylaxis (PEP). A hospital-based study was conducted among 360 animal bite patients in the Anti-Rabies Clinic (ARC) of Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi (VMMC and SJH).

Materials and Methods

A predesigned, pretested, structured questionnaire was administered by the interview technique to assess the compliance to PEP among the animal bite patients attending the ARC, which comprised assessment of wound washing practices adopted by the animal bite patients, administration of rabies immunoglobulin (RIG), and compliance to full course of anti-rabies vaccination (ARV).

Results

Out of 360 study participants, 131 (54.4%) had washed the wound using soap and water and 216 (89.6%) had washed the wound for less than 5 min. The compliance to the full course of ARV was seen among 172 (47.8%) study participants, whereas 164 (45.5%) were found to be non-compliant and 24 (6.7%) were found to be delayed compliant.

Conclusions

It was observed that a considerable segment of the study population did not practice the correct wound washing practices, and only about half of the total study participants (172; 47.8%) were found to be compliant to the full course of ARV. As rabies is a 100% preventable disease, increasing awareness pertaining to appropriate PEP may prove to be beneficial in improving the compliance to PEP and reducing the burden of mortality.

A Regional Analysis of the Progress of Current Dog-Mediated Rabies Control and Prevention

This study aimed to assess the current progress of dog-mediated rabies control and the level of political commitment among 88 rabies-endemic countries and to provide further recommendations for the elimination of dog-mediated rabies by 2030. A correlational study was conducted using data and relevant regulations from the websites of international organizations and NGOs. In general, rabies was yet to be considered a priority disease and only one out of five countries and territories has prepared a national strategic plan for rabies control and prevention. Likewise, scores of dog-mediated rabies control indicators such as dog vaccination rate and the number of post-exposure prophylaxis per 1000 people remained minimal. There were also regional differences in preparation for dog-mediated rabies control and progress towards elimination. In particular, more efforts are needed for Pan-African Rabies Control Network (PARACON) member countries. In order to meet the goal of global dog-mediated zero rabies by 2030, both dog-mediated rabies control activities such as dog vaccination and strong political commitment should be strengthened and promoted in all rabies-endemic regions of the world.

Evaluation of Our Rabies Prevention Practices: Is Our Approach Correct?

Background

Rabies disease is zoonotic disease-causing encephalitis and resulting in death. It is possible to prevent the disease with suitable prophylaxis approaches. This study examined the compliance of post-exposure prophylaxis approaches with the guidelines and the reasons for non-compliance in contact cases at risk of rabies.

Methods

This retrospective cross-sectional study includes patients who continued the vaccination program from 2014-2018 at the Ordu University Medical Faculty Hospital Rabies Vaccination Center in Ordu, Turkey. Cases were assessed in terms of sociodemographic features, previous rabies vaccination history, features of the contact with rabies risk, attendance duration after contact, and whether all stages of prophylaxis were completed after contact.

Results

Of the 748 cases attending the vaccination center, the age range was 1- 91 yr, with a mean age of 28.12 ± 21.60 yr. Of cases, 62.3% were male (n =466) and 37.7% were female (n =282). Of risky contact, 60% comprised stray animals. Of recorded cases, 55.2% displayed approaches compatible with guidelines. Among incompliant approaches, the most frequent was administering vaccines even though observation was sufficient. (n = 174, 52%).

Conclusion

Contact with risk of rabies may result in insufficient administration of the stages in prophylaxis after contact, or contrarily, mistaken administration based on acting with a sense of excessive safety. Stray dogs or domestic animals without sufficient vaccinations comprise a significant risk despite all efforts. In order to prevent risky contact, there is a need for the development of correct strategies and to ensure continuity of in-service training for health professionals.

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.

Rabies in dogs can be prevented by vaccination, and this approach has become a cornerstone in the control and eventual elimination of the disease. However, vaccinating hard-to-reach often free-roaming dogs are a challenge and represents one of the challenges to reach sufficient herd-immunity. A potential solution would be to vaccinate these dogs using oral baits filled with a vaccine. In this study we have assessed the acceptability of oral rabies vaccination (ORV) in Namibian dogs under field conditions. The results demonstrate that the method is acceptable both for the owners and the dogs, with a very high uptake of the egg-flavored bait. This supports the potential of ORV to contribute to vaccination programs where parenteral vaccination alone failed to reach sufficient vaccination coverage in the dog population.