Risk assessment on rabies entry through hunting dog movement with semi-quantitative approach to Sumatera Island, Indonesia

Molecular analysis and geographic distribution of the recent Indonesian rabies virus

Background and Aim

Some Indonesian islands, including Sumatra, Kalimantan, Sulawesi, Java, and East Nusa Tenggara, have endemic rabies. Rabies outbreaks in Bali began from 2008 to 2011 and continue to occur sporadically. This study aimed to study the molecular analysis and geographical distribution of Indonesian rabies virus (RABV) from 2016 to 2021 and compare to previous periods.

Materials and Methods

Virus isolates from 2016 to 2021 were extracted from dog brains and sequenced at the nucleoprotein gene locus. They were compared with data sequences available in the GenBank database. Indonesian RABV from the previous three periods (before 1989, 1997-2003, and 2008-2010) was extracted from the GenBank database. The genetic diversity in this study was based on the N gene of Indonesian RABV.

Results

Asian RABV, which is genetically close to the Indonesian virus, is a virus from China (ASIA-3 cluster) and from the Southeast Asia region, namely, virus isolates from Sarawak and Malaysia and some Cambodian isolates. Rabies virus, which was isolated from the Bali islands, was the new cluster first detected and published in Bali, Indonesia, in 2008, while RABV from West Sumatra Province, which was isolated from 2016 to 2021, was also considered a new cluster that is genetically distant from other clusters in Indonesia.

Conclusion

The RABV in Indonesia is divided into five clusters. The isolates from West Sumatra Province from 2016 to 2021 were a new cluster genetically distant from other Indonesian viruses.

Epidemiological Analysis of Rabies in Central China from 2013 to 2018

Objective

The study aimed to timely grasp the epidemiologic status of rabies in Central China from 2013 to 2018 and provide scientific evidence for the implementation of follow-up prevention and control measures.

Methods

We initiated a retrospective observational and descriptive study of bite-related injuries data and rabies disease data in Hubei province from 2013 to 2018, managed by the Center for Disease Control and Prevention.

Results

A total of 2,028,691 individuals were exposed to bites from 2013 to 2018, of which 221 were diagnosed with rabies and deceased. Among those cases, the incubation periods of rabies varied from 3 days to 18,406 days, which has been shown to be statistically associated with where the infected person was exposed and whether the wound care has been conducted.

Conclusion

Epidemiological studies have shown that from 2013 to 2018, the current situation of rabies in Central China is still severe. The case fatality rate keeps virtually 100%. The rural population is still the most vulnerable group to rabies, characterized by a high exposure ratio and low treatment rate as well as poor vaccination compliance. Hoewever, larger populations are warranted to validate our findings.

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

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