Rabies Virus Neurovirulence
Sunit K. Singh, Daniel Růžek in Neuroviral Infections, 2013
Rabies is an infectious encephalitic disease of mammals, caused by viruses of the genus Lyssavirus (Family Rhabdoviridae). Exposure to rabies virus, in the absence of timely medical intervention, almost invariably results in a fatal outcome. The term “rabies” comes from the Latin word rabere, which means “to rage or rave” and refers to the clinical disease progression seen following infection. This condition has been known, and feared, by people across the globe for thousands of years (Neville 2004). It is only within the last few centuries, however, that progress has been made in understanding the disease, and in the development of successful prevention and treatment strategies (Baer 2007). In the 1880s, Louis Pasteur developed the first successful postexposure prophylaxis (PEP) (Pasteur 1885). From this early innovation, scientific and technological advances during subsequent decades have provided the safe and efficacious vaccines available today (World Health Organization [WHO] 2005). Despite the existence of these tools, rabies continues to kill thousands of people every year, mostly in countries where people live on less than US$1 each day. The disease occurs in more than 75% of the world’s countries, causing innumerable animal deaths and an estimated 55,000 human deaths per year, the majority of which are children younger than 15 years (WHO 2010). It is likely that the predicted annual figure for human rabies fatalities is a gross under-estimate due to the lack of infrastructure and reporting systems in developing countries (Fooks 2007).
Rabies and other lyssaviruses
Avindra Nath, Joseph R. Berger in Clinical Neurovirology, 2020
There are at least 14 lyssavirus genotypes (International Committee on Taxonomy of Viruses) [5] based on criteria of genetic distance, a threshold 80%–82% nucleotide identity for N gene, or 80%–81% for concatenated coding regions of the N+P+M+G+L genes, phylogenetic tree topology and consistency, antigenic patterns and other characteristics such as ecology, host, geography, and pathological features (Table 13.1). Lyssavirus genus, based on genetic distance and serological cross-reactivity, consists of two phylogroups. Phylogroup I consists of rabies virus, which is the most prevalent worldwide, isolated from terrestrial mammals including dogs and hematophagous and insectivorous bats, and is the focus of this chapter [11,21,25,26], European bat lyssaviruses type 1 and 2, Duvenhage virus, Australian bat lyssavirus, Aravan virus, Khujand virus, and Irkut virus. Phylogroup II consists of Lagos bat virus, Mokola virus, and Shimoni bat virus. West Caucasian bat virus and Ikoma virus cannot be included in group I or II and are considered to be members of proposed phylogroup III. Bokeloh bat lyssavirus is another potential extension, phylogenetically related to European bat lyssavirus type 2 and Khujand virus. Bats are reservoirs and vectors of all lyssaviruses except for the Mokola virus and Ikoma lyssavirus.
Rabies
Meera Chand, John Holton in Case Studies in Infection Control, 2018
RABV is a member of the Rhabdoviridae family and Lyssavirus genus. Within the Lyssavirus genus, there are several closely related viruses, including viruses infecting fruit bats (Lagos bat virus) and insectivorous bats (Duvenhage virus, EBLV and Australian bat lyssavirus) in different parts of the world. All the lyssaviruses have a negative (anti-sense) stranded RNA genome of about 12 kb encoding just 5 proteins. Mature virus particles contain an RNA core, a polymerase complex made up of the polymerase, and L proteins responsible for transcription, as well as a phosphoprotein and the matrix and glycoproteins.
Current status of human rabies prevention: remaining barriers to global biologics accessibility and disease elimination
Published in Expert Review of Vaccines, 2019
Charles E. Rupprecht, Naseem Salahuddin
As a basic operational definition, rabies is an acute, progressive encephalitis caused by a lyssavirus [1]. Lyssaviruses are bullet-shaped, genetically mono-phyletic, single-stranded, negative-sense RNA viruses, taxonomically residing in the Order Mononegavirales, Family Rhabdoviridae [2]. With advances in pathogen detection methods, more than 17 lyssavirus species have been described since the 1950s [3–11]. Lyssaviruses are highly neurotropic, deposited into a wound from the saliva after an animal bite. Virions undergo retrograde transmission within the neuronal axoplasm, before replication in the CNS and subsequent passage to the salivary glands [12]. Rabies is distributed on all continents, except for Antarctica [13]. All warm-blooded vertebrates are susceptible, with significant representatives among mammalian carnivores and bats [14]. Rabies virus is the most important member of the Lyssavirus Genus. Although polyhostality is a significant feature in support of perpetuation, the domestic dog remains the major global reservoir and source of most human cases [15]. As with many neglected tropical diseases (NTDs), the actual burden of human fatalities is poorly known. This is due in part to inadequate reporting, with suggestions of tens of millions of human exposures, resulting in tens of thousands of deaths annually, typically with a substantial representation among a cohort less than 18 years of age, particularly among the Lesser Developed Countries (LDCs) in Africa and Asia [16].
Post-exposure prophylactic vaccine candidates for the treatment of human Risk Group 4 pathogen infections
Published in Expert Review of Vaccines, 2020
James Logue, Ian Crozier, Peter B Jahrling, Jens H Kuhn
Though PEP vaccines have been licensed sparingly by the FDA, the use of PEP vaccines can be very effective especially when routes of pathogen exposure are well documented, such as exposure due to contact with animals known to carry a particular pathogen. Perhaps the most well-known PEP vaccine strategy is deployed after known or potential rabies virus (RABV, Rhabdoviridae: Lyssavirus) exposure. RABV passes from infected mammals to humans when animal saliva is introduced through bites or scratches, particularly from dogs and bats [9]. If left untreated, the virus causes rabies, a debilitating encephalitis leading to 40,000–70,000 deaths annually [10,11]. Rabies prevention methods that included the large-scale vaccination of dogs to prevent RABV transmission to humans in the 1950s were effective in curtailing this disease, at least in the western hemisphere [12]. However, extensive postexposure studies in animals throughout the 1990s [13–17] prompted the US Centers for Disease Control and Prevention (CDC) to include the recommendation of a PEP vaccination in combination with passive antibody treatment in the event of potential RABV exposure [18]. Since the incorporation of vaccine plus antibody PEP into the treatment regimen and the large-scale vaccination of dogs, rabies cases have dramatically decreased in developed countries; only 33 rabies cases were diagnosed in the US from 2003 to 2014 [19].
Notifications of suspected rabies exposure increased in Finland: 26 years of one health surveillance, 1995–2020
Published in Infectious Diseases, 2023
Ruska Rimhanen-Finne, Jukka Ollgren, Tuija Gadd, Tiina Nokireki
Rabies is a fatal encephalitis caused by viruses of the Lyssavirus genus, typically the rabies virus, but other lyssaviruses can also cause clinical rabies [1]. Rabies is endemic in numerous countries around the world while almost all European Union member states, European Free Trade Association countries, the United Kingdom and the Balkan countries have eliminated rabies during the last years or decades.