Rabies, saliva, zoonose, biting, Lyssavirus, foxes, vaccination

Rabies

Rabies is a zoonosis (animal disease that can be transmitted to humans) caused by a virus of the genus Lyssavirus. Found in the saliva of infected animals in the final phases of the disease, the virus is generally transmitted to another animal or to humans through biting. Contamination may also occur if the saliva of an infected animal comes into contact with a wound or a mucous membrane.

There are 11 different genotypes of rabies virus, seven of which can cause rabies in humans. Genotypes are mainly differentiated according to the animal host species. Rabies in carnivores is usually caused by the genotype 1 virus, which is the most commonly identified in human rabies cases. Without treatment prior to the onset of clinical signs, the disease is always fatal.
Rabies, which causes over 55,000 deaths a year worldwide, is found all over the world, except in certain areas such as Australia and the British Isles due to their geographical particularities. Several European countries have become rabies-free thanks to oral vaccination programmes.
In industrialised countries, rabies persists mainly in wild animals whereas it remains an endemic disease in many developing countries, with the domestic dog as the principal reservoir and main source of human contamination.
In Western European Countries, rabies in dogs was eliminated several decades ago, but it continues to persist in fox populations. Thanks to oral vaccination campaigns conducted in foxes, vulpine rabies (i.e. rabies affecting foxes) has been eliminated in France. The last case was reported in 1998. France therefore now fulfils the OIE conditions enabling it to be declared a rabies-free country. To avoid any risk of reintroduction, the rabies situation in France is monitored on an ongoing basis. The illegal importation of infected animals from Africa remains a concern, and justifiably so since seven cases have been detected in France since 2001.
Certain types of rabies, however, can affect bats (chiroptera). In Europe, bat rabies viruses belong to genotypes 5 and 6. While these can infect humans, the risk of virus transmission from bats to humans is considered negligible in the general population considering the low probability of human exposure to bats.
Since 1970, 20 human cases of rabies have occurred in France; all of them were the result of contamination occurring outside of France.

Anses's role

The Nancy Laboratory for rabies and wild life, which specialises in animal rabies, plays a key role in the French rabies monitoring system. As a National Reference Laboratory, it diagnoses rabies in animals which have not contaminated humans. In 2009, 353 samples were received for rabies diagnosis. The laboratory also heads up a national network for monitoring lyssavirus infections in bats. In this framework, 220 bats were received and analysed by the laboratory in 2009.
In addition to these national activities, the laboratory also plays a key role at the European level as a European Union Reference Laboratory (EURL) for rabies and rabies serology. It is responsible for assessing the reliability of international laboratories involved in providing serological tests and issuing certificates for cats and dogs travelling to rabies-free countries in which quarantine regulations have been eased up (1).
At the international level, the Nancy Laboratory for rabies and wild life is an OIE Reference Laboratory, and in this regard plays an active role in developing and standardising methods of serology and diagnosis.
It is also a WHO Collaborating Centre and therefore participates in the development and application of guidelines related to rabies and issues scientific opinions on the methods for controlling animal rabies.

The laboratory performs research activities aiming to evaluate the pathogenicity of the French bat virus on domestic carnivores and foxes.

In terms of risk assessment, the national “Animal Health” scientific panel has produced opinions during the previous episodes of rabies reintroduction in imported dogs (particularly in 2004 in Aquitaine and 2008 in Seine-et-Marne), and issued a report in 2003 entirely dedicated to a risk analysis of rabies in bats.

(1) Pets from third countries in which rabies is not under control (countries not listed in Annex 2 Part C of Regulation (EC) 998/2003) entering a Member State, and pets circulating between Member States to Malta, Ireland, Sweden or the United Kingdom must be vaccinated against rabies with a validated serological test result. Pets from countries listed in Annex 2 Part C of Regulation (EC) 998/2003 and pets circulating between Member States (except to Malta, Ireland, Sweden or the United Kingdom) only require rabies vaccination.

May 2010