17th June 2024

Rabies

Rabies, caused by a virus of the Lyssavirus genus, is a fatal disease of the central nervous system if given time to propagate. It is transmitted through direct contact with infected mammals, often a bite. These mammals include dogs, bats, and raccoons. The first symptoms of rabies infection are a flu-like illness and irritation at the site of the bite. There is generally a long incubation period between exposure and CNS symptoms – in the order of weeks – as it takes time for the virus to travel backwards through peripheral nerves. This is shortened in children or in bites to the face as there is a smaller distance to travel. CNS symptoms include fluctuating periods of confusion, severe agitation and aggression. Other symptoms include hypersalivation and hydrophobia. The disease is almost always fatal once CNS symptoms are present.

Rabies is a vaccine-preventable disease. Post-exposure prophylaxis, involving a combination of vaccinations and immunoglobulins, is also available. As rabies is generally a disease of resource-poor areas, a patient may choose to observe a dog after a potential transmission event instead of immediately seeking medical attention. If the dog remains alive and well after around 10-15 days, then it did not have transmissible rabies infection at the time of the direct contact. As alluded to, this method may be risky if the incubation period is expected to be shorter than usual. The vaccination schedule and use of immunoglobulin therapy depends on whether it is pre-or post-exposure prophylaxis, as well as previous vaccinations, local endemicity of rabies, and severity of exposure. Please see the Green Book reference for further details and note that these are always subject to change.