Incubation period can be more than 1yr!

Nasty viral infection that travels slowly through the nervous system until it reaches the brain. Around 30 people have survived but often with severe disability.

A 15yr old girl from Milwaukee survived with only mild neurological sequelae (reported in 2005) after treatment with induced coma (midazolam, barbiturates, ketamine) and antivirals (amantadine and ribavirin). The aim was to maintain burst suppression until rabies antibodies in the CSF started to increase (day 8). Extubated on day 27. Since then this approach has been tried multiple times, with poorly reported outcomes – has been criticised for lack of evidence of benefit but also for poor evidence for underlying therapeutic principles [Alan Jackson, neurologist at University of Calgary].

Any warm blooded animal is a potential risk, including bats, monkeys and rodents as well as cats, dogs and foxes. Animals behaving abnormally represent a higher risk of infection (but normal appearance and behaviour do not exclude rabies) – unprovoked bites obviously suggest abnormal behaviour, and carry greater risk than provoked bites.

Domestic dogs or cats behaving normally at 15 days after an exposure would not have been infectious at the time of the exposure.

The risk of infection depends on:

• country of exposure – see below
• category of exposure – see below – higher risk with broken skin, including single or multiple transdermal bites, severe lacerations, or where mucous membranes or an existing skin lesion have been contaminated by the animal’s saliva or other body fluid (intact skin is a barrier against infection).
• site (on body) of exposure
• whether the patient is immunosuppressed or has any allergies
• any previous rabies vaccinations or immunoglobulin treatment

For more on bites, see PHS bat bites page and PHS other animal bites page.

Country and category of exposure

Determine “combined country or animal risk” – Rabies risks by country – GOV.UK

Determine category of exposure – grade 1-3, with 1 being no physical contact with saliva, 3 being direct contact. Slightly different rules for bats!

Combine the 2 according to the risk matrix –

Green get nothing, obviously, amber get rapid vaccine schedule (days 0, 3, 7, 21) – modified if fully immunised already or immunosuppressed. Red get rapid vaccine schedule plus Human Rabies Immunoglobulin.