Infectious Disease and Foreign Travel Emergencies 157
Bites with Rabies or other Lyssavirus Risk
Rabies and Lyssavirus risk
DIAGNOSIS
1 Transmission of rabies or other lyssaviruses usually occurs from the bite of a
dog, other canids such as foxes and wolves, cats, monkeys, bats, raccoons
and skunks.
2 Rabies is endemic in most continents apart from Australia, but several cases
of a similar disease caused by the Australian bat lyssavirus (ABLV), a
zoonotic virus closely related to rabies virus, have occurred following a bat
bite or scratch.
3 The incubation period is 3–8 weeks, but may be 3 months or more, by which
time a travel history and animal or bat bite history may have been forgotten.
4 Clinical signs of infection include anorexia, fever, pain at the bite site and
headache, progressing to confusion and agitation from encephalitis with
pre-fatal hypersalivation, hyperthermia and hydrophobia.
5 Discuss any laboratory test with the infectious diseases team or pathology
laboratory prior to sample collection.
(i) Laboratory confirmation includes immunofluorescent stain of
a skin biopsy from the nape of the neck, antibody detection in
blood or CSF, or PCR assay of saliva, blood or CSF.
MANAGEMENT
1 Established rabies is inevitably fatal. All cases of rabies exposure that have
sur v ived have been vaccinated before t he onset of clinica l disease.
2 Immediately wash and f lush all bite wounds and scratches for at least 5 min.
Check the patient’s tetanus immunization status, and give adsorbed diph -
theria and tetanus toxoid (ADT) as required.
3 Try to evaluate the exposure risk:
(i) Category I – touching or feeding animals, licks on the skin.
(ii) Category II – nibbling of uncovered skin, minor scratches or
abrasions without bleeding, licks on broken skin.
(iii) Category III – single or multiple transdermal bites or scratches,
contamination of mucous membrane with saliva from licks;
exposure to bat bites or scratches.
4 Discuss post-exposure rabies and ABLV prophylaxis (post-exposure prophy-
laxis [PEP]) immediately with an infectious diseases specialist or the on-call
population health unit specialist.
