Rabies

World Health Organization: case definition[41]World Health Organization. WHO expert consultation on rabies: WHO TRS N°1012 (third report). April 2018 [internet publication]. https://apps.who.int/iris/handle/10665/272364

Clinical description:

• An acute neurological syndrome (i.e., encephalitis) dominated by forms of hyperactivity (furious rabies) or paralytic syndromes (paralytic rabies) progressing towards coma and death, usually by cardiac or respiratory failure, typically within 7–10 days of the first signs if no intensive care is instituted. These may include any of the following:

  • Aerophobia

  • Hydrophobia

  • Paraesthesia or localised pain

  • Localised weakness

  • Nausea or vomiting.

Laboratory criteria for diagnosis:

• One or more of the following laboratory criteria should be used to confirm a clinical case:

  • Presence of viral antigens in samples (e.g., brain tissue, skin)

  • Isolation of virus from samples in cell culture or in laboratory animals

  • Presence of viral-specific antibodies in the cerebrospinal fluid (CSF) or serum of an unvaccinated person; and/or

  • Presence of viral nucleic acids in samples (e.g., brain tissue, skin, saliva, concentrated urine).

Case classification:

• Suspected: a case that is compatible with the clinical case definition

• Probable: a suspected case plus a reliable history of contact with a suspected, probable, or confirmed rabid animal

• Confirmed: a suspected or probable case that is confirmed in the laboratory.

Centers for Disease Control and Prevention: 2011 case definition[45]Centers for Disease Control and Prevention. Rabies, human: 2011 case definition. 2011 [internet publication]. https://wwwn.cdc.gov/nndss/conditions/rabies-human/case-definition/2011

Clinical description:

• An acute encephalomyelitis that almost always progresses to coma or death within 10 days after the first symptom.

Laboratory criteria for diagnosis:

• Detection of Lyssavirus antigens in a clinical specimen (preferably the brain or the nerves surrounding hair follicles in the nape of the neck) by direct fluorescent antibody test; OR

• Isolation (in cell culture or in a laboratory animal) of a Lyssavirus from saliva or central nervous system tissue; OR

• Identification of Lyssavirus specific antibody (i.e., by indirect fluorescent antibody [IFA] test or complete rabies virus neutralisation at 1:5 dilution) in the CSF; OR

• Identification of Lyssavirus specific antibody (i.e., by IFA test or complete rabies virus neutralisation at 1:5 dilution) in the serum of an unvaccinated person; OR

• Detection of Lyssavirus viral RNA (using reverse transcriptase-polymerase chain reaction) in saliva, CSF, or tissue.

Case classification:

• Confirmed case: a clinically compatible case that is laboratory confirmed by testing at a state or federal public health laboratory.