Technical documents - International Organizations
Technical documents - Caribbean countries
Geographical distribution of rabies for domestic animals in Caribbean between july and december 2010
An infectious, virulent disease inoculated mainly through a bite. The disease causes fatal encephalomyelitis.
The disease is of significant medical importance: human rabies originating from animals warrants rigorous prophylactic measures. It is however of less economic importance than other diseases except where cattle farms in certain South American countries are concerned.
Enzootic in several countries around the world and in Latin America. It was declared to the OIE in 2004 by the following countries: Argentina, Belize, Bolivia, Brazil, Canada, Chili, Columbia, Ecuador, Costa Rica, Cuba, Dominican Republic, Guatemala, Guyana, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, USA and Venezuela.
All domestic or wild mammals.
Man (major zoonosis).
An RNA virus from the family Rhabdoviridae, Lyssavirus genus, serotype 1 (rabies in the strict sense).
The virus is inactivated by heat, light and chemical agents thus the importance of washing / disinfecting cuts (quaternary ammonium, bleach, soap solutions).
The virus can be preserved in 50% glycerol (for long-distance sample transport).
Incubation period: long and of variable length. From 15 to 60 days on average but it may extend to several months or years. Once declared rabies is 100% fatal.
Clinical presentation is dominated by nervous disorders which vary according to species and depending on which parts of the nervous system are damaged. There are no pathognomonic symptoms: "rabies is all, rabies is nothing else".
In enzootic areas the elements leading to suspicion of rabies are:
- any abnormal change in behavior
- any difficulty in chewing or swallowing
Two forms exist. The aggressive form and the paralytic form but any intermediate combination of the two may be encountered. Rabies assumes protean form in humans and only paralysis is constant at the end of the disease.
Carnivores
Behavioral changes.
Difficulty in swallowing, salivation, changes in the voice.
Paralysis.
Bovines
Changes in behaviour (mooing, anxiety, yawning)
Hypersalivation, dysphagia, anorexia, interrupted rumination, tenesmus, constipation.
Flaccid paralysis.
Small ruminants
Milder symptoms.
Anorexia, behavioural disorders, digestive disorders.
Abnormal salivation, motor loss of coordination, paresis.
Equids
Anxiety, excitation and hyperesthesia (violent reactions to stimuli: noise, light, contact). Salivation, biting of the inoculation wound, pharyngeal paralysis followed by overall paralysis.
Suidae
Variable symptoms:
- excitation (biting of the inoculation wound, abnormal cries, etc.)
- or: paralysis and rapid death.
Man
Clinical polymorphism
Psychomotor excitation, hydrophobic spasm, sensory hyperesthesia.
Death in 3 to 6 days.
In animals
No treatment exists to date.
On clinical suspicion the animal concerned should be isolated.
The only really effective method to protect animals is vaccination.
In man
Treatment known as "post exposure" treatment exists in the form of a set of anti rabies vaccine injections immediately after contamination +/- serotherapy
Sanitary prophylaxis
In disease-free countries: avoidance measures
Prohibition of importation of animals in the rabies incubation stage (vaccination and/or quarantine).
Wild animals: awareness of the sanitary status of vector animals in neighbouring countries and preventive measures in border regions (reduction of vector populations, mass oral vaccination campaigns, etc.)
In affected countries: fight against rabies caused by vector animals.
Stray cat and dog population management, monitoring of wild animal vectors, reduction, immunisation (vaccinated bait).
Medical prophylaxis
Regular anti-rabies vaccine administration to vector species (domestic or wild carnivores) is effective.
Two methods of administration exist
Parenteral: inactivated virus vaccines replace modified virus vaccines as they are more effective.
Oral: reserved for carnivores (ERA, SAD, SAG2 strains, recombinant rabies vaccine). The liquid vaccine is placed in a plastic capsule inside meat or fish meal bait.