What are Rabies in prevention and control of terrestrial animal disease epidemics in Vietnam?

What are Rabies in prevention and control of terrestrial animal disease epidemics in Vietnam?

In Section 1, Appendix 15 issued together with Circular 07/2016/TT-BNNPTNT has the following provisions:

1.1. Disease concept

a) Rabies is a disease that is transmitted between animals and humans. This is an acute infectious disease of warm -blooded animals caused by Lyssa and Vesicoviruses and Rhabdoviridae. Animals infected with rabies virus have an incubation period that varies depending on the species, virulence of the virus and the site of the bite. The virus enters the body, replicates and attacks the nervous system, destroying nerve tissue, causing crazy agitation and ending in death. The incubation period in animals can range from a few days to several months, possibly longer, but 10 days before the onset of illness, the virus can infect humans and other animals. Rabies virus is abundant in the saliva of dogs, cats and infected animals, even when the animal has not shown any clinical signs.

b) Resistance of rabies virus: The virus has weak resistance and is easily inactivated at 56°C within 30 minutes, at 60°C for 5-10 minutes and at 70°C in 2 minutes. The virus is inactivated under sunlight and common disinfectants at concentrations of 2-5%. In cold conditions of 4°C, the virus can live from a few weeks to 12 months, at temperatures below 0°C the virus can live for 3 to 4 years. The rabies virus is preserved mainly in the host.

1.2. Disease source and route of transmission

a) Affected species: Warm-blooded animals, mainly dogs and cats.

b) Disease source: The main carriers of the disease are dogs (over 90%), domestic cats and wild animals such as wolves, jackals, in addition, cats, ferrets, civets, foxes and some animals other mammals such as raccoons, blood-sucking bats, and insectivorous bats.

c) Route of transmission: The virus enters through bites, licks, scratches, damaged skin and mucous membranes , and internal wounds.

1.3. Clinical symptoms 

a) Incubation period: The incubation period for rabies can vary from a few days to several months depending on the location of the bite. Most illnesses develop within 21 to 30 days after an animal is infected with the virus.

b) Clinical manifestations: it is usually divided into 2 types, which are crazy rabies and dumb rabies (polio). In fact, many dogs with rabies show both forms alternately, initially exhibiting a frenzy, agitated appearance and then transitioning to an inhibited form and paralysis.

- Insanity type: divided into 3 periods

+ Pre-clinical period: Dogs with rabies have unusual signs such as hiding in a dark corner, discreet, approaching the owner involuntarily or on the contrary, showing excessive hurry, barking occasionally aimlessly, howling every time; or fidgeting, hurling him up for air.

+ Insanity period: motor reflexes are strongly stimulated, fiercely biting and barking at strangers , too impulsive when the owner calls , just need to have a light sound and jump up to bark at long intervals. The wound where the bite is itchy , the dog licks or bites itself, scratches to the point of hair loss, bleeding. Dogs stop eating, have difficulty swallowing, fever, dilated pupils , animals show signs of thirst, want to drink but cannot swallow ; The dog begins to vomit water , foams at the mouth, appears restless, alert, fearful, will be aimless, startled, and walks aimlessly, become fierce , frenzy (2 - 3 days after the onset of illness). Animals run away from home and often do not return; On the way, if it encounters something strange, it will also bite , eat indiscriminately, attack other dogs, including people .

+ Period of polio: the dog is paralyzed, cannot swallow food and water, has paralysis of the lower jaw and tongue, so the jaw is delayed, the tongue sticks out, the drool drips out, and the paralysis of the hind legs becomes more and more obvious; Dogs die between 3 and 7 days after the first symptoms, from paralysis of the respiratory muscles and from exhaustion from not being able to eat or drink.

Insane rabies accounts for only about a quarter of dog rabies cases, with the remainder being mute rabies.

- Dumb rabies : is the form of the disease without the usual signs of mad rabies ; Dogs only have sad expressions . The animal may have paralysis of one part of the body, half a person or two hind legs, but usually paralysis of the jaw muscles, jaw retracted, tongue protruding; drool flowed, the animal couldn't bite, barked, just growled in its throat. This process progressed from 2 to 3 days.

In general, dumb rabies progresses faster than mad rabies, usually within 2 to 3 days because the medulla oblongata of the infected animal is affected by the virus, which disrupts the circulatory and respiratory systems early. 

Cats are less susceptible to rabies than dogs, rabies in cats is progressive as in dogs, cats often hide in secluded places or cry and fidget like in heat; When people touch it, it bites hard and pungent, creating deep wounds.

1.4. Lesions: Gross lesions in rabid dogs are less visible; Only the stomach is empty or has a foreign object. Microscopic lesions in the brain's Amon horns with Negri corpuscles are typical for rabies, which can be detected by fluorescence microscopy.

What is rabies monitoring in prevention and control of terrestrial animal disease epidemics in Vietnam? 

Pursuant to Section 5, Appendix 15 issued together with Circular 07/2016/TT-BNNPTNT has the following provisions:

5.1. Clinical surveillance is the primary means of early detection of rabies cases in animals.

5.2. Subjects of surveillance are mainly dogs raised in areas with old outbreaks, high-risk areas, and areas where dogs are suspected of being infected with human rabies disease causing death due to rabies attacks.

5.3. Pet owners have the responsibility to regularly monitor and supervise the family's pet dogs and cats. If an animal is found to be unreasonably biting, scratching or attacking other animals, it must be isolated and Immediately notify the local authority or the nearest veterinary authority.

5.4. Local veterinary authorities shall identify old outbreak areas and areas with high risk of rabies outbreak, and coordinate with functional agencies of the health sector to develop and submit to competent authorities for approval and implementent of the local rabies surveillance plan.

Best Regards!