This paper presents a case of naturally occurring rabies in a 3-year-old female, non- descript donkey from Debre Zeit, Ethiopia. The affected animals exhibited the signs of colic, restlessness, abnormal sound, ataxia, biting its legs and around udder besides rubbing against objects. As narrated by the donkey owner, the animal was bitten by a stray rabid dog. The donkey died 48 days following the bites by the rabies affected stray dog. The owner of the animal could not get the post bite treatment of the donkey. The diagnosis was confirmed by the detection of virus particles in the brain of the donkey by fluorescent antibody technique. There was no evidence of disease in other animals and also in the members of family. The abnormal behavior of the animal after the bite with a stray dog or other wild animals may be considered as an indication of rabies so that the animal may be kept under strict vigilance. Since rabies is a highly fatal viral zoonosis, the importance of pre -exposure and post -exposure immunization and dog population management is discussed from control point of view. We also recommend the wider application of fluorescent antibody technique for the rapid diagnosis of rabies in animals. In authors view, this seems to be the first confirmed case of rabies in a young donkey from Debre Zeit , Ethiopia.
Rabies (Hydrophobia, Lyssa, Rabbia, Rage, Raiva, Tallwut), one of the oldest infectious diseases known to be transmitted by animal bites, is invariably fatal to humans and other warm blooded animals (Pal, 2007). It ranks number ten worldwide as a cause of mortality with 50,000 to 60,000 deaths annually mostly in the rural areas of Africa and Asia (Deressa et al., 2011). The disease can occur in sporadic as well as in outbreak form (Pal, 1991; Jindal and Narang, 1998; Acha and Szyfers, 2003). The World Health Organization regards rabies as a neglected zoonotic disease and efforts are promoted to establish wider access to appropriate post-bite treatment .Many species of animals are involved in the maintenance and transmission of rabies in nature (Kreb etal al., 1998; Acha and Szyfres, 2003).However, dogs are recognized as the main transmitter of rabies to the people of the world including Ethiopia and India. Most human deaths due to rabies in Asia and Africa follow a bite from an infected dog. Children under the age of 15 years are the main victims of dog bites. The disease has been eradicated from several countries of the world such as Australia, England, Hawaii, Hong Kong, Ireland, Japan, New Zealand, Norway, Singapore, and Sweden (Hoque et al., 2006; Pal, 2007).In India, Andaman and Nicobar and Lakshwadweep Islands are considered free of rabies infection (Pal, 2007).The disease is caused by rabies virus of genus Lyssavirus,family Rhabdoviridae and order Moonegavirales. The virus is non-segmented, negative-stranded RNA genome that shaped like a bullet; and is sensitive to heat, drying, sunlight and common disinfectants. In Ethiopia, rabies is reported mainly from dogs followed by cats and cattle (Deressa et al., 2010).The information of disease in other animals is scanty and therefore, the present communication describes a spontaneous fatal case of rabies in a young female donkey from Debre Zeit, Ethiopia.
Materials and Methods
A 3- year –old female donkey belonged to a poor person of Debre Zeit, Ethiopia constituted the material for the investigation. The donkey was used by the animal owner for carrying the goods from one place to another. The animal while working was bitten by a stray dog. The donkey developed abnormal behavior and died 48 days following the bite by the stray dog. The head was removed after taking all the precautions and was sent to The Ethiopian Health and Nutrition Institute, Addis Ababa for the confirming the diagnosis of rabies. The fluorescent antibody test (FAT) was done as per the procedure recommended by Dean and co-workers (1996).We do not know the fate of the stray dog which had bitten the donkey. As per the information gathered from the animal owner, the donkey did not bite to other animals or humans in the family. Unfortunately, the owner of the animal could not manage post -bite vaccination to his donkey which resulted in fatal out come.
On clinical examination, the donkey showed the restlessness, colic, abnormal sound, rubbing against objects and biting its legs and around udder. The brain tissues ( brain stem, hippocampus etc.) was removed from the head of the dead donkey by taking all necessary precautions such as wearing double gloves ,disposable sleeve etc. Smears prepared from the fresh brain tissues were fixed in acetone and stained with a fluorescein isothionate conjugate labeled antirabies immunoglobulin. The stained smear was washed in buffer and read under the fluorescent microscope to detect the characteristic green fluorescence associated with rabies antigen ( Dean et al.,1996).Both positive and negative control were also kept. The brain of the dead monkey was found positive for rabies when confirmed by fluorescent antibody test.
Rabies is an important viral anthropozoonosis from public health as well economic point of view ( Pal, 2007). In India, rabies is responsible to cause 30,000 deaths annually (Pal, 2005). Bovine rabies in Latin America resulted into financial losses of US Dollar 50.0 million (Pal, 2005).The disease is fatal in all species of animals and occurs in two forms, one is furious form and other is dumb form (Pal, 2007). Ruminants and horses mostly tend to acquire dumb form of rabies. Death usually occurs within 2-14 days of the manifestation of neurological signs. In our case, the donkey succumbed to death three days after the development of symptoms. The clinical signs in domestic warm blooded animals are variable. However, rabies should always be suspected if there is sudden change in animal behavior. The infection of brain commonly leads to behavioral changes inducing the host to bite to other animals or objects. We suspected rabies in our patient due to sudden change in its behavior. However, the confirmation was done by demonstrating the vial antigen in the fresh brain tissues of the autopsied donkey by fluorescent antibody technique (FAT).Any animal with confirmed positive rabies by FAT is considered capable of transmitting rabies. The importance of FAT in the diagnosis of rabies in cats and dogs is described by Deressa and co-investigators (2011).As FAT is sensitive, rapid and reliable, it must be employed by all public health laboratories for confirming the diagnosis of rabies in animals.
Naturally occurring rabies has been recorded in several species of animals such as bat,buffalo,camel,cat,cattle,coyote,deer,dog,elephant,fox,goat,horse,jackal,lion,mongoose,pig,rabbit,raccoon,rat,sheep.shunk,squirrel,wolf(Pal,1991;WHO,1992; Jindal and Narang,1998;Kreb et al.,1998;Wimalaratne and Kodikara,1999;Ach and Szyfrez,2003,Kachawara et al.,2006;Pal,2007).The current investigation records the presence of rabies in a young working donkey from Debre Zeit ,Ethiopia. The present case is interesting as the animal showed abnormal behavior after 45 days of bites from a stray rabid dog and died within three days after the development of clinical signs. Currently, there is no satisfactory test which can be applied to diagnose rabies in live animals. The diagnosis in animals is always confirmed after the death of an animal. The same was true in the present case as the diagnosis was established on post-mortem of the donkey. It is important to mention that altered behavior after an animal bite should be considered an indication of rabies.
Rabies is a dreaded, neuroinvasive ,viral zoonotic disease that causes acute encephalitis in warm blooded animals and is over 99 per cent fatal once the symptoms of disease develop. The disease spreads to people through close contact with infected saliva of animals mainly dogs through bites or scratches. The carnivores and viverids represent the principal reservoir species, and are responsible for the maintenance of the infectious cycle. The destruction of stray dogs and unvaccinated dogs bitten by known rabid animal, compulsory registration, licensing and vaccination of all pet dogs, provision of free post bite vaccination to humans and animals, immediate attention of wound due to bite of rabid or wild animal, use of protective clothing while attending sick animal, reporting of rabies cases both in man and animals, prophylactic vaccination of high risk groups like veterinarian, dog catcher, kennel staff, animal handler, laboratory worker, hunter etc., health education to the public to seek immediate medical treatment for animal bites, pre-exposure immunization of children in rabies endemic areas and close between medical and veterinary departments are highly imperative in order to control the rabies which is a highly fatal direct anthropozoonotic disease of global importance ( Pal,2007).
As far as it could be ascertained, this appears to be the first report of confirmed rabies in a working young donkey from Debre Zeit, Ethiopia.
We wish to thank Prof. Dr. Ram Krishan Narayan for critically reviewing our paper.
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