THIRUVANANTHAPURAM: Rabies can only be diagnosed after death, but an ongoing research project at the Chief Disease Investigation Office, Palode, can shift paradigms. The project ‘Development and Standardisation of Antemortem Diagnostic Techniques for Rabies’ not only aims to develop an antemortem diagnostic technique, but also to make tests possible in the peripheral labs of the Animal Husbandry Department.
The incidence of rabies in livestock is increasing, and an antemortem diagnosis will be helpful, says Animal Husbandry Department Director S Chandrankutty. Rabies is one of the primary reasons for the loss of livestock in Kannur, Kozhikode and other areas, he says.
Some of the symptoms of rabies are similar to those of ketosis in cattle, canine distemper and toxicity. However, any animal which seems to be rabid is not given any medical attention. “If it can be established that an animal is not affected with rabies while it is still alive, clinicians will be able to treat and save the animal,” he says.
The diagnostic method in use right now involves detecting rabies virus antigen in brain smears collected from a biopsy, a method recommended by WHO. However this test can be done only in a laboratory with high biosecurity and biocontainment facility.
Moreover, bringing the whole carcass or the animal’s head to the laboratory is not easy especially in the case of large animals like cattle. Many a time, the body is disposed of before confirming that the cause of death was rabies.
The new technique which is being developed will simplify the process of diagnosis. If successful, it will help doctors detect rabies virus in saliva, corneal smears, eye secretions, cerebrospinal fluid and such easily accessible samples.
Researchers are validating and standardising the molecular tests. It is reckoned that it might take another couple of years before the research is completed.
Alongside, the project also aims to develop another chip-based molecular quick test, so that rabies tests can be conducted in peripheral laboratories with lesser biosecurity. If realised, this will take rabies diagnosis outside the three laboratories in Palode, Kollam and Thiruvalla. Even a field-level diagnosis might be possible, then.