Thiruvananthapuram: It was a deep dog bite on the nerve-rich part of her elbow, cubital fossa, that had led to the death of seven-year-old Niya Faisal even after she was given three doses of the rabies vaccine. This was the conclusion of the doctors at the SAT Mother and Child Hospital, Thiruvananthapuram, where the child breathed her last. 

According to the doctors, a direct bite on areas like the face, neck and elbow that are dense with nerves can lead to the virus reaching the brain and spinal cord before the vaccine could generate antibodies. Niya had taken three doses of the vaccine but succumbed to the rabies virus before she could be administered the fourth dose of the vaccine on May 6.

"This was a direct injury to the nerve, and the bite was deep," said Dr S Bindu, the superintendent of SAT Hospital. "So the chances of the virus reaching the brain before the vaccine could act was very high," she said. The cubital fossa, the fleshy area between the upper arm and forearm, is a junction through which major nerves and blood vessels travel. 

The virus journeys to the brain at the rate of 50-100 millimetres a day. Dr Aravind R, an infectious diseases specialist, said that it was rare for adults to be attacked by dogs on the face or neck or elbow. "However, children are highly vulnerable," he said. Dr Aravind is the head of department Infectious Diseases in Thiruvananthapuram Medical College. He said that Siya Faris, the six-year-old child who died in Kozhikode on April 29, had multiple bites on her neck. She too was given vaccination but still succumbed to the virus.

The doctors said that the deaths were not an indication that the vaccine was ineffective. "A recent study conducted on 200 samples had found that the vaccine could generate antibodies in sumptuous quantities," a doctor said. 

Along with the vaccine, immune globulin is also administered. This is done for "immediate neutralisation". It uses pre-formed antibodies to fight the virus, and its effect is short-term. In other words, if the rabies virus had been deposited deep inside the nerves, like in Niya and Siya's cases, the immune globulin will not be effective. The vaccine too could prove inadequate if not administered on time. 

Niya is the third child to die of rabies in one month. It was on April 8 that Niya was bitten by a dog near her house at Kunnikode in Kollam district. She was trying to protect her duck from the dog. The first dose of the vaccine was administered at the nearby Primary Health Centre that day itself. On April 11 and 15, she was administered the second and third doses. Her last and fourth dose was scheduled on May 6.