Anti-rabies serum administration crucial after dog bite: Health experts

More than 20 people have died of rabies infection in Kerala this year, and five among them suffered the casualty despite being vaccinated. A seven-member committee has been formed to study the efficacy of the vaccine. But it has not been enough to cure the soaring anxiety levels amongst the public in the state.

Onmanorama approached a couple of health experts to gather some insight on the issue.

The golden hour

The rabies virus is an RNA virus that enters the body through the bite of a vector organism. It remains around the wound for some time and then it migrates through the nervous tissues into the central nervous system and causes encephalitis.

“The first few hours after a dog bite are crucial. Washing the wound site thoroughly can remove up to 80 per cent of the virus,” Dr Presoon Kuruvilla, the Consultant Physician at Caritas Hospital & Institute of Health Sciences, Kottayam told Onmanorama.

“Washing the wounds with running water for 15 minutes is a must after a dog bite. Apply soap to clean the wound and wash away the germs. After washing, apply ethanol and iodine if available to sterilise the wound,” he advised.

Bites to critical body parts

A death audit report published by the Health Department has stated that all the five vaccinated rabies victims sustained third-degree wounds on critical body parts like the face, neck and fingers.

“Critical body parts have more nerves and that bites to these regions can increase the progression of the virus inside the body,” says Dr. Aravindan KP, Senior Consultant Pathologist, Kozhikode District Co-operative Hospital.

“The vaccine takes at least 2 weeks to develop antibodies. If bites are inflicted on critical parts like the face the virus will reach the brain before the vaccine can take effect,” he said.

Administration of serum, immunoglobulin

Hospitals offer immunoglobulin or serum to a patient during the first visit if the type of injury is classified as serious.

“Proper administration of the serum after a dog bite is crucial for any wound which elicits blood. The entire serum has to be administered to the wound. It is not easy when the bite is near the eye or other sensitive organs. Staff needs to be trained for the same,” Dr Aravindan says.

“While the serum is extracted from a horse, immunoglobulin includes humanised antibodies,” Dr Presoon clarified.

“Though immunoglobulin is more effective compared to serum, the latter is usually opted as it is cheaper,” he said.

Vaccine doses increase antigenicity

When asked why the vaccine is given in serial doses, Dr Presoon said that spacing out the doses increases the antigenicity of the vaccine. Antigenicity is the term used to define whether and how well the substance attaches to immune cells beginning the immune response process.

“Serial doses allow the body to develop the antibody within the minimum incubation. The booster doses are then given to enhance immunity,” Dr Presoon said.

Meanwhile, Dr Aravind said that India should consider the option of administering anti-rabies vaccines to high-risk persons prior to a bite as opposed to the standard convention.

Vaccine, serum storage is important

Though the anti-rabies vaccines, bought through the Kerala Medical Corporation Limited (KMCL), have the quality standard certification of the Centre, serious questions have been raised about the efficacy of the anti-rabies vaccine. Health experts, however, dismiss the possibility.

“Initiatives need to be taken to check if the vaccines and serum are stored and administered in the right manner. The quality of the vaccine shot is not the issue here. Quality of serum can be compromised if not stored in the right temperature,” Dr Aravindan said while adding that adequate training is required for the intra-dermal anti-rabies vaccine.

Any lapses in the manufacture, purification, handling, and storing of vaccines will reduce their efficacy.

Though there are no naturally occurring mutations of rabies as yet, health experts opine that genome sequencing must be done to observe the recent behaviour of the rabies virus.

Food waste creates an ecosystem for dogs to thrive

According to test reports of the Kerala Animal Husbandry department in Kerala, the number of dogs infected with the deadly rabies virus has almost doubled in the last five years. Out of the 300 samples collected from pet dogs and dead ones, as many as 168 cases turned positive for the disease.

The cases of the virus in other animals, including cats, also doubled during the last five years.

A chief reason for the substantial rise in rabies cases is cited as the stoppage of vaccinations, which were used to be provided with sterilization activities. The negligence in timely rabies vaccination has resulted in the spread of diseases among pet animals.

The huge amount of untreated food waste lying around is yet another reason for exploding dog population in Kerala.

“The food waste creates an ecosystem for these animals and vermin to thrive,” Dr Aravindan said.

Authorities need to look at immediate options like limited culling along with long-term options like animal birth control to address the issue.

“We neither have enough animal shelters to contain these dogs nor trained human resources to capture them. Animal Birth Control is an exercise that can take effect only a few years from now,” he added.

Meanwhile, experts argue that efforts by the administration will go to waste if it is not balanced by public awareness and education.

“The fact that the majority of the people who died of rabies did not take the vaccine is more worrying. The misinformation that vaccines are ineffective needs to be stopped. The public must be educated on the importance of getting anti-rabies shots,” Dr Aravindan said.