Fatal rabies cases preventable: How fast virus reaches brain depends on area bitten, emergency measures taken

Dr Chua sharing a slide on what to do if one is bitten by a rabid dog.

By Karen Bong

KUCHING, May 26: The speed at which the rabies virus spreads or travels to the brain depends on the distance of the bite wound on the body and possibly the height of a person.

The upper body, especially the neck and head regions, which contain a high concentration of nerves, presents the greatest risk as it offers a considerably shorter distance for the virus to reach the brain.

Sarawak General Hospital (SGH) Infectious Diseases chief Dr Chua Hock Hin emphasised that the saliva of a rabid animal or dog is highly infectious and the level of infectivity will depend on the viral load present in the saliva at the time of a bite, similar to that of the Covid-19 virus.

“The viral load introduced into the body depends on the depth of the wound and whether it hits the nerves. Notably, areas rich in nerves such as the head, neck, genitalia area and hands, pose a higher risk.

“Furthermore, the rabies virus cleverly bypasses the body’s immune system by entering through nerve pathways instead of the conventional route. This means that the infection can go undetected, making it challenging for the victim’s immune system to fight back unless there is a preexisting antibody,” he said while referring to the virus as remarkably intelligent.

Dr Chua highlighted this when presenting a talk during the ‘Dog Bite Kills: Rabies Awareness Public Forum’ organised by Malaysian Medical Association (MMA) Sarawak Chapter at Kuching South City Council (MBKS) auditorium today.

Earlier on, Sarawak Health director Dr Ooi Choo Huck revealed that 15 per cent of bite cases reported in Sarawak occurred in the head and neck regions, while 36 per cent occurred in the upper body.

Dr Chua presenting a talk during the ‘Dog Bite Kills: Rabies Awareness Public Forum’ on May 26.

Death can be prevented even if bitten

Dr Chua pointed out that a person bitten by a rabid dog does not get infected with rabies immediately or on the same day as there is an incubation period between three to eight weeks, indicating that there is a window of opportunity for action.

“The virus does not spread instantly but requires time to move from the bite site to the nerves, eventually reaching the brain. By that point, it is often too late,” he warned.

Once the virus enters the body, he explained that an incubation period follows, during which the virus seeks to infect the human host.

If successful, symptoms typically manifest between three to eight weeks after exposure.

Initial signs of infection include furious behaviour similar to meningitis or brain inflammation, confusion, aggression, shouting, or weakness in the limbs, starting from the area of the bite and progressively spreading to other limbs.

Dr Chua sharing a slide on how the rabies virus travels from wound site to the brain.

“Similar to infected dogs, humans with rabies usually succumb to the disease within seven to eight days after symptom onset,” he said.

However, Dr Chua added that there is a small percentage of the cases experiencing an extended period of up to six months.

He recounted a tragic case of a young individual from Siburan who was bitten while helping to remove a deceased or injured dog from the street. Despite the bite not being deep and the wound healing properly, the individual did not seek treatment until six months later, which proved fatal.

Proper wound washing with soap and running water crucial to saving lives

Whether or not an individual develops rabies depends on their response. Neglecting proper measures following a bite incident results in a 99.9 percent likelihood of contracting human rabies, Dr Chua reminded.

“Immediate and thorough wound washing is of utmost importance when bitten. Cleanse the bite wound and remove any saliva containing the rabies virus. By reducing the viral load, the likelihood of rabies infection entering the body decreases significantly.

“The World Health Organisation (WHO) has determined that proper wound washing can reduce the risk of rabies by 40 to even 90 per cent.

“A simple act of rinsing the wound with running water and soap for at least 15 minutes can potentially save a person’s life,” he said.

Following proper wound washing, Dr Chua added that it is essential to seek medical attention at a hospital or clinic for further assessment and, if necessary, receive a vaccination.

Dr Chua sharing a presentation slide on the measures to take when bitten by dogs or animals.

“However, no medical treatment guarantees 100 per cent effectiveness. The only assurance comes when the animal involved is confirmed not to be rabid,” he said.

Dr Chua thus called for a collective effort and immediate action to tackle rabies issue in Sarawak head-on.

“Whether you are a housewife, a community leader, a veterinarian, or anyone in the healthcare sector, we all share a common objective and that is achieving zero rabies cases by 2030.”

Officiated by Deputy Premier Dato Sri Dr Sim Kui Hian, the forum was also attended by Dr Ooi, Department of Veterinary (DVS) Sarawak director Dr Adrian Susin Ambud and its assistant director Dr Nicholas Jenek, MMA Sarawak chairman Dr Liew Shan Fap as well as SGH senior consultant paediatrician Dr Ooi Mong How. — DayakDaily