From Sept 1998 to May 1999, the Malaysia Nipah virus outbreak took place in the Malaysian states of Perak, Negeri Sembilan and Selangor.
Overall, there were 265 confirmed cases with 105 deaths reported during the outbreak. The disease was as deadly as the Ebola virus, but attacked the brain system instead of the blood vessels.
The World Health Organisation (WHO) lists it as one of the viruses mostly likely to cause a global pandemic.
It also served as an inspiration for American movie Contagion (2011) and Indian movie Virus (2019).
The chain of contagion involving bats and pigs in the Contagion (2011) is reminiscent of the trail of Nipah virus. The movie similarly involved the disturbance of a bat colony by deforestation as the source of the outbreak.
Meanwhile, Virus (2019) is a medical thriller set against thr backdrop of the 2018 Nipah virus outbreak in Kerala.
Here are 10 things you need to know about the Malaysia Nipah virus outbreak:
1.They first thought it was caused by JE
The virus first hit pig farms in Ipoh, Perak where the pigs were found to have respiratory illness and encephalitis.
At first, Malaysian authorities thought Japanese encephalitis (JE) was the cause of the outbreak. Hence the authorities deployed early control measures such as mosquito fogging and vaccination against JE.
However, none of the measures was effective since more cases emerged.
2.How the virus was first discovered
If the disease was coming from mosquitoes, it would have infected people of all races and religions. But then only those from the Chinese community were catching the disease.
The key person who realised that they were dealing with a brand new virus was Dr Chua Kaw Beng.
In an interview with US media outlet NPR, Dr Chua recounted how he had discovered the Nipah virus.
Back then, he was still a virologist in training at Universiti Malaya. When he showed his discovery to one of his professors, they told him to throw it away.
Instead of listening to his professor Dr Chua, he packed it up and brought the sample into the Centers for Disease Control (CDC) in the US. Under the pretext of studying mosquito-borne diseases, Dr Chua sealed the virus in his suitcase and hand-carried it on a flight to the US.
There, Dr Chua used CDC’s powerful microscopes to study the virus.
It turned out it was a type of paramyxovirus that actually came from livestock.
The minute he realised how dangerous the virus could be, Dr Chua made a phone call to Malaysian officials.
This time, the government listened and took the most drastic measure. The government deployed Malaysian army for the country’s largest animal culling.
In the end, almost one million pigs were shoved into pits and shot.
What Dr Chua did to bring the virus to the US might be unethical and even against the law (transporting a sample of a virus in your hand carry without authorisation is illegal) but if he did not do what he did, there might be more casualties from the outbreak.
3.What are the symptoms of Nipah virus infection
The symptoms of Nipah virus infection range from asymptomatic infection to acute respiratory and fatal encephalitis.
Initially, the infected people develop symptoms such as headache, muscle pain, vomiting and sore throat.
These symptoms can be followed by dizziness, drowsiness and neurological signs that indicate acute encephalitis.
In severe cases, the patient can progress to coma within 24 to 48 hours after experiencing encephalitis and seizures.
While the incubation period is believed to range from four to 14 days, there are reports of an incubation period as long as 45 days.
Once infected, the primary treatment for humans is supportive care.
Depending on different factors such as effective epidemiological surveillance and clinical capability, the fatality rate is estimated at 40% to 75%.
4.What is the natural host of the Nipah Virus
Scientists have found that fruit bats of the Pteropodidae- particularly species belonging to the Pteropus genus are the natural hosts for Nipah virus.
However, there is no apparent disease in fruit bats caused by the virus.
5.How the virus is transmitted
The virus was subsequently named after Kampung Sungai Nipah where the sample of the virus was taken.
During the outbreak in Malaysia, most human infections resulted from direct contact with sick pigs or their contaminated tissues.
But how did pig farms became the Nipah virus factories in the first place?
About a decade after the outbreak, scientists found that pigs had been getting Nipah virus for years. They most probably picked it up from fruit bats.
Since the outbreaks were small, nobody really noticed because the pig farms were smaller.
As the farmers changed the way they raised pigs by packing them into tight areas so they could produce more meat, the virus could multiply even faster.
6.Is there any vaccine?
According to WHO, there are no vaccines available against Nipah virus infection to date. Nonetheless, WHO has identified Nipah as a priority disease for the WHO Research and Development Blueprint.
As for treatment, intensive supportive care is recommended to treat severe respiratory and neurological complications.
The good news is that as of March 2020, it was reported that there is a set of newly potential vaccines against Nipah virus.
Developed by the University of Parma, Italy, the vaccines generated a strong immune response in pigs. This is promising news for protection against the Nipah virus.
7.What are the prevention and control for the Nipah virus infection?
Based on what happened in 1999, routine and thorough cleaning and disinfection of pig farms may be effective in preventing infection.
If an outbreak is suspected, the animal farms are to be quarantined immediately.
Culling of infected animals followed by close supervision of carcasses is also necessary.
8.The aftermath of the Malaysia Nipah virus outbreak
First of all, pig farms in Malaysia became a lot of cleaner after the outbreak. Farmers now keep pigs isolated from other animals and people.
Most surviving pig farmers of the outbreak have turned to palm oil and cempedak plantations.
In Kampung Sungai Nipah, visitors can go back in time to learn about the outbreak at Sungai Nipah Time Tunnel Museum.
There, visitors can listen to survivors’ stories and how their lives changed since the outbreak.
9.Nipah virus outbreak in other countries
Since 1998, there have been at least 15 more outbreaks of Nipah virus, all whicj occurred within Bangladesh and neighbouring parts of India.
The outbreak areas lie within the range of Pteropus species.
One of the outbreaks took place in the state of Kerala, India in 2018. The virus was traced to the fruit bats found in the area. While the outbreak was contained and declared over on June 10 that year, the virus infection managed to claim 17 lives.
10.The most important lesson from the Malaysia Nipah virus outbreak
Dr Chua and fellow researchers Dr Looi Lai Meng wrote a paper on the lessons from the Malaysia Nipah virus outbreak in 2007.
According to them, from political to law regulation, there were plenty of lessons to learn from the outbreak.
Yet, there was one particular lesson that we needed to be reminded over and over again and applicable to every other outbreak.
Chua and Looi stated, “Almost 75 per cent of emerging infectious diseases over the last century zoonoses, having jumped the species barrier to infect humans. The far-reaching effects of environmental mismanagement (such as deforestation and haze) cannot be overemphasised, as this can lead to encroachment of wildlife into human habitats and the introduction of zoonotic infections into domestic animals and humans.”
Basically, more humans are exposed to viruses that naturally exist in wildlife because we keep on encroaching into their habitats.
American politician Stewart Udall once said, “Plans to protect air and water, wilderness and wildlife are in fact plans to protect man.”
Once we humans fail to protect the environment and wildlife, we fail to protect ourselves.