Australian health officials are watching an outbreak of the deadly Nipah virus in India "very very closely," after two cases were confirmed this week in West Bengal.
India's neighbours are ramping up border protections against the RNA virus— which has no vaccine and a mortality rate between 40 and 75 per cent— while Indian authorities monitor 196 close contacts of the two cases.
All 196 people have so far tested negative for the virus and have shown no symptoms of infection.
"The Nipah virus is very rare, but it's also very deadly," Australian Health Minister Mark Butler told Today on Friday.
"The Indian authorities tell us they've got that outbreak under control, but nonetheless we're monitoring it very, very closely because this is a very serious virus."
The Nipah virus is carried by fruit bats and can spread to people.
Flu-like symptoms, such as fever, headache, or vomiting, usually appear between four days and three weeks after infection.
"In severe cases, Nipah can cause pneumonia and encephalitis," according to Macquarie University's Professor Michelle Power, an expert on zoonotic diseases.
Although Power says Australia has a "very low risk" of seeing a Nipah virus outbreak here.
"Bats shed the virus in their faeces and urine, which can contaminate fruits or food and lead to transmission to people."
The virus most often spreads to people through direct contact with infected animals and their bodily fluids, or less commonly by people eating fruit which has been contaminated.
Human to human transmission is rare because the virus does not spread through airborne particles, like COVID-19 or the flu.
Human to human transmission of Nipah would require, "the exchange of fluids like blood or saliva. Very close contact."
"There is no Covid-19-like risk posed by Nipah at the moment," Power said, "and there is very low risk of people infected with Nipah overseas carrying the virus to Australia."
The two confirmed cases of Nipah in India were both contracted by health workers.
"We also don't have the Nipah virus in Australian bats," Power said. "We have a related virus, called Hepa, in our flying fox bats. However, the Hendra virus must pass from a bat to a horse, to a person for transmission to occur. And Hendra doesn't transmit person to person.
"Hence there's no risk of catching the current Nipah virus that we're seeing overseas from our bats."
However, Power warns that as with any virus, there is always the possibility of mutation and change. "With any spillover of viruses from any animals, there can be mutation and change," she said.
"For example, what we've seen with avian influenza (bird flu) in America is that it's now spread to cats and is rife among dairy cattle. So while it's highly unlikely for Nipah, the growing connectivity between people and wildlife carries a risk of new disease transfer."
The School of Natural Sciences professor praised the Health Minister's proactive response to the two reported cases overseas.
"It's great that COVID-19 has prompted this kind of response and early warnings of disease risks. This is one virus, but there are many others which are potentially a risk for causing human disease. If precautions are implemented early, then we do work towards managing and preventing any global health impacts."
Our strongest lines of defence against virus outbreaks, "are border security, as well as public understanding and awareness so individuals can protect themselves from infectious diseases."
While Australian bats don't carry Nipah, Power would like to remind the public not to get up close and personal.
"Our bats obviously do carry other infectious risks and they're taking a hit at the moment with heat stress and the bushfires. My caution to people is: If you've got an injured bat that lands in your backyard, don't touch it or handle it. Contact WIRES to come and look after them. Don't risk a bite or scratch."
