Tuesday, January 12, 2021

The Nipah Virus: The Next Pandemic?



Now that the SARS-CoV-2 virus is still out of control, it is time to widen our focus. Global monitoring efforts have produced a list of potential future pandemic pathogens. Included on the top ten bad bug list is the innocent-sounding Nipah virus. Who could be afraid of a little Nipah? 

This little stinker lives in fruit bats and occasionally infects humans. There is no treatment for it and the death rate is at least 40% (up to 75%). The BBC writes:
It's first light in Battambang, a city on the Sangkae River in north-west Cambodia. At the morning market, which starts at 05:00, motorbikes weave past shoppers, kicking up dust in their wake. Carts piled high with goods and covered in colourful sheets are perched next to makeshift stalls selling misshapen fruits. Locals wander in and out of the stands, plastic bags bulging with their purchases. Elderly ladies in wide-brimmed hats crouch over blankets covered with vegetables for sale. In other words, it's a fairly normal morning market. That is, until you crane your neck to the sky.

Hanging quietly in the trees above are thousands of fruit bats, defecating and urinating on anything that passes below them. On closer inspection the roofs of the market stalls are covered in bat faeces. "People and stray dogs walk under the roosts exposed to bat urine every day," says Veasna Duong, head of the virology unit at the scientific research lab Institut Pasteur in Phnom Penh and a colleague and collaborator of Wacharapluesadee's.

The Battambang market is one of many locations where Duong has identified fruit bats and other animals coming into contact with humans on a daily basis in Cambodia. Any opportunity for humans and fruit bats to get near to one another is considered a "high risk interface" by his team, meaning a spillover is highly possible. "This kind of exposure might allow the virus to mutate, which might cause a pandemic," says Duong. 
From 2013 to 2016, Duong and his team launched a GPS tracking programme to understand more about fruit bats and Nipah virus, and to compare the activities of Cambodian bats to bats in other hotspot regions.  
Despite the dangers, the examples of close proximity are endless. "We observe [fruit bats] here and in Thailand, in markets, worship areas, schools and tourist locations like Angkor Wat – there's a big roost of bats there," he says. In a normal year, Angkor Wat hosts 2.6 million visitors: that's 2.6 million opportunities for Nipah virus to jump from bats to humans annually in just one location.

Two of these are Bangladesh and India. Both countries have experienced Nipah virus outbreaks in the past, both of which are likely linked to drinking date palm juice.

At night, infected bats would fly to date palm plantations and lap up the juice as it poured out of the tree. As they feasted, they would urinate in the collection pot. Innocent locals would pick up a juice the next day from their street vendor, slurp away and become infected with the disease. 
There you have it pandemic watchers. Remember the little Nipah.

Question: Should some resource and effort to develop a Nipah vaccine be initiated, or should the US wait until it mutates into a more transmissible, pandemic-ready version, then put Trump in charge of the US response so that we develop herd immunity the old-fashioned way?


 

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