Below, I've included targeted excerpts from a lengthy yet informative article.
The other virus that worries Asia
Asia has a high number of emerging infectious diseases. Tropical regions have a rich array of biodiversity, which means they are also home to a large pool of pathogens, increasing the chances that a novel virus could emerge. Growing human populations and increasing contact between people and wild animals in these regions also ups the risk factor.
Over the course of a career sampling thousands of bats, Wacharapluesadee and her colleagues have discovered many novel viruses. They've mostly found coronaviruses, but also other deadly diseases that can spill over to humans. These include the Nipah virus. Fruit bats are its natural host. "It's a major concern because there's no treatment… and a high mortality rate [is] caused by this virus," says Wacharapluesadee. The death rate for Nipah ranges from 40% up to 75%, depending on where the outbreak occurs. Across 11 different outbreaks of Nipah in Bangladesh from 2001 to 2011, 196 people were detected to have Nipah – 150 died.
There are several reasons the Nipah virus is so sinister. The disease's long incubation period (reportedly as long as 45 days, in one case) means there is ample opportunity for an infected host, unaware they are even ill, to spread it. It can infect a wide range of animals, making the possibility of it spreading more likely. And it can be caught either through direct contact or by consuming contaminated food.
Someone with Nipah virus may experience respiratory symptoms including a cough, sore throat, aches and fatigue, and encephalitis, a swelling of the brain which can cause seizures and death. Safe to say, it's a disease that the WHO would like to prevent from spreading.
Sixty percent of the world's population already lives in Asia and the Pacific regions, and rapid urbanisation is still taking place. According to the World Bank, almost 200 million people moved to urban areas in East Asia between the years 2000 and 2010. Meanwhile, Asia is home to nearly 15% of the world's tropical forests, but the region is also a deforestation hotspot. The continent ranks among the highest in the world for biodiversity loss.
The destruction of bat habitats has caused Nipah infections in the past. In 1998, a Nipah virus outbreak in Malaysia killed more than 100 people. Researchers concluded that forest fires and local drought had dislodged the bats from their natural habitat and forced them towards fruit trees – trees grown on the same farms as pigs. Under stress, bats have been shown to shed more viruses. The combination of being forced to relocate and being in close contact with a species they would not normally interact with allowed the virus to jump from bats to pigs, and onwards to the farmers.
Funding for the work that Duong and Wacharapluesadee are carrying out has been patchy in the past. The 10-year Predict programme was allowed to expire by the Trump administration, although US President-elect Joe Biden has promised to restore it. Meanwhile, Wacharapluesadee has funding for a new initiative called the Thai Virome Project, a collaboration between her team and the government's Department of National Parks, Wildlife and Plant Conservation in Thailand. This will allow her to sample more bats and a wider range of wildlife to understand the diseases they harbour and the threats to human health.
They have not yet managed to secure the money to continue their Nipah virus work. Without it, they say, a potentially catastrophic outbreak is more likely. "The long-term surveillance helps us… inform authorities [to enact] preventive measures and to prevent undetected spillover which would cause bigger outbreak," says Duong. And without continued training, scientists might not be able to identify and characterize new viruses rapidly, as Wacharapluesadee did with Covid-19 in Thailand. This information is needed to start working on a vaccine.
Duong and Wacharapluesadee hope to continue collaborating to fight Nipah virus in South East Asia, and the pair have drafted a proposal for Nipah virus surveillance in the region together. They plan to submit it to the Defense Threat Reduction Agency, a US governmental organization which funds work aimed at reducing the threats posed by infectious disease agents, once the Covid-19 crisis subsides.
https://www.bbc.com/future/article/2021 ... t-pandemic