Nipah Outbreak News in Bangladesh and elsewhere since 30 Jan 2023

One dies of Nipah virus in Rajshahi [Dhaka Tribune, 2 Mar 2023]

By Abdullah Al Dulal

Complications escalated after she was diagnosed with Nipah virus on Wednesday morning and was eventually referred to Nipah ICU

One woman died of Nipah virus in Rajshahi Medical College Hospital (RMCH) Wednesday afternoon.

The deceased, Farida Yasmeen, 25, was admitted to the neuro medicine ward of RMCH with common symptoms like fever and seizures.

Complications escalated after she was diagnosed with Nipah virus on Wednesday morning and was eventually referred to Nipah ICU. She died around 5pm while undergoing treatment.

Besides, her mother-in-law Rahima Begum is admitted in the Nipah Suspect Ward with the same symptoms. Farida's father-in-law Abdul Haque had died at home with the same symptoms two weeks ago.

Although the family thinks it was a natural death, however, doctors believe that her father-in-law was also infected with Nipah virus. Besides, it has been reported that their entire family eats date juice without boiling it, a common cause of the spread of this disease.

Dr Azizul Haque, medicine specialist at Rajshahi Medical College Hospital, said: “Relatives of deceased patients are at higher risk of infection. So, they need to be extra careful. We are working in coordination with IEDCR.”

He urged to be careful while drinking date juice.

However, Rajshahi Civil Surgeon Dr Abu Yusuf Mohammad Farooq said that there is no need for regular care of the patient's relatives. The IECCR has collected and tested the samples of everyone who came in contact with the infected patient. However, everyone should be careful while drinking date juice

A total of five people has died in Rajshahi Medical College Hospital (RMCH) so far. All of them have a history of drinking date palm juice. Besides, everyone was admitted to the general ward of the hospital with common symptoms like jaundice. Then suddenly the physical condition started to deteriorate. Death occurred on admission to the ICU. Nipah of one of the deceased was identified after death.

Another death from Nipah virus [The Business Standard, 14 Feb 2023]

A young man died from Nipah virus infection at Dhaka Medical College Hospital on Monday.

The deceased identified as Shah Alam, 20, hailing from Narshingdi's Raipura upazila, passed away around eight o'clock yesterday.

"The young man was undergoing treatment here since last week," Dhaka Medical College Director Brigadier General Nazmul Haque told The Business Standard.

"After the victim showed symptoms of Nipah virus infection, his sample was sent to the Institute of Epidemiology Disease Control and Research (IEDCR) for examination," he said.

The lab test report came out positive on Monday, the same day Shah Alam succumbed to the deadly infection, Nazmul Haque added.

With this, eight out of ten Nipah-infected people in the country have died so far this year pushing the mortality rate of Nipah virus infection even higher.

Nipah virus spreads via unfiltered date juice and partly eaten fruits, which has been contaminated by bats in Bangladesh.

No vaccine has been discovered for the virus yet. Bat is the main carrier of the deadly virus. A person can contract the virus from both people and animals. The virus killed many people in the country since 2001.

According to icddr,b, the Nipah virus emerged in Bangladesh in 2001. Even if people recover from the sickness, they remain vulnerable to severe neurological issues. It also causes complications toward the end of pregnancy for women.

Bangladesh reports two new Nipah virus deaths [bd24, 6 Feb 2023]

The death toll from the virus this winter reaches seven

Government’s disease control agency has reported two more deaths from Nipah virus infection, taking the toll this winter to seven.

Dr Tahmina Shirin, director at the Institute of Epidemiology Disease Control And Research, said on Sunday the number of Nipah virus cases this season was 10 until Feb 3.

The zoonotic virus can be transmitted from animals to humans, through foods contaminated by animals and from humans to humans.

Fruit bats, which infect date juice in winter, are the natural host of the virus, which is currently one of the deadly emerging pathogens.

Most of the cases were from Rajshahi Division and all were currently receiving treatment, Health Minister Zahid Maleque said on Jan 29, while revealing eight cases and five deaths from the disease this winter.

He said the number of infected was “higher” than last year. Efforts to prevent the disease from spreading were underway through promotional materials on TV and in newspapers, he added.

Health authorities have marked 32 districts in Bangladesh as being at risk of the Nipah virus infection and directed physicians to take adequate precautionary measures while attending to patients with fevers, a primary symptom of the illness, in hospitals.

The Dhaka North City Corporation's COVID-dedicated hospital in Mohakhali has also been instructed to prepare 20 beds for the treatment of Nipah virus patients.

Since 2001, Nipah virus patients have been found in 33 districts, according to the IEDCR
Any area where a case of the Nipah virus is detected is considered 'risky', said Dr Mushtuq Husain, an adviser at the IEDCR.

“This is because anywhere a Nipah virus patient is found is also likely to have bats and palm sap. All parts of the country are vulnerable to the Nipah virus, but the districts where it has been detected are advised to take extra precautions."

Last Thursday, Sheikh Daud Adnan, acting director of the health directorate's hospital and clinic wing, issued a letter to local health authorities as well as public and private hospitals across the country, urging doctors to take special precautions. These include wearing a mask and also washing hands with soap before and after seeing a patient.

They have also been advised to move a patient to the isolation ward if they start showing symptoms of a fever. In addition to fevers, patients should be admitted to the intensive care unit if their condition is critical. Caregivers of patients in intensive care are only required to wear gloves and masks.

But the Nipah virus is not aerially transmissible, according to the health directorate.

Cases of the virus have been reported in the Rajbari, Naogaon, Rajshahi, Shariatpur, Pabna and Dhaka districts this year, according to Prof Md Nazmul Islam, director of the DGHS's infectious disease control branch.

Dr Nazmul believes there is no need to panic, but stressed the need to proceed with 'extreme caution'.

“There is no vaccine for this disease. More than 70 percent of people affected by the disease die. Those who survive develop physical disabilities. The number of patients may not be high, but most of those who were infected have died. That is why we need to be extremely careful," he said.

Dr Nazmul advises against the consumption of raw date sap. Sales, marketing and promotion of raw date palm sap should also be restricted, he said.
In a follow-up on the Nipah virus situation in Bangladesh in 2023, the Institute of Epidemiology Disease Control and Research (IEDCR) is now reporting nine Nipah infections since the beginning of the year, the most cases seen since 2015 (15 cases/11 deaths).

The nine cases (three in children, six in adults up to age 35) have been reported from six districts – Rajshahi, Naogaon, Rajbari, Shariatpur, Pabna, and Dhaka. Five fatalities, including two in childtren have been reported.

The primary source of infection in the cases has been the consumption of date palm sap contaminated with bat saliva or urine.

Nipah virus: An introduction

Since the first cases were reported in Bangladesh in 2001, 334 cases, including 235 deaths (70% case fatality rate) have been recorded.

Nipah virus infections at highest numbers in Bangladesh since 2015 [Outbreak News Today, 5 Feb 2023]

In a follow-up on the Nipah virus situation in Bangladesh in 2023, the Institute of Epidemiology Disease Control and Research (IEDCR) is now reporting nine Nipah infections since the beginning of the year, the most cases seen since 2015 (15 cases/11 deaths).

The nine cases (three in children, six in adults up to age 35) have been reported from six districts – Rajshahi, Naogaon, Rajbari, Shariatpur, Pabna, and Dhaka. Five fatalities, including two in childtren have been reported.

The primary source of infection in the cases has been the consumption of date palm sap contaminated with bat saliva or urine.

Nipah virus: An introduction
Since the first cases were reported in Bangladesh in 2001, 334 cases, including 235 deaths (70% case fatality rate) have been recorded.

Nipah virus spreads to 28 districts of Bangladesh [Dhaka Tribune, 3 Feb 2023]

DGHS issues directive to keep hospital beds ready for Nipah virus patients

The government on Friday gave directives to the relevant authorities to keep the Dhaka North City Corporation (DNCC) Dedicated Covid-19 Hospital ready in the wake of the spread of the Nipah virus in 28 districts of the country.

The Directorate General of Health Services (DGHS) issued the directives asking the hospital authorities to keep 10 beds at the isolation ward and 10 Intensive Care Unit (ICU) beds prepared, said a press release signed by Dr Sheikh Daud Adnan, director (hospitals and clinics) of the DGHS.

On January 29, Health Minister Zahid Maleque said a total of five people died of Nipah virus across the country this year.

Eight people were infected with Nipah virus and of them five people died.

Usually more than 70% of infected people die and people who drink raw date juice and fruits partially eaten by birds, especially bats, have the possibility of being infected with the virus.

Besides, healthy people who come in contact with the infected ones also have the possibility of being infected with the virus and it spreads from person to person quickly which is a matter of concern.

9 diseases that keep epidemiologists up at night [Oregon Public Broadcasting, 31 Jan 2023]

By Sheila Mulrooney Eldred

Just three years ago, on Jan. 30, 2020, the head of the World Health Organization made a landmark declaration: A “novel coronavirus” that had first been identified in China had spread to a degree where it was now a “Public Health Emergency of International Concern (PHEIC).”

The virus now known as SARS-CoV-2 — which causes the disease COVID-19 — is still spreading. But for those who study infectious diseases, talking about possible next pandemics is a necessity.

That's why the World Health Organization keeps a list of viruses and bacteria with pandemic potential. Jill Weatherhead of Baylor College of Medicine says prioritizing diseases is generally based on two factors: their ability to spread and the ability of humans to treat them.

The list helps guide scientists, governments and organizations in investing energy and funds to study the pathogens most likely to cause the greatest devastation to humans. The WHO develops "blueprints" with strategic goals and research priorities for each disease on the list.

Here are the diseases on the current list. A revised list is expected in the coming months: In late 2022, the World Health Organization convened more than 300 scientists to assess and update the list.

Note: The infrastructure to detect diseases in different parts of the world varies, as does the fact that mild cases of an illness may not be known or reported. Fatality rates are based on the best available data.

Nipah virus
What animals carry it: fruit bats, including those called flying foxes, and domestic animals such as pigs, horses, cats and dogs

How it spreads: Nipah virus can be transmitted to humans from animals or contaminated foods. It can also be transmitted directly from human to human.

Its toll: 40% to 75% fatality rate. The virus can also cause encephalitis, or swelling of the brain.

Medical toolbox: There is no vaccine available for either people or animals. Monoclonal antibody therapies are in development.

Pandemic potential: Outbreaks occur almost every year in parts of Asia, but there are known ways to prevent spread of the virus. Prevention efforts include avoiding exposure to bats and sick animals, avoiding consumption of fruits that bats may have nibbled on and not drinking certain raw juices from fruits that bats feed on. The risk of international transmission can be lowered by washing those fruits and fruit products thoroughly and peeling them before eating.

Crimean-Congo hemorrhagic fever
What animals carry it: ticks, livestock
How it spreads: Humans usually get the virus from contact with ticks or infected livestock. To get the virus from another person requires close contact with blood or other bodily fluids from an infected person.

Its toll: 10% to 40% fatality rate. The disease is endemic, meaning it occurs regularly, in Africa, the Balkans, the Middle East and Asia. The virus causes severe outbreaks of viral hemorrhagic fever, a condition that can damage the body's organ systems and cardiovascular system and that often includes severe bleeding.

Medical toolbox: Although a vaccine is in use in Bulgaria, no research has been published on how well it works, and it's not licensed anywhere else. Other vaccines are in development, and an antiviral drug called ribavirin appears to help treat infections.

Pandemic potential: It's difficult to tell when an animal is infected and should be avoided, and the WHO says the ticks that carry the virus are numerous and widespread. The threat could be reduced by trying to avoid tick bites and wearing gloves and other protective clothing when around livestock.

Lassa fever
What animals carry it: rats and other rodents
How it spreads: The virus is endemic in parts of West Africa. Rats excrete the virus, and humans pick it up when exposed to the rodents' urine and feces, either through direct contact or eating contaminated food. It can also spread between humans through direct contact with an infected person's secretions (blood, urine, feces), through sexual contact and in medical settings via contaminated equipment.

Its toll: 1%, but up to 15% in severe hospitalized cases. It can be deadly for people and fetuses in the third trimester of pregnancy. Besides death, a common complication is deafness, which can be permanent.

Medical toolbox: There is no vaccine, but ribavirin seems to help treat infections.

Pandemic potential: Because the primary method of transmission is exposure to a certain type of rat, potential for the spread of the disease is most likely limited to the countries where the rat lives.

Rift Valley fever
What animals carry it: mosquitoes. The insects can transmit the virus to both humans and their own offspring. Livestock such as cattle, sheep, goats, buffalo and camels can also get infected.

How it spreads: It spreads to people through contact with blood, other body fluids or tissues of infected animals.

Its toll: Although the fatality level is less than 1% and the disease is mild for most people, about 8% to 10% of people infected develop severe symptoms, including eye lesions, encephalitis and hemorrhagic fever.

Medical toolbox: Although a vaccine has been developed, it is not yet licensed or available.
Pandemic potential: Rift Valley fever has spread from Africa to Saudi Arabia and Yemen.

Flooding seems to contribute to more Rift Valley fever because more virus-infected mosquitoes buzz about after heavy rainfalls. Rapid case detection, including prompt laboratory testing of people with symptoms, has limited recent outbreaks.

Zika
What animals carry it: mosquitoes
How it spreads: In addition to mosquito bites, the virus can spread from a pregnant person to a fetus. The disease can also be transmitted through sex and probably through blood transfusions.

Its toll: It's rarely fatal, but Zika can cause severe brain defects in fetuses, including microcephaly. It has also been linked to miscarriage, stillbirth and other birth defects.

Medical toolbox: No treatment or vaccine

Pandemic potential: So far, it's largely limited to areas where Zika-carrying mosquitoes live.
Ebola and Marburg virus disease

What animals carry them: Bats and nonhuman primates are believed to carry the viruses, from the filovirus family, that cause these hemorrhagic fevers.

How they spread: Both viruses are believed to spread in the same way. After the initial spillover from an animal, humans spread the viruses to other humans through direct contact with blood or other bodily fluids of a person who is symptomatic or who has died from the disease. The viruses can also spread through objects or surfaces contaminated with bodily fluids and through semen from people who have recovered from the disease.

Their toll: The average fatality rate is about 50%, though rates have varied from 25% to 90% in past outbreaks.

Medical toolbox: Vaccines have been used for Ebola in Guinea and the Democratic Republic of Congo. Monoclonal antibodies approved by the Food and Drug Administration in 2020 can also help with treatment of Ebola. Vaccines for Marburg virus are in development.

Pandemic potential: These viruses can spread quickly in health care settings, especially when proper sterilization isn't used. However, the disease spreads only when a person is symptomatic, making it easier to control.

MERS (Middle East respiratory syndrome)
What animals carry it: camels
How it spreads: After the initial spillover event from camels to humans, this coronavirus can spread from person to person through close contact with an infected person.

Its toll: The reported fatality rate, according to the WHO, is 35%.

Medical toolbox: Several vaccines are in development, but none has been approved.

Pandemic potential: 27 countries have reported infections since 2012. Unlike SARS-CoV-2, the coronavirus that causes MERS grows deep in the respiratory tract, making it much less likely to be transmitted through sneezing and coughing.

SARS (severe acute respiratory syndrome)
What animals carry it: Palm civets were largely blamed for the 2003 outbreak. Bats and possibly other wildlife also carry it.

How it spreads: After the initial spillover event from animal to human, SARS can spread from person to person through close contact with an infected person. It's believed to usually spread through droplets from coughs and sneezes and sometimes through surfaces touched by infectious people.

Its toll: less than a 1% fatality rate

Medical toolbox: No treatment or vaccine has been approved.

Pandemic potential: Unlike SARS-CoV-2, which can spread before people know they're infectious, this SARS virus is usually spread only by those with known symptoms, making it much easier to contain through public health measures such as quarantining. The 2003 outbreak was contained after causing about 8,000 cases and 700 deaths in 29 countries.

Disease X
The WHO says it does not rank diseases in any order of potential threat, but it acknowledges the possibility that an as-yet-unknown disease could cause a serious pandemic.

In her work with bat viruses, for example, Raina Plowright of Cornell University says that even in the small proportion of bat species that have been studied, the animals carry thousands of viruses, "and we have no clue how many present risk," she says. "We don't have the technology to take a sequence and say with certainty whether it can infect humans or can transmit from human to human. We're blind, really."

Not to mention that variants pose threats, she says. "Just the tiniest genetic change can have a profound effect. What if we had [a pathogen] with a 50% fatality rate that transmitted efficiently?"

Trying to crack the Nipah code: How does this deadly virus spill from bats to humans? [KVPR, 31 Jan 2023]

By Ari Daniel, Rebecca Davis

Nipah virus, which can rapidly infect and kill members of a community, is carried by bats.

Exactly how does it cross over into humans? Researchers in Bangladesh are trying to find out.

It's dusk in central Bangladesh, in a community within the district of Faridpur. A 50-year-old man sits outside his home beside a rice paddy. His name is Khokon. A fiery beard, dyed a bright orange, rings his chin.

He says the procession of disease and death all started in the spring of 2004. "So the first one was the mother-in-law of my elder brother. She was really sick," Khokon says. "She had been sick for some time. Then she died. We took her to the grave. Then my father got sick."

Khokon stares off into the distance as he explains that his father was a spiritual leader in the community. When he became ill, many came to pay their respects and offer their prayers. "Just 12 days after, my father died," he says. "Suddenly, he was no more."

Many of his visitors also got sick. One person traveled to an adjacent village, where four more people fell ill. "It was not understood what was happening," says Mahmudur Rahman, who worked for the Bangladeshi government around that time as director of the Institute of Epidemiology, Disease Control and Research. "Some people who were transporting the patients to the hospital were also getting sick."

Sick often meant encephalitis — a swelling of the brain. Epidemiologist Emily Gurley led an on-site outbreak investigation back then and is now based at Johns Hopkins University. She says, "The signs and symptoms of encephalitis are fever, headache, but often altered mental status or coma." Disorientation and seizures were common. "But many of these patients also had respiratory disease," Gurley adds, which often led to coughing, vomiting and difficulty breathing.

The virus appeared to be spreading through respiratory droplets and saliva. And the sicker people got, the more infectious they became.

For Khokon and his wife, Anwara, the nightmare continued for weeks as they watched relative after relative get sick, suffer and die. Khokon's older brother, his sister, two uncles, his aunt, his nephew and his mom and dad ... all dead. It was numbing. "In Bangla, they say 'it is a bad wind' or 'an act of God,'" explains Rahman.

Anwara says, "When people started dying out of the virus, people were very afraid. No one came here! Nobody, not even a dog came to this house."

And then, the two of them came down with the virus. (Because the disease carries such a stigma, we are using only their first names.) "I actually have no recollection of that time," says Khokon. "I don't even remember who carried me to the hospital or who carried me to the bed. I was in no shape to remember anything. Me and my wife were unconscious. People couldn't say if we were dead or alive."

In addition, Khokon says those caring for them "said that we had high fever, very high fever."

Anwara says a neighbor told her, "Like whenever they were touching us, it was like touching fire."

Somehow, they survived. "It was a miracle," says Khokon.

This outbreak, says Rahman, made something brutally evident. The as yet unidentified virus was "obviously showing that we are unable to control it, and it is spreading," he says, from person to person. "That is the clear message."

And with a kill rate of roughly 70%, what virus could be that deadly? At the time, Gurley says,

"We didn't know! I was just looking at the data to see what do we think is going on here?"

Gurley wondered, could it be SARS — a coronavirus that infected some 8,000, mainly in China and Hong Kong, from 2002 to 2004?

Or perhaps another, and even more disturbing possibility — could it be a rare, poorly understood virus called Nipah?

"Nipah is terrifying, unusually terrifying," says Dr. Stephen Luby, currently a professor of medicine at Stanford University, who was in charge of the outbreak investigation for eight years at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). He says it's terrifying, in part, because the virus is so deadly in people. Also, the outbreaks are tightly clustered. "And so the people who are sick know each other," he says. "And because of this, it is a clear community crisis."

In addition, part of what makes Nipah so worrisome is that its history offers evidence that it might, under the right conditions, launch a pandemic. It had first shown up in Malaysia and Singapore in the late '90s. Around that time, Malaysia had started farming pork at an industrial scale — huge numbers of pigs wedged into cramped conditions. When the pigs got Nipah from local fruit bats, the virus spread easily. And then, pig farmers caught it as well.

But in Bangladesh, things were different. "There were a few pigs being raised in this village," says Gurley. "None of them had been sick. And none of the cases had had any contact with these pigs. Pretty clearly," she says, pigs didn't seem to be behind these Nipah outbreaks.
A puzzle to solve: How does the virus spill from bats into humans?

A few weeks later, the Centers for Disease Control and Prevention in Atlanta sent an email to Gurley and her colleagues confirming the deadly virus to be Nipah. So they wondered: Just how was the virus spilling over from bats into humans? This was the puzzle that needed solving for two reasons. First, to prevent more people from getting sick. And second, to rein the virus in.

"So what we did is walk through the village and thought about all the possible ways people could come into contact with bats or bat secretions, bat urine, bat saliva," says Gurley.

They thought that maybe it came from climbing trees where the bats had fed or roosted. Or eating fruit off the ground that bats had already taken a bite out of. They considered a much beloved local delicacy: the sap traditionally harvested from date palm trees. "And we thought, 'Well, this would be a great way to have contact with bat secretions because I'm sure the bats love the sap and so do people,'" says Gurley.

The urgency to figure out the connection between bats and humans continued to mount, as Nipah flared again the following year. The investigators came to realize there had also been earlier outbreaks — in 2001 and 2003. Bangladesh decided to set up its own Nipah surveillance system.

Finally, a link emerged, but the researchers needed more evidence. In 2007, they got their chance with yet another outbreak, this time in Thakurgaon in northwest Bangladesh. Of the seven people who contracted Nipah, three were dead. People were again in a panic.

Rebeca Sultana, an anthropologist with the icddr,b, remembers a call to join the investigation team. "Our colleague called me and asked, 'Rebeca, would you like to go? Are you ready?' I said, 'Yes, I am ready to go there.'"

The next morning, Sultana drove with the team from Dhaka to Thakurgaon. Once she arrived in the village, she went straight to the home of patient zero. "I tried to talk to the elder sister-in-law of the guy who died," she says, "and she was so upset and she just ran and came to me, and hugged me and started crying."

Getting that close to her scared Sultana. As Syed Moinuddin Satter, who leads the Emerging Pathogen research group at icddr,b, says, doing this work is like putting "your soul in your hand. You don't know what is waiting for you in the field."

But Sultana's heart went out to the woman. And she hugged her back. She said to her, "Please don't worry. We're here." She explained that although they didn't know for sure what had caused her relatives to fall ill, "we are here to understand why this happened" by listening openly to the people who had witnessed Nipah firsthand.

(At the research center icddr,b, anthropologists are routinely asked to join these kinds of outbreak investigations when trying to piece together routes of transmission. Their job, in Sultana's words, is "to learn from the community." As Sultana's colleague, Shahana Parveen, says, "Our role as anthropologists, when we get into the community, first we give them space to listen to them — their anger, their stress. But we didn't respond, 'OK, this is not right, or this is wrong.'")

After Sultana finished her preliminary interviews, she then asked the community to meet her in the town market to help draw a map of the village. About two dozen people showed up. "I don't do anything," she explains. "I just ask questions. And then they draw it."

Using sticks in the dirt, the residents roughed out houses, roads, bat roosts. The shape of the outbreak gradually emerged. Soon, the villagers began sketching in date palm trees.

"This is the first time the people informed me," Sultana says, of multiple date palm trees and "a sap harvester in this community."

She hadn't seen the date palm trees on the drive in. But staring back at her from the dirt was the possible link between how the fruit bats had passed Nipah into this community. In particular, when the bats drank the sap, the researchers suspected that Nipah could have moved from their saliva or urine into the sap stream, contaminating the sweet liquid. So someone who drank that sap would be in danger of becoming infected.

Sultana and her colleagues tracked down the sap harvester. And he led them to some friends of the guy who was patient zero for this outbreak.

"They said 'we all used to drink raw sap in the morning,'" she says. This was Sultana's aha moment — that patient zero had drunk raw sap before falling ill. She says this helped the researchers trace a line between the bats, the sap and the outbreaks. "It's a long journey," she admits. This journey included work over the next few years where researchers took infrared cameras and caught the bats (among other creatures, including rats, bugs and owls) at night drinking from the same stream of sap that people were harvesting.

Eventually, the government had enough evidence to launch a campaign against the drinking of raw sap. However, it was a lot to ask people to set aside something that had been a cultural practice for hundreds of years. So despite the warnings, people continued to drink the sap.
Ausraful Islam, a veterinarian and infectious disease specialist at the icddr,b, explains that the consumption of raw date palm sap "is not something you can control. You cannot send police to every house, every village to stop them drinking it. It is not possible."

Sultana and her team developed an alternative messaging campaign to promote "safe sap." They helped produce a couple of TV docudramas in which the actors explain how to collect the sap safely — by putting a protective skirt (called a "bana") around the part of the tree with the tap, which keeps the bats out. But people don't always do it. So not every tree is protected. And the spillovers of Nipah virus from bats to people have continued.

Two tricks are the key to Nipah's persistence
It has been 20 years since the harrowing, practically yearly outbreaks started rocking Bangladesh, claiming more than 200 lives to date. And still there's no treatment for Nipah.

There's no vaccine. It remains on the World Health Organization's list of viruseswith pandemic potential. That's because it has two main tricks.

First, it can jump between species. "We've shown cattle, goats, pigs, cats, dogs can all get infected with Nipah and have been infected with Nipah in Bangladesh," says Gurley. "We don't know how." Perhaps, she says, it's through sap or dropped fruit. Or for pigs and carnivores, it may be through scavenging bat carcasses or placentas. "We're starting a new study to try to figure this out," Gurley says.

The second trick is that Nipah spreads from person to person. So far, Nipah doesn't do a particularly good job of that because the virus tends to kill its host. That means that despite these nearly yearly outbreaks in Bangladesh (with a larger one every four or five years), each has fizzled relatively fast. But each time Nipah makes that leap from bat to person, it gets another chance to find the right combination of mutations to become more transmissible, which could propel it into the realm of a deadly pandemic.

"If we want to contain the virus," says Islam, "we have to understand the virus."

That's why, at 3 a.m. on a cold December morning, Islam stops at the edge of a forest and looks up into the sky, some four stories above the ground, where a 70-foot net stretches between two mahogany trees. He's out here early "because the bats will start coming back from foraging after 3, so this is the best time to catch them," he says.

Early December marks the beginning of what's notoriously known as Nipah season: the four months when the virus is most likely to show up in people. This is when the date palm sap is flowing.

Every month, Islam brings a team out near Faridpur to capture bats. This place is nestled inside the "Nipah Belt," the chunk of central and northwest Bangladesh where — in the words of local physician Dr. Abu Faisal Md Pervez — the virus is synonymous with "death."

The answer isn't getting rid of the bats. Islam has enormous respect for the animals and their importance to the local ecosystem.

Rather, years of studying and sampling thousands of greater Indian fruit bats out here have shown that most of them carry Nipah virus. However, fewer than 1% of them actually release it into the environment. Islam is trying to work out why that is — what's prompting those few animals to shed it.

Most likely, it's connected to some kind of stress the bats are facing. "Is it lack of food?" he wonders. "Is it pregnancy stress? Is it lack of habitat?"

And knowing the answers to those questions could help Islam and his colleagues figure out what action to take to keep Nipah from finding its way into people in the first place.

On and off over the past 15 or so years, Islam and his team have analyzed which strains of the virus are circulating and — in so far small and unconcerning ways — how it's evolving. One of Islam's colleagues, Mohammed Ziaur Rahman, who heads up the One Health Laboratory at icddr,b, says this is the information they need to ultimately conquer the virus. And yet, "we are at the very earliest stages of preparing ourselves to combat Nipah," he confesses.

Nabbing bats and pondering a glass of date sap
The coming dawn is full of sound. Multiple calls to morning prayer from nearby mosques envelop the small research team. Jackals cackle. And birds flute.

Finally, about an hour before daybreak, a female bat is caught in the net. The team brings her down to earth and untangles her with care. She's big — an adult's wingspan easily reaches 3 feet. Her body is brown and furry. The wings are deep black, like a silky, papery fabric. Islam points out her big eyes, like two orbs of amber staring back.

"If it gets the chance," Islam cautions, "it will bite you, like, 10, 15 times. They're very bite-y." To avoid such an outcome, the team has the bat well restrained. The researcher whose hand is in the most vulnerable position has protected himself with a thick glove.

The team finishes untangling the bat and places her in a cotton bag. For now, the bag hangs from a line strung between two trees. It's possible to just make out the contorting and wriggling bat inside.

The researchers nab one more bat, then call it quits. It's getting too light, and any remaining bats will easily spot and avoid the net. They'll transport the animals to a local one-room lab, but not in a van. "Sometimes bats urinate on themselves to mark them," Islam explains. "So if you carry it in the van, the whole van will be stinking."

So they put the bats into a little three-wheeled car and ferry them to the lab some 20 minutes away, where they'll take blood and urine samples. When they're done, they'll release the two bats.

On the drive to the lab, Islam makes a pit stop at a village with a household that's harvesting date palm sap. "It is possible that they will offer you a glass of sap," he remarks to the group. "Please gently deny it, OK?"

When Islam arrives, he walks up to a huge metal tray over a fire. The air is sugary. Gallons of caramel-colored sap are at a rolling boil. It's thickening into molasses.

"It's really sweet," says Muhammad Seraj Khan, the 74-year-old property owner. "It gets sold all around the village. People will buy it to make household sweets and cakes."

The molasses, says Islam, is harmless — any virus gets cooked away. But that's not the case with raw sap. Still, the villagers like to down glasses of the traditional delicacy when they have the chance. And before Islam leaves, Khan offers some of the raw sap.

And there it is — a slightly cloudy liquid. A delicacy and possible poison all at once, because you never know if that invisible menace is lurking within the sweetness.

Scientists hope to curb the deadly Nipah virus that terrorizes Bangladesh villages [KVPR, 30 Jan 2023]

By Ari Daniel

Valley Public Radio

JUANA SUMMERS, HOST:
Three years ago today, the World Health Organization declared COVID-19 a public health emergency of international concern. That emergency eventually turned into one of the world's deadliest pandemics. To keep this from happening again, scientists have been studying how to detect and stop viruses with pandemic potential.

AILSA CHANG, HOST:
One of those is the deadly Nipah virus. Today, to kick off our series Hidden Viruses: Stopping The Next Pandemic Before It Starts, NPR's Ari Daniel takes us to a part of the world known as the Nipah Belt.

ARI DANIEL, BY LINE: It's early morning in a lush, rural community in central Bangladesh. I'm with a group, and we've just made a pit stop in a village within the district of Faridpur, deep in the heart of the Nipah Belt. It's the start of the season when sap is harvested from date palm trees and is then turned into molasses. That's what I'm here to see.
(SOUNDBITE OF FIRE CRACKLING)

DANIEL: I walk up to a huge metal tray over a fire. Gallons of caramel-colored sap are at a rolling boil, thickening into molasses. Mohammed Siraj Khan (ph) is the 74-year-old property owner.

MOHAMMED SIRAJ KHAN: (Through interpreter) This is actually a delicacy in Bangladesh. Mostly, we make cakes and sweets with it.

DANIEL: Then I'm offered some of the raw sap to drink. And there it is, the slightly cloudy liquid I've heard so much about, a delicacy and possible poison all at once. I was warned that this exact thing might happen. I was given advice about what to say.

(SOUNDBITE OF CHICKEN CLUCKING)

DANIEL: The evening before, just a few miles away, I pay a visit to a local family. A 50-year-old man named Kokon (ph) sits outside his home beside a rice paddy. A fiery beard dyed a bright orange rings his chin. And he says he'll never forget the spring of 2004, when the procession of disease and death came on suddenly.

KOKON: (Through interpreter) The first one was the mother-in-law of my elder brother. She was really sick. She had been sick for some time. Then she died. We took her to the grave. Then my father got sick.

DANIEL: Kokon stares off into the distance as he tells me his father was a spiritual leader in the community. When he became ill, many came to pay their respects.

KOKON: (Through interpreter) Just 12 days after my father died, suddenly, he was no more.

DANIEL: As for the visitors, they also got sick. One traveled to an adjacent village, where four more people fell ill.

MAHMUDUR RAHMAN: It was not understood what was happening.

DANIEL: Mahmudur Rahman is the former director of the Institute of Epidemiology, Disease Control and Research for the Bangladeshi government.

RAHMAN: Some people who were transporting the patients to the hospital were also getting sick.

DANIEL: Sick often meant encephalitis, a swelling of the brain. Epidemiologist Emily Gurley, now at Johns Hopkins University, was leading an on-site investigation at the time.

EMILY GURLEY: The signs and symptoms of encephalitis are, well, fever, headache but often altered mental status or coma, seizures.

DANIEL: Then Kokon and his wife Anwara (ph) fell ill. It's why I'm only using their first names - because the disease carries stigma.

ANWARA: (Through interpreter) People couldn't say if we are dead or alive.

They said that we had high fever. Like, whenever they were touching us, it was like touching fire.

DANIEL: Miraculously, they both survived. But Kokon's older brother, his sister, two uncles, his aunt, his nephew and his mom and dad - all dead. This outbreak, says Dr. Rahman, made something brutally evident.

RAHMAN: This is obviously showing that we are unable to control it, and it is spreading.

DANIEL: And with roughly 70% of those who got it dying, what virus could be that lethal?

GURLEY: We didn't know. I was just looking at the data. I was just looking at data to see what do we think is going on here?

DANIEL: A few weeks later, Gurley and her colleagues got an email from the CDC in Atlanta that this was the Nipah virus. They knew the virus came from bats 'cause in the '90s in Malaysia, when it first emerged, Nipah was spreading from local fruit bats to pigs to pig farmers. That's bad enough, but in Bangladesh, the virus was behaving differently.

GURLEY: It was being transmitted person to person, which had never been reported before. So that was a scary time.

DANIEL: An urgent question hung over Gurley. Just how did Nipah spill over from bats into humans in the first place? That was what needed answering to shut this thing down.

GURLEY: So what we did is walk through the village and thought about all the possible ways people could come into contact with bats or bat secretions, bat urine, bat saliva.

DANIEL: Finding this link - it's agonizingly slow work that takes years because an outbreak blazes quickly. The victims are dead, and eyewitnesses often flee or clam up. But the outbreaks kept happening almost every year afterwards, which was deeply worrying to experts because each time the virus leaps from bat to person, it gets another opportunity to mutate, possibly becoming more transmissible - the fear being the right combination of mutations could propel it into the realm of a deadly pandemic. Finally, the connection emerged, one that offered a remedy for stopping the Nipah spillovers. But the researchers needed more evidence. In 2007, they got their chance.

REBECA SULTANA: Our colleague called me and asked, Rebeca, are you ready? I said, yes, I'm ready to go there.

DANIEL: The next morning, anthropologist Rebeca Sultana joined the Nipah outbreak investigation team. She's with the International Centre for Diarrheal Disease Research, Bangladesh, or icddr,b for short. When she arrived in the village, she went straight to the home of patient zero.

SULTANA: I tried to talk to the elder sister-in-law of the guy who died. And she was so upset, and she just ran and came to me and hugged me and started crying.

DANIEL: Getting that close to her scared Sultana. As one Nipah researcher told me, doing this work is like putting your soul in your hand. But Sultana - she hugged her back and said...

SULTANA: Please don't worry. We are here to understand why this happened.

DANIEL: She asked the community to meet her in the town market to help her draw a map of the village. About two dozen people showed up.

SULTANA: I don't do anything. I just ask question, and then they draw it.

DANIEL: Using sticks in the dirt, the residents roughed out houses, roads, bat roosts, and then they began sketching in date palm trees.

SULTANA: This is the first time the people informed me, you know, there is a date palm tree, and there is a sap harvester in this community.

DANIEL: Sultana hadn't seen the date palm trees on the drive in. But staring back at her from the dirt, there it was, the possible link between how the fruit bats had passed Nipah into this community - through the drinking of the sweet sap. Emily Gurley.

GURLEY: We thought, well, this would be a great way to have contact with bat secretions because I'm sure the bats love the sap and so do people.

DANIEL: So Rebeca Sultana and her colleagues tracked down that sap harvester, and he led them to a few pals of the guy who was patient zero.

SULTANA: They said, we all used to drink raw sap in the morning.

DANIEL: This was Sultana's aha moment, that patient zero had had raw sap before falling ill. The line between the bats, the sap and the outbreaks was becoming clear.

Over the next few years, researchers took infrared cameras and caught the bats at night drinking from and sometimes peeing into the same stream of sap that people were harvesting.

Eventually, the government had enough evidence to launch a campaign against the drinking of raw sap. But many people have continued to drink the sap, and the spillovers of Nipah virus from bats to people have continued, too.

(SOUNDBITE OF PLANTS RUSTLING)

DANIEL: It's December 1, the beginning of what's known around here notoriously has Nipah season, the four months when the virus is most likely to show up. This is when the sap is harvested and when Zhahirul Islam keeps an especially close eye on Nipah.

ZHAHIRUL ISLAM: If we want to contain the virus, we have to understand the virus.

DANIEL: It's 3 in the morning. Islam stops at the edge of a patch of forest and looks up into the sky. A net stretches between two mahogany trees.

Why are we out here so early?

ISLAM: Because the bats soon start coming back from foraging after 3. So this is the best time to catch them.

DANIEL: Islam is a veterinarian and infectious disease specialist at the icddr,b. He's searching for another way to stop Nipah. Every month, he brings a team out here near Faridpur to capture bats. The answer isn't getting rid of these animals. Islam has great respect for their importance to the local ecosystem. Rather, years of studying thousands of greater Indian fruit bats have shown that most of them do carry Nipah virus. But here's the thing - fewer than 1% of them actually release it into the environment through their urine or saliva. Why do so few of these animals shed the virus? Islam thinks for that small group, it's likely connected to stress.

ISLAM: Is it lack of food? Is it pregnancy stress? Is it lack of habitat?

DANIEL: Knowing what's behind the shedding could help Islam and his colleagues figure out how to keep Nipah from infecting people in the first place.

(SOUNDBITE OF BATS CHIRPING)

DANIEL: The coming dawn is full of sound. There are jackals and fruit bats.
What just happened?

UNIDENTIFIED PERSON: We able to capture bat.

DANIEL: OK. So a bat just flew into the net. The bat's body is like a brown and furry, and the wings are just deep black, like a silky papery fabric.

ISLAM: If you go around, you'll see the big eyes.

DANIEL: I gaze into them, like two orbs of amber. She's big. An adult's wingspan easily reaches 3 feet.

ISLAM: If it gets the chance, it'll bite you, like, 10, 15 times. They're very bitey.

DANIEL: Just untangled it.

The team nabs one more bat and then calls it quits. It's getting too light. They put the bats into a three-wheeler and ferry them to a local lab, an unassuming one-room building, and yet a crucial outpost in the battle against Nipah. It's where the researchers will sample blood and urine from the bats. And once they're done, they'll release the animals back into the woods. It's on the drive to the lab when Islam makes a pit stop in that village. He wants to show me the date palm trees, the boiling molasses. That's when he'd given me that advice.

ISLAM: It is possible that they will offer you a glass of sap. Please, gently deny it, OK?

DANIEL: The bubbling molasses I see before me is harmless. Any virus gets cooked away. And to be fair, Khan, the property owner, he doesn't recommend drinking it raw. But before we leave, sure enough, I'm offered a taste of the cool, cloudy sap, a chalice of what could be delectable poison. I smell the sweet air, and I politely decline.