India Is Panicking About a Virus Passed by Bat Poop
The Nipah virus is awful. Hysteria makes it worse.
When I advised the script development of Steven Soderbergh’s 2011 movie, Contagion, screenwriter Scott Burns and I puzzled over what sort of virus ought to be the center of the Matt Damon-starring film. Fellow advisor Ian Lipkin, a veteran virus hunter from the Mailman School of Public Health at Columbia University, shared no such confusion: It should be a Nipah-like virus. After all, he argued, the virus that first hit the Malaysian village of Kampung Sungai Nipah in 1998 kills more than 70 percent of people it infects, making it one of the most lethal human pathogens on Earth. Lipkin then made up a genetic sequence for his hypothetical virus, based on a real Nipah strain, with genes added to render it highly contagious from human to human.
The Nipah virus now spreading in southern India doesn’t possess Lipkin’s imaginary contagion-inducing genes, which is why most people don’t acquire their infections from other people. Though the virus can spread via saliva, Nipah is not an airborne supercontagious agent like measles or influenza. The current outbreak has claimed 17 lives, all in the southern state of Kerala, and authorities there have placed 2,000 people under observation. Among the deceased was Lini Puthussery, a 28-year-old nurse who became infected while treating the first Nipah cases — adult brothers from a rural district.
But since fear rarely bothers to rest on a foundation of fact, the Indian outbreak has spawned outsized fears of spread and contagion around the world (if not yet in the West). It already dominates the news on the Indian subcontinent and in Middle Eastern countries with large Indian and Bangladeshi labor forces. The United Arab Emirates, Qatar, and Bahrain, in particular, have all banned import of various Indian foods and livestock and asked the estimated 1.6 million members of the Kerala diaspora living in the three countries to avoid traveling home.
Meanwhile, all Indian schools and colleges in the outbreak epicenter, the Kerala districts of Kozhikode and Malappuram, are closed until at least June 12. The neighboring state of Karnataka was on full alert, fearing travelers from Kerala were infected: All samples there subsequently tested negative for Nipah. When Indian Army soldier Seenu Prasad — a native of Kerala — died at his military base in distant Kolkata, the nation’s armed forces went on alert, and the base was quarantined. Prasad and his fellow soldiers were never Nipah-infected. Even more distant places, such as Hyderabad, have gone on alert, fearing travelers from Kerala or in response to the discovery of dead bats, only to reverse alert orders when no evidence of the virus is found.
Instant so-called experts have emerged all over Indian media, advising people to eschew fresh fruit (especially mangoes) and avoid potato juice and palm oil. Some even recommend bathing a certain way: “While bathing the body, your nose and face should be covered with a towel, and after bathing, if possible, take a bath with your soap immediately.” Worse advice and false rumors have filled WhatsApp and other social media, as, sadly, is the case worldwide these days whenever populations feel threatened by viruses. Perhaps the peak of India’s unique mélange of politics and hysteria was reached on May 27, when Haryana State Health Minister Anil Vij — a high-profile, controversial politician in the Bharatiya Janata Party, which currently rules the nation — lashed out at the leader of the rival Indian National Congress, calling Rahul Gandhi “similar to Nipah virus. Any political party that comes in contact with him will be destroyed.”
Hysteria can obviously be political advantageous, but it almost always detracts from public health. This case is no different.
Although this isn’t the first time the world has encountered Nipah, the origins of its periodic outbreaks have only recently become less mysterious. In April 2008, during the last major outbreak in South Asia, I spoke with scientists at the ICDDR,B research institute in the Bangladeshi capital of Dhaka, including Stephen Luby of the U.S. Centers for Disease Control and Prevention (CDC). By then Luby was certain that the key to Nipah outbreaks was bats and their connection with palm sap.
The region’s nocturnal bats, with their 3-foot wingspans, fly from treetop to treetop sucking sap, like bees flitting among flowers in search of honey. Along the way, the flying mammals urinate and defecate, occasionally passing Nipah viruses into the palm sap, which is a national delicacy. Children shimmy up the trees early in the morning to harvest the sap when it is at its sweetest, not yet cooked under the hot sun and fermented naturally into alcohol, which is taboo for local Muslims. Harvesting sap later in the day might risk alcohol consumption but would likely offer a lower risk of infection because ultraviolet light exposure kills the viruses. It was impossible to find the specific bat that passed viruses to a particular child, and very difficult to track contaminated palm sap, but Luby, who is now at Stanford University, said all evidence pointed to this ancient bat-to-palm-to-human link.
“I suspect people have been dying for centuries, but it’s not been recognized,” Luby explained. “I don’t think it’s a new phenomenon. If you look at the virus, it’s really co-evolved with the bat, and it’s a thousands-of-years-old virus.”
Luby’s colleague Nazmun Nahar, a medical anthropologist, said the palm sap season was January to April, precisely when most outbreaks in Bangladesh occurred, and a village area I had visited where the 2008 outbreak began was one of Asia’s major centers of palm sap harvesting. The ICDDR,B team devised cheap ways that palm farmers could net their trees, keeping the big bats away from the sap, but Nahar was doubtful of their success. “A guy harvests 80 to 100 trees each day, and that’s a lot of netting to do,” she said, shrugging.
Other CDC researchers have found Nipah in dozens of bat species across Asia, including in places such as Cambodia where no human outbreaks have ever been reported. After 20 years of research, Luby and his counterparts at the CDC and institutes all over Asia share frustration that they cannot stop the transmission, predict when and where it will occur, or figure out how and why any given bat is infected — harmlessly to the flying creature, but dangerously for humans who come in contact with contaminated palm sap.
All over the world, bat populations are under deep stress. Vital to the pollination of millions of types of trees and plants, bats are losing habitats amid logging and deforestation, as well as food thanks to rising temperatures in upper forest canopies due to climate change. Starving, the animals are migrating closer to human habitation, taking up residence in orchards and agricultural zones. Worldwide bat migration and feeding patterns have adjusted due to environmental stress, changing where they are likely to nest and eat. In America, bat migrations have shifted, in some cases farther north in the summer, and fungal diseases amid rising humidity are killing off animals that hide from the sun inside moist caves.
Changes in bat migration and feeding directly impact agricultural pollination and mosquito control; many species eat insects that can carry diseases including dengue, malaria, Zika, and yellow fever.
But bats also carry hundreds of different types of viruses inside of them that are harmless to the animals: SARS, Ebola, MERS, Marburg disease, rabies, mumps, Hendra virus. The EcoHealth Alliance has found some 600 viruses in more than 750 mammal species, with many bats carrying multiple pathogens simultaneously. Some newly discovered bat viruses are genetically close to Nipah, SARS, and MERS, suggesting there could be more mysterious human outbreaks looming. Some scientists have offered evidence that bats have hyperstrong immune systems that can control all these deadly microbes, keeping the animals healthy. How? Because they fly, researchers say, expending huge amounts of energy that heats up their bodies and pushes their immune systems into hyperdrive.
So whether the concern is Nipah, Ebola, SARS, or any of a long list of other pathogens that may reside inside bats, the risk cannot be eliminated. The bats are essential to the ecologies in which they live, and human farming and hunting will always put some minute number of people near the animals at infection risk.
The problem is hospitals. Like a loudspeaker that transforms a singer’s dulcet tones into a cacophony, hospitals can amplify a single case into dozens, even hundreds, in a matter of days. It’s called nosocomial transmission — spread within medical settings. And nosocomial disease is a problem for all types of health facilities, from impoverished rural clinics to the most technologically sophisticated facilities in the world. The 2003 SARS outbreak was primarily nosocomial, spreading like wildfire inside top-of-the-line hospitals in wealthy areas: Canada, Singapore, Hong Kong. Every Ebola outbreak since the first in 1976 has been fueled by nosocomial people-to-people spread.
The current Nipah outbreak in India is no different: It, like all Nipah epidemics since 1998, expanded with spread among patients, health care workers, and visitors. The Government Medical College in Kozhikode committed no grave sins or malfeasance in its hygienic practices, and nurse Lini Puthussery cannot be blamed for her fatal infection. The risk of Nipah, or any other dangerous bat-borne virus, cannot be ascribed simply to “poor countries” or “bad hospitals.”
The next time you find yourself visiting an emergency room at your local hospital, perform this simple mental exercise: Cast your glance about until you settle on somebody who looks weak and feverish. Imagine that person has Nipah virus. Watch closely to see who touches that person or what physical surfaces the patient contacts. Are those touches protected by gloves? If the patient is coughing, who is nearby — are they wearing masks? You will quickly recognize why hospitals can be fonts of contagion with nosocomial disease.
The Nipah outbreak in India will soon die down as the virus stops spreading from person to person and the palm sap season comes to its end. But Nipah will return — as will dozens, if not hundreds, of other bat viruses — in unpredictable times and places. Take heed, hospital administrators and those who control government purse strings: Preventing serious outbreaks means putting time and money every day into training and equipment that limit the risk of nosocomial spread. Waiting to take steps in an atmosphere of fear and hysteria — or, worse, feeding those fears — risks needless anxiety and grievous mistakes.