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How Do Bats Live With So Many Viruses? How Do Bats Live With So Many Viruses?
(3 days later)
If previous outbreaks of coronavirus are any indication, the Wuhan strain that is now spreading may eventually be traced back to bats.If previous outbreaks of coronavirus are any indication, the Wuhan strain that is now spreading may eventually be traced back to bats.
Dr. Peter Daszak, president of EcoHealth Alliance, who has been working in China for 15 years studying diseases that jump from animals to people, said, “We don’t know the source yet, but there’s pretty strong evidence that this is a bat origin coronavirus.” He said, “It’s probably going to be the Chinese horseshoe bat,” a common species that weighs up to an ounce.Dr. Peter Daszak, president of EcoHealth Alliance, who has been working in China for 15 years studying diseases that jump from animals to people, said, “We don’t know the source yet, but there’s pretty strong evidence that this is a bat origin coronavirus.” He said, “It’s probably going to be the Chinese horseshoe bat,” a common species that weighs up to an ounce.
If he’s right, this strain will join many other viruses that bats carry. SARS and MERS epidemics were caused by bat coronaviruses, as was a highly destructive viral epidemic in pigs.If he’s right, this strain will join many other viruses that bats carry. SARS and MERS epidemics were caused by bat coronaviruses, as was a highly destructive viral epidemic in pigs.
One bat can host many different viruses without getting sick. They are the natural reservoir for the Marburg virus, and Nipah and Hendra viruses, which have caused human disease and outbreaks in Africa, Malaysia, Bangladesh and Australia. They are thought to be the natural reservoir for the Ebola virus. They also carry the rabies virus, but in that case the bats are affected by the disease.One bat can host many different viruses without getting sick. They are the natural reservoir for the Marburg virus, and Nipah and Hendra viruses, which have caused human disease and outbreaks in Africa, Malaysia, Bangladesh and Australia. They are thought to be the natural reservoir for the Ebola virus. They also carry the rabies virus, but in that case the bats are affected by the disease.
Their tolerance of viruses, which surpasses that of other mammals, is one of their many distinctive qualities. They are the only flying mammals, they devour disease-carrying insects by the ton, and they are essential in the pollination of many fruits, like bananas, avocados and mangoes. They are also an incredibly diverse group, making up about a quarter of all mammalian species.Their tolerance of viruses, which surpasses that of other mammals, is one of their many distinctive qualities. They are the only flying mammals, they devour disease-carrying insects by the ton, and they are essential in the pollination of many fruits, like bananas, avocados and mangoes. They are also an incredibly diverse group, making up about a quarter of all mammalian species.
But their ability to coexist with viruses that can spill over to other animals, in particular humans, can have devastating consequences when we eat them, trade them in livestock markets and invade their territory.But their ability to coexist with viruses that can spill over to other animals, in particular humans, can have devastating consequences when we eat them, trade them in livestock markets and invade their territory.
Learning how they carry and survive so many viruses has been a deep question for science, and new research suggests that the answer may be how the bats’ evolutionary adaptations to flight changed their immune systems.Learning how they carry and survive so many viruses has been a deep question for science, and new research suggests that the answer may be how the bats’ evolutionary adaptations to flight changed their immune systems.
In a 2018 paper in Cell Host and Microbe, scientists in China and Singapore reported their investigation of how bats handle something called DNA sensing. The energy demands of flight are so great that cells in the body break down and release bits of DNA that are then floating around where they shouldn’t be. Mammals, including bats, have ways to identify and respond to such bits of DNA, which might indicate an invasion of a disease-causing organism. But in bats, they found, evolution has weakened that system, which would normally cause inflammation as it fought the viruses.In a 2018 paper in Cell Host and Microbe, scientists in China and Singapore reported their investigation of how bats handle something called DNA sensing. The energy demands of flight are so great that cells in the body break down and release bits of DNA that are then floating around where they shouldn’t be. Mammals, including bats, have ways to identify and respond to such bits of DNA, which might indicate an invasion of a disease-causing organism. But in bats, they found, evolution has weakened that system, which would normally cause inflammation as it fought the viruses.
Bats have lost some genes involved in that response, which makes sense because the inflammation itself can be very damaging to the body. They have a weakened response but it is still there. Thus, the researchers write, this weakened response may allow them to maintain a “balanced state of ‘effective response’ but not ‘over response’ against viruses.”Bats have lost some genes involved in that response, which makes sense because the inflammation itself can be very damaging to the body. They have a weakened response but it is still there. Thus, the researchers write, this weakened response may allow them to maintain a “balanced state of ‘effective response’ but not ‘over response’ against viruses.”
How to manage and contain the current outbreak of the virus officially known as 2019-nCoV, is, of course, of paramount importance now. But tracing its origin and taking action to combat further outbreaks may depend partly on knowledge and monitoring of bats. “The outbreak can be contained and controlled,” Dr. Daszak said. “But if we don’t know the origin in the long term then this virus can continue to spill over.”How to manage and contain the current outbreak of the virus officially known as 2019-nCoV, is, of course, of paramount importance now. But tracing its origin and taking action to combat further outbreaks may depend partly on knowledge and monitoring of bats. “The outbreak can be contained and controlled,” Dr. Daszak said. “But if we don’t know the origin in the long term then this virus can continue to spill over.”
Scientists in China were already studying the bats carefully, well aware that an outbreak like the current one would most likely happen.Scientists in China were already studying the bats carefully, well aware that an outbreak like the current one would most likely happen.
Last spring, in an article on bat coronaviruses, or CoVs, a group of Chinese researchers wrote that “it is generally believed that batborne CoVs will re-emerge to cause the next disease outbreak.” They added, “In this regard, China is a likely hot spot.” This wasn’t clairvoyance, but conventional wisdom.Last spring, in an article on bat coronaviruses, or CoVs, a group of Chinese researchers wrote that “it is generally believed that batborne CoVs will re-emerge to cause the next disease outbreak.” They added, “In this regard, China is a likely hot spot.” This wasn’t clairvoyance, but conventional wisdom.
Certainly, rodents, primates and birds also carry diseases that can jump and have jumped to people; bats are far from alone in that regard. But there are reasons they have been implicated in several disease outbreaks and are likely to be implicated in more.Certainly, rodents, primates and birds also carry diseases that can jump and have jumped to people; bats are far from alone in that regard. But there are reasons they have been implicated in several disease outbreaks and are likely to be implicated in more.
They are numerous and widespread. While bats account for a quarter of mammalian species, rodents are 50 percent, and then there’s the rest of us. Bats live on every continent except Antarctica, in proximity to humans and farms. The ability to fly makes them wide-ranging, which helps in spreading viruses, and their feces can spread disease.They are numerous and widespread. While bats account for a quarter of mammalian species, rodents are 50 percent, and then there’s the rest of us. Bats live on every continent except Antarctica, in proximity to humans and farms. The ability to fly makes them wide-ranging, which helps in spreading viruses, and their feces can spread disease.
People in many parts of the world eat bats, and sell them in live animal markets, which was the source of SARS, and possibly the latest coronavirus outbreak that began in Wuhan. They also often live in huge colonies in caves, where crowded conditions are ideal for passing viruses to one another.People in many parts of the world eat bats, and sell them in live animal markets, which was the source of SARS, and possibly the latest coronavirus outbreak that began in Wuhan. They also often live in huge colonies in caves, where crowded conditions are ideal for passing viruses to one another.
In a 2017 report in Nature, Dr. Daszak, Kevin J. Olival and other colleagues from EcoHealth Alliance, reported that they had created a database of 754 mammal species and 586 viral species, and analyzed which viruses were harbored by which mammals and how they affected their hosts.In a 2017 report in Nature, Dr. Daszak, Kevin J. Olival and other colleagues from EcoHealth Alliance, reported that they had created a database of 754 mammal species and 586 viral species, and analyzed which viruses were harbored by which mammals and how they affected their hosts.
Updated June 5, 2020Updated June 5, 2020
A study by European scientists is the first to document a strong statistical link between genetic variations and Covid-19, the illness caused by the coronavirus. Having Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator, according to the new study.
The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April.The unemployment rate fell to 13.3 percent in May, the Labor Department said on June 5, an unexpected improvement in the nation’s job market as hiring rebounded faster than economists expected. Economists had forecast the unemployment rate to increase to as much as 20 percent, after it hit 14.7 percent in April, which was the highest since the government began keeping official statistics after World War II. But the unemployment rate dipped instead, with employers adding 2.5 million jobs, after more than 20 million jobs were lost in April.
Mass protests against police brutality that have brought thousands of people onto the streets in cities across America are raising the specter of new coronavirus outbreaks, prompting political leaders, physicians and public health experts to warn that the crowds could cause a surge in cases. While many political leaders affirmed the right of protesters to express themselves, they urged the demonstrators to wear face masks and maintain social distancing, both to protect themselves and to prevent further community spread of the virus. Some infectious disease experts were reassured by the fact that the protests were held outdoors, saying the open air settings could mitigate the risk of transmission.Mass protests against police brutality that have brought thousands of people onto the streets in cities across America are raising the specter of new coronavirus outbreaks, prompting political leaders, physicians and public health experts to warn that the crowds could cause a surge in cases. While many political leaders affirmed the right of protesters to express themselves, they urged the demonstrators to wear face masks and maintain social distancing, both to protect themselves and to prevent further community spread of the virus. Some infectious disease experts were reassured by the fact that the protests were held outdoors, saying the open air settings could mitigate the risk of transmission.
Exercise researchers and physicians have some blunt advice for those of us aiming to return to regular exercise now: Start slowly and then rev up your workouts, also slowly. American adults tended to be about 12 percent less active after the stay-at-home mandates began in March than they were in January. But there are steps you can take to ease your way back into regular exercise safely. First, “start at no more than 50 percent of the exercise you were doing before Covid,” says Dr. Monica Rho, the chief of musculoskeletal medicine at the Shirley Ryan AbilityLab in Chicago. Thread in some preparatory squats, too, she advises. “When you haven’t been exercising, you lose muscle mass.” Expect some muscle twinges after these preliminary, post-lockdown sessions, especially a day or two later. But sudden or increasing pain during exercise is a clarion call to stop and return home.Exercise researchers and physicians have some blunt advice for those of us aiming to return to regular exercise now: Start slowly and then rev up your workouts, also slowly. American adults tended to be about 12 percent less active after the stay-at-home mandates began in March than they were in January. But there are steps you can take to ease your way back into regular exercise safely. First, “start at no more than 50 percent of the exercise you were doing before Covid,” says Dr. Monica Rho, the chief of musculoskeletal medicine at the Shirley Ryan AbilityLab in Chicago. Thread in some preparatory squats, too, she advises. “When you haven’t been exercising, you lose muscle mass.” Expect some muscle twinges after these preliminary, post-lockdown sessions, especially a day or two later. But sudden or increasing pain during exercise is a clarion call to stop and return home.
States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people.States are reopening bit by bit. This means that more public spaces are available for use and more and more businesses are being allowed to open again. The federal government is largely leaving the decision up to states, and some state leaders are leaving the decision up to local authorities. Even if you aren’t being told to stay at home, it’s still a good idea to limit trips outside and your interaction with other people.
Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks.Touching contaminated objects and then infecting ourselves with the germs is not typically how the virus spreads. But it can happen. A number of studies of flu, rhinovirus, coronavirus and other microbes have shown that respiratory illnesses, including the new coronavirus, can spread by touching contaminated surfaces, particularly in places like day care centers, offices and hospitals. But a long chain of events has to happen for the disease to spread that way. The best way to protect yourself from coronavirus — whether it’s surface transmission or close human contact — is still social distancing, washing your hands, not touching your face and wearing masks.
Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.Common symptoms include fever, a dry cough, fatigue and difficulty breathing or shortness of breath. Some of these symptoms overlap with those of the flu, making detection difficult, but runny noses and stuffy sinuses are less common. The C.D.C. has also added chills, muscle pain, sore throat, headache and a new loss of the sense of taste or smell as symptoms to look out for. Most people fall ill five to seven days after exposure, but symptoms may appear in as few as two days or as many as 14 days.
If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)If air travel is unavoidable, there are some steps you can take to protect yourself. Most important: Wash your hands often, and stop touching your face. If possible, choose a window seat. A study from Emory University found that during flu season, the safest place to sit on a plane is by a window, as people sitting in window seats had less contact with potentially sick people. Disinfect hard surfaces. When you get to your seat and your hands are clean, use disinfecting wipes to clean the hard surfaces at your seat like the head and arm rest, the seatbelt buckle, the remote, screen, seat back pocket and the tray table. If the seat is hard and nonporous or leather or pleather, you can wipe that down, too. (Using wipes on upholstered seats could lead to a wet seat and spreading of germs rather than killing them.)
Taking one’s temperature to look for signs of fever is not as easy as it sounds, as “normal” temperature numbers can vary, but generally, keep an eye out for a temperature of 100.5 degrees Fahrenheit or higher. If you don’t have a thermometer (they can be pricey these days), there are other ways to figure out if you have a fever, or are at risk of Covid-19 complications.Taking one’s temperature to look for signs of fever is not as easy as it sounds, as “normal” temperature numbers can vary, but generally, keep an eye out for a temperature of 100.5 degrees Fahrenheit or higher. If you don’t have a thermometer (they can be pricey these days), there are other ways to figure out if you have a fever, or are at risk of Covid-19 complications.
The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing.The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing.
If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.
If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.
They confirmed what scientists had thought: “Bats are host to a significantly higher proportion of zoonoses than all other mammalian orders.” Zoonoses are diseases that spill over from animals to humans.They confirmed what scientists had thought: “Bats are host to a significantly higher proportion of zoonoses than all other mammalian orders.” Zoonoses are diseases that spill over from animals to humans.
And they don’t just survive the viruses they harbor. Bats are remarkably long-lived for small mammals. The big brown bat, a common species in the United States, can live nearly 20 years in the wild. Others live closer to 40. One tiny bat in Siberia lived at least 41 years. Animals like house mice live about two years on average.And they don’t just survive the viruses they harbor. Bats are remarkably long-lived for small mammals. The big brown bat, a common species in the United States, can live nearly 20 years in the wild. Others live closer to 40. One tiny bat in Siberia lived at least 41 years. Animals like house mice live about two years on average.
While the bats must be studied, their physiology understood, and the viruses they harbor monitored for the sake of public health, that does not mean that the bats are to blame for the outbreak. As others have pointed out, humans have encroached on the lives of bats, not vice versa.While the bats must be studied, their physiology understood, and the viruses they harbor monitored for the sake of public health, that does not mean that the bats are to blame for the outbreak. As others have pointed out, humans have encroached on the lives of bats, not vice versa.
Dr. Daszak stressed that stopping the sale of wildlife in markets is essential to curtail future outbreaks. But since such outbreaks are inevitable, Dr. Daszak says, monitoring and studying wildlife, like bats, is equally important. He compared the situation to terrorism. Both terrorist attacks and disease outbreaks seem inevitable. To get a jump on them, he said, intelligence is vital.Dr. Daszak stressed that stopping the sale of wildlife in markets is essential to curtail future outbreaks. But since such outbreaks are inevitable, Dr. Daszak says, monitoring and studying wildlife, like bats, is equally important. He compared the situation to terrorism. Both terrorist attacks and disease outbreaks seem inevitable. To get a jump on them, he said, intelligence is vital.