Sunday, February 26, 2006

Fido can get sick, too

What is it about the flu these days?

First it crosses from birds to humans, creating a panic that it will develop the ability to transmit person-to-person too.

Now, it has crossed species barriers again, this time from horses to dogs. Man’s best friend is at risk, and given how close we are to our dogs, we could be at risk again too.

This “dog flu” was first identified in racing greyhounds in Florida in 2004 and was found to closely resemble a horse flu strain. Although the virus initially infected dogs directly from horses, at some unknown point it developed the ability to transmit from dog-to-dog too, probably by modifying its genetic information slightly.

“The significance is that historically, the transmission of an influenza virus from one mammal to another is a rare event,” says Cynda Crawford, a veterinary immunologist from the University of Florida’s College of Veterinary Medicine and the lead researcher in the study. This is also the first evidence of a flu virus ever spreading between dogs, she says: “We don’t have much precedence for this.”

Since dogs are kept in close contact with people – and are so very generous with their saliva – dog flu strains could start infecting people and eventually develop the ability to transmit person-to-person, as is feared could occur with current strains of bird flu.

Animal flu strains are more dangerous to people than human strains because people’s immune systems are not used to fighting them, so if such a virus acquires the ability to transmit between people, it could potentially lead to a pandemic. The flu pandemics of 1957 and 1968, which are believed to have killed over 100,000 Americans, were bird flu strains that had acquired the ability to infect people and transmit easily between them. If the dog flu also evolved in this way, it could potentially cause a pandemic too.

Edward J. Dubovi, Director of virology at the Cornell University College of Veterinary Medicine, who first isolated the dog flu, says that the potential for a second species jump from dogs to humans is “a low probability event,” but adds that, since dogs and humans are so frequently in close contact, dogs would be “the perfect species” from which to jump.

However, Ruben Donis, Chief of the molecular genetics section at the Influenza Branch of the Centers for Disease Control and a collaborator in the study, explains that the horse flu has existed for at least 40 years and that there is no evidence that it has ever infected a person, via dogs or otherwise. While the virus has changed slightly since it began infecting dogs, the modifications have been small and are unlikely to significantly increase the risk for humans.

“We are going to monitor all cases of possible human exposure, but at this point, there is no reason to panic,” Donis said in a CDC Media Telebrief in September.

Over the course of the past few months, over 3,000 samples from potentially infected dogs around the country have been sent to Dubovi and other Cornell University scientists. However, all but five or six of the samples have been difficult to fully analyze because they were taken from dogs in late stages of infection.

“The samples we are getting are not appropriate for what we’re after,” he says.

Because of this, it has been difficult to determine how the virus has been changing as it spreads – information that is very important to ensure that it does not become more virulent or pose a danger to people. Dubovi explains that it will be crucial in the coming months to maintain surveillance and get better samples.

Analysis has, however, revealed that dogs in 18 states, including New York, have had the flu, says Crawford. And virtually all exposed dogs have become infected, according to the American Veterinary Medical Association website.

While no one knows how many dogs have been killed, only about one in every 20 infected dogs dies, and household pets have fewer complications than dogs in shelters, says Crawford. A number of infected dogs never experience any symptoms, although they can still make other dogs sick.

Crawford advises that there is no need for people to panic – they should still feel comfortable taking their dogs to parks and dog runs and allowing them to participate in community activities with other dogs.

Scientists have also been developing a dog flu vaccine, and Crawford estimates that it will be available by this summer. The vaccine should limit transmission and greatly reduce the risk posed to people.

If your dog is coughing or seems to be suffering from a respiratory infection, it is important to have it checked immediately by a veterinarian, says Dubovi, who explains that post-flu complications like bacterial infections are usually more dangerous than the flu itself.

“The critical thing is for the dogs to be treated quickly once they develop clinical signs,” he says.

Sunday, February 12, 2006

Solving the Climate Change Problem

Governmental organizations are attempting to stifle top scientists, says James Hansen, the longtime director of NASA’s Goddard Institute for Space Studies. Hansen, who has spent over 30 years studying climate trends and models, claims that NASA blocked his attempts to speak out about global warming.

If scientists are being censored, what aren't we being told about global warming? How can we establish sound policies on environmental issues if information is being witheld?

These are questions that a handful of leading American scientific and political scholars – including Hansen himself – addressed at a panel discussion last Friday, part of the two-day conference “Politics and Science: How Their Interplay Creates Public Policy” held at The New School for Social Research in Greenwich Village.

“Unless the public is given information that accurately reflects what is going on in science, then policy making is likely to suffer,” Hansen said.

According to Hansen, average global temperatures have increased about 1° F since 1950, and he predicts a further increase of at least that much in the coming years due to a built-in lag between when atmospheric changes occur and global temperatures subsequently rise.

Anthropogenic warming is primarily caused by greenhouse gas emissions – especially carbon dioxide. Carbon dioxide is released into the air when fossil fuels like coal, oil and gas are burned. According to the US Department of Energy, the amount of carbon dioxide released into the atmosphere during the last 30 years is as much as was released in the 200 years preceding it.

Carbon dioxide acts like a blanket, absorbing heat from the sun and preventing it from escaping back into space. Other gases, including methane and aerosols, also contribute to global warming, but in more complicated ways.

The warming caused by carbon dioxide could have a number of deleterious effects, with sea level rising as one of the most catastrophic. According to a 2004 Scientific American article authored by Hansen, global warming-induced flooding could cost trillions of dollars and endanger a number of species, including polar bears, seals and walruses.

“If we don’t begin actions to get us on a different path, within the next couple years we will pass a point of no return,” Hansen warned.

So, what can be done? Far from being a hopeless skeptic, Hansen is confident that, if we address the problem now, we can prevent these disasters. First, we need to halt the growth of air pollutants like soot, atmospheric ozone and methane, which he argues can be done using a “reward approach” for emission reductions. Methane capture, which removes methane from the atmosphere, is another option that would actually have economic benefits since methane’s value as a fuel would more than cover capture costs.

Secondly, Hansen says, we need to keep carbon dioxide emissions at about the same level they are today – something that can be achieved with improved energy efficiency, nuclear power, alternative energies, and carbon capturing.

To realize these goals, aggressive environmental policies will be essential. Michael Oppenheimer, director of the Program in Science, Technology and Environmental Policy at Princeton University, believes that strong scientifically-focused non-governmental organizations will play a critical role in transforming climate change issues into global regulatory regimes. By both pressuring the government and getting the message out to the public, these organizations “can serve as a bulwark against undemocratic and unrepresentative government,” he told the panel audience.

It’s not just up to specialist organizations to get the message out, though – scientists, teachers and even concerned citizens can help. “As a pedant, the first thing I think of is education,” said Paul Ehrlich, president of the Center for Conservation Biology and Professor at Stanford University. “We need discourse,” he said, and we have to “find much better ways to insert decent science and decent social science into the discussion.”

Indeed, in a democracy, it is up to us to change things. “The ultimate policy maker is the public,” Hansen said.

Can education, specialist organizations and progressive technologies really solve the climate change problem? “Yes” was the resounding answer from Friday’s refreshingly optimistic discussion – if we set our minds to it. The public has the power and the responsibility to demand sound environmental policies to protect our planet and future generations. “This is not a pipe dream,” Oppenheimer said.

Obviously, though, in order for this to happen, scientists must be given the freedom to speak out to the public, so we need to demand this from our government too. Stifling the truth, said Hansen, is “not the way science works, and it’s not the way a democracy should work.”