More about patients NOT HAVING A FEVER with H1N1.

Can your doctor spot H1N1?
By Caleb Hellerman, CNN Medical News Senior Producer
November 20, 2009 1:26 p.m. EST

http://www.cnn.com/2009/HEALTH/11/20/h1n1.fever.doctor/

Comment: The article begins with the story of 5-year-old Danelle Olivares who died from H1N1 and "never even ran a fever."

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The World Health Organization and U.S. Centers for Disease Control and Prevention each list fever as a defining feature of H1N1. But that's being called into question, most recently in the medical journal the Lancet. This week, physicians in Queensland, Australia, wrote that 36 of the 106 patients admitted to Gold Coast Hospital with confirmed H1N1 infections actually had no fever.

Dr. Richard Wenzel, an infectious disease specialist at Virginia Commonwealth University, visited hospitals in Mexico City in the spring when the virus first exploded onto the scene, and in Chile in July, during that country's outbreak. In both places, he says, the pattern was like Australia -- a third or more of adult H1N1 patients were afebrile, or without fever. "If the CDC doesn't recognize flu without fever, we're going to miss a huge number of cases," Wenzel says. "What it really means is we're going to have an incredibly difficult time controlling the virus."

In fact, the CDC does recognize flu without fever. Its guidelines on preventing the spread of H1N1 in hospitals dutifully report that "depending on the case series, the proportion of persons who have laboratory confirmed 2009 H1N1 infection and do not have fever can range from about 10 to 50 percent." But that warning isn't reflected in most of the agency's practical guidance, including when to keep children home from school or when parents should stay home from work or avoid public crowds. In those cases, flu is defined -- in part -- by having an elevated temperature.

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Of course, any guidelines are only as good as the science that underlies them. Flu experts still don't know whether a significant number of patients are sick enough to spread the virus, despite not being feverish. Wenzel and the Australian researchers put the figure at 30 percent or higher, but a Canadian study last month in the Journal of the American Medical Association found that only 10 percent of patients in intensive care were afebrile. Some infectious disease experts say that even 10 percent sounds too high.

One skeptic is Dr. Bruce Ribner at Emory, who says, "Maybe it's because we're not especially [testing] most people who are afebrile, but among the ones we've seen in the hospital, almost all of them have a fairly high fever."

If that picture is still hazy, it's clear that H1N1 is different from seasonal flu in other ways. For one thing, it's far more likely to cause gastrointestinal symptoms such as nausea and vomiting. The Canadian study reported that nearly half the patients admitted to intensive care were suffering GI problems. While many of those patients had mainly respiratory illness, Dr. Anand Kumar, the lead author, said, "About 10 to 15 percent complained primarily of GI symptoms, and not the standard symptoms of cough and runny nose. That's unusual."

Dr. Jorge Parada, an infectious disease specialist and medical director of infection control for Loyola University Health Systems in Chicago, Illinois, says "It's underappreciated that even normal flu can give some GI symptoms, but this is an order of magnitude more. It's definitely a difference."

What we don't know is why, Parada says. "I don't know how much is because this is a novel virus, and so our whole body is out of whack trying to respond to it, or because this particular virus has a predilection for reproducing in the gastrointestinal tract." It may be that H1N1 is simply shedding light on a larger truth about viruses in general. "We're discovering more and more that respiratory viruses don't transmit only through respiratory symptoms. With SARS, a lot of the spread was linked to diarrhea. Avian flu was also spread through the GI tract."

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Dr. Joe Bresee, a pediatrician and epidemiologist with the CDC, says that H1N1 is not so different from seasonal flu in its mix of symptoms -- mostly fever, cough and muscle aches. What is different, he emphasizes, is that H1N1 is far more likely to cause severe illness in young and otherwise healthy people. Here's one stark comparison: Last week the CDC estimated that 540 children had died of H1N1 between April and October, before the usual flu season has even begun. Most years, pediatric deaths from flu rarely total 100 for the entire year.

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