'Rapidly fatal' swine flu kills in different ways: study

WASHINGTON — People who die of swine flu contract a "rapidly fatal" form of the disease and tend to die of lung injury, although it strikes different people in different ways, an autopsy study showed Thursday.

In the first study of its kind, researchers in Brazil examined 21 patients aged one to 68 who died in Sao Paulo with confirmed (A)H1N1 infections in July and August.

All 21 patients "presented a progressive and rapidly fatal form of the disease," the study, which will be published in the January 1 issue of the American Thoracic Society's "American Journal of Respiratory and Critical Care Medicine", found.

All were found to have died of severe acute lung injury, but with three distinct patterns of damage to the lungs, the study said, indicating to the researchers that swine flu "killed in distinct ways".

"All patients have a picture of acute lung injury," said the study's lead author, Thais Mauad, an associate professor of the Department of Pathology at Sao Paulo University.

But some of the patients had only acute lung injury while in others it was associated with necrotizing bronchiolitis -- severe inflammation of the small airway passages in the lungs -- and in others there was "a hemorrhagic pattern," Mauad said.

Patients with necrotizing bronchiolitis were more likely to also have a bacterial co-infection, while patients with heart disease and cancer were more likely to have a hemorrhagic condition in their lungs.

"It is important to bear in mind that patients with underlying medical conditions must be adequately monitored, since they are at greater risk of developing a severe H1N1 infection," said Mauad.

Sixteen of the patients had chronic underlying health conditions, such as heart disease or cancer, the study found.

The researchers also found evidence of an "aberrant immune response" in the lungs of some of the patients, which "suggests that an overly vigorous host inflammatory response triggered by the viral infection may spill over to and damage lung tissue, causing acute lung injury and fatal respiratory failure," said John Heffner, a former president of the American Thoracic Society.

P.S. Boost your immune system by eating Vitamin C and Vitamin D rich foods and fruits.

source

H1N1 flu activity down, H1N1 flu-associated deaths up-Is H1N1 getting more deadly?

The latest U.S. Centers for Disease Control and Prevention (CDC) swine flu update shows that H1N1 flu activity is decreasing once more, for the 6th week in a row. H1N1 swine flu-associated deaths, however, are going up. At the same time, reports of an H1N1 mutation that attacks the lungs and is resistant to the antiviral medication Tamiflu are circulating here in the U.S., as well as other locations around the world.

CDC swine flu update

According to the CDC swine flu update for December 11, 2009, key flu indicators are all decreasing, except for H1N1 flu-related deaths. Doctor's visits for flu and hospitalizations for flu have gone down for the 6th week in a row, and there are now only 14 states reporting widespread flu activity. At the same time, swine flu-related deaths have increased. This may result from the spread of a deadlier strain of H1N1 mutation that attacks the lungs and is resistant to the antiviral medication Tamiflu.

H1N1 mutation D225G/D225N

Learn more about the H1N1 mutation that attacks the lungs here:

New York swine flu victims show lung damage

Utah patient with lung hemmorhaging

Source of swine flu samples may explain low numbers of D225G

Swine flu vaccine ineffective against D225G in Ukraine

H1N1 deaths increase as mutations combine

Fatality in France due to mixture of swine flu mutations

Iowa medical examiner reports local H1N1 lung damage

Demographic information in Ukraine fatalities linked to D225G receptor binding domain

D225G swine flu mutation same as Spanish flu

Swine flu mutation H274Y/H274Y

Learn more about the swine flu mutation that is resistant to Tamiflu here:

Tamiflu-resistant H1N1 spreading

Swine flu pandemic complicated by antiviral resistance

Tamiflu doesn't work anymore

Tamiflu-resistant strain of H1N1 found around the world


P.S. BOOST your immunity by eating Vitamin C and Vitamin D rich foods and fruits.



source

H1N1 Swine Flu Less Severe Than Feared

H1N1 swine flu won't be as severe as was feared, but the pandemic is nothing to sneeze at, new predictions suggest.

When the fall/winter wave of H1N1 swine flu is over, it will have been no more severe than an average flu season, predict Harvard researcher Marc Lipsitch, DPhil, and colleagues from the U.K. Medical Research Council and the CDC.

"The good news is that ... the severity of the H1N1 flu may be less than initially feared," Lipsitch says in a news release.

There are some big asterisks next to that prediction:

* Most of the deaths and hospitalizations in a typical flu season are elderly people. Most of those killed or hospitalized in the H1N1 swine flu pandemic are children and young adults.
* Deaths attributed to seasonal flu include heart attacks, strokes, and other fatal conditions triggered by the flu. Nearly all deaths attributed to H1N1 flu are due to flu or to bacterial complications of flu.
* The new predictions would be four or five times higher in populations without access to mechanical ventilation or intensive care.
* All bets are off if the H1N1 swine flu shifts to older populations.

Even so, the new numbers are cause for relief if not for celebration. Before the 2009 H1N1 swine flu came along, planners were preparing for a pandemic with a case/fatality ratio of 0.1% -- that is, for one death in every 1,000 symptomatic infections.

The Lipsitch team now calculates that the H1N1 swine flu has a case/fatality ratio no higher than 0.048% -- and maybe seven to nine times lower, depending on the methods used for calculation.

"This is a serious disease," Lipsitch says in the news release. He noted that between one in 70 and one in 600 people who fall ill with H1N1 swine flu will be hospitalized.

The CDC has been careful not to characterize the severity of the 2009 H1N1 pandemic. The new predictions are very much in line with CDC's working estimates, says Beth Bell, MD, MPH, associate director for science at the CDC's immunization and respiratory disease center.

"This study sends the message that this is primarily a young person's disease and highlights the importance of taking advantage of this window of opportunity to get the vaccine and take preventive measures," Bell tells WebMD. "While most people who get this illness do OK, it can be very severe -- and the severity is concentrated in younger people."
H1N1 Swine Flu: Same Lung Damage as 1918 Flu

Highlighting the H1N1 flu's ability to turn deadly is a new study from James R. Gill, MD, from the New York City Medical Examiner's office, and Jeffrey Taubenberger, MD, PhD, of the National Institutes of Health.

Detailed autopsies of 34 people who died of H1N1 swine flu show that the virus typically kills by damaging the upper airways, although damage in the lower airways and deep lung was not uncommon.

Strikingly, the damage was very familiar.

"This pattern of pathology in the airway tissues is similar to that reported in autopsy findings of victims of both the 1918 and 1957 influenza pandemics," Taubenberger says in a news release.


P.S. Boost your immunity by eating Vitamin C and Vitamin D rich foods and fruits.



source

A "window of opportunity" for preventing another wave of Swine Flu

With activity of the pandemic H1N1 influenza virus declining across the country and the availability of the vaccine against it growing, health authorities have "a window of opportunity" for preventing or minimizing another wave of infections in the coming months, said Dr. Thomas R. Frieden, director of the Centers for Disease Control and Prevention, at a news conference this morning.

In planning for the short-term future, CDC officials conducted an informal poll of about a dozen internationally recognized flu experts, asking them if they thought there would be another wave of infection this winter. "About half said yes, half said no, and one said 'Flip a coin,' " Frieden said. "We don't know what the future will hold."

Figures released Monday showed that influenza activity had declined for the fourth consecutive week, with only 32 states now reporting widespread activity, down from 48 states a month ago. "Flu is going down, but it is far from gone," Frieden said. "The flu season lasts until May. Only time will tell what the flu season will bring."

Frieden said nearly 70 million doses of swine flu vaccine are now available, an increase of 9 million since Wednesday. "We are seeing that more people are getting vaccinated and protected and, as that happens, it becomes harder for the virus to spread," he said. But he also cautioned that, as more people become immune, that puts increasing pressure on the virus to mutate to a new form.

Frieden spoke briefly about the mutated strains of the virus that have been detected in some patients recently in Norway and China. There has been speculation that the mutant form may be somewhat more virulent because it is able to penetrate farther into the lungs. But Frieden noted that the virus has been observed sporadically during the pandemic and many scientists believe that it is a mutation that evolves in an infected patient, allowing the virus to burrow farther into the lungs. He noted that physicians have seen patients with the mutant strain deep in the lungs and a different strain higher up, suggesting that the mutant strain was created in situ. In any case, he added, there is no evidence that the mutant strain is spreading and "it is not likely to become the dominant strain."

P.S. Boost your immunity by eating Vitamin C and Vitamin D rich foods and fruits.

source