Encouraging news on H5N1

[Vic303]

From REUTERS:

Blood of bird flu victims offers treatment: study

 

By Maggie Fox, Health and Science EditorTue May 29, 6:15 AM ET

 

Blood taken from four Vietnamese survivors of the H5N1 bird flu virus protected mice from several strains of the virus, researchers reported on Monday.

 

Their finding may offer a new way to treat bird flu infections in people and another potential weapon to stockpile ahead of a feared pandemic of avian influenza.

 

The researchers created human monoclonal antibodies -- immune system proteins -- trained to recognize the H5N1 virus.

 

"We have shown that this technique can work to prevent and neutralize infection by the H5N1 bird flu virus in mice," said Dr. Cameron Simmons, of the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam.

 

The approach is not new. Antibodies taken from human blood can treat or prevent a number of infections, including hepatitis, rabies and respiratory syncytial virus.

 

"The transfusion of human blood products from patients recovering from the 1918 'Spanish 'flu' was associated with a 50 percent reduction in influenza mortality during the pandemic," the researchers wrote in their study, published in the Public Library of Science journal PLoS Medicine.

 

Antibodies are immune system proteins that recognize and help orchestrate an immune attack on bacteria, viruses and parasites.

 

Monoclonal antibodies are specially engineered to attack a certain protein -- in this case, one found in H5N1.

 

Dr. Kanta Subbarao of the National Institute of Allergy and Infectious Diseases; Dr. Antonio Lanzavecchia of the Institute for Research in Biomedicine in Bellinzona, Switzerland; and Simmons and colleagues worked on the study.

 

It is freely available online at: http://medicine.plosjournals.org/perlserv/...t=get-document& doi=10.1371/journal.pmed.0040178.

 

"The four adult blood donors in this study were diagnosed with highly pathogenic avian influenza H5N1 infection between January 2004 and February 2005 at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam," the researchers wrote.

 

Lanzavecchia extracted antibody-producing white blood cells, called memory B cells, from the samples. He used a treatment he has developed to make them produce antibodies continuously.

 

Subbarao's lab screened these for antibodies that could neutralize H5N1. The researchers produced more of these antibodies and then tested mice infected with lethal doses of

 

H5N1.

 

Most of the mice who got the new antibodies survived, while all untreated mice died, the researchers said.

 

The antibody treatment protected the mice as late as 72 hours after infection. This is important because antiviral drugs needs to be given quickly after infection -- best within 48 hours -- to be effective.

 

More tests would be needed but it would be useful to have another treatment alongside Tamiflu and other antiviral drugs in case of a pandemic.

 

The H5N1 avian influenza virus has killed 186 people out of 307 infected since 2003, according to the World Health Organization.

 

It mostly affects birds but if it acquires the ability to pass easily from one person to another, it could spark a pandemic that would kill millions.

 

Vaccines take months to formulate and antivirals are in short supply.

 

[Vic303]

Also this from Reuters today:

 

New device detects avian flu strains fast

 

By Maggie Fox, Health and Science Editor2 hours, 42 minutes ago

 

A new device can quickly detect 92 different viruses, including several strains of the feared H5N1 avian flu virus or other emerging new infections, U.S. researchers reported on Tuesday.

 

They said their mass spectrometer device can also be used in big hospitals to watch for outbreaks of dangerous drug-resistant infections.

 

"Therefore, we can keep up with the virus, even if there is a new variant of H5N1 circulating that is different from last year's," Ranga Sampath, executive director of Ibis Biosciences Inc., told Reuters.

 

Carlsbad, Californina-based Ibis, a division of Isis Pharmaceuticals,, worked with U.S. military researchers to fine-tune their device and test it against a range of flu viruses.

 

Flu is difficult to monitor because spot tests cannot identify the precise strain. When testing people for the H5N1 flu virus, the World Health Organization uses specialized labs that can spend weeks first growing and then testing tiny samples of virus.

 

The new detector, called the T5000, works in just four hours to identify the precise strain, the company reported in the Public Library of Science.

 

Ibis researchers worked with teams at the Naval Medical Research Unit in Cairo, Egypt, U.S. Army Medical Research in Infectious Diseases at Ft. Detrick, Maryland, Johns Hopkins University in Baltimore and other groups to test the T5000.

 

"We detected and correctly identified 92 mammalian and avian influenza isolates, representing 30 different H and N types, including 29 avian H5N1 isolates," the company said.

 

The device was 97 percent accurate in identifying the flu strain infecting 656 people who gave specimens between 1999 and 2006, it said.

 

WHO and the U.S. Centers for Disease Control and Prevention have been calling with greater and greater urgency for new and better diagnostic tests for flu and other microbes.

 

WATCHING FOR A PANDEMIC

 

H5N1 is especially feared now because it has killed 186 people out of 307 infected. Although it only rarely infects humans, it could mutate into a form that transmits easily from one person to another.

 

That would cause a pandemic that could kill millions in a few months, or something else could. Experts would like quick tests so they know what is infecting people who become suddenly or mysteriously ill.

 

"Everybody's worried about H5N1. It might be H5N1, or it could be any other avian flu off the charts of everybody's radar at the moment," Ibis's Dave Ecker said in a telephone interview.

 

"Molecular tests are like launching a ship. You just can't keep up with either the breadth of infectious agents or the way they mutate and change over time," Ecker added. "We design the test for whole groups of microbes or all families of microbes."

 

The T5000 first uses a process called polymerase chain reaction or PCR to amplify the genetic material in a sample of virus or bacteria so it can be tested. It then uses an advanced mass spectrometry technique to identify the sample.

 

Ecker said the device is not portable and is not cheap.

 

It is about 6 feet long and three feet tall (two meters long and a meter tall) . It costs between $400,000 and $500,000, so only large institutions or governments could invest in one.

 

But Ecker said using the device to screen for outbreaks of drug-resistant bacteria could save a big hospital close to that much in a year, because such infections are difficult to control and very expensive to treat.