From The Washington Post

Seasonal influenza is spreading widely throughout the United States, with nearly half the cases caused by strains of the virus that are not directly covered by this year’s flu vaccine.

Whether the winter will end up being worse than usual remains to be seen. Flu mortality in adults has been higher than in the past two years, but deaths in children — an important marker of severity — have been rare.

Nevertheless, this winter is likely to be one of the few times that public health experts lose the bet they make each year when they devise the formula for the flu vaccine — eight months before the virus starts circulating in the fall. Experts must decide on the formulation then because of the time it takes to produce mass quantities of the vaccine.

“Most years, the prediction is very good,” said Joseph S. Bresee, an influenza epidemiologist at the Centers for Disease Control and Prevention. “In 16 of the last 19 years, we have had a well-matched vaccine.”

But probably not this time.

Each year, the vaccine contains representatives of the three huge families of flu virus that are currently circulating. They are two main types of influenza A, H1N1 and H3N2, and influenza B.

The viruses in the vaccine are either dead or, in the case of the nasal-spray flu vaccine developed four years ago, crippled so they cannot cause illness. What they can do is stimulate the body’s immune system to mount a defense, sometimes a lifesaving one, should the virus be encountered.

The viruses in each of these lineages are constantly changing through mutation. Inevitably, one appears that is different enough from its ancestors that a person protected against them, through either previous infection or vaccination, is not protected against the new variant.

Such an emergent virus easily finds victims because almost nobody has immunity against it.

A version of this scenario — muddied, of course, by real life — apparently happened twice this year.

A new strain of H3N2 virus was identified in Brisbane, Australia, last February, a few weeks after the components of this winter’s vaccine were chosen. (Later studies showed it had been around at least since January 2007.) But it was too late to substitute “Brisbane/10″ — the short version of its name — for the H3N2 strain that had been in the vaccine since the 2006-2007 season, called “Wisconsin.”

Even if there had been time, it was not certain the Brisbane strain would take off and spread. It has.

From the start of flu season until the beginning of February, 34 percent of flu viruses taken from patients around the country were Brisbane strains.

At the same time, a strain of influenza B called “Yamagata,” which is significantly different from the “Victoria” B strain in the vaccine, was taking off.

About 16 percent of all flu samples this winter are influenza B, and of them 93 percent are Yamagata.

Together, the Brisbane and Yamagata strains are accounting for 44 percent of all flu samples this winter — and neither is in the vaccine.

That does not mean the vaccine is of no benefit. The immunity conferred by the Wisconsin strain may protect somewhat against its Brisbane descendant. A vaccinated person may have milder symptoms. But the vaccine is unlikely to prevent infection altogether in lots of people.

A study done by the Defense Department last year after Brisbane emerged found that it was 52 percent effective in preventing infection. That is much lower than the 70 to 90 percent protection provided by a well-matched vaccine given to healthy young adults. But it is not useless, either.

“It wouldn’t be optimal, but there should be a measure of protection, based on our past experience,” said Nancy J. Cox, the chief flu virologist at CDC.

The agency is doing three studies to determine with precision how much protection the vaccine is providing against the Brisbane strain this winter. Results of the first may be available in a few weeks.

The vaccine’s protection against the Yamagata strain is probably also poor. The best evidence that Yamagata is not well covered by the vaccine is that it is just about the only strain of influenza B around.

“That probably indicates that the effectiveness of the vaccine may be less than ideal,” Bresee said.

Early this season, most of the virus samples collected from patients were from the H1N1 family and were adequately protected against by the vaccine. There were few H3N2 or influenza B viruses circulating.

Now, however, the new strains of those latter two types have arrived, and they are encountering millions of people who are vulnerable because they have not been vaccinated, or partly vulnerable because the vaccine offers partial protection. As a result, the new strains have taken off.

The portion of each week’s samples made up of H3N2 viruses has been rising steadily for more than a month. For the past two weeks, it has exceeded the fraction containing H1N1 viruses, and it has not yet peaked. In four of the nine surveillance regions across the United States, H3N2 viruses are now more common than H1N1 viruses.

All of which suggests the flu season may be far from over.

As a defense, CDC officials say vaccination, even now, may be of some benefit. They say antiviral drugs can both prevent infections and lessen their severity, and are especially useful in people at high risk for flu complications because of other illnesses. They also urge people to cover their coughs, wash their hands often and stay home if they are sick.

Meanwhile, influenza virologists from around the world will gather in Geneva this week to decide the formula for next year’s vaccine.

Norovirus can live on surfaces for several days, experts say

From HealthDay

The highly contagious norovirus, often called the stomach flu, can be passed from one person to another through contact with commonly shared items such as computer keyboards and computer mice, U.S. health officials report.

The virus, which is common in winter and is the most frequent cause of outbreaks of vomiting and diarrhea in the United States, is often contracted in schools, at work and on cruise ships.

On Thursday, the U.S. Centers for Disease Control and Prevention reported on a norovirus outbreak at a Washington, D.C., elementary school last February in which some of the victims picked up the virus from contaminated computer equipment.

“There is evidence that shared objects and surfaces help transmit disease,” said Dr. Shua Chai, a CDC epidemiologist and co-author of the report, published in the Jan. 4 issue of the CDC’s Morbidity and Mortality Weekly Report.

“This is the first time that we have demonstrated that keyboards and computer mice can be a source of transmission of norovirus,” he added.

Of the 314 students and 66 staffers at the D.C. school, 103 came down with the illness — 79 students and 24 staff members. To find the sources of contamination, samples were taken from various surfaces around the school. In one first-grade classroom, a computer mouse and keyboard tested positive for norovirus, according to the report.

The virus can live on surfaces for several days, Chai said. To prevent infection with the virus, people should wash their hands after using shared objects, and computer keyboards and mice should be disinfected regularly with diluted bleach, he said.

“In addition, people who are ill should stay home for one to three days after they have had their last symptom, because they continue to shed the virus and can still contaminate objects,” Chai added.

One infectious disease expert said norovirus is a common infection, second only to the common cold.

“These outbreaks are extremely common, and they occur in a variety of settings,” said Dr. Pascal James Imperato, distinguished service professor, chairman of the department of preventive medicine and community health, and director of the master of public health program at the State University of New York Downstate Medical Center, in New York City.

Most outbreaks are food-borne, Imperato said. “A smaller percentage are due to person-to-person contact, and an even smaller proportion are water-borne,” he said. “Outbreaks in schools account for about 12 percent of all the outbreaks.”

Contamination of surfaces such as computer keyboards is fairly common, Imperato added.

Norovirus causes severe vomiting and diarrhea that can last for several days. The virus is usually not serious, and most people get better without treatment. However, it can be life-threatening to infants, older people and those with weakened immune systems.

In New York City, an outbreak of norovirus has been ongoing since November. Some 500 infected people have been showing up each day at emergency rooms around the city, health department officials said.

“The best way to stop the spread of norovirus is to wash your hands regularly with soap and stay home from work or school if you are sick,” Dr. Sharon Balter, director of enteric disease for the New York City Health Department’s Bureau of Communicable Disease, said in a prepared statement. “Norovirus is common at this time of year and is not serious for most people, but it is important to take these steps to keep others from getting sick.”

Imperato agreed. “Hand-washing remains the foundation of preventing the spread of norovirus,” he said.

From USATODAY.com

Thirteen states don’t have adequate plans to distribute vaccines and antidotes in the event of a flu pandemic or a bioterrorism attack, according to a health preparedness report out Tuesday.

The Trust for America’s Health, a non-partisan research organization, found that states have made significant progress in preparing for major health emergencies since 9/11 and the anthrax attacks of 2001. But large gaps in readiness still exist, the report said.

“Emergency health preparedness is on the national radar, but until all states are equally well prepared, our country is not as safe as it can or should be,” said Jeff Levi, director of the Trust.

The Trust used 10 indicators to rate a state’s preparedness. They ranged from the state’s ability to distribute drugs from the national stockpile to whether the state uses a disease surveillance system that’s compatible with the government system at the federal Centers for Disease Control and Prevention (CDC) in Atlanta.

Seven states got a perfect score: 10 out of 10. Six were at the bottom of the spectrum, scoring six out of 10.

FIND MORE STORIES IN:Centers for Disease Control and Prevention | Emergency | Flu | Irwin Redlener

Among the findings outlined in the report:

Flu vaccination rates decreased among the elderly in 11 states during the past year.

Seven states and Washington, D.C., lack sufficient capacity to test for biological threats.

21 states don’t give liability protection to health care workers who volunteer during emergencies.

Six states cut their public health budgets between fiscal 2005 and fiscal 2006.

Seven states haven’t joined a federal program to buy lower-cost antiviral drugs.

Richard Besser, director of Terrorism Preparedness and Emergency Response at the CDC, said states have made tremendous strides in the past five years. In the 13 states that don’t have plans to distribute drugs from the stockpile, various creative approaches are being tested, he said.

Among them: Giving employers caches of drugs to distribute during a crisis and having postal workers deliver drugs house to house.

Long-term, Besser says he’s worried about how to keep emergency preparedness fine-tuned in the absence of an attack or a major outbreak.

“A well-working public health system is invisible to the community, but it’s absolutely essential,” he said.

Irwin Redlener, associate dean of Public Health Advocacy and Disaster Preparedness at Columbia University’s Mailman School of Public Health, said he’s particularly concerned about hospitals and their ability to deal with sudden surges of large patients during a disaster.

“Hospitals have become way stations for the millions of Americans that don’t have health care, so emergency rooms already are overcrowded,” Redlener said.

“I shudder to think what would happen in the event of a large-scale disaster.”

The infection can cause severe respiratory disease in otherwise healthy adults. Scientists don’t know what has caused the outbreaks.

From Los Angeles Times

A virulent new form of a common cold virus has killed 10 people and hospitalized at least 53 since May 2006, the national Centers for Disease Control and Prevention reported Thursday.

The adenovirus serotype 14 virus has sickened more than 360 people in Texas, Oregon, Washington and New York, the report said. One of the largest outbreaks occurred at Lackland Air Force Base in Texas, where 106 soldiers were infected and one died.

“Adenoviruses have been known to cause severe disease in the very young and the very old and people with medical problems,” said a coauthor, Dr. John Su, a CDC infectious diseases investigator. “What brought this to our attention is that it can cause severe respiratory diseases in otherwise healthy adults.”

Researchers did not know what caused the virus to mutate or what sparked the outbreaks.

Adenoviruses come in 51 distinct types, causing a range of illnesses that include pink eye, bronchitis and gastrointestinal problems. There is no drug specifically designed for adenovirus infections, but most infections resolve on their own.

Adenovirus 14 tends to cause colds or respiratory illnesses and can be spread by contaminated surfaces and through air in a cough or sneeze, Su said.

It caused respiratory disease among military recruits in the Netherlands in 1955 but has only been detected sporadically since.

The strain of adenovirus 14 involved in the recent outbreaks is genetically distinct from the 1955 strain, Su said.

The largest outbreaks occurred at four Air Force bases in Texas.

In addition to the cases reported at Lackland, three bases in Texas reported 220 adenovirus-14 infections between March and September.

The outbreaks at the military bases “may potentially have to do with crowding,” Su said.

Oregon identified 31 cases, and the median age of those who fell ill was 53, which is younger than the typical age for patients with severe disease, Su said. Seven people, with a median age of 64 years, died from severe pneumonia.

Washington identified four cases; one, a middle-aged patient with AIDS, died. New York reported one death in a 12-day-old infant.

The CDC report follows a study last month from the Naval Health Research Center in San Diego that found infections at military bases in California, Missouri, Illinois and Georgia in addition to Texas, starting in early 2006.

At least 37 people at the Marine Corps Recruit Depot in San Diego got sick with adenovirus 14, the paper said.

The paper’s lead author, David Metzgar, a microbiologist, said his group had found evidence that the same virus has circulated in civilians in California since 2001.

Metzgar, who also contributed to the CDC report, said this new variety of adenovirus 14 might be causing severe outbreaks because people today had not been previously exposed to this strain.

“My personal feeling is it’s not particularly bad, but it’s just new,” he said. “Its newness is generating a rather wicked epidemiological profile.”

FromUSATODAY.com

In the early weeks of a flu pandemic, the first to receive scarce supplies of vaccine will include the military, medical and emergency workers, pregnant women and babies,nearly 23 million people,under a draft federal plan to be outlined Tuesday in Washington.

At the back of the pack, in a pandemic of the sort that killed 500,000 Americans in 1918, would be 74 million sick and elderly adults and 122 million healthy people ages 19-64.

The plan was developed by a government working group that met with scientists and business and community representatives over several months. It provides guidelines for pandemic planners and offers a glimpse into some agonizing decisions that could be necessary in the context of a swift-moving infectious disease and a shortage of protective vaccine.

“Once a pandemic starts, vaccine will come rolling off the line in lots, so there has to be a priority scheme on who would receive it first,” says William Raub, science adviser to Health and Human Services Secretary Michael Leavitt.

“The committee tried to identify those who would be critical to national and homeland security, critical to fighting the flu itself, and critical to maintaining a functioning society.”

In meetings, the working group and other participants highlighted pregnant women and children as a priority, the report says. This also is an efficient use of vaccine, it says, because immunizing pregnant women protects their newborns, too, and children need lower doses, stretching limited supplies.

Jeffrey Levi of Trust for America’s Health, an advocacy group, says the report, being presented at a meeting of the National Vaccine Advisory Committee, is “logical,” but more discussion is needed to refine how vaccine will be distributed and used in different populations.

The plan provides for changes based on local needs and severity. In mild pandemics, which cause fewer deaths among the young and healthy, it makes sense to move those at risk of serious illness, such as the elderly and people with chronic illnesses, higher on the list, Raub says.

For instance, the plan doesn’t target such groups as banking, food and agriculture, postal or chemical workers in a mild or moderate pandemic. But in a severe pandemic, those groups are in the third tier for vaccination, just behind electricity, natural gas, communications and water personnel and essential government workers.

“The more severe the pandemic, the more aggressive people would be in trying to protect critical workers,” Raub says. “But if it’s at the milder end, critical workers would be a smaller group, so there would be more emphasis on getting everyone vaccinated. The disruption of society wouldn’t be the same.”

A pandemic occurs when a new flu virus emerges that can spread as easily as the seasonal flu, which causes 200,000 hospitalizations and 36,000 deaths each year. Because it’s different from known flu viruses, people have no built-in immunity, so everyone is at risk.

Planning for the next possible pandemic moved into high gear when a new flu strain, H5N1, also known as bird flu, emerged 10 years ago and began causing illness and death in humans. The World Health Organization warned then that the world could be “on the brink” of the next pandemic. Since 2003, WHO has documented 331 human cases, including 203 deaths from the virus, most of them in Southeast Asia.