The flu fighters

Once the H1N1 influenza outbreaks begin - and Maryland health officials have no doubt that they will - this series of nondescript scientific laboratories, located past security guards instructed not to let anyone in without an official escort, will certainly be humming.

Here, inside the state office complex on Preston Street in Baltimore, dozens if not hundreds of polyester swabs will arrive each week, containing what doctors believe is evidence of swine flu's resurgence. Lab workers will then determine whether it is the flu - H1N1 or seasonal, or something else entirely - and whether the virus seems to be gaining strength. One of the most important roles these labs may play in the H1N1 pandemic will be determining whether this new flu has developed resistance to the antiviral medications stockpiled to make the sick well again.

Maryland is one of a dozen states that will be testing samples of the swine flu virus for hints that it has mutated. As summer turns into fall, what most worries flu experts is that the only tool to fight the H1N1 virus will no longer be available to at least slow the march of the disease that could affect as many as half of Americans.

"That information is very valuable," said Dr. Robert A Myers, deputy director of the state public health laboratory. "We're trying to get this information in quickly."

Last week, in its first week of drug resistance testing, none of the 20 samples examined at the Maryland lab had become resistant to Tamiflu or the other antiviral medications. A handful of tests around the world have revealed a virus that is resistant to these drugs, but so far they have been isolated cases and do not appear to have spread.

Drug resistance has been a problem in the past. In March, a study in the Journal of the American Medical Association showed that more than 98 percent of the influenza A virus that circulated last winter was resistant to Tamiflu. If prescribed within 48 hours of the onset of symptoms, antiviral medicines can reduce the severity of flu and shorten its duration by about a day.

Yesterday, reporters were given a tour of the facility that will provide some of the first confirmation that swine flu, which never left Maryland, is picking up steam. Doctors say they might be seeing an uptick in swine flu cases in Maryland, which peaked in June. There have been no cases of seasonal influenza detected in the state since spring.

More than 550 people in the United States have died from swine flu, including seven in Maryland and three in Virginia. Roughly 36,000 people die in the United States each year from seasonal flu.

As Myers began to explain his lab's different testing processes - one that takes a single workday, another that can take three days and another that can take weeks - he said: "I try to dispel the 'CSI' fact that everything takes 15 minutes."

He showed how lab workers put the virus in test tubes and pipettes and mix them with chemicals to determine the presence and type of flu. He later showed a lab where the job is to amplify one of the genes on the virus, particularly where Tamiflu works, to look for mutations in the genetic code. In another lab, if a sample comes back negative for flu, workers will grow more virus in culture to determine what made the person sick.

Not every flu swab taken in Maryland will end up here. The public health lab tested every suspected case in the spring, when swine flu was discovered. Now, they test a fraction of the suspected cases of H1N1 virus.

They look at swabs from a series of what are called "sentinel" providers - doctors across the state who act as a sort of heads-up that there is flu in the community - as well as from suspected outbreaks when they occur, so that officials will know how the disease is spreading. They will also examine samples from patients with severe cases, including those who are hospitalized and from people they believe have died from the flu. Those will allow workers in Myers' lab to see if there is something about the flu that is changing and making it more likely to cause severe infection.

"If we see something that's very divergent, we'll be forwarding information" to the federal Centers for Disease Control and Prevention in Atlanta, Myers said. "We're constantly trying to keep ahead of the virus, which is very difficult to do. It's constantly changing."

Thomas Frieden, the CDC's director, told reporters in a briefing yesterday that what officials in Maryland are seeing - continued sensitivity to antiviral drugs and few significant mutations - is what is being seen around the world.

"The good news is that, so far, everything that we've seen, both in this country and abroad, shows that the virus has not changed to become more deadly," Frieden said. "That means that although it may affect lots of people, most people will not be severely ill."

But Frieden cautioned that the virus is unpredictable and said officials will continue to vigorously monitor whether it is mutating and how people are being affected by it.

"We have to be ready and prepared to change our approach, depending on what the virus does," he said.

Through federal dollars set aside for preparing for an H1N1 pandemic, the Maryland lab has received new equipment to help it conduct its testing more quickly and efficiently in case it is flooded with virus samples.

The lab is also prepared to ramp up its work if the need arises. Myers said employees have been cross-trained to do the various tasks needed as part of the testing processes, and that lab workers and scientists from the Maryland Department of Agriculture and some from the University of Maryland are on standby if additional help is required.

The lab sees 500 to 1,000 flu samples during a typical flu season. It has tested 2,200 since April.

"If we have to do this for month after month after month, we need to be like a football team with a depth chart," Myers said.

Baltimore Sun reporter Kelly Brewington contributed to this article.