Two children died from influenza in New York in the past two weeks, just as 11 states reported widespread flu activity across the U.S.

The victims were a 7-month-old infant and a 7-year-old who were from the New York counties of Monroe and Orange, respectively. The two tested positive for the influenza A and influenza B strains of the virus.

Although this debilitating seasonal scourge usually peaks in mid-February, this year health officials are already on alert.

The complications seen in recent years, such as the rise in pediatric flu deaths with bacterial infections, have been compounded by concerns of a drug-resistant strain that has cropped up in various countries. While the season has not been severe thus far, flu experts at the U.S. Centers for Disease Control and Prevention are not taking any chances.

“We are intensifying our surveillance for these resistant strains,” said Dr. Joseph Bresee, chief of the epidemiology and prevention branch in the CDC's influenza division. “So we’re requesting that more samples are sent to CDC to see if this is changing and becoming more common.”

All of the drug-resistant viruses are found within the H1N1 strain, one of the three main types of influenza affecting humans this year. Of those strains, 6.7 percent have been found to be resistant to Tamiflu (oseltamivir), an antiviral medication that has been shown to shorten the duration of the flu when taken within two days of infection.

Similar percentages of the drug-resistant strain were also found in Europe and Canada. “Historically, resistance to Tamiflu has been quite rare, less than one percent,” Bresee said. “Now that it’s higher, it’s not a cause for alarm, but we’ve taken notice of it.”

Health officials still insist the best way to stay protected is to receive a flu vaccine. A record 132 million flu shots were made at the beginning of the season, and are still available nationwide. Bresee said the vaccine even probably offers some protection against the Australian strain that was identified too late to be included in this year’s vaccine.

Although some health experts say it is too early to tell whether this flu season will follow in the footsteps of last year’s mild outbreak, some clinicians are already seeing more cases.

“The ERs have been swamped,” said Dr. Fred Pelzman, associate professor of medicine at New York-Presbyterian Hospital/Weill Cornell. “Once it’s in the primary care clinics, that’s when you know it’s going to be a big season.”

Pelzman pointed out that most people do not even want to leave the house when they have the flu, so when they’re coming into the doctor’s office in large numbers, it’s a sign the flu is hitting hard.

But it is also not too late to get a flu shot. “We’ve had unlimited access and had an amazing number of people getting vaccinated,” Pelzman noted.

It takes about two weeks to have full protection, but doctors agree it is still worthwhile to be vaccinated as the season begins to deliver its potentially fatal blows.

An Outbreak?

Numbers of deaths are hard to pin down for flu season, but the CDC estimates it claims 36,000 lives in the U.S. annually. The last three months of 2007 saw death rates due to flu and pneumonia comparable to the past three years. However, just one week in January 2008 saw an increase to 954 reported deaths from those two infections, which is above the threshold for a major outbreak.

One of the most startling trends in recent years is the rise of pediatric flu deaths associated with bacterial infections, and in particular Staphylococcus aureus, or staph. The 2006 – 2007 flu season had 73 deaths from influenza in children, 69 of which had bacterial co-infection. Staph accounted for nearly half of those bacterial infections, a five-fold increase from previous years.

The two children in New York State who died last week were not reported to have bacterial co-infections, but the New York State health department said full reports have not been submitted to the CDC. The federal agency requires that all deaths for children under 18 get reported, and they issued an advisory for doctors to test for bacterial infections in children hospitalized with flu-like symptoms.

But like adults, getting definitive numbers on children who succumb to the flu is difficult. “The exact number of kids who die,” Bresee said, adding that, “we don’t exactly know.”

The CDC is closely monitoring the relationship between influenza and bacterial infections, but they have not produced any reports to explain the increase.

Although the past few years have been mild, doctors warn that no one should be lured into a false sense of security this year. “It is a very serious illness,” Pelzman said. “It causes a lot of sickness, a lot of lost work, and lost life.”