The United States has crossed the thresholds of the A/H1N1 flu epidemic as soon as the country officially began the flu season on October 4.

"Influenza is widespread in the country and illness, hospitalizations and deaths continue to increase," Dr. Ann Schuchat, director of National Center for Immunization and Respiratory Diseases, told reporters on Friday.

Earlier in the day, the Centers for Disease Control and Prevention (CDC) confirmed on its web site that 41 states had reported geographically widespread influenza activity, Guam and eight states reported regional influenza activity during the past week.

"It's unprecedented for this time of year to have the whole country seeing such high levels of activity," Dr. Schuchat explained at the CDC weekly press conference in Atlanta.

Most noticeable figure the CDC released on Friday is that the proportion of deaths attributed to pneumonia and influenza (P&I) based on the 122 Cities Report has crossed what is recognized as threshold of a epidemic.

From August 30 to October 10, 2009, according to the CDC latest statistics, 4,958 laboratory-confirmed influenza associated hospitalizations, 292 laboratory-confirmed influenza associated deaths, 15,696 pneumonia and influenza syndrome-based hospitalizations, and 2,029 pneumonia and influenza syndrome-based deaths, were reported to the federal agency.

The CDC confirmed 537 more deaths in the past week, bringing the death toll to 2,321 since the beginning of September.

"During week 40 (last week), 6.7 percent of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I." the CDC said, pointing out to the fact that "this percentage was above the epidemic threshold of 6.5 percent for week 40."

Meanwhile, visits to doctors for influenza-like illness (ILI) continued to increase all over the country, and overall, are far higher than levels expected for this time of the year.

Nationwide, 6.1 percent of patient visits reported through the US Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI), comparing 5.1 percent in the previous week.

"This percentage is almost three times the national baseline of 2.3 percent," the CDC experts explained.

Both the World Health Organization (WHO) and US National Respiratory and Enteric Virus Surveillance System (NREVSS) reported to CDC's Influenza Division that all subtyped influenza Aviruses being reported to CDC in recent weeks were 2009 influenza A/H1N1 viruses.

All these key figures indicate that the country as a whole has crossed the thresholds of the epidemic of A/H1N1 virus and the CDC officials and experts are urging people to get vaccination as soon as possible.

A nationwide campaign to inoculate at least half the US population -- and perhaps the entire country -- against the new A/H1N1 virus started last week with doctors, nurses and other health workers in a number of states.

The federal government has spent 2 billion dollars to purchase about 250 million doses of vaccine and has pledged to buy enough to immunize every American if there is enough demand.

However, the CDC officials disclosed on Friday that delivery of the A/H1N1 flu vaccines has been delayed in some states because companies cannot make them as fast as they had hoped.

Dr. Schuchat said that while 40 million doses had been anticipated for the end of October, only about 28 to 30 million doses would be available.

"Some of the manufacturers have let us know that the production of vaccine is likely to be a bit delayed in terms of the number of doses they were expecting to have out in future weeks," Schuchat admitted.

Even there will be enough production and delivery of vaccine, only 53 percent of adults said they plan to get vaccinated, with 41 percent saying they won't, according to a telephone poll of 1,042 people conducted by the Harvard University School of Public Health last month.

About 70 percent of parents said they will get the vaccine for their children. Nearly 30 percent parents said they are concerned about side effects from the new vaccine even though nothing serious has turned up in tests so far.

Health and Human Services Secretary Kathleen Sebelius last week appealed for widespread inoculation against the A/H1N1 flu, vouching unconditionally for the vaccine and saying that "we know it's safe and secure."

Special A/H1N1 flu vaccination clinics at schools are being planned in many states. Experts believe that children are the main spreaders of infectious disease, and if large numbers are coming down with the new flu, there are ripple effects for everyone else.

"But the delays that the manufacturers have let us know will have an impact, a substantial impact for the states in their planning efforts," Schuchat predicted.

(Xinhua News Agency October 17, 2009)