CDC: U.S. H1N1 swine flu cases approach 1500

The number of case of confirmed and probable H1N1 swine flu cases in the U.S. now stands at 1486, according to the U.S. Centers for Disease Control and Prevention (CDC).

Most of the illnesses have been mild or moderate and only 35 of the confirmed cases and 17 probable cases have needed to be hospitalized, the CDC’s Acting Director Dr. Richard Besser said in a Webcast press briefing Wednesday.

However, there have now been two deaths in the U.S.: a 23-month-old child from Mexico who had been flown to Texas for care and a 33-year-old woman who died earlier this week also in Texas.

“This reminds us that this infection can be very serious, and it’s one we need to take very seriously,” Dr Besser said.

So far younger people seem to be more susceptible to the new virus with 58% of cases being younger than 18.

Usually, the typical seasonal flu that strikes in the fall and winter hits the elderly and very young hardest.

Why this virus seem to be hitting younger people harder is not known, Dr. Besser said.

It may be that young people who had gone to Mexico for spring break simply contracted the disease first and then spread it to their friends at school.

If that’s the case the first cases are appearing among the young first, Dr. Besser said, and with time the virus will work its way into the older population.

But it is also possible that older people were exposed to a similar virus in the past and that exposure has given them a degree of immunity that makes it possible for them to resist the virus more effectively, he said.

While the new virus has not proven to be as dangerous as was once feared, “we need to remain vigilant and not let up” because they virus could become more virulent, Dr Besser said.

“One of the hallmarks of flu viruses is that they undergo constant and dramatic change,” he said.

In the coming months, scientists will be watching for such changes as the virus moves into the Southern Hemisphere, where flu season is just beginning, Dr. Besser said.

“What takes place there is incredible important,” he said. “How does the virus compete with other viruses that are circulating in those countries? Does it change? Does it mutate? If so, in what way? Does it develop resistance (to anti-viral drugs)?”

Dr. Besser said work was already underway so that a vaccine will be ready in the U.S. in time for the next flu season. Whether the virus will return, however, cannot be predicted, he said.

“We could see the current strain fizzle out and never come back again; we could see the current strain come back as it currently is; or we could see it mutate and change and come back in a more severe form,” he said.

So far, however, the virus has shown a “fair amount of stability”, he said.

In related news: The U.S. Food and Drug Administration announced it had approved a new influenza vaccine production facility owned by Sanofi Pasteur.

For more information about Swine flu:

Swine Flu and You
http://www.cdc.gov/swineflu/swineflu_you.htm (English)
http://www.cdc.gov/swineflu/espanol/influenza_porcina_usted.htm (Espanol)

Facts about Swine Flu
http://www.cdc.gov/swineflu/key_facts.htm (English)
http://www.cdc.gov/swineflu/espanol/swine_espanol.htm (Espanol)

Preventing the Flu
http://www.cdc.gov/flu/protect/habits.htm?s_cid=swineFlu_outbreak_internal_003 (English)
http://www.cdc.gov/flu/protect/espanol/habits.htm (Espanol)

Latest news from CDC
http://www.cdc.gov/swineflu/ (English)
http://www.cdc.gov/swineflu/espanol/ (Espanol)

Symptoms and precautions from the Washington State Department of Health
English (PDF) 
Spanish (PDF)
Chinese (PDF)
Korean (PDF)
Russian (PDF)
Vietnamese (PDF)
Large type (PDF)

Tags: 2009/H1N1, A/H1N1, Besser, CDC, Flu, H1N1, Influenza, Influenza A, Swine Flu

Category: Influenza