duncan228
01-08-2009, 01:39 AM
Two-fisted flu season is hitting S.A. (http://www.mysanantonio.com/news/local_news/Two-fisted_flu_season_is_hitting_San_Antonio.html)
By Don Finley - Express-News
Local health officials alerted doctors Wednesday that two influenza strains now infecting San Antonians both require a little special handling.
While flu season still is mild here, two different strains are circulating almost evenly. One of them is similar to a strain contained in this year's vaccine, A/Brisbane.
Those who have had a flu shot are fairly well protected against that strain, officials say. But for those who aren't vaccinated, or who get sick anyway, the remaining options now are a little more limited.
The Centers for Disease Control and Prevention reported three weeks ago that the A-type strain, which falls within the family of flu viruses known as A/H1N1, is resistant to the antiviral drug Tamiflu — typically given to people after they catch the flu to reduce the severity of symptoms.
Health officials are recommending doctors use zanamivir, sold under the brand name Relenza. While two older antivirals work against that flu strain too, they're ineffective against B-type strains like the one also making people sick this flu season.
That's even more important because this year's vaccine apparently doesn't protect well against the B-type flu now circulating. About 70 percent of the B-type flu cultures from across the country tested by the CDC did not match up with the vaccine.
“We're telling physicians that perhaps they need to use Relenza instead of Tamiflu, because Relenza will cover all (the circulating flu strains), both the A's and the B,” said Roger Sanchez, an epidemiologist with the Metropolitan Health District.
Many doctors offices use a rapid test that indicates only whether someone has the flu. It doesn't distinguish between types of flu.
And even though the flu shot isn't completely protective against the B-type strain, Sanchez stressed it still offers good protection the A strain and about 30 percent of the B's. It's still a good idea to get a flu shot if people haven't already, he added.
Health officials say those who should definitely get a flu shot are children between 6 months and 18 years of age, adults 50 and older, pregnant women, those with certain chronic illnesses such as diabetes and asthma, health care workers and household contacts of those at high risk.
Antiviral-resistant flu strains have been a growing problem. In 2006, the CDC recommended doctors stick to the newer antivirals because of growing resistance to the older-line drugs amantadine and rimantadine among another common family of flu viruses, A/H3N2.
And last flu season, about 10 percent of the A/H1N1 viruses were resistant to Tamiflu.
While the antiviral drugs can be effective, they work best when they're given within a day or two after symptoms begin.
Even though the flu hasn't yet sickened people in large numbers here, a lot of other viruses are circulating, said Kathy Lawless, supervisor of the virology lab at the University Health System.
“About 25 percent of the samples we receive are positive for other respiratory viruses,” Lawless said.
They include two types of parainfluenza, adenovirus, respiratory syncytial virus or RSV, and human metapneumovirus — a virus first identified in 2001 similar to RSV.
Lawless said flu season is running a little later this year than last, when it was in full swing by this time.
Flu is the most serious of the respiratory viruses that circulate in winter months, killing 36,000 Americans on average each year and hospitalizing 200,000.
Symptoms often include high fever, body ache, headache, fatigue, a runny nose, sore throat and cough.
THE PROBLEMS
Health officials urge doctors to consider using a particular antiviral drug, Relenza, for patients who get the flu — either because they didn’t get a flu shot or because they were vaccinated and got sick anyway.
Two flu strains are circulating here, although still at low levels. They are:
An A-type strain, similar to one of the three viral strains in this year’s flu shot. The virus, part of the H1N1 family of flu viruses, is resistant to Tamiflu, another common antiviral drug.
A B-type strain. This year’s vaccine doesn’t protect well against most of these B viruses. Relenza also works against these strains, as do the other antivirals.
Source: CDC, Metropolitan Health District
By Don Finley - Express-News
Local health officials alerted doctors Wednesday that two influenza strains now infecting San Antonians both require a little special handling.
While flu season still is mild here, two different strains are circulating almost evenly. One of them is similar to a strain contained in this year's vaccine, A/Brisbane.
Those who have had a flu shot are fairly well protected against that strain, officials say. But for those who aren't vaccinated, or who get sick anyway, the remaining options now are a little more limited.
The Centers for Disease Control and Prevention reported three weeks ago that the A-type strain, which falls within the family of flu viruses known as A/H1N1, is resistant to the antiviral drug Tamiflu — typically given to people after they catch the flu to reduce the severity of symptoms.
Health officials are recommending doctors use zanamivir, sold under the brand name Relenza. While two older antivirals work against that flu strain too, they're ineffective against B-type strains like the one also making people sick this flu season.
That's even more important because this year's vaccine apparently doesn't protect well against the B-type flu now circulating. About 70 percent of the B-type flu cultures from across the country tested by the CDC did not match up with the vaccine.
“We're telling physicians that perhaps they need to use Relenza instead of Tamiflu, because Relenza will cover all (the circulating flu strains), both the A's and the B,” said Roger Sanchez, an epidemiologist with the Metropolitan Health District.
Many doctors offices use a rapid test that indicates only whether someone has the flu. It doesn't distinguish between types of flu.
And even though the flu shot isn't completely protective against the B-type strain, Sanchez stressed it still offers good protection the A strain and about 30 percent of the B's. It's still a good idea to get a flu shot if people haven't already, he added.
Health officials say those who should definitely get a flu shot are children between 6 months and 18 years of age, adults 50 and older, pregnant women, those with certain chronic illnesses such as diabetes and asthma, health care workers and household contacts of those at high risk.
Antiviral-resistant flu strains have been a growing problem. In 2006, the CDC recommended doctors stick to the newer antivirals because of growing resistance to the older-line drugs amantadine and rimantadine among another common family of flu viruses, A/H3N2.
And last flu season, about 10 percent of the A/H1N1 viruses were resistant to Tamiflu.
While the antiviral drugs can be effective, they work best when they're given within a day or two after symptoms begin.
Even though the flu hasn't yet sickened people in large numbers here, a lot of other viruses are circulating, said Kathy Lawless, supervisor of the virology lab at the University Health System.
“About 25 percent of the samples we receive are positive for other respiratory viruses,” Lawless said.
They include two types of parainfluenza, adenovirus, respiratory syncytial virus or RSV, and human metapneumovirus — a virus first identified in 2001 similar to RSV.
Lawless said flu season is running a little later this year than last, when it was in full swing by this time.
Flu is the most serious of the respiratory viruses that circulate in winter months, killing 36,000 Americans on average each year and hospitalizing 200,000.
Symptoms often include high fever, body ache, headache, fatigue, a runny nose, sore throat and cough.
THE PROBLEMS
Health officials urge doctors to consider using a particular antiviral drug, Relenza, for patients who get the flu — either because they didn’t get a flu shot or because they were vaccinated and got sick anyway.
Two flu strains are circulating here, although still at low levels. They are:
An A-type strain, similar to one of the three viral strains in this year’s flu shot. The virus, part of the H1N1 family of flu viruses, is resistant to Tamiflu, another common antiviral drug.
A B-type strain. This year’s vaccine doesn’t protect well against most of these B viruses. Relenza also works against these strains, as do the other antivirals.
Source: CDC, Metropolitan Health District