Announcement

**HenryN** · June 5, 2009, 02:59 PM

Re: Swine H1N1 Explosion in United States

Latest CDC data leaves no doubt that swine H1N1 explosion is accelerating. Detection rate is well above seasonal flu at peak of flu season.

**HenryN** · June 5, 2009, 03:02 PM

Re: Swine H1N1 Explosion in United States

1706 swine H1N1 in week 21 compared to 87 for seasonal H1N1, H3N2 and influenza B, combined.

**wotan** · June 5, 2009, 03:04 PM

Re: Swine H1N1 Explosion in United States

For the sake of understanding what I am seeing, is week 40 what the CDC considers the start of flu season?

**alert** · June 5, 2009, 03:30 PM

Re: Swine H1N1 Explosion in United States

Originally posted by wotan View Post

For the sake of understanding what I am seeing, is week 40 what the CDC considers the start of flu season?

I see three single "could not be subtyped" cases from before the novel H1N1 was discovered: One each in weeks 7, 14, 15. Are we to assume that those are just due t obad laboratory testing? The cases in weeks 14 and 15 could be the new H1N1 and just no one knew what to look for (and the samples are not preserved to test now), but week 7 could not be that.

Any idea about that week 7 case?

**HenryN** · June 5, 2009, 03:42 PM

Re: Swine H1N1 Explosion in United States

see reply in next post

**HenryN** · June 5, 2009, 03:43 PM

Re: Swine H1N1 Explosion in United States

Originally posted by niman View Post

For the sake of understanding what I am seeing, is week 40 what the CDC considers the start of flu season?

Yes, week 40 is the 40th week of the calender year and the beginning of flu season for the northern hemisphere. As seen by the number of H1, H3 and influenza B isoaltes, flu season is over, and normally the weekly survey would be stopped for the summer.

However, even though state agencies are limiting testing and refusing to test peopel with OBVIOUS swine flu, teh frequency of positives has jumped to 31.05%, comapred to 23.61 for last week, or 25.01 on week 6 which is the middle of February and the peak of the flu season.

**HenryN** · June 5, 2009, 03:45 PM

Re: Swine H1N1 Explosion in United States

Originally posted by alert View Post

I see three single "could not be subtyped" cases from before the novel H1N1 was discovered: One each in weeks 7, 14, 15. Are we to assume that those are just due t obad laboratory testing? The cases in weeks 14 and 15 could be the new H1N1 and just no one knew what to look for (and the samples are not preserved to test now), but week 7 could not be that.

Any idea about that week 7 case?

The earlier examples were swine flu cases that were do to swine expsoure (and did not spread).

**alert** · June 5, 2009, 03:48 PM

Re: Swine H1N1 Explosion in United States

Originally posted by niman View Post

The earlier examples were swine flu cases that were do to swine expsoure (and did not spread).

Possible. But the only swine this virus has been detected in were the ones in Alberta that were infected by a human.

I assume because they cannot subtype these samples, that they are not still available for testing. They could be the novel H1N1, or they could be just about anything else.

**HenryN** · June 5, 2009, 04:06 PM

Re: Swine H1N1 Explosion in United States

Originally posted by alert View Post

Possible. But the only swine this virus has been detected in were the ones in Alberta that were infected by a human.

I assume because they cannot subtype these samples, that they are not still available for testing. They could be the novel H1N1, or they could be just about anything else.

WRONG. These cases were reported as H1N1 swine.

**HenryN** · June 5, 2009, 04:09 PM

Re: Swine H1N1 Explosion in United States

Originally posted by alert View Post

Possible. But the only swine this virus has been detected in were the ones in Alberta that were infected by a human.

I assume because they cannot subtype these samples, that they are not still available for testing. They could be the novel H1N1, or they could be just about anything else.

Please. The week 7 isolate was described in week 8:

Novel Influenza A Viruses:

One case of human infection with a novel influenza A virus was reported by the Iowa Department of Public Health during week 8. The person was infected with a swine influenza A (H1N1) virus, and reported contact with ill pigs. Although human infection with swine influenza A virus resulting in illness appears to be uncommon, a few sporadic cases have been reported each year, usually among people in direct contact with ill pigs or who have been in places where pigs may have been present (e.g. agricultural fairs or farms). The sporadic cases of human infections with swine influenza viruses identified in recent years have not resulted in sustained human-to-human transmission or community outbreaks. Nonetheless, when cases are identified, CDC recommends thorough investigations to evaluate the extent of the outbreak and possible human-to-human transmission, as transmission patterns may change with changes in swine influenza viruses.

**wotan** · June 5, 2009, 04:11 PM

Re: Swine H1N1 Explosion in United States

Although human infection with swine influenza A virus resulting in illness appears to be uncommon, a few sporadic cases have been reported each year, usually among people in direct contact with ill pigs or who have been in places where pigs may have been present (e.g. agricultural fairs or farms). The sporadic cases of human infections with swine influenza viruses identified in recent years have not resulted in sustained human-to-human transmission or community outbreaks.

Wow, hard to believe that was written just a few weeks ago, considering where we are now.

**HenryN** · June 5, 2009, 04:17 PM

Re: Swine H1N1 Explosion in United States

Originally posted by alert View Post

Possible. But the only swine this virus has been detected in were the ones in Alberta that were infected by a human.

I assume because they cannot subtype these samples, that they are not still available for testing. They could be the novel H1N1, or they could be just about anything else.

Although this has been posted several times previously, it may be worth repeating. Samples that are not typable with human reagents are not human. They are are almost always swine H1N1 and happen several times a year. These untypable isolates rarely spread. The largest outbreak prior to the current outbreak was in 1976 at Fort Dix, NJ. The number infected were limited to a hand full of residents in NJ, and one soldier died. The outbreak ended long before the swine flu vaccine was ready.

The last time swine H1N1 was efficiently transmitted in a human population was 1918.

**HenryN** · June 5, 2009, 04:19 PM

Re: Swine H1N1 Explosion in United States

Originally posted by wotan View Post

Wow, hard to believe that was written just a few weeks ago, considering where we are now.

Actually, the CDC has been writing the same thing for years. Week 7 was just the most recent example. There were a few cases last summer (avian PB2 loves the heat).

**HenryN** · June 5, 2009, 04:29 PM

Re: Swine H1N1 Explosion in United States

Originally posted by wotan View Post

Wow, hard to believe that was written just a few weeks ago, considering where we are now.

From week 46:

One case of human infection with a novel influenza A virus was reported by the Texas Department of State Health Services during week 46. The person was infected with a swine influenza A (H1N1) virus, and reported several swine exposures including close contact with an ill pig. Although human infection with swine influenza is uncommon, sporadic cases have occurred in many years, usually among people in direct contact with ill pigs or who have been in places where pigs may have been present (e.g. agricultural fairs, farms, or petting zoos). The sporadic cases of human infections with swine influenza viruses identified in recent years have not resulted in sustained human-to-human transmission or community outbreaks. Nonetheless, when cases are identified, CDC recommends thorough investigations to evaluate the extent of the outbreak and possible human to human transmission, as transmission patterns may change with changes in swine influenza viruses.

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Swine H1N1 Explosion in United States

Swine H1N1 Explosion in United States

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