Are We Done Yet?

[indigo girl]

Flu: Georgia on CDC's mind

A day or two after CDC's Morbidity and Mortality Weekly Reports (MMWR) released a report about risks to pregnant women from pandemic 2009 flu, CDC held a suddenly announced press briefing about the current H1N1 situation (I listened in but a transcript should be up on the site by the time you read this; check this page). The occasion for the briefing was a worrisome increase in hospitalizations and deaths in CDC's Georgia backyard. Despite housing CDC, Georgia has one of the lower flu vaccination rates in the country and now is experiencing an unexpected recrudescence of H1N1 flu, with numbers of hospitalizations not seen in the state since the height of the pandemic last October. The cases were described as "adults," many with pre-existing medical conditions, with a geographic distribution that, on a preliminary view, might be hitting areas less hard hit than the fall wave of cases. Since late February, Georgia was seeing more hospitalizations (in numbers) than any other state in the union and the reason isn't known. What we know so far is that it is the 2009 H1N1 pandemic, laboratory confirmed and said not to be different than before. What that is based on we don't know. It is not either of the previous seasonal flu strains, seasonal H1N1 or seasonal H3N2, nor influenza B, which is circulating at many locations at very low levels.

Is this the harbinger of a third wave that will spread more generally? It is uncharacteristically late in the usual flu season for this to happen, although this particular flu did poke its head above water just about this time of year last year. Maybe there is something about the virus that makes its seasonal pattern different. Perhaps it's because Georgia citizens have less herd immunity than elsewhere, a not too thinly veiled suggestion by CDC's Dr. Anne Schuchat on the conference call. She did use the opportunity to urge reporters to remind their readers that a flu vaccine, which she noted has an excellent safety record, is the best protection against influenza. This is a CDC Talking Point that has the added virtue of being true. At one point she suggested many of the seriously ill had not been vaccinated, although she gave not data. Back to the question, What does this mean, the truthful answer is, "We don't know."

Asked why the estimated 12,000 deaths for pandemic 2009 H1N1 didn't indicate that this was a much milder flu season than the usual estimate of 36,000 flu deaths in other years, Schuchat made the observation that 11,000 of the 12,000 deaths were in people under the age of 65, a much higher number (not just proportion) than usual. This is another way of saying that the difference is in the epidemiology, i.e., the pattern of disease and death in the population. It's also true, however, that the 36,000 death figure is not just an average, but an estimate of excess mortality calculated in a particular way and that it represents the estimated excess averaged over 30 seasons. Calculated that way, in some seasons the excess is essentially zero, even though in those years many people's deaths would not have happened had they not had the flu (if you want to know more, here's one of a number of posts we wrote on the subject).

More at: http://scienceblogs.com/effectmeasure/2010/03/flu_georgia_on_cdcs_mind.php

The Editors of Effect Measure are senior public health scientists and practitioners. Paul Revere was a member of the first local Board of Health in the United States (Boston, 1799). The Editors sign their posts "Revere" to recognize the public service of a professional forerunner better known for other things.

[indigo girl]

spike in atlanta georgia deaths raise pandemic concerns

http://www.recombinomics.com/news/03301001/h1n1_atlanta.html

surgeon general dr. regina benjamin and dr. anne schuchat, director of the centers for disease control and prevention's (cdc's) national center for immunization and respiratory diseases, told reporters on a conference call that they are particularly concerned about the "worrisome trend" in georgia, where "more than 40" people were hospitalized in the past week for lab-confirmed flu.

the increases in region 4 have been clear for many weeks. the percent positive cases rose to double digits in february and have been at that level throughout february and march. states in region 4 reported increases in hospitalizations and deaths, but the biggest jump came from georgia which reported 80 new hospitalizations between march 3-9. this jump was 1 shy of the record weekly total from last fall and suggested a third wave was beginning. the ga department of health then put out a march 24 press release noting the jump in hospitalizations and deaths and the need for vaccinations. they cited 1012 h1n1 hospitalizations and 72 deaths. the tables that that time showed 940 hospitalizations and 58 deaths, so the difference of 72 hospitalizations was in line with the prior week's jump, but the deaths were 14 higher.

another approach to monitoring deaths is through p&i reports from 122 cities in the us. atlanta shows a dramatic jump in deaths. a year ago the rate for weeks 8-11 was 3.3%, but this year the rate was 9.2%, which would represent 31 excessive deaths. the jump for the past two weeks was even more dramatic. in 2009 the rate was 1.8%, but it 2010 it rose to 11.2%. thus, in 2009 there were 6 p&i deaths for weeks 10 and 11, while in 2010 there were 28.