When I read the AP story further down in this post Friday evening I was immediately reminded of something that one of the Reveres from EffectMeasure had blogged on this spring. The entire post, well worth the read, may be found here. The post deals with a strange influenza epidemic in England during 1951 where the excess mortality is stated to have been 40% above normal.
The point of the paper, and Revere’s blog entry, is that regional presentations of "normal" (seasonal) flu can be significantly different, and in this case, far more lethal, than other geographic locations.
The entire concept is eerily similar, in my "average person" opinion, to what appears to be happening to some of Alabama’s children. Perhaps a reminder that antigenic drift may play a role in regional differences in seasonal influenza epidemics.
We are now realizing that in some years there are extraordinary mortalities that exceed those seen in pandemics, including the pandemic of 1918. Our relative ignorance about these variations is emphasized dramatically in a fascinating paper in CDC’s Emerging Infectious Disease journal by NIH’s Cecile Viboud and her co-authors.
Viboud et al. detail a new investigation of the 1951 H1N1 epidemic:
Anecdotal accounts exist in the literature of historical influenza epidemics associated with unusual numbers of deaths, such as occurred in the 1951 epidemic in England in the midst of the first era of A/H1N1 viruses (1918–1957). In Liverpool, where the epidemic was said to originate, it was "the cause of the highest weekly death toll, apart from aerial bombardment, in the city’s vital statistics records, since the great cholera epidemic of 1849". This weekly death toll even surpassed that of the 1918 influenza pandemic. (Viboud et al.; all cites omitted)
No viral isolates or genetic sequences are available for the 1951 virus, so the source of the unusual virulence of the Liverpool strain remains unknown. This intriguing paper underlines once again how much we don’t know. The elderly seemed to do relatively well in the pandemics of 1957 and 1968, but suffered disproportionately in the non-pandemic year of 1951 where they did worse than in two of the three 20th century pandemics in England, Wales and Canada and worse in Liverpool than in any pandemic, including 1918.
A well-known flu researcher said to me recently he thought he knew more about flu 20 years ago than he does now. With the publication of this paper, we might say we also know less about seasonal influenza now than we did last month.
The latest AP story on the children on life support in Birmingham and the CDC being called in to investigate. I am confident that if an answer is to be found, they will find it.
CDC asked to probe severe pediatric flu in Birmingham area
Associated Press Fri, Dec. 29, 2006
BIRMINGHAM, Ala. – The Centers for Disease Control and Prevention has been asked to investigate several severe influenza cases in the Birmingham area that have caused at least nine children to be hospitalized, officials said.
Five of six children who were on life support at Children’s Hospital have improved, but three more children were admitted with severe flu cases in the past week, hospital officials said.
"I would say that the situation is a little better than last week, but not substantially better," said Dr. David Kimberlin, who specializes in pediatric infectious diseases at the University of Alabama at Birmingham.
"There are still a lot of children going to the emergency room and a number of children admitted to the hospital."
Kimberlin told The Birmingham News in a story Friday that the CDC in Atlanta was contacted after the severity of pediatric flu cases raised concerns in Birmingham’s medical community.
He said none of the original six children on life support had been vaccinated. Doctors have identified the presence of both A and B strains of the virus and the CDC will further research the flu strains that were causing some of the more severe cases.
Alabama, Florida and Georgia are the three states experiencing widespread outbreaks of flu, according to the CDC.