H1N1 Influenza in the U.S.
While it’s too soon to be sure, influenza numbers are dropping and the season may be coming to an early close. The CDC has these numbers:
During week 51 (December 20-26, 2009), influenza activity decreased slightly in the U.S.
154 (3.9%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.
Translation: of thousands of tested cases of “might be flu”, 154 turned out to really be flu, only 3.9% of the total specimens tested. Lots of sneezing and coughing out there, and not an insubstantial number of hospitalizations and deaths for “influenza-like-illness and pneumonia” , but no influenza viruses are the main cause at this point.
2009 H1N1 virus did turn out to be more dangerous to children than the typical yearly influenza virus: the CDC received 225 reports of deaths this year, 130 last year, 88 in 2007 and 78 in 2006.
The breakdown by age:
Since August 30, 2009, CDC has received 225 reports of influenza-associated pediatric deaths that occurred during the current influenza season (42 deaths in children less than 2 years old, 25 deaths in children 2-4 years old, 83 deaths in children 5-11 years old, and 75 deaths in children 12-17 years old).
How likely was a child under 2 to die from H1N1 based on these numbers?
Live births in 2007: 4,317,000, minus 29,000 infant deaths, gives us a starting number of 4,288,000. The number of births has been going up every year for the last few years, so if we assume the same number in 2008 we are erring on the side of caution. We’ve got a total of roughly 8,576,000 children in the U.S. under the age of two. Forty-two of those children died this year as a result of H1N1, according to the CDC. This means that one child out of every 204,190 died from 2009 H1N1 according to the reported number of cases.
Are the reported number of cases reflective of the true burden of illness? Probably not entirely, but in November, CBS news reported that:
It’s a little counter intuitive,” Frieden said, “but the best way to estimate the total burden of illness is not to count the cases, but to estimate them based on the best available science.”
However, Ashton pointed out, things are very different when reporting pediatric flu deaths. She said states are required to document each case with the CDC, and every week the updated numbers are an accurate reflection of the entire country.
The numbers of pediatric deaths from 2009 H1N1 are based, therefore, on actual case counts in the U.S., during 2009.
Infants and toddlers were one of the groups recommended for the 2009 H1N1 vaccine. However, if saving the maximum number of lives is our goal, then there are several other causes of death in infants and toddlers which we feel should be addressed with a vigor to match the actual death and injury rates for each category.
Among 1- to 4-year-old children, injuries accounted for 42 percent of all deaths, followed by deaths due to congenital malformations (birth defects), malignant neoplasms (cancer), homicide, and diseases of the heart.
Or to give some comparative numbers:
More than 16,500 lives could be saved each year in the United States alone if our under-5 mortality rate was the same as Iceland. If the U.S. rate of under-5 mortality was similar to that of France, Germany and Italy (all 4 per 1,000 live births), over 12,000 child lives could be spared.
The causes of child deaths in the industrialized world differ dramatically from those in developing countries. In the developing world, over half of under-5 deaths are caused by pneumonia, diarrhea or newborn conditions. In the industrialized world, these problems rarely lead to death. Children’s deaths are most likely the result of injury suffered in traffic accidents, intentional harm, drowning, falling, fire and poisoning.