US Week 1 P&I Death Rate Crosses Epidemic Threshold
Recombinomics Commentary 12:00
January 11, 2013
Today’s CDC FluView (week 1) will show that the Pneumonia and Influenza (P&I) death rate for the United States (7.3%) will cross the epidemic threshold, which is not unexpected. Last week (week 52) the rate of 7.0% was just below the threshold of 7.1%, and the flu epidemic, particularly the cases due to H3N2, was starting to take off in the northern portion of the country. Recombinomics Commentary 12:00
January 11, 2013
Deaths are a trailing indicator and numbers reported for week 1 were striking in several states. In Pennsylvania there were 3 deaths in week 52, bring the season’s total to 4, but in week 1 there were 18 more deaths. Similarly in Minnesota the seasonal total at the end of week 52 was also 4, but there were 23 more deaths in week 1, once again signaling that the spike in cases seen in late December was translating to a spike in deaths (and hospitalizations) in early 2013.
The above state reports are for lab confirmed cases, which represent a tiny fraction of the total deaths. This season H3N2 is dominating, and the elderly are targeted, leading to significant outbreaks in long term care facilities. In most cases the patients are not tested for flu and therefore not included in the reports of confirmed hospitalizations or deaths. However, the P&I total is based on patients who have influenza or pneumonia indicated on death certificates, which are used to determine a rate based on the total number of death certificates from the 122 largest cities in the United States.
The totals for the end and beginning of the calendar year may be impacted by holidays. So the number of P&I and total deaths are somewhat reduced due to reporting delays. However, the large spike in lab confirmed hospitalizations and deaths indicate a rate above the epidemic threshold will also be seen in the upcoming weeks when holiday effects diminish.
In addition to the P&I rate and the total number of confirmed deaths, the death of adolescents (children under the age of 18) is also tallied.
Reporting of adolescent deaths of lab confirm cases is now mandatory in the US due to the high number of deaths in the 2003/2004 season, which were not tallied because such deaths were not reportable. The new regulations allow for more accurate determinations, although many such deaths are not lab confirmed and therefore not reported. The reporting of these cases also frequently lags because a report has to be filed and lab confirmation may produce delays.
Today’s FluView will have 2 additional cases (from Kansas and Texas) to bring the season total to 20, but the number of media or state lab reported cases is already at least 33, reflecting the lag as well as the lack of lab confirmation (although the vast majority of the 13 cases not included in the week 1 report are lab confirmed and reported by the state labs.
