Dallas County Severe H1N1 Cases Spike Higher
January 15, 2014
During weeks 52-1, 70 new ICU admissions were reported, including 30 ventilated patients, 27 BiPAP patients, and 2 patients on ECMO.
During weeks 51-52, 60 new ICU admissions were reported, including 24 ventilated patients, 24 BiPAP patients, and 1 patient on ECMO.
The above comments from the Dallas County week 1 report (in red) and week 52 report (in blue) describe the dramatic rise in serious influenza cases. Texas prepared a special report on pH1N1 cases during the 2009/2010 season, which included a breakdown by county. For that entire season, Dallas County reported 56 ICU cases. This marked increase in cases in Dallas County is similar to the spike in hospitalized cases reported in California, which tracks P&I hospitalizations. The data in the California report also showed numbers that topped the 2009/2010 season, as well as 2012/2013, which was dominated H3N2, which targeted the elderly.
These numbers, at a relative early point in the flu season, raise concerns that the current pH1N1 in circulation has acquired polymorphisms which target the human lung, such as L194I, D225G, and Q226R. Recently released sequences by the CDC demonstrated the presence of these changes in almost all egg isolates, as expected since human lung and chicken eggs have high levels of gal 2,3 receptors, for which affinity is increased by the genetic changes cited above.