The Power of III
AND ALSO:. . . .Pandemic H1N1 has eliminated seasonal influenza A, which sets the stage for a new wave, which may be beginning. The fall wave was generated because most of the target population had no existing immunity to the new H1N1 and the development of immunity led to the end of the fall wave. However, low reactors have been identified pointing toward the emergence of a new wave with H1N1 that avoids the immunity generated against the H1N1 circulating in the fall.
One of the low reactors, D225G, was tightly linked to fatal cases in the fall, and recent sequences from Italy and Russia pairs that change up with another low reactor change, G158E, raising concerns that such recombinants can evade the existing immunity and generate cases which are more severe and fatal.
Recent reports in Tennessee and North Carolina have described patients with a higher frequency of ICU admissions and deaths and recent increases in other states in Region 4 raise concerns that these trends could spread. A 52% rise in weekly cases in colleges has been reported and the highest number was in North Carolina. Moreover, junior high schools are now reporting double digit absenteeism in Washington state. These increases in populations that were targeted in the fall raise additional concerns regarding the emergence of variants that have escaped the immunity generated last fall.
more at links providedSome of the nation's emergency departments are noting increases in flu-like illness cases that appear to be pandemic H1N1, and colleges are reporting the first increase in flu-like illness since the end of November, but it's not clear if these are early signs of a third pandemic flu wave.
The American College of Emergency Physicians (ACEP) said today in a Twitter post that some of its members were anecdotally reporting a new wave of pandemic H1N1 patients coming to emergency departments and asked if other physicians were seeing similar patterns.
Carl Schultz, MD, professor of emergency medicine at the University of California at Irvine, told CIDRAP News that the increase in the number of influenza-like illnesses appears to be real, but he cautioned that many of the cases have not been confirmed as the pandemic H1N1 strain, because many departments stopped specifically testing for it because of low flu activity. Schultz chairs ACEP's disaster preparedness and response committee.
The above comments provide additional data that a third wave in the United States has begun. Reports on flu at universities has increased 52% over last week, which is supported by anecdotal reports from emergency room physicians. The largest number of new student cases was again in North Carolina.
These developments parallel the start of the fall wave. The initial cases were in region 4 and this area has had the highest percent of samples being H1N1 positive. Similarly, state reports showed recent increases in North Carolina and Alabama, while earlier reports describe more severe cases in hospitals in Tennessee and North Carolina.
The initial reports from region 4 may signal the emergence of a more evolved H1N1 since the time between the current outbreak and cases reported in the fall would be greatest. A recent report on Allegheny County, location of metropolitan Pittsburgh found H1N1 antibody in 45% of patients age 10-17. If this population is again being targeted, it is likely that there are re-infections and the new virus has escaped the immune response generated against the fall wave. . . .