Thursday, December 31, 2009

When flu comes home...

This week's New England Journal of Medicine has a study that looks at transmission of H1N1 flu in the household setting. The investigators studied 216 persons with flu (index cases) and their 600 household contacts over a 7-day follow up period. The attack rate for household contacts developing influenza-like illness (ILI) was 10%. The median age of the secondary cases was 14.5 years (median age of all household contacts was 26). Risk of acquiring ILI was age-dependent (compared to adults aged 18-50 years, children 0-4 years had a 3-fold risk, children 5-18 had a 2-fold risk, while the risk for those over 50 years was one-third that of adults under 50 years). The time from onset of symptoms in the index case to onset of symptoms in a secondary case was a median of 2.6 days.

1 comment:

  1. Last week in Maryland, a total of 129 specimens were submitted to the Health Dept. lab for influenza testing. Of these, 6 (5%) were PCR positive. Three were type A (H1N1) 2009 viruses, two were type A (H3) seasonal flu viruses, and one was a flu B. So we have a bit of seasonal flu circulating. I hope everyone has gotten or will get there seasonal flu vaccine. We are requiring all HCW to get vaccinated (or decline) by January 15th.