Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households

[mixin]

Preliminary Findings of a Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households

Background
There are sparse data on whether non-pharmaceutical interventions can reduce the spread of influenza. We implemented a study of the feasibility and efficacy of face masks and hand hygiene to reduce influenza transmission among Hong Kong household members.

Conclusions/Significance
The secondary attack ratios were lower than anticipated, and lower than reported in other countries, perhaps due to differing patterns of susceptibility, lack of significant antigenic drift in circulating influenza virus strains recently, and/or issues related to the symptomatic recruitment design. Lessons learnt from this pilot have informed changes for the main study in 2008.

Discussion (This is only part of the discussion)
In conclusion, there remains a serious deficit in the evidence base of the efficacy of non-pharmaceutical interventions. The US Centers for Disease Control and Prevention have awarded grants to study non pharmaceutical interventions in community settings [40], including this study. Other funded study designs include symptom-based recruitment (as in our study) and longitudinal studies of initially uninfected cohorts, in children and adults and in various settings including households, schools and student halls of residences. We eagerly anticipate that conclusive evidence will become available as these studies proceed in the coming months, finally allowing empirically-driven pandemic planning.

Full article:
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002101#pone.0002101.s004

 

[gsgs]

Re: Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households

useful study, quick preliminary report.(IMO)

25% of household contacts of flu-confirmed people in France and Seattle
developed clinically confirmed influenza before,
but only 6% here, (Hongkong 2007).
No effect of NPIs was observed, but the sample-size was small.

 

[mixin]

Re: Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households

They also had problems with the participants:

We observed generally low adherence to interventions. More than one in four household contacts in the face mask group did not wear a surgical mask at all during the follow-up period. However more than one in four index cases in the control and hand hygiene intervention arms reported wearing masks at home of their own accord, thereby contaminating this intervention.

we note that contamination of this intervention may be lower firstly because the control and face mask group did not receive the education component on proper hand hygiene, secondly because those groups did not receive the alcohol sanitizer and hand rub.

Hopefully, the larger study will go better for them.

 

[gsgs]

Re: Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households

my study:

just encourage everyone with flu-symptoms to fill in
a questionaire so to figure out, who infects whom.

People should report, whenever they have some suspicion
who spreads infectious disease to whom. (i.e. household)
and maybe even on what occasion