I should have said don't wait too long in the "waiting area of healthcare premises" especially if another occupant/patient has measles, as the authors of a new study in BMC Infectious Diseases report. The authors analyzed the likelihood of acquiring TB, influenza or measles during stays of 30 or 60 minutes in a standard waiting room using a mathematical model simulation. One caveat is that they assumed one person in the waiting room was infectious with one of the organisms. Thus, while the results provide nice theoretical estimates of airborne transmission for these highly (measles), moderately (influenza) and minimally (TB) infectious organisms, they don't adjust for the probability of an occupant having the infection in the first place (influenza>TB>measles).
With that important caveat, the likelihood of acquiring TB during a 30 minute stay in a waiting room was 0.3% and was 0.8% for a 60 minute stay. For influenza, the numbers were 2.6% and 6.6% at 30 and 60 minutes and were 13% and 31% for measles. With those numbers, if there is measles in the community at all, it's probably best to avoid any waiting area (unless you've been vaccinated). Nothing surprising in the results, really, but still worth quantifying and thinking about. During the H1N1 season last year, I was always worried about transmission in the various hospital waiting areas. In those situations, it was likely that >1 person had infectious influenza in the waiting room. I hope future studies analyze the impact of # of infectious occupants and likelihood of those infectious occupants being present during various seasons (RSV, Influenza etc).
Once last thought. Next time a clinician keeps you waiting, you might mention that he/she has put you at increased risk for getting sick.
Beggs et al. BMC ID article