Flying soon? Worried about contagious diseases?
This is an interesting article posted on Medscape
Localized Risk for Infection Transmission on Planes, Study Finds
“Transmission is limited to one row in front of or in back of an infectious passenger. This is more conservative than current public health guidance, calling for surveillance of passengers within two rows of an infectious passenger. Our simulations also indicate that an infectious flight attendant can generate several infections; thus, it is imperative that flight attendants not fly when they are ill,” the authors explain.
Vicki Stover Hertzberga, PhD, from the Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia, and colleagues published their findings online today in the Proceedings of the National Academy of Sciences.
More than a dozen documented cases of inflight transmission have occurred, and research on severe acute respiratory syndrome (SARS) and pandemic influenza (H1N1p) transmission on airplanes shows that air travel can help newly emerging infections and pandemics spread rapidly, the authors explain. However, the average risk for transmission of respiratory infections on commercial airline flights remains unknown.
The investigators observed one passenger on one flight coughing moderately and none coughing severely. No crew members were seen coughing.
Infection Transmission Closely Linked to Movement of Passengers and Crew
Estimated infection transmission was closely linked to movement of passengers in the airplane, and the extent to which passengers moved varied according to where they were seated. More than one third (38%) of passengers remained in their seats for the duration of the flight, 38% left once, 13% left twice, and 11% left more than twice. Those who moved spent a median of 5.4 minutes out of their seats. The proportion of passengers who left their seat more than once was highest for passengers seated in an aisle seat (80%), followed by those in a middle seat (62%) and passengers in a window seat (43%).
For passengers, the most frequent behaviors were waiting for, using, or leaving a lavatory (825 passengers; average time, 4.3 minutes) and checking the overhead storage bin (135 passengers; average time, 1 minute.)
Passengers waited for the front lavatory almost twice as long as they waited for the back lavatories (3.1 vs 1.7 minutes).
During an average flight (238 minutes of observation), each crew member was in contact with passengers for 67 minutes and spent an average of 155 minutes in the galley.
The number of contacts fell the farther patients were seated from the aisle, with the greatest average number of contacts for passengers seated in aisle seats (n = 64), followed by those in middle (n = 58) and window seats (n = 12).
The researchers developed a model in which they simulated direct influenza transmission occurring during a flight, using two scenarios and a transmission rate that has been used in previous transmission studies.
Simulations for other seats show an average of no more than two additional infected passengers per flight.
In addition to running simulations, the researchers collected 228 samples from the air and hard surfaces and tested them for 18 common respiratory viruses. All samples tested negative, even though eight flights occurred during influenza season in the northern hemisphere.
The authors say their findings should not be extrapolated to short-hop domestic flights, international flights, or flights on other airlines. Passengers on short-hop flights may move around less, and those on longer international flights may move much more. “Our results also cannot be extrapolated from single-aisle cabins to double-aisle cabins commonly used for international flights. Different airlines will have different cabin-disinfection protocols and supervise their cabin-cleaning staff in different ways,” the researchers conclude. Troy Brown, RN