Having just gotten off a plane yesterday for my return from the IAHCSMM meeting in Reno, I thought it appropriate to share with you this interesting little tidbit (especially in light of the blog I wrote almost  two years ago called “One Big Petri Dish in the Sky”). A team of researchers from the University of Massachusetts Amherst, the National Institute for Occupational Safety and Health, and HarvardUniversity has measured concentrations of bacteria in the cabin air of 12 commercial passenger aircraft, and found that flying may be safer than we think.

“In general, bacterial concentrations and types found during the study should not pose a risk to travelers,” says Christine Rogers, a professor of public health at UMass Amherst. “While we did find elevated levels of bacteria at several intervals during the flight, they were common residents of human skin and mucus membranes, dust and outdoor air, including Pseudomonas, Bacillus and Staphylococcus.” Rogers adds that passengers infected with diseases such as tuberculosis are a special case that could pose a risk to fellow travelers.

The study, spearheaded by Lauralynn Taylor McKernan of the National Institute for Occupational Safety and Health, was published in the March 2008 issue of the Annals of Industrial Hygiene.

The team sampled cabin air on 12 randomly selected flights using Boeing 767 aircraft, with flight times lasting from 4.5 to 6.5 hours. Samples were taken in the front and rear of the coach-class cabin at six times during the flight, including boarding, mid-climb, early cruise, mid-cruise, late cruise and deplaning. Additional air samples were taken from the outside and inside of airline terminals at the cities of departure and landing. Flights were sampled during the summer to eliminate the effect of seasonality.

An analysis of the data showed some interesting trends that could be used to predict how disease organisms would move through an aircraft in the event of an emergency. The highest concentrations of bacteria were measured during boarding and deplaning. “Human activity during boarding and deplaning is greatest, which stirs up a lot of dust and causes increased shedding of bacteria from skin,” says Rogers. “This activity may also stir up microbes hidden in the seats of the plane.”

Bacteria levels dropped during the middle of the flight when compared to boarding and deplaning. The drop in mid-flight bacteria may be the result of less human activity, and the settling of bacteria from outdoor air brought into the plane before takeoff.

Since samples were taken from different locations in the plane at several time intervals, the researchers were able to study the pattern of air movement during the flight, and notice how human activity and bacterial shedding changed over time.

“Concentrations of bacteria were higher in the front of the plane during boarding, which makes sense since the planes were boarded back to front, with standing lines common at the front of the plane,” says Rogers. “This pattern shifted during the flight, with slightly higher bacterial concentrations in the rear of the plane. This could be the result of passengers shedding bacteria as they moved to the restrooms in the back of the plane.”

Levels of bacteria detected in the aircraft were compared to a study by the EPA documenting bacteria in the air of indoor offices. Concentrations of total bacteria were higher in the aircraft during boarding, cruise and deplaning, probably due to the number of occupants in a given space and higher levels of human activity.

“Workers and passengers in commercial airliners are exposed to higher levels of common bacteria than people in office buildings,” says Rogers. “This points to the need for additional research to evaluate disease transmission on commercial aircraft.”

My colleagues who travel agree with me that it's difficult not to fear contracting everything from pink eye to the common cold, to -- albeit rare -- TB, while serving time in a cramped tincan with sneezing seatmates, recirculated air and high-touch surfaces. Anyone have a wet wipe handy?  

Greetings from Reno, Nev., where the 50^th anniversary meeting of the International Association of Health Care Central Service Materials Management (IAHCSMM) has been underway since Saturday. This year’s annual event, benefiting from last year’s merger with ASHCSP, has broken all records for membership attendance (more than 900) as well as exhibitor presence (112 companies from the healthcare industry). IAHCSMM president Richard Schule expressed the sentiments of the collective audience when he remarked on the tremendous momentum the association is achieving and the unified voice it creates for the profession. This kind of success cannot be taken for granted and must be recognized as a byproduct of the hard work of numerous individuals acting for the good of the community, according to famed football player and coach, Mike Ditka, who served as today’s keynote speaker. Ditka reminded audience members that the difference between success and failure is sheer perseverance, even in the face of resistance. He also introduced the IAHCSMM membership to his watchword, ACE, which stands for attitude, character, and enthusiasm. He explained that these three traits can propel an individual into the highest levels of achievement, and that we must watch our thoughts because they become words; we must watch our words because they become actions; we must watch our actions because they become habits; we must watch our habits because they become our character; and we must watch our character because it becomes our destiny. Words to live by, don’t you think?

In a press briefing held yesterday, experts from the Centers for Disease Control and Prevention (CDC) provided an update on the measles outbreaks cropping up throughout the country.

“We have had more cases of measles this year than in any year since 2001,” reported Dr. Anne Schuchat, director of the NationalCenter for Immunization and Respiratory Diseases at the CDC. “People have heard about outbreaks in individual communities, but in the country as a whole, between Jan. 1 and April 25, there have been 64 cases of measles reported to CDC. These are occurring in nine different states. And there are a couple important themes that I want to stress about these cases.”

Schuchat continued, “Many people have forgotten about measles. It causes about 20 million infections around the world every year. But fortunately in the U.S., we declared the condition eliminated in 2000 after we interrupted ongoing transmission within the country. But measles is still in many parts of the world and can come in easily through visitors or through Americans traveling abroad who bring it back. What we have this year is 64 cases to date reported to us, and 20 percent of those have been hospitalized.  None of them have died, fortunately.”

Schuchat emphasized three issues — importations and travel, the role of healthcare settings, and unimmunized individuals. Schuchat explained, “Most of the importations that we are seeing are coming from the World Health Organization's European region, in particular from outbreaks that are ongoing in Switzerland and Israel. In Switzerland, there have already been more than 2,000 cases in their outbreak, and in Israel, more than 1,000. Many people don't think of traveling to Europe as a place where you can come down with an infectious disease, but, of course, measles is still endemic in most of the European region. It's very important for travelers heading off to Europe to make sure that they're up to date on their immunizations and that measles is an ongoing risk. Measles is extremely infectious and it really is able to find that one unimmunized person in a population.”

Next, Schuchat addressed the transmission of measles in healthcare settings: “Many of the cases that we're seeing this year have been in children who are too young to have been immunized with measles vaccine, children who are under 12 months of age. At least one of those children acquired measles in the doctor's office, in the waiting room. And other cases have been acquired in the hospital setting, emergency rooms or in healthcare workers. It's very important for people who are working in healthcare settings to make sure that they are immune from measles, either by being fully immunized or having their immunity checked with a titer or by a documented birth before 1954. Because measles can be severe, most people do seek medical care. And it's in those medical settings where they can transmit the infection.”

Lastly, Schuchat discussed the unimmunized population: “In the United States, we're very fortunate to enjoy very high levels of immunization. When we look at our toddler population around the country, more than 92 percent of toddlers are immunized with the MMR vaccine. When we look at kindergarten entry, about 96 percent of kindergartners have gotten their measles immunizations. They're supposed to get a second dose by kindergarten. But that doesn't mean that there aren't pockets of unimmunized children and adults around the country. And we know that measles can make its way to those communities. In the outbreaks so far this year, two-thirds of children who are old enough to be immunized but are not turned out to not be immunized because of personal belief or religious exemption. So we want to make sure that parents who are making decisions about immunizing their children are aware of the measles risk that's ongoing around the country and make sure that they have a chance to talk with their provider about opportunities for protection. We have seen resurgences of measles in the past. Between 1989 and 1991, the United States suffered 55,000 cases of measles and 123 deaths.  The measles vaccine is extremely effective, 99 percent effective, and we strongly recommend unimmunized persons to be immunized.”