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Last August and September, a nasty cold swept through the Harvard Medical School campus.
As documented by J Bradley Segal in the Harvard Medical Student Review, a survey of 400 students at the med school and the Harvard School of Dental Medicine found that it hit roughly a quarter of first-year students and a third of second-year students.
Ugh. But surely a "teachable moment." Segal explores what's known about the common cold in his review and case study, titled "The Most Common Illness," and analyzes which factors may have helped determine who fell victim to the virus and who did not:
...going to a bar or party with classmates in the last week and studying with classmates some or all of the time significantly increased the risk of contracting the illness. For both classes, living in the medical school dorm, spending more than 30 minutes a day in the medical education building, or regularly attending lecture did not significantly alter the risk of becoming ill.
Interesting. Reminds me of past findings in schoolchildren, that playdates can influence contagion. Bars and parties and study dates are the young-adult versions of viral playdates, it seems.
And as for prevention, it just can't' be repeated often enough: Wash your hands, wash your hands, wash your hands. Segal writes:
Hand Washing — The Punch Line
What do we have to prevent the cold, then? The answer can be gleaned from a classic experiment in 1980 in which one group of random volunteers dipped their fingers in dilute iodine solution—it was known to have virucidal properties (Hendley et al., 1978)—and were compared to volunteers who dipped their hands into water that was died to look and smell like iodine (Gwaltney et al., 1980). Immediately after drying their hands, volunteers made hand contact with rhinovirus-positive donors who had just picked their noses (“The donors contaminated their hands with nasal secretions by finger-to-nose contact”), and 15 min later, volunteers touched their own eyes and noses. This was repeated for 3 days. None of the eight iodine-exposed volunteers became infected, while all seven controls became ill (p < 0.001). Unfortunately, routine iodine use is impractical given that many patients do like having iodine-stained hands.
Subsequent randomized controlled trials demonstrated that good hand hygiene leads to a 20% decrease in cold incidence (Carabin et al., 1999; Ladegaard and Stage, 1999). One crossover study found that giving children hand-sanitizer to compliment normal hand washing resulted in a 50% decline in ARI incidence (Dyer et al., 2000). A meta-analysis of 67 studies on preventing ARI transmission concurred hygienic measures are the most effective measure to prevent ARI infection (Jefferson et al., 2011).
Read the full piece in the Harvard Medical Student Review here.
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