The next time you order a Diet Coke at the bar, you tell that 'tender he better hold the garnish, pal, because those lemons are positively riddled with disease-causing microbes. At least that's what a 2007 study that was recently cherry-picked for inflammatory purposes by Yahoo subtly suggests you do. But the implied connection between sickness and a grubby gin & tonic garnish is tenuous at best.
The study, which was published in the Journal of Environmental Health, does have some clout -- microbes definitely were discovered on restaurant beverage lemon slices -- but the likelihood of anyone actually getting sick from this "contaminated" fruit is entirely unexplored in the research.
Though most health codes dictate that bartenders must use tongs or wear gloves when handling fresh fruit (or at least NYC's does), every be-lemon'd drink I've ever ordered in this fair metropolis has been prepared and presented to me with bare hands. As far as I can tell, I've never gotten sick because of this. In fact, according to a different study than the one above that I cherry-picked to demonstrate an entirely different point, that lemon may actually be acting as a natural disinfectant.