STATE OF MIND : Salsalarm

You’re sitting at a booth at your favorite Mexican restaurant, waiting your turn to dip your chip into the communal salsa bowl. Your dinner companion, suffering, let’s say, from a sore throat, dips his already-bitten-into chip back into the bowl.

That’s more than a common etiquette faux pas (and fodder for a recent “Seinfeld” bit); it’s a great way for friends to mingle microorganisms.

“Just because salsas are spicy doesn’t mean they are hostile environments for bacteria,” says Chris Peter, chief of San Diego County’s Public Health Lab, who has analyzed many salsa samples.

Several saliva-borne microorganisms can survive a lip-to-dip trip. One of them, Peter found, is streptococcus, which causes strep throat.

If streptococcus sounds familiar, if a “flesh-eating bacteria” alarm went off in your head, not to worry. Researchers at the federal Centers for Disease Control say that group A streptococcus causes tissue death--by choking off capillaries--only after entering the body through a cut or other skin injury.

So even if your double-dipping dinner date’s sore throat is really strep throat, you can relax; you might be coughing but you won’t be decaying.

Still, there is the matter of that cold sore...