Beyond the bites and the itching, the bother and the expense, victims of the nation’s most recent plague are finding that an invisible scourge awaits them in the form of bedbug stigma. Friends begin to keep their distance. Invitations are rescinded. For months, one woman said, her mother was afraid to tell her that she had an infestation. When she found out and went to clean her mother’s apartment, she said, “Nobody wanted to help me.”

Fear and suspicion are creeping into the social fabric wherever bedbugs are turning up, which is almost everywhere: “Public health agencies across the country have been overwhelmed by complaints about bedbugs,” said a joint statement this month from the Centers for Disease Control and Prevention and the Environmental Protection Agency.

Some of the fear is rooted in fact: The bugs, while they are not known to transmit disease, can travel on clothing, jump into pocketbooks and lurk in the nooks of furniture. And they do, of course, bite.

Wenay James, a credit card account executive in Chicago, said that last year, a friend who had just had an infestation brought her children over for a visit. “I’m staring at their seat,” she said, “wondering if the cushion is going to run across the room.”

“I haven’t been over to her place in a year,” Ms. James said. “I don’t want the cooties.”

Even in New York, where the roach and the rat are considered members of the melting pot, no one wants to be associated with the minuscule pests that treat sleeping bodies as smorgasbords.