But the calls never came.
While ordinary Americans were stockpiling hand sanitizers and face masks, the chronic hand-washers were apparently coping.
But, experts say, if the mystery and the intensity of the swine flu does not let up soon, obsessive-compulsives may be singing a different tune.
"If the swine flu dies down like SARS and West Nile virus did, it will probably stay out of people's awareness," said Jeffrey Szymanski, executive director of the Obsessive Compulsive Foundation.
"But if it is prolonged and becomes a 'we really don't know,' this is really going to bug people with OCD," he told ABCNews.com.
About one in 59 adults in the United States has obsessive-compulsive disorder (OCD) and about twice that many have had it at some point in their lives, according to the Obsessive Compulsive Foundation.
In OCD, the brain "gets stuck on a particular thought or urge and just can't let go," sort of like "mental hiccups."
The hallmarks of OCD are a preoccupation with germs and cleanliness and constant "checking" -- over and over again.
Obsessions include contamination fears from germs and dirt, losing control or hurting oneself or others. Common compulsions are: washing, repeating, checking, touching and counting.
According to a national poll on swine flu released last week by the Harvard School of Public Health, 46 percent of Americans are concerned about catching swine flu in the next year.
In response to the outbreak, 59 percent say they have washed their hands or used a hand sanitizer more frequently.
In a new Gallup Poll conducted Sunday, 19 percent said they personally worried "yesterday" about getting swine flu, down from 25 percent Thursday night.
The percentages of people who said they were taking precautions -- such as staying home, keeping kids home, not shopping, avoiding mass transit and canceling air travel -- all remained in low single digits.
But for OCD sufferers, who engage in excessive hand-washing, health warnings can cause a conundrum. How does one take reasonable precautions, yet not overreact?
One 38-year-old woman who is in treatment at the live-in Obsessive-Compulsive Disorder Institute at Boston's McLean Hospital, said she is worried more about her "intrusive thoughts" than germs right now.
"I have heard about it on the news but people aren't talking about it much," the supermarket cashier, who did not want to be identified, told ABCNews.com.
Still, she says, "I don't want to get it and I have to shower and brush my teeth here."
Mary Ellen, a 54-year-old administrative assistant from New Jersey who asked that her last name not be used, is a chronic hand-washer ever since she was diagnosed with diabetes in 1996.
Hand Shakes Are the Worst
She hasn't changed her regimen since the swine flu outbreak.
"I'm very germ conscious, but I'm not at all phased by the news," she told ABCNews.com. "It hasn't caused me any angst and doesn't prevent me from doing what I would normally do."
Typically Mary Ellen washes her hands after touching a doorknob or shaking a hand.
"If we approach the elevator, I let my husband push the button," she said. "I don't expect people to open doors for me, but I don't open a door if I don't have to.
"I'm not like Michael Jackson, but I'm really conscious about washing it," she said.
The latest figures from the World Health Organization show 1,025 lab-confirmed cases of swine flu and 26 deaths in 20 countries. Though many health experts say the virus is at the moment mild, that could change.
"Why this is such a big story is because it's a new strain and a new strain is potentially dangerous," Szymanski said. "But with OCD, it's really about whether your OCD happens to grab on to it or not.
"In talking to patients, I've had some say, 'I'll take swine flu any day, as long as you promise me I'm not going to get AIDS,'" he said. "During the anthrax scare, we were flooded with calls. But I never heard a thing for the avian or West Nile viruses."
Szymanski notes that sufferers seem to be more preoccupied with sexually transmitted disease, perhaps in part because of the nature of OCD -- sufferers imagine losing control, have intrusive sexual thoughts or urges, or excessive religious or moral doubt.
"Typically, when you think about herpes and HIV, there is a kind of personal responsibility that goes along with it," he said. "It's tied up with sexual issues and taboos: 'I wasn't careful enough and I'm a bad person. But when I get the swine flu, I get it like anyone else.'"
At the same time, as publicity ramps up, experts like Szymanski don't want to give sufferers any more "triggers" that might create a new obsession.
Buzzing About OCD Online
Some mental health Web sites like PsycheCentral.com have listed warnings for OCD patients on how to react to the swine flu, urging them not to ignore Centers for Disease Control and Prevention (CDC) warnings.
"For people who have any type of significant anxiety ... times like these are especially difficult," write their psychologists. "You should probably consult with a mental health professional if you are not currently in treatment and feel your distress is climbing.
"If you're already a worrier," they add, "You're likely to need some extra help."
Some online message boards have also been buzzing with those who say they suffer from OCD.
"Is there anyone out there that read the words, 'swine flu' in my title and had sudden onset anxiety?" wrote one person on BeliefNet.com "That was me 16 years ago, except then it was ebola.
"My OCD kept me in a closed loop of thought: It's the end of the world. In my mind, it was going to happen for real," the posting continued. "I went non-functional for days. When I wasn't full 'fight or flight' brain chemical flush, then I was deeply depressed. The cycle last for weeks."
But others, like Mary Ellen, are less panicked.
"I watch everyone freaking out and just kinda laugh," wrote another.
Studies find that it takes an average of 17 years from the time OCD begins for people to obtain appropriate treatment. The disorder tends to be under diagnosed as many sufferers are secretive or ignorant about their symptoms.
Treatment has been improved markedly with the advent of selective serotonin reuptake drugs, according to Dr. Robert Edger, a psychiatrist at Northwest Memorial Hospital and Children's Memorial Hospital in Chicago.
Those drugs are even more effective when they go hand in hand with psychotherapy.
"We teach these folks who are overly worried about germs to moderate, to put things in perspective and not to go to excess," said Edger. "Yes, we must wash our hands, satisfy our common sense, but we don't want to harm our skin."
Doctors say that a habit becomes an obsession when hand washers go to extremes.
"Sometimes it tips off the diagnosis when we see raw, chafed hands," he told ABCNews.com. "Sometimes people make their hands bleed. It's terribly uncomfortable for the patient and they know it."
Most patients are aware they have an anxiety disorder, but are often ashamed to seek help.
"It becomes a disorder when the worry is out of control and painful to the person and those around them," Edger said. "When you get to the painful consequence of anxiety, that is a disorder."
"This is a real condition and the anxiety is real," he said.
OCD Includes Phobias
Anxiety disorders common and manifest themselves in different ways -- social anxiety and the fear of interacting with people, to phobias like fear of heights.
Doctors believe there is a genetic component. "It's probably a multiplicity of genes and we are not there yet with this as a cause. Certain parts of the brain are oversensitive and overactive and more worried than average."
Treatment starts with "a warm compassionate and empathetic approach."
"Oftentimes people tend to laugh and be judgmental about obsessive compulsive disorder," Edger said. "You have to build a rapport and a relationship and take them seriously."
As for the current swine flu scare, OCD sufferers need to "steer a steady ship," according to Edger, and "not let panic take over."
"The central theme of the condition is worry, worry, worry," he said. "Our job as therapists is to put things in perspective."
"We have marvelous capacity to learn," Edger said. "They learn moderation, what is dangerous and what is not. That is a powerful tool we have as people."