PALO ALTO -- The campaign battling deadly hepatitis B could not have come up with a better poster child than former California Assemblywoman Fiona Ma.

Ma didn't realize that she suffered from chronic hepatitis B until she appeared at an awareness campaign six years ago -- and a doctor pulled her aside to quietly inform her.

On Sunday, the campaign led by a coalition of groups targeting the disease screened more than 200 people around the Bay Area to mark World Hepatitis Day. The disease affects one in 12 Asian-Americans and one in 10 Asians worldwide.

One-quarter of those people will go on to suffer liver cancer or disease.

"I am lucky today," Ma said. "I am OK."

Many of the dozens of people getting tested at a tutoring center in downtown Palo Alto expressed the public perception of hepatitis B -- that it's a vague problem, not an imminent threat.

But Ma knows better. At age 22, she offered to donate blood but was turned down because she tested positive for hepatitis B. It turned out that her grandmother transmitted the virus to Ma's mother, who transmitted it to Ma and her brother. Hepatitis B is passed on from mothers to newborns -- common in areas in Asia where hepatitis B is endemic -- and also by sex and through needles.

A good service

Ma thought she was merely a silent carrier.

But years later at an event promoting hepatitis B awareness, she learned otherwise. Dr. Sidney So, director of the Stanford Asian Liver Center, told her: There are no silent carriers, only people with active and inactive cases.

Ma immediately sought a liver test and asked family members to do the same. Because of that vigilance, her mother's liver cancer was detected in early stages; she underwent surgery and is now fine, Ma said.

Many of those getting tested Sunday said they vaguely had heard of hepatitis B dangers and had assumed they were OK because they got regularly physicals. But hepatitis B may not be screened in routine blood panels.

"This is a very good service for the community," said Bob Zhang, of Palo Alto, as he pressed a cotton ball on his just-poked arm.

He was recruited by his daughter Lily, a rising senior at Palo Alto High. She was one of dozens of student clients of ThinkTank Learning, a tutoring and test-prep company offering 10 of its Bay Area sites for hepatitis B screening.

Its clientele, 95 percent Asian-American, was the perfect demographic match for hepatitis B testing, ThinkTank founder Steven Ma (no relation to Fiona Ma) said. The company offered its students four hours of community service credit for every adult recruited for screening.

Lily Zhang -- the Olympic table tennis star -- also recruited seven visiting Chinese table tennis players, who said they didn't recall being tested for hepatitis B in China.

A life saver

The campaign sponsors, including Hep B Free Santa Clara County, hoped to help set a world record Sunday for the number of people screened for the disease.

The testing was funded in part by the federal Centers for Disease Control and Prevention, which has launched a vigorous screening campaign. It's been embraced in Santa Clara County, where 33 percent of the residents are Asian-American.

In this country, routine vaccination of newborns and shots for children have cut into the disease among young adults. However, Dr. Jiayi Li of the Palo Alto Medical Clinic said that the vaccine isn't a cure-all. In cases of a heavily infected mother, hepatitis B can survive in inoculated children. In the United States, fewer than half of births to women with chronic hepatitis B occur with prenatal case management.

So the campaign aims to educate medical professionals as well as the general public.

"Please get your family members screened and tested," said Fiona Ma, who gets a liver test twice a year. "You can potentially save someone's life."