Like many parents around the nation, Cathi Thomas of Arcadia was perplexed this spring when a pediatrician recommended a new immunization--against the hepatitis B virus--for her children.
"I was totally surprised," says Thomas, whose children are 5 and 2. She didn't know the disease had become so widespread, she says, and was "confused about what hepatitis B is."
Thomas is hardly alone. Physicians, health clinic operators and many parents are taking a crash course on the hepatitis B virus (HBV), after the release of new guidelines from the federal government and the American Academy of Pediatrics that call for vaccination for all infants, children and adolescents.
The new strategy is unusual in that most childhood vaccines target diseases that threaten children, like measles, mumps and pertussis.
Children under age 12 are generally not considered to be at high risk for HBV. But by immunizing infants now, health officials hope to eradicate the disease in the next three decades. "The thinking is if we can immunize newborns at this time, perhaps we will have a completely immunized population in 15 years or so," says Dr. Richard J. Duma, director of the National Foundation for Infectious Diseases.
A scarcity of funds to purchase vaccine will mean the recommendations will not go into effect for several months in many public health departments.
Hepatitis B is a highly contagious virus that can produce flu-like symptoms, jaundice and, eventually, cirrhosis or liver cancer. It has no cure, although treatment can reduce the symptoms. The consequences for infected youngsters are particularly grave: An estimated 25% of all carrier infants will die from liver cancer or cirrhosis during their adult lives.
Although the disease is spread primarily through sexual contact or from infected mothers to their infants at birth, it also can be transmitted through blood products, contact with open skin lesions and saliva.
Infection rates in the United States increased dramatically in the 1970s and early '80s before a vaccine became available. Although the vaccine has been available for the last decade, federal health officials say the national strategy on who should get the vaccine has failed. In recent years, the vaccine was recommended for anyone at high risk: primarily pregnant women with HBV, heterosexuals and homosexuals with multiple sex partners and intravenous drug users.
But hepatitis B rates have not dropped significantly. An estimated 300,000 Americans are still infected yearly, making the virus second only to gonorrhea as the most common reportable sexually transmitted disease. One in 20 Americans is estimated to be infected with HBV. The virus is 100 times more contagious than the virus that causes AIDS, says Duma.
"We've tried just to target high-risk groups," Duma says. "That strategy has failed. It has not cornered the disease at all."
High-risk adults still should be immunized and widespread immunization of adolescents should have a more immediate effect, curbing HBV rates during the next few years.
"The incidence of hepatitis B really takes off between the ages of 12 and 18," says Dr. Wilbert Mason, director of the division of infectious diseases at Childrens Hospital in Los Angeles. "That's when adolescents start acquiring it because of (sexual) activity."
Two major problems remain in the effort to eradicate hepatitis B:
* The federal government has not allocated sufficient funds to make the vaccine available to all children and adolescents.
* Many people know little about HBV. Because the virus can be spread from mother to child or through casual contact, public health officials say even many pediatricians fail to recognize it as a common sexually transmitted disease. Parents rarely view it as a threat to their children and teen-agers.
For reasons that are poorly understood, some people become permanent carriers (at least one million Americans) and can infect others.
Among those carriers, about half suffer from active, chronic infections and become very ill. The rest, who experience no infection or symptoms, can infect others unknowingly and are called silent carriers.
"Of the large percentage of people who become infected, there is a significant number who will go on to experience chronic relapsing hepatitis, or cancer of the liver or cirrhosis," Duma says.
The younger a person is when infected, the more likely that person will become a carrier and become severely ill later in life. Between 25% and 50% of children infected before age 5 become carriers; 6% to 10% of all infected adults do.
Because sexually active people ages 18 to 39 are most likely to contract the disease, they are a priority for immediate immunization. Among children, the dearth of public funds for immunization will mean that only newborns and adolescents will be targeted for vaccination now.