It was only 11 a.m. on a recent day in Montebello and already the heat was oppressive. Shade trees are few in this careworn neighborhood of newly arrived immigrants, and fear keeps many from opening their doors to strangers.
But Lydia Cardenas has adapted to the hardships of her job. When people refuse to open their doors, she shouts her message through the keyholes.
"I'm from the health department . . . are there children living with you?" Cardenas calls, switching easily from English to Spanish as needed. "May I see their immunization cards?"
Cardenas represents the latest effort by public health officials in California and across the nation to accomplish what faxes and flyers, radio and television ads have failed to do--halt the worst measles epidemic in decades. In a move reminiscent of the pre-vaccine era, people are being asked to carry the lifesaving message of immunization.
In Los Angeles, Cardenas reaches out to people isolated by poverty and language, hoping to lead them back into the health care system.
In Rochester, N.Y., staff members in hospital emergency rooms are preparing to discuss immunization with every family that takes a child in for care and to administer vaccine on the spot.
In rural Riverside County, nurses are preparing to travel to desert horse ranches with vaccine for the families of migrant workers.
Federal, state and private money is paying for these efforts as policy makers come to grips with the epidemic's implications.
As serious as measles is, much more is at stake: Epidemiologists consider measles a sentinel disease. The outbreak, some say, signals a basic weakness in the public health care system that, if left uncorrected, could permit the resurgence of other contagious diseases, such as polio or diphtheria--diseases that vaccines almost have relegated to the history books.
Flaring in late 1987, the measles epidemic now extends from South America to Canada, with no end in sight, according to Dr. Walter Orenstein, director of immunization for the federal Centers for Disease Control. Every state except North Dakota reports measles. U.S. cases through June totaled nearly 14,000, compared to 8,663 for the same period last year.
Measles is the suspected cause of 42 deaths in California, more than twice the number in 1989. Most of the victims are children under 5.
In San Diego County, there are no door-to-door campaigns planned, but special immunizations clinics will be held in August, said Dr. Donald Ramras, public health officer. The county has had more than 800 measles cases reported this year, including three deaths of children, all Latino.
Now, only about half a dozen cases are being reported weekly, but that summer lull is normal, Ramras said.
"The disease cycles, and the low part of the cycle is during the summer months," he said. "But in a year when we weren't in an outbreak, we wouldn't be seeing any now. It's highly likely our caseload will pick up in late fall or early winter."
Many now say the measles epidemic was an inevitable result of inadequate funding of the public health system. Where once an elaborate network of community-based nurses kept tabs on such basic family health needs as immunization, today the system in the United States depends largely on parents to know when their children need care and how to obtain it.
And what minimal community services exist have not adapted adequately to new immigrant waves, urban growth and other social changes that have eroded traditional channels of communication.
The result is a growing number of families outside the health care system, their children unimmunized, their infections overlooked by keepers of the nation's health statistics--ideal fuel for an epidemic.
"Everyone knows that when immunization levels drop, it is just a matter of time before you get an epidemic," said Dr. Philip A. Brunell, professor of pediatrics at UCLA.
Health officials concede that they have lost track of a lot of young and mostly poor families in casting their immunization net. Dr. William L. Atkinson, the Centers for Disease Control's head of measles surveillance, said the problem is most acute in big cities.
Recent national studies of preschool-age children show that fewer than half of the urban poor are properly immunized.
Health officials are turning to the community to hand-carry the immunization message to people's doorsteps.
"We've utilized Kiwanis Club, Lions Club, the Red Cross, boys and girls clubs, the NAACP," said Gary Euler, disease control manager for the San Bernardino County health department. "We've given vaccine at churches, at the local (minor league) baseball games. About the only thing we haven't done is drive trucks with loudspeakers mounted on top to order people in for measles shots."
But changing the way health care is delivered takes time and money.
California's lawmakers have met the epidemic with $7.8 million in special measles appropriations, most of which has been spent, according to Dr. Loring Dales, immunization chief for the state Department of Health Services.
Congress, meanwhile, has given the CDC an extra $12 million to help the states, money that Dales expects to receive a share of this fall.