Tuberculosis, once a feared and deadly disease in this country, is again on the upswing, and school officials in several districts are expanding efforts to prevent the highly contagious illness from gaining access to the classroom.
In New York City, Houston, and Los Angeles County, for example, school officials are requiring all new students to prove that they have been tested for the disease.
And other districts are looking with renewed interest at requiring tuberculin tests of their staff members.
Long thought by health officials to be a disease on the decline in the United States, tuberculosis has made an unwelcome comeback in recent years. Although some medical experts believe much of the rise in tuberculosis cases can be traced to the AIDS epidemic, others note that high levels of immigration from Southeast Asia, Mexico, and Central America, where the disease is more common, also might have fueled the increase. About 80 percent of all tuberculosis patients are members of minority groups, and most are poor.
A highly communicable illness, tuberculosis can be spread merely by the cough of an adult or teenager with an active case of the disease.
Although a young child can easily become infected with the disease, he is unlikely to spread his illness because his cough typically lacks the force of that of an adult.
Active cases of the disease can be treated successfully with medication, but no effective vaccine to prevent the disease now exists.
Experts at the U.S. Centers for Disease Control estimate that as many as 10 million Americans may be infected with the disease. But only about one-tenth of these people eventually will develop an active case, and thus be capable of infecting others, they said. Those who are ' infected but do not have the disease have no symptoms and pose no danger to others, they noted.
Children Hard Hit
The disease is caused by several species of microorganism called Mycobacteriurn. Active cases involve lesions of the lung, bone, and other parts of the body. Onset of the disease is accompanied by lack of energy, weight loss, and persistent cough.
After three decades of steady declines in the number of Americans with active tuberculosis, physicians began reporting larger w.B. caseloads in 1985. Daring the past three years in particular, the percentage of children with the active disease has grown much faster than among the population as a whole.
In 1990, 25,701 Americans were diagnosed as having tuberculosis, 1,596 of whom were under the age of 15. While the overall number of cases has increased 14.6 percent since 1988, the percentage of children with the disease grew by more than 40 percent over the same time period.
Alan Bloch, a medical epidemiologist in the tuberculosis-elimination division of the C.D.C., said it is important to test high-risk children for the disease because “they are a sentinel of transmission in the general population.”
“Kids are young,” Dr. Bloch said. “By definition, they must have gotten infected recently.”
But he acknowledged that political, rather than medical, reasons have fueled universal school-entry testing requirements in some districts.
“You can’t blanket say that every child in the U.S. should be tested,” Dr. Bloch said. “Some school systems have found that it is easier to test everyone, so that way, no one is stigmatized.”
New Teachers Targeted
Last year, the c.D.c. recommended that children from high-risk groups, such as poor or foreign-born children, annually receive a test for the disease, which costs less than a dollar to administer. The American Academy of Pediatrics, meanwhile, recommends a similar schedule for high-risk children, and suggests that low-risk children be tested around the time of their first birthday and before they enter kindergarten and high school.
In some districts, it is the new teachers, not the new pupils, who are required to take a tuberculosis test. In the Fergnson-Florissant district in Missouri, for example, officials decided to add this requirement after a teacher with an active case of T.B. infected nearly half of an elementary school’s pupils last fall.
The school district, along with local health officials, developed a plan for annually monitoring all the students and teachers who were infected by the physical-education teacher, said Shirley Salmon, the district’s assistant superintendent for student-support services. One student, she said, developed an active case of the disease but was successfully treated.
In cities where the disease is more common, health officials have urged or required students entering school for the first time to prove that they have undergone tuberculin tests. By noting which children are infected, they said, it is relatively easy to trace the adults, typically family members and adult friends, who may have passed along the disease.
Follow-Up Important
Typically, children who test positive for the infection are urged to get follow-up tests to determine if they have an active case of the disease. If it is active, they are put on a drug regimen and kept out of school for several weeks, until they no longer pose any threat to others.
Children who are infected but who have not yet developed the disease can take preventive medicine for six to nine months that reduces their risk of getting the disease by 90 percent.
This fall, for the first time, the approximately 160,000 students who entered public and private schools in New York City were required to prove they had been tested for the disease. Since the city is responsible for about 15 percent of all of the nation’s tuberculosis cases, virtually every child in the district could be considered at high risk and should be tested, said Jack Adler, the medical director of the tuberculosis bureau in the city’s health department.
“We think that an effective T.B. evaluation process should be in place here, “said Dr. Adler.
But the problem, health officials in other cities say, is ensuring that children who test positive receive the proper follow-up care.
“If you don’t have a good mechanism for following up on these kids, then there is no reason to do this screening,” said Jeffrey Starke, an assistant professor of pediatrics at Baylor College of Medicine in Houston. He said that city dropped its testing requirement in 1984, but reinstated it last fall.
Paul T. Davidson, the director of T.B. control for Los Angeles County, acknowledged that local public health officials do not have the resources to follow up on the results of every child’s tuberculosis test, which has been required for school entry in the county since 1985. “We don’t have a good way of tracking” preventive treatment for all the city’s infected children, he said.
He said some have also questioned whether resources now devoted to juvenile testing would be better spent on treating adults with active tuberculosis. “It’s not a simple, straightforward issue,” he said.
