Tuberculosis Is Disappearing in the U.S. — But Not Fast Enough
Posted March 26, 2018 8:17 p.m. EDT
Tuberculosis rates reached a historic low in the United States in 2017, but infection rates did not fall as quickly as in previous years — and not fast enough to eradicate the disease.
The Centers for Disease Control and Prevention reported that there were 9,093 new cases of TB in 2017, continuing the steady decline since 1993. The rate of infection declined by 2.5 percent over the last year. But eliminating the disease before 2100 would require a sustained annual decline of 3.9 percent.
TB is spread when a person infected in the lungs or throat speaks, coughs, sneezes or spits, sending the bacterium aloft. It is not transmitted by shaking hands or touching something a person with TB has handled.
People can be infected without symptoms, a form called latent TB. These people cannot transmit the disease, and an otherwise healthy person can carry it for a lifetime. But the disease can be activated if the immune system becomes weakened.
“We need to focus on TB infection among people who are not having symptoms,” said a co-author of the report, Clarisse A. Tsang, an epidemiologist with the CDC.
Treatment requires a combination of drugs taken over six to nine months. The drugs must be taken exactly as prescribed — stopping too soon, or taking them irregularly, can result in the development of drug-resistant strains of TB.
Almost 70 percent of cases were in people not born in the United States; the rate among the foreign-born was 15 times that of those born in this country. The highest rates were among people from Mexico, the Philippines, India, Vietnam and China.
“TB disparities reflect more complicated factors that drive infection and the risk of disease, rather than some inherent biological susceptibility,” said Dr. Ted Cohen, an associate professor of epidemiology at the Yale University School of Public Health. Cohen was not involved in the report.
Rates were highest in California, Hawaii, Alaska, Texas and New York, and lowest in Wyoming, Montana and Idaho. Among those with TB who were born in the United States, 37 percent were African-Americans and 30 percent were non-Hispanic whites.
“The U.S. has done a great job in controlling TB,” said the lead author, Rebekah J. Stewart, a nurse epidemiologist at the CDC. “We have the lowest case numbers and rates on record.
“But the slowing rate of decline reminds us that we need to renew our efforts. TB is not a disease of the past.”