Chicago TB cases overall declines; increases among foreign-born residents

The Chicago Department of Public Health's soon to be released Tuberculosis Morbidity Report for 2007 shows a downward trend in TB cases throughout Chicago.

But the proportion of cases among foreign-born Chicagoans is growing.

Of all TB cases reported in 2007, 51.4 percent occurred among foreign-born Chicago residents, compared with 45.2 percent a year earlier. Last year, there were 20.8 cases of TB per 100,000 foreign-born residents compared with a 2006 figure of 21.1 cases per 100,000.

"We really have to forge international partnerships if we're ever really going to defeat TB," said Dr. Ronald Hershow, an associate professor of epidemiology and medicine at the University of Illinois at Chicago.

The increased frequency of TB among foreign-born residents is an unfortunate circumstance considering Chicago's progress in decreasing TB cases overall. With a rate of 8.9 cases per 100,000 people, TB occurrences in Chicago are lower than those in New York City and Los Angeles, according to comparable data from 2006.

However, Chicago's rate for 2007 is still double the national rate - 4.4 cases per 100,000 people - and the state rate - 4.1 cases per 100,000.

Directly Observed Therapy (DOT), an initiative by the World Health Organization, is one of the reasons why Chicago's TB rate is down, said Dr. William Clapp, the medical director of CDPH's TB Control Program. DOT in Chicago involves nursing case management, where each person with an active case of TB is assigned a nurse to help him or her with logistical issues or medical side effects, Clapp said.

In addition, the DOT program ensures that "Every time a person takes a dose of medication, it is observed by a person," Clapp said. "We're reassuring that the patients get their medications and that they get the right combinations of medications."

Drug resistance is one problem medical care providers deal with when battling TB among foreign-born residents, according to Hershow.

"The unfortunate truth about TB therapy is it's unlike other infectious diseases that you treat over three weeks, it's a disease you treat over three months." Hershow said. "And so-called sustained treatments for a period of 6 months require resources [and] careful follow up, and that is beyond the economic wherewithal of many countries."

So why do the foreign-born fall victim to TB in higher proportions than other groups of Chicagoans?

"There's just a lot more people coming to our country right now. " Clapp said. "The second reason is that immigration policies are really only designed to screen people who are official immigrants or refugees and not people who are traveling for pleasure, traveling for business, students and certainly not undocumented people."

The 2007 data also shows that Mexico, the Philippines and India are the top three countries of origin for TB cases among the foreign-born in Chicago. More than one-third of Chicago's foreign-born cases originate in Mexico.