The rate of tuberculosis among Montgomery County residences is twice the national average and is the highest in Maryland, state data show.
The county saw 73 cases of tuberculosis in 2011, for a "case rate" of 7.6 cases per 100,000 residents, Montgomery County Health Officer Ulder Tillman told the Montgomery County Council on Tuesday. By comparison, Maryland had 234 cases, for a rate of four cases for every 100,000 residents, while the United States had a case rate of 3.6.
The U.S. had 11,182 cases of TB in 2010, according to data from the Centers for Disease Control and Prevention, though 2011 data were not available.
Sources: Virginia Department of Health, Maryland Department of Health and Mental Hygiene, Centers for Disease Control and Prevention, District of Columbia Department of Health
|TB in the Washington region|
|Number of cases||26||20||19||13||9|
|Case rate (per 100,000)||13||10.7||9.4||5.8||4.2|
|District of Columbia|
|Number of cases||59||54||41||44||Unavailable|
|Case rate (per 100,000)||10||9.1||7.2||6.8||Unavailable|
|Number of cases||108||98||86||87||82|
|Case rate (per 100,000)||10.3||9.5||8.2||8.0||7.2|
|Number of cases||82||88||70||69||73|
|Case rate (per 100,000)||8.8||9.3||7.2||7.1||7.6|
|Prince George's County|
|Number of cases||66||68||65||43||47|
|Case rate (per 100,000)||7.9||8.3||7.8||5.0||5.4|
|Number of cases||270||278||218||220||234|
|Case rate (per 100,000)||4.8||4.9||3.8||3.8||4.0|
|Number of cases||309||292||273||268||221|
|Case rate (per 100,000)||4||3.8||3.5||3.4||2.7|
Montgomery County has had the highest rate of TB infection in the state for nearly a decade because of its large immigrant population, Tillman said. Of the county's 73 cases last year, 8 percent occurred in residents born in the U.S.
In the last three years, Montgomery County residents from Ethiopia, India and China had the highest infection rate, according to the county's Tuberculosis Control Program.
By contrast, neighboring Prince George's County -- which has a smaller share of immigrants -- had 47 cases in 2011, at a rate of 5.4 cases per 100,000 residents. Only 19.4 percent of people who lived in Prince George's between 2006 and 2010 were born in another country, census data show, compared with 30.9 percent of Montgomery County residents.
Across the Potomac, Fairfax County faces a similar situation to Montgomery's. Fairfax saw 82 cases of tuberculosis in 2011, for a rate of 7.2 cases per 100,000 residents. There, 28.8 percent of the population was born in another country.
Between 2005 and 2011, 12.6 percent of Fairfax's incidents occurred in immigrants from India, 12.3 percent in immigrants from Vietnam and 8.5 percent in immigrants from Ethiopia, according to the Fairfax County Health Department.
"Fairfax County is an immigrant gateway and TB incidence remains high due to the continued predominance of foreign-born individuals among local TB cases," according to a Fairfax County Health Department report to be released in the coming weeks.
The pattern is not unique to the Washington region. While the country has seen a roughly 4.7 percent drop in tuberculosis cases every year, the number of cases in foreign-born residents has remained steady, the report said.
In 2011, roughly 62.5 percent of TB cases were among foreign-born individuals, according to the Fairfax report. A 2010 CDC report shows that, of foreign-born cases of TB, 45 percent were in Asian populations and 37 percent in Hispanic.
The CDC points to language and culture barriers, as well as socioeconomic factors like insufficient access to health care, housing, jobs or transportation, as reasons for the difference in infection rates.