Mycobacterium tuberculosis disease in Somali immigrants in Minnesota.

Abstract

STUDY OBJECTIVE: To characterize pulmonary and extrapulmonary Mycobacterium tuberculosis cases in the Somali community in Minnesota. DESIGN: Retrospective chart review of active tuberculosis cases in Somalis reported to the Minnesota Department of Health between January 1993 and June 1998. PATIENTS: Ethnic Somalis in the state of Minnesota with M tuberculosis diagnosed by positive culture or radiographic findings consistent with tuberculosis and clinical improvement when treated with antituberculous drugs. RESULTS: Eighty-two Somali patients were diagnosed with tuberculosis during the study period. Extrapulmonary disease (typically lymphadenopathy) was present in 46% (n = 38). The 1997 incidence of tuberculosis in Minnesota's Somali population was estimated at 170 cases per 100,000 population compared with a national incidence of 20.5 per 100,000 among African Americans and 2.5 per 100,000 among whites. Ninety percent of Somali patients were < 40 years of age; 63% were diagnosed within 1 year of immigration, and > 90% had positive results with the purified protein derivative skin test. M tuberculosis was confirmed in 24 of 25 isolates from extrapulmonary cases. Multidrug resistance was present in 3.4%, and only two patients had AIDS. CONCLUSIONS: Somalis have a high incidence of active disease, with frequent extrapulmonary involvement in the absence of AIDS, clinical presentation shortly after immigration, and infrequent infection with resistant organisms. Health-care providers should maintain an increased awareness for tuberculosis when evaluating Somali immigrants.