Tuberculosis, 2019

In 2019, 148 tuberculosis (TB) cases (2.6 per 100,000 population) were reported. This represents a 14% decrease in the number of cases compared to 2018, when there were 172 new cases. The TB incidence rate in Minnesota was lower than the overall rate in the United States, which was 2.7 per 100,000 in 2019. The TB case count has decreased 38% since 2007, when 238 cases were reported, and has remained under 200 since 2009. Seven cases (5%) from 2019 have died, all due to TB disease.

Twenty-four counties (28%) had at least 1 case in 2019. The majority of cases (73%) occurred in the metropolitan area, primarily in Hennepin (36%) and Ramsey Counties (20%). Twenty-six cases (18%) were from the other five metropolitan counties, and the remaining 27% of cases were reported from greater Minnesota. Among metropolitan area counties, the highest TB incidence rate in 2019 was reported in Ramsey County (5.3 per 100,000), followed by Hennepin County (4.2 per 100,000). The combined TB incidence rate for the other metropolitan counties (excluding Hennepin and Ramsey Counties) was 2.0 per 100,000, and 1.6 per 100,000 for all greater Minnesota counties.

The largest group of new TB cases were those 25-44 years of age at time of diagnosis (42%), followed by cases 45-64 years of age (22%). Two percent of new cases were <5 years of age when they were diagnosed.

only after seeking medical care for symptoms of disease. Various targeted public health interventions identified the majority of the remaining 15% of cases. Such case identification methods are high priority core prevention and control activities, and include contact investigations (6%) and follow-up evaluations of individuals with abnormal findings on preimmigration exams where infectious TB disease had been ruled out (<1%). An additional 4% were identified through other screening (e.g., other immigration medical exams, employment screening, and other targeted testing for TB). Six cases (4%) were diagnosed with active TB disease incidentally while being evaluated for another medical condition.

TB incidence is disproportionately high among racial and ethnic minorities in Minnesota as well as nationally. In 2019, 11 cases occurred among non-Hispanic whites, a case rate of 0.2 per 100,000. In contrast, among non- Hispanic persons of other races, 72 cases occurred among blacks/Africanborn persons (17.7 cases per 100,000), and 54 among Asian/Pacific Islanders (17.9 cases per 100,000). Eleven cases were Hispanic persons of any race (3.6 cases per 100,000). The majority of Hispanic (100%), Asian (94%), and black cases (89%) were non-U.S. born.

In 2019, the percentage of TB cases in Minnesota occurring in persons born outside the United States was 88%, compared to 71% of TB cases reported nationally. The 130 non U.S.-born TB cases represented 25 different countries of birth; the most common region of birth among these cases was Sub-Saharan Africa (49% of non- U.S. born cases), followed by South/ Southeast Asia (35%), Latin America (including the Caribbean) (9%), and East Asia/Pacific (4%). Patients from other regions (North Africa/Middle East, and Eastern Europe) accounted for the remaining 4% of cases (Figure 6).

Compared to the percentage of cases who have lived in areas of the world where TB is more common, individuals in other high risk groups comprised smaller proportions of the cases. Note that patients may fall under more than one risk category. Thirty-eight percent occurred in persons with certain medical conditions that increase the risk for progression from latent TB infection to active TB disease (e.g., diabetes, prolonged corticosteroid or other immunosuppressive therapy, end stage renal disease). The next most common risk factor was substance abuse (including excess alcohol use and/or injection and non-injection drug use) during the 12 months prior to their TB diagnosis (3%). Three percent of cases were co-infected with HIV. Three percent reported being homeless during the 12 months prior to diagnosis, 1% were residents of long-term care facilities, and 1% were in a correctional facility at time of diagnosis.

By site of disease, 53% of cases had pulmonary disease exclusively. Another 18% had both pulmonary and extrapulmonary sites of disease, and 28% had extrapulmonary disease exclusively. Among the 69 patients with an extrapulmonary site of disease, the most common sites were lymphatic (46%), followed by musculoskeletal (25%). Extrapulmonary disease is generally more common among persons born outside the United States. Forty-eight percent of non U.S.- born cases in Minnesota had at least one extrapulmonary site of disease, compared to only 39% of U.S.-born cases.

Of 123 culture-confirmed TB cases with drug susceptibility results available, 17 (14%) were resistant to at least one first-line anti-TB drug (i.e., isoniazid [INH], rifampin, pyrazinamide, or ethambutol), including 13 cases (11%) resistant to at least INH. There were 6 new cases of multidrug-resistant TB (MDR-TB, or resistance to at least INH and rifampin) reported in 2019, making up 5% of culture-confirmed cases.

• Find up to date information at>> Tuberculosis (TB)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2019