(HealthDay)—In 2020, there was a large decrease in tuberculosis (TB) cases, according to research published in the March 26 issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.

Molly Deutsch-Feldman, Ph.D., from the CDC in Atlanta, and colleagues describe the incidence of TB in the United States in 2020.

The researchers found that 7,163 TB cases were provisionally reported to the CDC National Tuberculosis Surveillance System by the 50 U.S. states and District of Columbia (DC), representing a 20 percent relative reduction compared with 2019. The incidence of TB per 100,000 persons was 2.2 compared with 2.7 during 2020 and 2019, respectively. Overall, 39 states and DC, eight states, and three states reported a decrease in cases, an increase in cases, and no change, respectively. The highest number of cases was reported in California (1,703 cases), while the highest incidence was seen in Alaska (7.9 cases per 100,000 persons). Pandemic mitigation efforts and reduced travel could have contributed to this decline, although the magnitude and breadth of the decrease suggests potentially missed or delayed diagnoses.

"Further work is in progress to examine the causes of the steep decrease in reported TB cases," the authors write. "Identifying reversible causes of underdiagnosis or actual causes of an actual reduction in TB cases during 2020 will help identify effective public health responses."

More information: Abstract/Full Text

Journal information: Morbidity and Mortality Weekly Report