A notable decline in tuberculosis cases in 2020 may be followed by an uptick once the COVID-19 pandemic wanes, according to researchers with the Centers for Disease Control and Prevention. Clinicians should be prepared to detect cases and control spread, they say.
Cases fell by 20% in 2020 when compared to 2019, investigators said. It is unlikely that the drop was due to underreporting, but it isn’t possible to rule out that it was caused by underdiagnosis, they added.
To better clarify what may have caused the drop in cases during the pandemic, researchers compared national case counts from the U.S. National Tuberculosis Surveillance System with TB medication dispensing data. The biggest decline in cases occurred in April and May 2020, when large swaths of the country had restrictive infection mitigation measures in place that reduced individual mobility and personal contact, they reported.
Documented treatment delays also add to evidence that underdiagnosis of TB was at play, the investigators said. Fully 41% of US adults had delayed or avoided seeking medical care by June 2020.
Delayed or missed diagnoses could result in increased transmission as patients remain infectious for longer periods of time, they warned clinicians and public health officials.
“TB cases should continue to be monitored closely, especially given the highly infectious nature of TB and the chance of increased illness and deaths if treatment is delayed,” the investigators concluded.
TB can be insidious in long-term care facilities, lurking undetected and sometimes missed by intake testing. Although the current study did not investigate cases in these settings, 1.7% of individuals 15 years of age or older diagnosed with the disease were current residents of long-term care facilities in 2020 compared with 1.8% in 2019, according to the CDC.
Full findings were published in the CDC journal Emerging Infectious Diseases.
