COVID-19, TB coinfection linked to reduced survival

Key takeaways:

• Median time to death was 21 days for COVID-19 plus tuberculosis deaths, 52 days for COVID-19 deaths and 168 days for TB deaths.
• The TB mortality rate was 10.8% and the COVID-19 mortality rate was 13.1%.

Patients who died of a COVID-19 and tuberculosis coinfection had a shorter median time to death compared with patients who died of either COVID-19 or TB alone, according to results published in European Respiratory Journal.

“Most patients who died were in the group in which the COVID-19 diagnosis was before/during TB treatment [vs. after TB treatment], underscoring that concomitant TB and COVID-19 is associated with greater severity and worse outcomes and faster median time to death,” members of the Global Tuberculosis Network and TB/COVID-19 Global Study Group wrote.

To determine the long-term outcomes of a COVID-19 and TB coinfection, the study group assessed 788 patients (mean age, 45.5 years; 67.8% men) from 174 centers in 31 countries who had both infections between March 2020 and September 2022.

Results showed COVID-19 was more often the reason for hospitalization vs. TB (44.3% vs. 38.5%) as well as for use of mechanical ventilation (4.4% vs. 2%) and supplemental oxygen (19.2% vs. 11%).

Among those with data on the time of their diagnoses (n = 777), COVID-19 occurred before/during TB treatment among 495 patients — 59.8% of whom contracted COVID-19 before treatment, 14.9% during treatment and 25.3% within the same week — and after TB treatment among 282 patients. A majority (72.3%) of patients diagnosed after TB treatment finished the treatment more than a year before their COVID-19 infection.

Looking specifically at TB outcomes, researchers observed that 77.2% of patients achieved treatment success, with higher rates of success among patients who received their COVID-19 diagnosis after vs. before/during TB treatment (90.8% vs. 69.7%; P < .0001).

“TB treatment success and completion of treatment was greater when the diagnosis of COVID-19 occurred after the end of TB treatment; that is, when the diagnosis of the two diseases was not concomitant,” researchers wrote.

Researchers noted 85 deaths, for a TB mortality rate of 10.8%. Of them, 46 died of TB and COVID-19, 17 died of TB and nine died of COVID-19. The remaining deaths were caused by TB, COVID-19 and “other” (n = 4) or “other” (n = 9).

Looking specifically at COVID-19 outcomes, researchers noted COVID-19 recovery appeared more likely when it was diagnosed prior to/during vs. after TB treatment (76.3% vs. 60.1%; P < .0001). Of the 102 deaths (13.1% morality rate), 38 died of COVID-19 alone, six died of COVID-19 plus “other,” seven died of “other,” one died of TB, and the remainder died of coinfections as noted above.

Researchers found that patients who died of both COVID-19 and TB had a shorter median time to death (21 days; interquartile range [IQR], 8-90 days) compared with patients who died of COVID-19 (52 days; IQR, 30.5-227.5 days) or TB (168 days; IQR, 45.3-342.8 days; P < .001) alone.

Using Cox proportional risk-regression models, researchers looked at risk factors for overall mortality and for mortality attributable to either TB or COVID-19.

Adjusted risk factors for overall mortality in this cohort included a supplemental oxygen requirement (adjusted HR = 3.77; 95% CI, 1.98-7.17), invasive ventilation (aHR = 2.28; 95% CI, 1.39-3.72) and age (aHR = 1.03; 95% CI, 1.02-1.05).

Adjusted risk factors for both TB mortality and COVID-19 mortality included older age (aHR = 1.05; 95% CI, 1.03-1.07; aHR = 1.03; 95% CI, 1.02-1.04) and invasive ventilation (aHR = 4.28; 95% CI, 2.34-7.83; aHR = 2.19; 95% CI, 1.36-3.53).

Having an HIV infection (aHR = 2.29; 95% CI, 1.02-5.16) was only a significant risk factor for TB mortality, whereas needing supplemental oxygen (aHR = 7.93; 95% CI, 3.44-18.26) and male sex (aHR = 2.21; 95% CI, 1.24-3.91) were significant risk factors only for COVID-19 mortality.

“In our cohort, [more than] 70% of surviving patients had favorable outcomes (ie, recovered COVID-19 and successful TB treatment),” the study group wrote. “Future studies should evaluate the long-term pulmonary sequelae of these patients and elicit the effectiveness of and establish the need for pulmonary rehabilitation, as well as the protective role of anti-COVID-19 vaccination, and potentially of other available vaccines.”