PURPOSE: Pulmonary Tuberculosis presents in many ways; some patients develop a slowly progressive, insidious disease whilst others develop a rapidly progressive, fulminating respiratory failure. no information is available as to whether strain types affect the severity of disease. We hypothesized that patients who develop ARDS due to Mycobacterium tuberculosis are infected with a more virulent strain of mycobacterium tuberculosis that is distinct from the strain causing less aggressive pulmonary disease.
METHODS: Patients admitted to AKUH with ARDS due to microbiologically-confirmed pulmonary tuberculosis were reviewed. Preserved specimens were prospectively recultured and isolates spoligotyped for strain identification. The control group was patients diagnosed with pulmonary TB in the outpatient setting on respiratory secretion culture. Clinical data demographics, treatment (steroids, ATT) and outcomes (mortality rate, sensitivity patterns, strain typing of isolates) are reported as means and proportions with standard deviations.
RESULTS: 12 cases met criteria for enrollment. 12 consecutively sampled, control patients were included for comparison. 91.6% [11 patients] were admitted from the emergency room. 33% [4 patients] had Acute Respiratory Distress Syndrome [ARDS] at admission while in 66% [8 patients] ARDS developed an average of 1.14 days [range 1–7 days] after admission. 41.6% [5 patients] were treated with intravenous corticosteroids for ARDS caused by mycobacterium TB. Inpatient mortality rate was 61% [11 patients]. The mean length of hospitalization was 11.8 days ± 12.2 [range 1–50]. The most common strains identified in the ARDS group were CAS I (58.3%) and UNQUE (25%).BIEJING and CAS subfamily were identified in 8.3% patients each. In the control group, UNQUE (33.3%) was most common, followed by CAS subfamily (25%) and CAS I (25%). BEIJING strain was the least common (16.6%).
CONCLUSION: Patients who develop ARDS due to pulmonary TB, have a different preponderance of mycobacterial strains compared to those who do not develop ARDS.
CLINICAL IMPLICATIONS: These results have implications for vaccine development and early steroid use in TB-induced ARDS.
DISCLOSURE: Nawal Salahuddin, No Financial Disclosure Information; No Product/Research Disclosure Information