1382. Acid-Fast Bacilli Testing Trends at 43 In- and Outpatient Facilities and Nontuberculous Mycobacterial Pulmonary Isolation Rate, United States, 2009–2015

Abstract

BackgroundThe prevalence of nontuberculous mycobacterial pulmonary disease (NTM PD) is increasing in the United States and globally. The reasons for this increase are not clear but could be related to both gained awareness leading to increased mycobacterial testing, or to a true NTM PD increase. To further examine the role of testing rates in the observed increase, we studied trends in Acid-Fast Bacteria (AFB) testing and NTM isolation positivity using a large Electronic Health Record (EHR) dataset in the United States.MethodsUsing the Cerner Health Facts EHR dataset, we extracted microbiologic, demographic, and clinical data for patient encounters (inpatient or outpatient), with ≥1 orders for AFB respiratory cultures. The analysis was limited to the 43 facilities reporting continuously for the period 2009–2015. A patient with at least one AFB test was considered tested (AFB) and a patient with at least one pathogenic NTM respiratory isolate was considered positive. Trends in AFB testing and NTM positivity were estimated using log-linked Poisson regression (P < 0.05).ResultsFrom 2009 through 2015, of 14.8 million patients, 65,010 had 142,315 AFB tests, averaging 2.2 AFB tests/patient, for an overall testing prevalence of 0.43%; the annual testing prevalence remained unchanged during the study period (P = 0.44) (Figure 1). Of the 65,010 patients with AFB tests, 3,942 (6.1%) had ≥1 pathogenic NTM species, for an overall pulmonary NTM isolation prevalence of 2.7/10,000 patients represented in Cerner Health Facts dataset. Of the patients that had at least one pathogenic NTM, 3,094 (78%) had M. avium complex, and 265 (7%) had M. abscessus/chelonae, (Figure 2). Among patients with at least 1 NTM-positive culture, 138 patients had concomitant growth of M. tuberculosis.ConclusionIncreases in NTM PD are not explained by increases in AFB testing, which remained constant in the population represented here. This study was funded in part by the Division of Intramural Research, NIAID, NIH. Disclosures All authors: No reported disclosures.