A 68-year-old Caucasian male presented for an infectious disease consult with intermittent fever, night sweats, atrial flutter, and a productive cough of 6-month duration. His sputum was clear/white in the morning and improved during the day although he reported that his sputum sometimes became gray during the day. The patient's weight decreased from 210 to 130 pounds over the last year, which he described as intentional. Past medical history included a 55-year history of cigarette smoking (2 ppd), a 50-year history of marijuana use, chronic obstructive pulmonary disease, peripheral vascular disease, peripheral artery disease, and basal and squamous cell skin cancer. The patient reported no recent sick contacts and no one in his family had similar symptoms.
The patient was born and raised in Illinois and currently lives in a rural area of Michigan with his wife, children, dogs, a parrot, and canaries. The birds are kept in cages, which he cleans without wearing a mask. He served in Vietnam from 1966 to 1968 and denied exposure to M. tuberculosis during that time. He was employed as a nurse with his most recent employment in a prison in Allegan, Michigan where he worked for 2 years before retiring 6 years ago. His PPD (purified protein derivative) tests were negative during his employment, and no inmates had a positive PPD while he worked at the prison. He indicated a remote history of close exposure to tuberculosis while working as a nurse in the 1970s when he performed CPR without a barrier on a patient with active tuberculosis. Serial chest x-rays and four PPD skin tests in the following year were negative.
On examination, he appeared alert and well-oriented with decreased breath sounds bilaterally on auscultation. Chest x-rays revealed bilateral upper lobe caviation with coarse interstitial markings, parenchymal distortion, hilar retraction, and pleural thickening consistent with possible infection with M. tuberculosis, atypical mycobacteria, or a fungus. Computed tomography angiography of the chest demonstrated a single small embolus in the right upper lobe artery and severe emphysematous changes bilaterally, with extensive cavitation in each upper lobe consistent with a mycobacterial infection (Fig. 1, Fig. 2, Fig. 3). The patient was admitted with a presumptive diagnosis of reactivation pulmonary tuberculosis based on his history of employment as a nurse in several hospitals and a prison, and his history of direct contact with a patient with active tuberculosis. Quadruple anti-tuberculosis therapy with isoniazid, rifampin, pyrazinamide, and ethambutol was initiated. Sputum samples were collected for microscopic analysis and culture, and blood was collected for labs and testing for HIV and hepatitis B and C.
Lab results for HIV, hepatitis B and hepatitis C were negative, however two separate acid-fast bacilli smears of sputum demonstrated numerous acid-fast bacilli. During the second week of admission, the quadruple anti-tuberculosis therapy was discontinued due to elevations in alanine aminotransferase (305 U/L) and aspartate aminotransferase (185 U/L) levels, and a negative interferon gamma release assay (Quantiferon-TB Gold) for tuberculosis. Despite discontinuing the anti-tuberculosis therapy, the patient improved and was released from the hospital. The discharge plan was thoroughly discussed with the patient and a follow-up visit was scheduled.
During initial outpatient follow-up two weeks later, the patient was clinically improved and reported feeling "much better." However, repeat acid-fast bacilli stains continued to demonstrate numerous acid-fast bacilli and the patient's chest x-ray remained unchanged. Sputum cultures were negative when examined with a direct M. tuberculosis complex gene probe (AccuProbe, Hologic), and broth cultures (Middlebrook 7H9 broth) were sent to the Michigan Department of Community Health Bureau of Laboratories and subsequently identified as M. celatum by high performance liquid chromatography (HPLC) and chemistries. The patient was started on clarithromycin, ciprofloxacin, and ethambutol. Four weeks later, the patient reported no fever, no sweats, diminished cough, and a sputum with decreased viscosity and coloration. The patient has continued follow up in the outpatient setting, and six months after discharge, both acid-fast bacilli smears and cultures for M. celatum have continued to be negative.