JOHNS HOPKINS
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Department of Pathology
600 N. Wolfe Street / Baltimore MD 21287-7093
(410) 955-5077 / FAX (410) 614-8087
Division of Medical Microbiology
THE JOHNS HOPKINS MICROBIOLOGY NEWSLETTER Vol. 26, No. 17
Tuesday, September 18, 2007
A. Provided by Emily Luckman, Division of Outbreak Investigation, Maryland Department
of Health and Mental Hygiene.
There is no information available at this time.
B. The Johns Hopkins Hospital, Department of Pathology, Information provided by,
Danielle Wehle, M.D., M.S.
Case presentation: A 34-year-old otherwise healthy woman followed at an outside hospital in Atlanta,
Georgia, presented to JHH for a second opinion regarding a complicated history of chronic bilateral otitis
media. The patient had experienced left-sided otorrhea and gradual hearing loss for approximately two
years. She had two previous tympanoplasties and mastoidectomies, the last one in 10/2006. In January,
2006 she began to develop right-sided otorrhea. She was treated with antibiotics and a pressureequalization tube. She went on to develop osteomyelitis and osteonecrosis of the right temporal bone. She
was intermittently treated with oral antibiotics. At presentation to JHH she complained of right otorrhea
and decreased hearing bilaterally. Her extensive medical work-up at the outside hospital which included
testing for autoimmune diseases and Wegners granulomatosis was entirely negative. An audiology visit in
April, 2007 at JHH showed moderately-severe conductive hearing loss bilaterally. She was given oral
ciprofloxacin and otic corticosporin with no improvement in hearing. A second audiology visit resulted in
the decision to perform right tympanoplasty and mastoidectomy (performed 8/1/2007) due to blockage.
Tissue samples from the surgery sent for Mycobacterial cultures were positive at 13 days for
Mycobacterium Tuberculosis complex. The surgical pathology specimen showed caseating an noncaseating granulomas which were AFB positive and GMS negative. The patient had a negative chest xray
and TB skin test.
Epidemiology: Tuberculosis (TB) remains a major health concern. After a resurgence in the 1980s, there
has been a steady decline of the disease in the United States. However, this steady decline requires
continued vigilance by the Public Health infrastructure. According to the CDC, in 2006 a total of 13,767
tuberculosis (TB) cases (4.6 per 100,000 population) were reported in the United States, representing a
3.2% decline from the 2005 rate. The TB rate in 2006 was the lowest recorded since national reporting
began in 1953, but the rate of decline has slowed since 2000. Foreign-born persons and racial/ethnic
minority populations continue to be affected disproportionately by TB in the United States. In 2006, the
TB rate among foreign-born persons in the United States was 9.5 times that of U.S.-born persons.
Approximately 85% of reported cases involve the lungs and the remainder involve extrapulmonary sites.
Tuberculous otitis media is rare among the extrapulmonary cases. In South Korea (one of the sites with the
highest incidence of disease) tuberculous otitis media represents 0.9% of chronic otitis media cases.
Microbiology: The genus Mycobacterium consists of a diverse group of strongly acid-fast bacilli (AFB)
with high lipid content consisting of waxes with long chain mycolic acids. These mycolic acids confer
acid fastness which is the hallmark of the genus. This is a diverse genus with over 80 species identified but
few associated with human infection. M. tuberculosis, M. bovis, M. africanum, and M. leprae have a high
propensity for causing disease and are always considered pathogenic.
Clinical features: The most common symptom of tuberculous otitis media infection is otorhea and most
patients demonstrate moderate to severe hearing loss. Additional findings may include tinnitus, vertigo,
facial palsy and tympanic membrane perforation. The largest retrospective review of TB chronic otitis
media involved 52 patients in South Korea. In this study the highest incidence of tuberculous otitis media
was seen in patients in the third decade (as in this case) and only 5 of the 52 patients had a history of prior
treatment for TB (2 pulmonary and 3 extra-pulmonary). Additionally, this study compared TB chronic otitis
media patients with a control group of non-TB otitis patients and found that facial palsy and ossicle bone
erosion were more common in the TB patients.
Diagnosis: Clinical specimens are examined first by direct smear examination using either an acid fast stain
such as Kinyoun or Ziehl Neelsen (red, curved organisms) or auramine-rhodamine fluorochrome stains. The
latter acts as a screening test with high sensitivity the result of which must be confirmed by an acid fast
stain. Suspected mycobacteria may be cultured on both solid and broth media. Solid media includes
Lowenstein-Jensen and Middlebrook 7H11 agars and broth media are numerous. Members of the strictly
pathogenic MTB complex are slow-growers and, having buff colored colonies, are considered nonpigmented.
Newer methods for direct recognition of mycobacteria in specimens include HPLC analysis utilizing a
sensitive fluorescent detection column and genomic amplification strategies using PCR or other nucleic acid
amplification assays.
Tuberculous otitis media diagnosis is difficult not only because the index of suspicion is usually low, but
there are typically numerous other bacteria in the specimen that interfere with growth of TB. Additionally,
the clinical presentation is quite variable and there is an infrequent association with systemic involvement
making the condition difficult to recognize. As a result of these difficulties, most cases are diagnosed intraoperatively or post-operatively (as in this case).
Treatment: According to the CDC, the principles that underlie the treatment of pulmonary TB also apply
to extrapulmonary forms of the disease. A 6-month regimen is recommended as initial treatment for patients
with extrapulmonary TB, unless the organisms are known or strongly suspected of being resistant to the
first-line drugs. The exception to these recommendations is tuberculous meningitis where the optimal length
of therapy is not known. Corticosteroids should be used as additional therapy for patients with TB
meningitis and pericarditis.
References:
1. Cho, Y, et al. “Tuberculous Otitis Media: A Clinical and Radiologic Analysis of 52 Patients.” The
Laryngoscope 2006; 116:921-927.
2. Centers for Disease Control and Prevention: http://wwwn.cdc.gov/TB
3. McClatchey, KD. Clinical Laboratory Medicine 2nd edition. 2002.