Clinicopathological ConferenceClinicopathological ConferenceMedical Grand RoundsMedical Grand Rounds

September 20, 2007September 20, 2007

Julie L. Gerberding, M.D., M.P.H.Director, Centers for Disease Control and Prevention

Javier Romero, M.D.Radiology, MGH

Mary Jane Ferraro, Ph.D., M.P.H. Pathology, MGH

Clinicopathological ConferenceClinicopathological ConferenceMedicine Grand RoundsMedicine Grand Rounds

September 20, 2007September 20, 2007

Howard M. Heller, M.D.MGH/MIT

Skip Atkins, M.D.Occupational Health, MGH

Mary L. Pisculli, M.D., M.P.H Case Presentation

A 58-year-old woman with neck pain A 58-year-old woman with neck pain and fever.and fever.

Presentation of CaseMary Louise Pisculli, M.D., M.P.H.

A 58-year-old woman with neck pain and feverA 58-year-old woman with neck pain and fever

time

Acupressure massage - Tingling in 1st 3 fingers of right hand

Intermittent neck pain & headaches - “work strain”

3mo

Right anterior neck swelling. Neck pain R. shoulder

~2 wks 5d

Urgent Care Visit:Increasing neck pain, R. hand numbness

• T 38.2o, neck ROM• wbc 7.9 • C-spine XR normal• ketorolac for pain

3d

Urgent Care Visit:Fever, cough, difficulty swallowing - Exam normal x for limited neck ROM - Azithromycin x 5d

PCP & Orthopedist:•Temp 39.4o , DTRs, • wbc 7.9 (66P, 18 bands, 4 atyp lymphs)• MRI c-spine: extradural filling defect in disc space C4-7 w/ mild cord compression

2d

Past Medical HistoryPast Medical History• “Very” positive PPD years ago

– h/o BCG vaccine in childhood– No treatment initiated

• Occupational exposure to Brucella melitensis seven months prior to admission– Occupational Health assessment 2wks post-exposure

• Declined prophylactic antibiotics• Weekly follow-up x 3.5 months

– 7mo PTA: Brucella total Ab <1:20– 3mo PTA: Brucella total Ab <1:20; IgG titer <1:20

Case presentationCase presentation• Social History:

– Microbiology lab technologist– Born in Taiwan, immigrated to US 30 yrs ago, lived in

New England– Married, two children (healthy)– Occasional alcohol, no tobacco or illicit drug use

• Medications: – Azithromycin, ketorolac, ibuprofen, aspirin,

alendronate, conjugated estrogens & medroxyprogesterone

– NKDA

Case presentationCase presentation• Evaluated by an infectious disease specialist for

persistent fever

• Physical Examination– T 36.8°, severe pain on palpation of the right lateral

neck without palpable masses or lymphadenopathy

• MRI with gadolinium: C5-C6 epidural abscess with mild mass effect on the spinal cord

• Pt admitted, Vancomycin IV 1gm q12 hours initiated

Radiology StudiesRadiology Studies

Javier Romero, M.D.

A sagittal short-tau inversion-recovery MRI scan of the cervical spine, obtained at another MRI facility, shows highsignal intensity of the posterior aspect of the C5 and C6 vertebral bodies, representing edema

A T2-weighted image shows a focal epidural collection at the same level, with increased signal intensity (,arrows), representing an epidural fluid collection.

A sagittal gadolinium-enhanced, T1-weighted MRI scan of the cervical spine shows an epidural fluid collection with an enhancing rim at the C5–C6 level ( arrow), representing an epidural abscess. There is extensive enhancement of the dura anteriorly.

Axial T1 post G

Differential DiagnosisDifferential Diagnosis

Julie L. Gerberding, M.D., M.P.H.

SummarySummary• 58 Taiwanese woman; employed as microbiology

laboratory technician; in the United States for 30 years; gardener; history of BCG vaccine and positive TB skin test in the past

• 7 months before admission: exposed to Brucella melitensis; no symptoms for 4 months

• 3 months before admission: left neck symptoms• 3 weeks before admission: right neck symptoms and

parasthesias right hand• 5 days before admission: fever, neck spasm

• 3 days before admission: fever persists; chills, cough; pain with swallowing

• 2 days before: fever persists; decreased tendon reflexes right arm; MRI – cervical filling defect with mild cord compression

• 1 day before: fever persists• On admission: MRI with gadolinium – epidural

abscess posterior C5 C6; Vancomycin treatment initiated

Laboratory FindingsLaboratory Findings

• Over past three months: progressive anemia• Elevated ESR for 3 months• Increased transaminases and alkaline

phosphatase when first checked 5 days before

• Blood glucose abnormal• Brucella serology < 1:20 2 weeks and 4

months after exposure

Spinal Epidural AbscessSpinal Epidural Abscess

• Classic triad: fever, pain, neurologic deficits• Etiologies:

– Staphylococcus aureus– Other aerobic and anaerobic bacteria– Mycobacterium tuberculosis– Fungal and parasitic infections

BrucellaBrucella• Systemic disease• Zoonosis; transmission via ingestion, by direct

contact, or by inhalation• Controlled in developed world; serious health

problem in Mediterranean area, Arabian Peninsula, Mexico, Central America, and South America

• Spinal involvement is common – usually spondylitis; abscess is rare

• Abscess usually arises from direct invasion of infection in vertebral body, but may be hematogenous

Case Series from Turkey Case Series from Turkey (Karaaslan et al)(Karaaslan et al)

• 9 patients with brucella spinal epidural abscess– Long lag from symptoms to diagnosis (15 days

to 4 months; median 2 months)– Lumbar = 6; thoracic 2; cervical = 1– 3 with normal ESR

“The often elusive diagnosis of brucellosis and the need to treat it with a combination of antimicrobial agents underscores the unique challenges in managing a spinal epidural abscess that is caused by brucella.”

Rabih Darouiche, M.D.NEJM 2007

Brucella is the single most common cause of

laboratory-acquired infection.

• Clinicians should suspect Brucella among patients from endemic areas

• Clinicians must alert laboratories when Brucella is suspected

• Laboratorians must use precautions (and never sniff plates!

Clinical ImpressionsClinical Impressions

Howard M. Heller, M.D.

PathologyPathology

Mary Jane Ferraro, Ph.D., M.P.H.

Positive Blood CulturePositive Blood Culture

• After 6 days of incubation one aerobic bottle grew small, gram-negative coccobacilli; oxidase +, catalase +, urease +

• Suspicious for Brucella sp.; isolate referred to MA State Lab for further identification according to the CDC / LRN BT protocol

• Many published reports of Brucella being misidentified in the lab; some with subsequent laboratory-acquired infections

Misidentification of Misidentification of BrucellaBrucella

• Psychrobacter phenylpyruvicus (formerly called Moraxella phenylpyruvica)

• Haemophilus spp.

• Bordetella bronchiseptica

• Oligella ureolytica

• Acinetobacter spp.

• Micrococcus spp.

• “diphtheroids”

Brucella IdentificationBrucella Identification• Presumptive ID of Brucella sp. by SLI next day; Genus-

specific Brucella DNA detected by PCR

• Brucella melitensis and biovar 3 identification received many weeks later from CDC (initially reported as biovar 2)

• Index patient: 65 y.o woman with back painFNA of T7-T8 collection grew B. melitensis biovar 3

• Biochemical ID tests and biovar serotyping are not

standardized and are subject to technical variation

Molecular Typing by MLVA 15 Molecular Typing by MLVA 15

• To clarify the biovar issue and more definitely link this patient’s isolate to that of the source patient, the CDC performed genetic profiling to determine relatedness of the two strains.

• MLVA 15 – based on variable number tandem repeat analysis at 15 different genetic loci, which allows species identification and strain typing (forensic based method)

Genetic relatedness of 3 B. melitensis-3 isolates (from MA DPH) by MLVA 15

Courtesy of Barun Kumar De, CDC, Atlanta, GA

VNTR 01: 243 bpVNTR 07: 300 bp

VNRT 01: 299 bpVNTR 07:300 bp

VNTR 01: 243 bpVNTR 07: 316 bp

WIFE: 14 out of 15 VNTRs matched with that of Lab worker.HUSBAND: 13 out of 15 VNTRs matched with that of Lab worker.CONCLUSION: Lab worker was most probably infected while

working with B. melitensis culture isolated from wife

Index patient: Hospital 1

WifeHusband of index ptHospital 2

Lab WorkerHospital 1

Additional Brucella SerologyAdditional Brucella SerologyDate Method Result Reference

7 mo before MAT * <1:20 (total) <1:160

<1:20 (IgG)

3 mo before MAT * <1:20 (total)

<1:20 (IgG)

2 days before ELISA** 17 (IgG) <9 neg

46 (IgM) 9-11 equiv

>11 pos* Microagglutination test (SLI & CDC)

** ELISA (Commercial Lab )

Brucella Serology Repeat TestingBrucella Serology Repeat TestingDate Method Result Reference

7 mo before MAT <1:20 (total) <1:160

<1:20 (IgG)

3 mo before MAT <1:20 (total)

<1:20 (IgG)

2 days before ELISA 17 (IgG)

46 (IgM)

MAT 1:320 (total)

ELISA 2 (IgG) <9 neg

26 (IgM) 9-11 equiv

>11 pos

Brucella Serology Repeat TestingBrucella Serology Repeat TestingDate Method Result Reference

7 mo before MAT <1:20 (total) <1:160

<1:20 (IgG)

3 mo before MAT <1:20 (total)

<1:20 (IgG)

2 days before ELISA 17 (IgG)

46 (IgM)

MAT 1:320 (total)

MAT Repeat (total) (1:40; 1:80) 4-fold increase

MAT Repeat IgG (<1:20; 1:20)

Questions AskedQuestions Askedand and

Lessons LearnedLessons Learned

Microbiology laboratory

Q1 Should the Microbiology Lab Q1 Should the Microbiology Lab change the biosafety level change the biosafety level practices practices for tissue specimens?for tissue specimens?

• Our lab biosafety policy & procedures specified that all initial workup of positive blood cultures, and any

slowly growing organism resembling Brucella from other specimen types should be performed in a biosafety

cabinet using Biosafety Level 3 practices

• Technologist initially suspected Haemophilus . . . “protocol drift” resulted in some initial tests performed on

the open bench with only BSL-2 practices

Q1 Should the Microbiology Lab Q1 Should the Microbiology Lab change the biosafety level change the biosafety level practices practices for tissue specimens?for tissue specimens?

• Complete retraining with written exam of entire lab on protocol for slowly-growing bacterial pathogens from tissues and fluids

• Not feasible nor necessary given low incidence to convert lab into BSL-3 facility

• Currently discussing risk stratification of specimens by body site (e.g. all paraspinal aspirates) to mandate initial BSL-3 workup. Staffing, space, and equipment

considerations

Q2 Are our serologic testing Q2 Are our serologic testing methods adequate?methods adequate?

• Serology is imperfect and both sensitivity and specificity of tests may vary and use different antigens

• Microagglutination Test is considered “gold standard”; detects antibody directed against S-LPS; some reports of lower sensitivity than newer EIA tests

• False positive IgM results may occur with EIA tests

• If there is any suspicion, we will request both methods and determine appropriate tie breaker if needed!

Questions AskedQuestions Askedand and

Lessons LearnedLessons Learned

Occupational HealthSkip Atkins, MD

Q3 What should we change? Q3 What should we change?

• Post-exposure prophylaxis- strongly encourage (doxycycline/rifampin)

• Post-exposure monitoring - longer period (6-12 months) - both MAT and EIA

Q3 What should we change? Q3 What should we change?

• Clinical evaluation - suspect even if symptoms are delayed, up to 6 months, perhaps more - suspect even in the absence of fever - include serologies, blood culture,

evaluation of localized symptoms

Q4 How can clinicians help? Q4 How can clinicians help? • A clinician’s suspicion should be immediately communicated to the lab to minimize risk of exposure as well to all other clinicians caring for the patient, e.g, FNA, interventional radiology, surgery, who may be involved in obtaining the specimen and sending it to the lab

• Knowing what is suspected would facilitate work-up of specimen or special procedures

• This does not apply only to Brucella, but also other organisms, e.g. Francisella, Bacillus anthracis, Coccidioides, Histoplasma, H5N1, SARS, etc.

Follow up and QuestionsFollow up and Questions