infectious diseases cases hospitalists - internal medicine · • more likely to affect lower...
TRANSCRIPT
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Infectious Diseases Cases for Hospitalists
Loreen A. Herwaldt, MD
Disclosures
• No relevant financial conflicts of interest.
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http://www.upworthy.com/van‐goghs‐starry‐night‐was‐re‐created‐with‐bacteria‐its‐as‐cool‐as‐it‐sounds?c=upw1&u=e54842d8a1edeb75eb010cfb1cb0d7eabddf02b2
Patient’s History
• 36 yo AA male w/ hx of:– Uncontrolled DM (HgA1C 12.5)
– Recurrent MRSA abscesses on his back
– Anaphylaxis to PCN
• No history of IVDU
• Work: sprays equipment with water to remove pig hair
• Fell on concrete at work X 2
• 10‐12 watery stools X 3 d before admission
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Patient’s History• 7/27: Presented to OSH c/o feeling warm, swelling & pain in his arms, & difficulty moving his arms for 2 days
• WBC > 50,000; blood glucose > 700• Rx: IV fluids, vancomycin, aztreonam, & insulin IV WBC 23,000.
• MRI of both arms: extensive inflammation; myositis vs myonecrosis
• Orthopedics & surgery consultants: no operation; medical management
• 7/30: To the UIHC: WBC = 49,700, 91% PMNs. • Rx: IV vancomycin, aztreonam, & metronidazole
Physical Exam on UIHC Admission• Constitutional: Pulse 124 | BMI 22.82 kg/m2• Alert & oriented X 3. • Respiratory: No respiratory distress. Normal breath sounds, no crackles
• CV: Normal S1 and S2, no murmur, regular rhythm, tachycardia
• GI: Abdomen is soft, non‐tender • Skin: No skin lesions• MSK: Bilat arm & forearm swelling, L > R. L arm red. Bilat arm tenderness. No pain on finger flexion or extension bilat. Pulses present bilat.
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8/1/15: Ortho Consult• UE: No obvious skin lesions or open wounds. Decreased ROM at the elbow due to pain. Diffuse swelling & tenderness to palpation of the forearms bilaterally.
• LE: Anterolateral L upper thigh is tender to palpation & swollen diffusely. Active movement about the knee & hip is limited due to significant pain in L thigh.
• Back: Numerous 1 x 1cm regions of fluctuation over back & buttock region; some were lanced previously & are healing. Perianal tenderness & fullness.
THOUGHTS?
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8/1: CT Abdomen, Pelvis, & Legs
• Decreased enhancement of L tensor fascia lata concerning for myositis & myonecrosis
• Increased fat stranding & fluid in anterior compartment of L thigh concerning for fasciitis
• Subcutaneous fluid collections in low back at L5‐S1 c/w abscess: 1.6 x 0.9 cm & 4.8 x 2.1 cm
• Small (2‐4 cm) fluid collections in subcutaneous tissues of gluteal region concerning for perianal fistula
8/1/15: Incision & Drainage
• 2 noncommunicating abscesses in the lower back
• 1 R gluteal abscess tracking superiorly & anteriorly towards the anal verge & separate tracking towards the anal canal
• Described as “pus filled cavities”
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THOUGHTS?
8/2/15: Transfer to MICU
• Increasing oxygen requirement 10L O2
• CXR: pulmonary congestion
• Lung exam: crackles bilaterally
• Rx: 40 mg IV Lasix urine output of 1.7 L
• Patient was transferred to MICU; put on BiPAP
• Labs: WBC 56.7, RBC 3.15, hgb 8.7, plt 506, ESR 116, CRP 16.5, CK 306, lactic acid 2.3
• ABG: pH 7.52, pCO2 34, pO2 47, bicarbonate 28
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Additional Findings & Rx
• Bilateral pitting edema• CXR: Bilateral diffuse airspace disease• HIV negative• 8/3/15: US guided drain placement in 3 abscesses: R prox forearm, L distal medial upper arm, L anterolateral groin
• 8/3 TTE: Normal L ventricular size. Mild LVH. Normal LV systolic function. Normal RV size & systolic function. Small pericardial effusion.
• Cultures of abscesses: all grew MRSA; all BC neg
THOUGHTS?
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8/4/15: ID Note• Continues to maintain sats with high O2 needs. • He is doing generally well. • Pain in joints is much better. • Denies subjective respiratory distress, fevers or chills.
• Drains aren’t draining much.• “We also do not have a clear explanation for the extent of his leukocytosis . . . this will merit further investigation if it does not respond to treatment of his infection (down‐trending).”
• Discontinue aztreonam & metronidazole
8/5/15: CXR
Interval development/progression of bilateral symmetric airspace disease throughout both lungs consistent with worsening pulmonary edema (likely lung injury edema) based upon distribution.
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8/6/2015
• Intubated for acute hypoxemic respiratory failure
• WBC: 33,300
• Would you continue the same abx Rx or change it?
• ID recommendation: add clindamycin 600 mg IV Q 8 hours
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I & DMICU
Drains Intubated
Clindamycin
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Patient’s Clinical Course
• 8/8/15: extubated & transferred to RSCU
• 8/14/15: drains removed
• 8/17/15: discharged to a skilled care facility on vancomycin for a total of 3 weeks of IV vancomycin therapy from 7/30
• At discharge: – He was off supplemental oxygen & was able to ambulate short distances without difficulty.
– He had some subjective L arm weakness.
Case Summary: MRSA Pyomyositis Complicated by Sepsis
• Patient had poorly controlled diabetes & fell
• GI sx early in the course
• Multiple abscesses in muscles
• WBC count remained high & respiratory failure occurred after I & D + drain placement & abx Rx
• Improvement after clindamycin was added
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Pyomyositis• Pyomyositis is a purulent infection of
skeletal muscle that arises from hematogenous spread, usually with abscess formation
• More likely to affect lower extremity (Bickels et al. J Bone Joint Surg Am, 2002)
• Vast majority caused by S. aureus
• Three stages:1. “invasive”
2. “purulent” or “suppurative” with deep abscess and symptoms like fever/chills;
3. “late” final stage involving systemic inflammation progressing to septic shock
Bickels et al. J Bone Joint Surg Am, 2002; 84(12):2277
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Genetic/Racial Risk vs. Environmental Risk• May be less common among Caucasians in tropics
(Shepherd. Lancet, 1983;2:1240)
– 50K Europeans in East Africa in the 1960s & thousands in New Guinea: no cases
– 50:50 Polynesian:Caucasian in Hawaii; Polynesians affected
– One Caucasian female child in South Africa
– Outbreak among soldiers in Malaysia is an exception
• Little evidence for race association for temperate pyomyositis (Christin & Sarosi. Clin Infect Dis, 1992;15:668)
• Males predominance: 72% (Gibson et al. Am J Med, 1984)
• In tropics environmental factors may be important
Immunocompromise Is Associated with Temperate Pyomyositis
• The incidence of pyomyositis increased in the U.S. during in the 1970s & 80s (Gibson et al. Am J Med, 1984;77:768)
• First case in patient w/ AIDS in 1988 (Gaut Arch Intern Med, 1988;
148:1608)
• Associated w/ advanced HIV/AIDS patients in a study of 98 cases (Christin & Sarosi. Clin Infect Dis, 1992;15:668)
• Patients with pyomyositis should be tested for HIV
• Increasingly seen in patients w/ other chronic immunocompromising conditions including diabetes (Crum NF. Am J Med ,2004;117:420)
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S. aureus Carriage and HIV Infection & Diabetes
Diabetes (Pan et al. J Infect Dis, 2005;192:811) & HIV infection may increase the risk of S. aureus carriage (Vu et al. mBio, 2015;6:e02554)
Physical Trauma May Increase the Risk of S. aureus Pyomyositis
Christin & Sarosi. Clin Infect Dis, 1992;15:668
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WHAT WOULD YOU EXPECT THE CHARACTERISTICS OF THE MRSA ISOLATES TO BE?
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Infecting MRSA Isolate• USA300
• Dominant super antigen = Staph Enterotoxin C (SEC)
• Did not produce TSST‐1
S. aureus Nasal Carriage – NHANES Study, 2001‐2002
• MSSA: 32.4% (95% CI, 30.7%‐34.1%); population estimate 89.4 million
• MRSA: 0.8% (95% CI, 0.4%‐1.4%); population estimate 2.34 million
• 75 MRSA isolates, 6 (8%) USA300 (5/6 PVL +); 1 USA400 (1/1 PVL +)
Kuehnert, et al JID 2006;193:172‐9
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EMERGEncy ID NET• ED patients age > 18 years
• soft tissue infections (SSTI) < 7 days duration
• 422 enrolled in Fall 2004:
– S. aureus: 76% of culture + cases
– 78% of S. aureus were MRSA
– 97% of MRSA were clonal type USA300
Moran, et al. N Engl J Med 2006;355:666‐674
General Comments about CA‐MRSA
• Often affects young healthy people—including healthcare workers
• Frequently causes skin & SSTI
• Can cause necrotizing pneumonia especially after influenza or influenza‐like illness
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Patient #1
LA Wibbenmeyer, et al. J Burn Care Res 2008;29:790‐797
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General Comments about CA‐MRSA
CA‐MRSA vs. HA‐MRSA
• Fewer co‐resistances (often < 2 other classes)
• Different PFGE (USA300/USA400) patterns than those seen in usual HA‐MRSA (USA100/USA200)
• Different SCCmec element (type IV)
• Carry Panton‐Valentine leukocidin (PVL) genes
F Vandenesch, et al. Emerg Infect Dis 2003;9:978‐998
BA Diep, et al. J Infect Dis 2006;193:1495‐1503
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C Garcia, et al. Emerg Infect Dis 2013;19:123‐125
Pyomyositis & S. aureus Enterotoxins
Clindamycin• Clindamycin inhibits protein synthesis
• At sub‐lethal concentrations, Clindamycin suppresses exotoxin production Stevens et al. J Infect Dis, 2007
• Clindamycin may suppress endotoxin‐induced TNF production by monocytes, which might prevent systemic inflammatory responseStevens et al. Clin Infect Dis, 1995; 20(Suppl2):S154
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Case Presentation
• 23 year‐old man with history of schizophrenia presented to the ED:– nausea,
– vomiting,
– subjective fever
– headache
– acute‐onset right lower quadrant abdominal pain.
• His medications included chlorpromazine and benztropine.
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Case Presentation
• Vital signs: T = 39C, P = 155, R = 18, BP =116/58.
• Admission exam: marked right lower quadrant tenderness to palpation.
• WBC = 14,400, 89.3% neutrophils.
• LFTs & BMP WNL.
THOUGHTS?
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Case Presentation
• CT scan of the abdomen & pelvis demonstrated a normal appendix and scattered subcentimeter lymph nodes in the RLQ mesentery
• Any other thoughts?
Case Presentation
• The patient received intravenous normal saline and empiric piperacillin/tazobactam.
• General surgery was consulted.
• The next morning, the patient’s severe RLQ pain, fever, and leukocytosis persisted.
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Case Presentation
• Headache had resolved
• New onset of chills, soaking sweats, & sore throat.
• Oropharyngeal exam revealed very large tonsils with purulent discharge
• Faint erythematous lacy rash on the back & erythema on the upper torso that blanched to touch.
THOUGHTS?
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Culture Results
• Blood cultures were negative.
• The tonsillar exudate grew penicillin‐susceptible Streptococcus pyogenes
• Piperacillin/tazobactamc Rx was changed from to oral amoxicillin.
• The patient clinically improved.
Mesenteric Adenitis• Mesenteric lymphadenitis = inflammation of the mesenteric lymph nodes
• Unusual pathophysiology: – Microbial agents gain access to the lymph nodes via the intestinal lymphatics.
– Organisms elicit varying degrees of inflammation and, occasionally, suppuration.
• Lymph nodes:– Gross: enlarged & often soft. – Microscopic: nonspecific hyperplasia &, in suppurative infection, necrosis with PMNs.
• The adjourning mesentery may be edematous, with or without exudates
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Mesenteric Adenitis
• The true incidence is not known, because it can be easily missed or mistaken for other diagnoses.
• Up to 20% of patients having appendectomy have nonspecific mesenteric adenitis.
Mesenteric Adenitis
• More common in children & adolescents < 15
• Rare but recognized mimic of acute appendicitis in adults.
• This patient met radiographic criteria for MA, with > 3 lymph nodes > 5mm in the smallest diameter, but his lymphadenopathy was less dramatic than that seen in most MA cases.
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Mesenteric Adenitis: Radiographic Findings
M Macari, et al. AJR 2002;178:853‐8
Mesenteric Adenitis
• Yersinia enterocolitica
• MA has been associated with streptococcal pharyngitis.
• The S. pyogenes isolate produced exotoxins A, B, & C.
• Streptococcal pyrogenic exotoxins A & C are associated w/ streptococcal toxic shock syndrome, & their presence may explain the severity of this patient’s illness.
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Case
• 62 yo male with hx HTN, aortic dissection in 3/2013 w/ aortic arch repair
• 9/2014: 60 lb weight loss, fatigue, fevers, LFTs, pancytopenia
• Physical exam: massive HSM
• Biopsies of liver and bone marrow: granulomas, all micro stains negative.
• Extensive ID workup negative.
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THOUGHTS?
Normocellular bone marrow (40‐50%) with trilineage hematopoiesis. Multiple, non‐necrotizing granulomas. GMS & AFB stains negative.
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University of Iowa M. chimaera InfectionsConfirmed Cases
Case 1 Case 2 Case 3
Age, gender 59 yo M 62 yo M 65 yo M
Procedure AVRThoracic aortic
aneurysm repair
1) VAD placement
2) VAD replacement/AA repair
3) VAD replacement
4) Heart transplant
Procedure date 10/4/12 3/25/131) 11/21/11 2) 6/5/12
3) 7/20/12 4) 12/13/12
Sites of positive culturesBlood, bone
marrow, BALBlood Blood
Time to symptom onset 14 months 15 months ??
Time to diagnosis 39 months 35 months 40 ‐ 53 months
Current status Died 5/14/16 Under treatment Under treatment
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• Invasive M. chimaera infection in 6 patients
• All the case patients had cardiac implants
• Time from surgery to diagnosis: 1.7‐3.6 years
• Investigation of water sources revealed:– Water in heater‐cooler units (HCUs) grew M chimaera
– Air samples grew the outbreak strain when units ran
– Ventilation fan distributed air throughout operating room
H Sax et al. Clin Infect Dis 2015 (July 1);61:67
Clinical Manifestations• Disseminated infection (prosthetic valve, vascular graft in place)– Splenomegaly
– Arthritis
– Osteomyelitis
– Cytopenias (bone marrow)
– Chorioretinitis
– Hepatitis
– Nephritis
– Myocarditis
• Sternal wound infection
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Disseminated M. chimaera: Device Associated
Kohler, et al. Eur Heart J 2015;36:2745
Current approach to therapy includes multiple drug treatment(macrolide, ethambutol, rifamycin, +/‐ amikacin, moxifloxacin) , and removal of involved devices (valve, graft) if possible.
H Sax, et al. Clin Infect Dis 2015 (July 1);61:67
Stöckert 3T Heater‐Cooler Unit (HCU) & Bio‐aerosols
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16: Ventilation
Although water from heater‐cooler unit never contacts patients directly, the circuit is not airtight (or watertight), so the ventilation fan can aerosolize contaminated water from the circuit
https://www.youtube.com/watch?v=YZ41aLoHrhQ
M. chimaera detected in heater‐cooler unit water and in air samples, but only while the unit is running.
Risk Factors for M chimaera after Cardiothoracic Surgery
• Case control study in Pennsylvania
– 10 cases, 48 controls
– Cases: NTM from sterile body site up to 3.5 years after cardiothoracic surgery
– Controls: no + culture after CT surgery
• Exposure to HCU (OR = 5.6 [1.1‐29.2])
• Exposure > 2 hours (OR = 16.5 [3.2‐84])
• Molecular typing linked patient isolates
Lyman, et al. EIS conference, May 2‐5, 2016.
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M. chimaera after Cardiothoracic Operations
• Whole genome sequencing results of isolates from patients & from HCU water are consistent with a point source outbreak.
• CDC estimates that in hospitals where at least one infection has been identified, the risk of a patient getting an infection from the bacteria was between about 1 in 100 and 1 in 1,000.
• http://www.cdc.gov/mmwr/volumes/65/wr/mm6540a6.htm
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THANK YOU