Grand rounds 8/15/2017

Case 1 : Ulceroglandular tularemia associated with Feline Tularemia

68 yr old presented with fevers for 2- 3 weeks and increasing pre-auricular, and submandibular painful lymphadenopathy. He had two cats, one recently passed away. He remembered that the cat had a febrile illness and the patient sustained several scratches prior to his illness.
Francisella turarensis antibody returned positive 1:1280

1.  The incidence of tularemia is mostly centered in midwest US with highest numbers reported in Missouri (19%), Arkansas (13%), and Oklahoma (9%).  Subspecies tularensis (Jellison Type A) is the most virulent subspecies of Francisella tularensis and is the primary subspecies found in North America. There are six clinical tularemia syndromes defined by site of inoculation and presentation. The ulceroglandular and glandular forms are the two most common types in North America . Oropharyngeal,oculoglandular and typhoidal forms are less common.  Of 106 Francisella tularensis isolates, mostly from Nebraska, collected during 1998–2012: 48% of   cases were feline-associated.

2. The most common confirmatory study for tularemia is the microagglutanin test using antibody titers which develop about two weeks after incident infection. A one-time titer of 1:160 or a four-fold increase in titers from serums taken two weeks apart are considered diagnostic.

3.The WHO recommends using the bactericidal antibiotics  gentamicin for 10 days or bacteriostatic antibiotic doxycycline for 14 days

The patient above had a good response to oral doxycycline.


Case 2: Varicella Zoster meningoencephalitis 

65 yr old with myasthenia gravis presented with right ear pain and headaches and subjective fevers. She was on 40 mg of prednisone two days a week. She was febrile to 38.2C and had small vesicular lesions on her right external ear and one vesicular lesion on her right knee and L1 dermatome.

CSF examination revealed 329 WBC's (91% Lymphocytes), Protein74 and glucose of 57. CSF VZV PCR was positive
 1. Involvement of the CNS with cutaneous herpes zoster is probably more common than recognized clinically.  A rare manifestation of CNS involvement by herpes zoster is granulomatous cerebral angiitis, which usually follows zoster ophthalmicus. Rash is usually present but not always before the CNS disease.
2. Zostavax   developed specifically for protection against herpes zoster contains higher  plaque-forming units (PFU) per dose, compared to chickenpox vaccines . Although contraindicated in patients with immunecompromise as it is live vaccine - it could be considered in patients ≥50 years old who are receiving therapies that induce low levels of immunosuppression ( prednisone < 20 mg / day).

AUGUST 8, 2017 GRAND ROUNDS

CASE 1: DISSEMINATED HISTOPLASMOSIS

43/M with rheumatoid arthritis (receiving methotrexate and etanercept), p/w chronic pneumonia; additional studies showed an elevated urine Histoplasma antigen and a GMS stain of a bronchoalveolar lavage that demonstrated numerous yeasts forms consistent with Histoplasma

1. Histoplasmosis is the most common invasive fungal infection among people receiving anti-TNF therapy.

2. Anti-TNF therapy should be discontinued in patients who develop histoplasmosis.

3. Be aware of immune reconstitution syndrome (IRIS) in patients with histoplasmosis while receiving effective antifungal therapy (in 9% of cases). This occurs after anti-TNF medication is discontinued.

CASE 2: DISSEMINATED PARVOVIRUS B19 INFECTION

57/M w/ primary biliary cirrhosis s/p liver transplantation 11 years prior (receiving tacrolimus and mycophenolate), p/w chronic fatigue and new-onset pancytopenia (Hgb 6.6, WBC 1.9, platelet 65); additional studies showed low reticulocyte count and a positive blood parvovirus B19 PCR test

1. Suspect parvovirus B19 in immunocompromised patients with:

·         Unexplained anemia (seen in 99% of patients) or pancytopenia

·         Clinical syndromes: fever (25% of patients), rash, arthralgia

·         Others: hepatitis, myocarditis, pneumonitis, neurologic manifestations, vasculitis

2. Two-thirds of infection occurs within 3 months after transplantation (can be late as well).

3. The diagnosis commonly rests on detecting a positive serum parvovirus Ig M (in 75% of transplant patients) or PCR. If both tests are negative but the suspicion remains, a bone marrow biopsy can be done and this normally shows characteristic giant pronormoblasts.

4. IVIG 400 mg/kg/day for 5 days is the treatment of choice. It can recur in 28% of transplant patients even after therapy. 

JULY 25, 2017 GRAND ROUNDS

CASE 1

21 year old previously healthy male w/ fever, cough, sore throat, and acute numbness of the left side of the face; CXR showed left lower lobe cavity and head CT demonstrated a right parietal lobe abscess; blood culture grew Fusobacterium necrophorum (Lemierre’s syndrome)

1. Lemierre’s syndrome is an infectious thrombophlebitis of the internal jugular vein that is notorious for causing septic embolization to the lungs (97%; which can appear as a cavity, an infiltrate, abscess, or empyema), brain, bone and joint. 92% of cases are caused by Fusobacterium.

2. It should be suspected in patients with a prior history of pharyngitis and now p/w fever and septic embolization (“an infectious embolic disease similar to infective endocarditis”).

3. Prolonged antibiotics is required (usually 4 weeks). The use of anticoagulation is controversial but is usually beneficial if thrombosis continues to progress despite antibiotic therapy. Ligation of the jugular vein is reserved for patients with persistent sepsis despite antibiotics.

CASE 2

A 12 week old term infant w/ 6 weeks of fever and diffuse interstitial nodular opacities on CXR; exam: 1^st percentile for weight/length, hepatosplenomegaly; BAL showed Pneumocystis jirovecii on stain and Histoplasma capsulatum on fungal culture; urine Histoplasma antigen was highly positive; immunodeficiency work-up showed pan-T cell lymphopenia that were naïve and thymic-derived; suspected to have dyskeratosis congenital

1. High yield facts about dyskeratosis congenita:

•       Mutation in a variety of genes involved in telomere lengthening/protection
• I     Inheritance: recessive (X-linked or autosomal), autosomal dominant
•       Can be seen in adults: median age of diagnosis is 15 years but the range of presentation is wide (birth to 75 years)
•       Classic triad (ABSENT in the neonatal period but seen in <50% of older patients and ¾ of cases will have at least 1): abnormal skin pigmentation (reticular hyperpigmentation in the neck/chest), nail dystrophy, oral leukoplakia
•           Complications: bone marrow failure (50% by age 50), immunodeficiencies (lymphocyte subset most prone) à most common cause of death; others: pulmonary fibrosis, head/neck squamous cell carcinoma, myelodysplastic syndrome
•       Treatment: bone marrow transplant (for bone marrow failure), androgen therapy

CASE 3

78 previously healthy male from Fairport, New York, p/w fever and chills for 10 days; labs showed anemia (Hgb 10.7), thrombocytopenia (58,000), and mildly elevated liver enzymes; other w/u showed a haptoglobin < 1 and an elevated LDH; smear showed evidence of babesiosis (3% parasetemia) and Babesia microti PCR was detected

1. Suspect babesiosis in patients you suspect to have tickborne illness (fever, elevated transaminases, and thrombocytopenia). It is transmitted through the bite of the deer or blacklegged tick Ixodes scapulars.

2. Ixodes scapularis also transmits: Anaplasma, Borrelia burgdorferi (Lyme disease), and Powassan virus type II.

3. Babesiosis can by asymptomatic (made manifest only during splenectomy or w/ development of an immune compromising condition), mild (this can be self-limited), or severe. Hemolytic anemia is the principal clue in a lot of cases (“think, malaria w/o a history of travel to malaria-endemic areas; the trophozoite/merozoite forms in the blood can look like malaria).

4. Typically has long incubation period after a tick bite (up to 3 months; typically 1-6 weeks) and even longer after blood transfusion (up to 6 months; typically 1-9 weeks).

5. Co-infection w/ Anaplasma or Lyme sometimes occurs. Hence, suspect concurrent babesiosis in patients who don’t respond to therapy for Anaplasma or Lyme. Diagnosis is through blood smear and PCR testing.

6.Treatment:

• Asymptomatic parasetemia requires treatment to prevent transmission and progression to disease especially in immunocompromised patients.
• Mild: atovaquone + azithromycin
• Severe (e.g. >4% parasetemia): clindamycin + quinine; consider exchange transfusion
• Duration: 7-10 days for immunocompetent patients; at least 6 weeks or up to 2 weeks after parasites are no longer present on smear (whichever is longer) for immunocompromised hosts

7. Rapid review of ticks (for more information, click here):

• Ixodes scapularis (Eastern, northern Midwest): as mentioned above
• Ablymoma americanum (lone start tick; Midwest, Southern, southeastern): Ehrlichia, Heartland, southern tick-associated rash illness (STARI), tularemia, Bourbon (? maybe)
• Dermacenteor variabilis (American dog tick; eastern, south central, Pacific coast): RMSF, tularemia
• Dermacentro andersoni (Rocky Mountain wood tick; west of Mississippi, Pacific coast): RMSF, tularemia, Colorado tick fever

July 17th , 2017 Listeria Rhombencephalitis

CASE 1 : Listeria Rhombencephalitis (Brainstem Encephalitis) with Brain Abscess

A 44 year old man from rural Wisconsin presented with progressive ataxia, diplopia , fatigue and fevers and chills . He was otherwise ,an healthy dairy farmer.  Since admission - he had a rapid worsening of his sensorium requiring intubation. His MRI revealed small ring enhancing lesions in the right cerebellum and pons consistent with microabscesses. CSF exam revealed 39 WBC's 43%PMN's and 31% Lymphocytes, glucose of 54 and protein of 71. CSF HSV,VZV PCR's and crypto antigens were negative. CSF and blood cultures later returned positive for Listeria monocytogenes.

1. CNS Listeriosis : Unlike other organisms that cause bacterial meningitis frequently ( Strep pneumonie, Neisseria and Haemophilus), Listeria has a tropism for the brain parenchyma itself , particularly the brain stem, as well as meninges. CSF features particular to Listerial Meningitis include subacute presentation, fluctuating mental status (75%), positive blood cultures (50-75%) and normal CSF glucose (>60%).

2.  Brainstem Encephalitis (Rhombencephalitis):  In contrast to other listerial CNS infections, these occur in healthy adults. Typical clinical picture is of a bi-phasic illness with fevers, headaches lasting 3-4 days followed by abrupt onset cranial nerve deficits and cerebellar signs . 2/3rd s of patients are bacteremic . 

3. Treatment :  Bacteremic patients without CSF abnormalities can be treated for 2 weeks with Ampicillin  .Gentamicin is  added for synergy in patients with CNS listeriosis and those immunecompromised . Patients with rhombencephalitis or brain abscess should be treated for at least 6 weeks .  In a nonrandomized study of 22 patients with severe listerial meningoencephalitis, TMP-SMX plus ampicillin was associated with a much lower failure rate and fewer neurologic sequelae than ampicillin combined with an aminoglycoside (Merle-Melet M, J Infect. 1996;33:79-85.)

JULY 11, 2017

CASE 1: CRYPTOCOCCAL MENINGITIS

A 54/F with ESRD s/p deceased donor kidney transplantation in 2012, p/w 3-months of headache and progressive decline in mental status; CSF showed lymphocytic pleocytosis and low glucose with an opening pressure of 23 cm H₂O; brain MRI was normal; BioFire FilmArray PCR testing for bacteria, yeast, and viruses (performed at another institution) only notable for a positive HHV-6; on transfer to our hospital, serum and CSF cryptococcal antigen were both positive (1:10 and 1:20, respectively); treated with liposomal amphotericin with good clinical response.

1. Symptoms of meningitis (i.e. headache ± fever) that persist for > 4 weeks and run an indolent course suggest chronic meningitis. The differential diagnoses shift away from common bacterial and viral pathogens that cause acute meningitis. Some of the important etiologies of chronic meningitis are:

• Fungal: Cryptococcus, endemic fungi particularly Coccidioides and Histoplasma

• Bacteria: Mycobacterium tuberculosis, syphilis, Lyme disease

•  Non-infectious: lymphomatous meningitis, sarcoidosis, Behcet’s syndrome

2. The discussion of the case centers on the uncertainty in diagnosing cryptococcal meningitis using tests other than direct microscopic examination, culture (gold standard), histopathology, and serum/CSF antigen detection. This patient had a negative BioFire FilmArray PCR testing at another institution (likely a false negative test) but positive serum and CSF cryptococcal antigen test in our hospital. This resulted in a missed opportunity to diagnose and treat cryptococcal meningitis early. Below is a summary of important points that you should know about this test.

• It is a qualitative PCR that tests for 14 microorganisms (6 bacteria, 7 viruses, and 1 yeast: Cryptococcus neoformans/gattii).

• Compared to cryptococcal antigen testing, it has a sensitivity of only 12.5% (from the FDA licensing data: 7 specimens were positive by cryptococcal antigen testing but were negative by FilmArray; all 7 specimens were collected after patients received antifungal therapy).

• False negative FilmArray results usually come from specimens with low cryptococcal antigen titers.

• The bottom line is that given the low sensitivity of this test for diagnosing cryptococcal meningitis, the results should be interpreted with caution. 

CASE 2: RAT BITE FEVER

An 8 year old girl p/w 5 days of vomiting, diarrhea, fever, joint pains and rash; exam showed scleral icterus, significant bilateral MCP and PIP joint swelling and tenderness, petechial and macular lesions on the distal extremities; at home, has dogs, cats, ferrets, rabbits, hamsters, and recently purchased pet rats; diagnosed with rat bite fever

1. Five things you should remember about rat bite fever (RBF):

• RBF is caused by Streptobacillus moniliformis in the US and Spirillum minus in Asian countries. Both are gram negative bacilli.

• Suspect in patients (i.e. lab personnel, children) with any rat exposure (bites > scratches > others: even handling of rats). Bites/scratches from animals that prey on rats (e.g. dogs, cats, ferrets) can also transmit the disease.

• Cardinal symptoms that should raise suspicion for RBF: fever + distal extremity petechial rash (can be in the palms and soles) + migratory arthralgia/arthritis (knees > ankles, elbows, wrists, hip).

• Diagnosis is difficult as the bacteria require enriched media to grow. Hence, empiric diagnosis and treatment for RBF are oftentimes done. Culture (blood > synovial fluid) confirms the diagnosis. Examination of the specimen to look for the characteristic bacteria can also be done.

• PCN is the treatment of choice (alternative drug: doxycycline) given IV x 1 week then switched to oral antibiotic for another week. The Jarisch-Herxheimer reaction can sometimes occur after antibiotic treatment is started.

2. Since empiric diagnosis and treatment for RBF are sometimes done, keep these differential diagnoses always in mind to guide diagnostics and treatment:

• Leptospirosis: differs from RBF in that joint pain/swelling is not a prominent symptom

• RMSF: striking similarity with RBF in the presence of petechial/purpuric rash in the distal extremity/palms/soles; joint pain/swelling is not a prominent symptom

• Disseminated gonococcal infection (DGI): striking similarity with RBF in the presence of migratory arthritis; the rash in DGI is very different (pustular > vesicular, very few in number, usually 2-10 in total) 

CASE 3: POSTOPERATIVE PYODERMA GANGRENOSUM

A 54/M with a prolonged hospital stay after a CABG procedure because of non-healing of his surgical wounds (thoracotomy, chest tube, vein harvest sites) associated with purulent drainage and non-response to broad-spectrum antibiotics and multiple debridement; all cultures were unrevealing; diagnosed with postoperative pyoderma gangrenosusm; treated with steroids with good response

1. Suspect postoperative pyoderma gangrenosum (PPG) in a patient with non-healing or worsening surgical wounds after debridement (pathergy), nonresponse to broad spectrum antibiotics, and with negative bacterial/fungal cultures. Consult Dermatology if PPG is suspected.  

2. PPG is a non-infectious, chronic neutrophilic dermatosis that is pathologically similar to pyoderma gangrenosum associated with systemic diseases (e.g. inflammatory bowel disease, rheumatoid arthritis). In a review of literature, most patients diagnosed with PPG, however, lack any systemic autoimmune diseases.

3. Other causes of pathergy: Behcet’s disease, Sweet’s syndrome.