Category Archives: Infectious Disease

Moffitt Pearls 3.23.18 – Chlamydia Proctitis and Syphilis

Thank you to Michelle for presenting the case of a young man presenting with symptomatic anemia found to have chlamydia proctitis and a positive RPR.

Key Pearls

  1. The diagnostic test of choice for chlamydial infection of the genitourinary tract is nucleic acid amplification testing (NAAT) of vaginal swabs for women or urine for men. Many laboratories have also validated NAAT on rectal swabs to diagnose chlamydial proctitis
  2. CDC recommended regimen for treatment of chlamydia proctitis is CTX 250 mg IM x1 PLUS Doxycyline 100 mg PO x 7 days
  3. In high risk patients diagnosed with chlamydia proctitis it is important to treat them for gonorrhea b/c of the risk of co-infections (hence the dual coverage above).
  4. Patients with severe proctitis may have lymphogranuloma venereum (LGV) which requires a full 3 weeks of therapy. See more info on LGV from prior blogs!
  5. As in this case, if the timing of syphilis is not known, late latent syphilis is presumed. Penicillin G IM once weekly for 3 weeks is the treatment of choice.



Inflammation of the lining of the rectum within 10-12 cm of the dentate line.

Differential Diagnosis:

# Infectious

  • Most commonly gonorrhea or chlamydia (including LGV strains with rq longer duration of therpay)
  • Other causes include HSV (more common in immunosuppressed patients), syphilis (usually secondary), C. difficile or parasites (amebiasis).

# Inflammatory

  • Crohn’s disease and Ulcerative colitis

# Ischemia

# Radiation or Chemical

# Trauma/instrumentation


Review of Syphilis and Therapy can be found in table form here.

See prior blog from the amazing Grant Smith for more on LGV


Ambulatory Report 3.20.18 – EBV and Elk

Thanks Dan for presenting your patient a young male with 1 month of fever and cough after hunting deer in New Mexico ultimately diagnosed with EBV.

Jin reminded of us one way to approach a problem is to use a Venn Diagram of symptoms, in this case cough and fever, to help us focus our differential on the diagnoses that fall in the overlap region.  Check out a recent Clinical Reasoning publication (with Goop as senior author!)  describing a slightly different way of using venn diagrams called the Pivot and Cluster.  This approach focuses on a common diagnosis as the pivot around which you can group a cluster of alternative diagnoses.

EBV Serologies

  • Presentation
    • Typical presentation of infectious mononucleosis: fever, pharyngitis, adenopathy, fatigue, and atypical lymphocytosis
      • Typically cervical posterior chain lymphadenopathy, the the lymphadenopathy can be more generalized as well
    • Variants
      • Mild disease: mild pharyngitis or tonsilitis
      • “Typhoidal form” fever and lymphadenopathy without the pharyngitis
      • Very young or very old often present less typically
  • EBV diagnostic tests
    • Monospot – rapid heterophile antibody test
      • If patient has consistent symptoms and positive monospot, there is no need for further testing.
      • However the sensitivity is ~85% and therefore there is the possibility of false negative.
    • EBV-specific antibodies
      • IgM Viral Capsid Antibody is present at the time of infection remains positive for ~ 3 months
        • Other herpesviruses (eg, CMV) can induce IgM antibodies to cell lines that express EBV antigens
      • IgG Viral Capsid Antibody becomes positive at the time of infection whereas IgG nuclear antigen takes 6-12 weeks to be present


Elk Exposure

  • We started to think about how exposure to elk could contribute to the patient’s presentation.  Here are three infectious disease agents to know about when it come to elk
    • Brucella – can be contacted when butchering infected game animals including elk or from handling raw meat or eating undercooked meat from infected animals.
    • Echinococcus granulosus (Tapeworm) – primary infection often asymptomatic and then clinical manifestations depend on involved organ, most often affects lung or liver.  Primarily seen outside the US (Middle East, sub-saharan Africa, South America, China) but local transmission has been documented in part of the United States including the SW US.
    • Chronic Wasting Disease – bovine spongiform encephalopathy prion disease that has an increased incidence in the western united states elk population. The CDC states there is NO evidence it can be passed to humans

Evernote link:

SFPC Ambulatory Report 3.8.18 – Buboes!

Thanks Soraya for presenting the case of a young male with HIV intermittently on ARVs with a painful groin mass likely a bubo due to LGV.

The following pearls are thanks to Soraya!

Differential for a bubo:
  • syphilis – painless ulcer, followed by LAN (usually b/l)
  • gonorrhea (proctitis)
  • HSV – painful vesicles, LAN (usually b/l)
  • chancroid – painful vesicles that become pustular and exudative  (tx: azithro 1g x1 or CTX 250 IM x1)
  • granuloma inguinale/donovanosis (Klebs granulomatosis) – painless, ulccerative lesions (friable, bleed); tx doxy x3 weeks (or azithro q week x3
  • cat scratch disease (bartonella henselae) – self limited LAN in kids x2-8 weeks; can tx azithromycin immunocompromised host or mod sxs
  • Tularemia – 1200 cases between 2000 and 2010, think ticks, outdoor activity, or with dead animals or skin, summer time, missouri/arkan/oklah. highly infectious (warn lab). tx streptomycin
  • bubonic plaque (y pestis) – fleas, few cases in US but reported. Southwest US. Tx doxy, FQ.
  • lymphoma
  • incarcerated inguinal hernia
  • TB or MAC
  • amebiasis (e. histolytica) – should see signs of invasive coliits wtih diarrhea, dysentery, heme-pos stools
Starts as ulceration (PAINLESS, usually not noticed) –> 2-6 weeks later you get regional tissue invasion & constitutional sxs. will penile, urethral, or vulvar inoculation –> inguinal LAN, whereas w/rectal disease, you get back pain or rectal pain from retroperitoneal LAN.  If you don’t treat the LGV, you get scarring and obstruction of lymphatics, which can cause regional lymphedema and genital elephantiasis (rectal diseaes –> strictures, anal fistulas).
Chlamydia and LGV (tips from Mark Jacobson): 
1.      All patients with clinical proctitis (e.g. tenesmus, rectal discharge) should have a standard rectal swab submitted for chlamydia nucleic acid testing (click on Chlamydial rectal TMA [PHL] when browsing in the Treatment/Labs section of eCW), AND a separate rectal swab in viral transport media (same tube and swab you use to submit a swab for herpes simplex) for LGV. For the latter, click on Chlamydial TMA Other (PHL) when browsing in the Treatment/Labs section of eCW and complete the PHL lab requisition attached to this memo with patient, clinician, and insurance info required, print, and give to our lab.
2.      LGV testing should only be ordered on a rectal swab obtained from a patient with clinical proctitis.  The LGV assay is not validated for other specimens, and asymptomatic LGV infection is not a clinically significant entity.
3.      Patients who have a positive rectal Chlamydia result can be treated with single dose azithromycin IF they have no symptoms or signs of proctitis.
4.      Patients who have a positive rectal Chlamydia result and signs or symptoms of proctititis should receive a one to three week course of doxycycline 100 mg bid, depending on the severity of symptoms.
5.      Patients have a positive rectal Chlamydia result, signs or symptoms of proctititis, and a positive LGV test result should receive a full three week course of doxycycline 100 mg bid.
6.      Note that the LGV assay will not be done if the simultaneously submitted standard rectal chlamydia assay result is negative.
Evernote link:

VA Ambulatory Report 3.7.18 – TB in clinic

Thanks Chris for presenting your patient who is an elderly man with a history of CAD and HTN who presented to clinic with history of tuberculosis and chest xray findings of apical scaring and pulmonary nodules.  We had a great discussion about the challenge of diagnosing TB and management strategies for active and latent TB in the outpatient setting.

TB Epidemiology

  • In countries with a low incidence of TB such as the US, the most common cause of active TB is reactivation of old disease.
  • In San Francisco the most common risk factor for TB is being foreign born in particular individuals from China, the Philippines, and Vietnam.
    • Check out this SFDPH Disease Control and Prevention Report for more epidemiology of TB in San Francisco.

Diagnosing TB 

  • Tuberculin skin testing (TST) vs. Interferon Gamma Release Assay (IGRA)
    • The decision to use TST vs. IGRA is based on patient characteristics, local resources, and cost.
    • The CDC recommends sending IGRA testing over TST in patients you have decided to test due to risk of exposure AND have a history of BCG vaccination or are unlikely to return for ppd read.
    • In other adult patients TST or IGRA are reasonable testing choices, although IGRA is slightly preferred due to better test characteristics (it is more specific)
    • A negative reaction in either test does NOT exclude TB
  • Sputum – AFB smear, culture, and gene expert
    • The policies at our hospitals have been updated and you only need 2 AFB smears and gene experts to decide about airborne isolation discontinuation for inpatients
  • Check out these clinical practice guidelines on the diagnosis of TB.

Management of TB

  • Is this active TB?
    • The diagnosis of active TB is based on symptoms, imaging, sputum AFB smear, culture, and gene expert
    • If a diagnosis of active TB is confirmed, most patients will be treated with directly observed therapy at TB clinicW
  • Which patients with LTBI should be treated?
    • There is a push these days to treat nearly all patients with confirmed LTBI if the patient agrees to be treated
    • There is a strong recommendation to treat patients who are at high risk of reactivation
      • Risk of activation in immunocompetent host is 5-15% over their lifetime
        • ~5% risk within the first 2 years of exposure and ~5% risk over the rest of the lifespan
      • Risk factors for reactivation TB or high incidence of TB: age (young children and elderly), HIV, meds that inhibit cellular immunity (TNF alpha inhibitors, steroids), history of head and neck or hematologic malignancies, organ transplant candidates/recipeints, ESRD, silicosis, low body weight, history of bypass surgery, prisoners, illicit drug use, smokers, homelessness, healthcare workers, foreign born, diabetes, or recent seroconversion.
    • Treatment regimens: Should be based on patient preference, comorbidities, side effects, and drug interactions
      • INH for 6-9 months
      • Rifampin for 3-4 months
      • INH + Rifampin for 3-4 months
      • Rifapentine + INH for 3 months

More TB related resources

Evernote link:

Pulmonary Report Pearls – 2/12/18 – Pleural Effusions

Thank you to Max for presenting the case of a middle aged woman with history of SLE c/b Evans syndrome on steroids (20 grams x 2 weeks) re-presenting to medicine after treatment strep pneumonia on oral amox with recurrent cough, fevers and pleuritic chest pain. She was found to have a left sided effusion and will be evaluated today for drainage and possible chest tube (incomplete source control!!).

  • 15-20% of patients with Strep Pneumonia will have bacteremia. These patients should be continued on abx for 14 days and it is important to ensure there are no metastatic complications before abx are discontinued.
  • Remember wrong drug, wrong bug or incomplete source control in any patient presents with ongoing fevers. However, as we discussed other causes of ongoing fevers include failed immune system (immunosuppression preventing host from clearing an infection) and/or another problem (such as a rheum flare) driving fevers.
  • Pulmonary complications associated with strep pneumo bacteremia include empyema, necrotizing pneumonia, and lung abscess.
  • The main difference with a high resolution CT vs. standard CT at Moffitt is air dynamics – inspiration and expiration comes with HRCT. We no longer skip lesions with the high resolution CT. This is not true in the community…yet.
  • Effusions related to infection run on a spectrum from simple parapneumonic à complicated à empyema. See more details below on delineation and implications for management.
  • Never let the sunset on a pleural effusion without tapping it! In general, all parapneumonic effusions, EXCEPT those that are free flowing and layer less than 10 mm on a lateral decubitus film, should be sampled by thoracentesis.


The Gradient of Pleural Effusions

Stages Macro Appearance Pleural fluid characteristics Management
Simple Parapneumonic Clear Fluid pH > 7.2

LDH < 1000 IU/I

Glucose > 2.2 mmol/l

No organisms on culture or gram stain

Will resolve with abx alone

Chest tube for symptoms only

Complicated Parapneumonic Clear fluid or cloudy/turbid pH < 7.2

LDH > 1000

Glucose < 2.2 mmol/l

May be + organisms on gram stain/culture

Requires chest tube drainage
Empyema Frank pus May be + organisms on gram stain/culture Requires chest tube drainage
  • Other indications for drainage of an effusion include: large + free flowing ( > 1/2 the hemithorax), loculated effusions, or effusions with a thickened parietal pleura.

Morning Report 2/7/18 – Neutropenia, Fevers and Subdural Empyema

Thank you to Nadine for presenting a case of a young woman with very complex medical history including cryptogenic cirrhosis s/p TIPS, hepatic encephalopathy on lactulose and rifaximin listed for transplant, aplastic anemia, CAD s/p mid-LAD thrombectomy, LAD dissection, APS antibody positive on ASA, short telomere syndrome, who was admitted for neutropenic fever and evolution of spontaneous subdural hematomas in the setting of coagulopathy and thrombocytopenia. Wow!

Neutropenic Fever:

  • ANC <500 or <1000 with anticipated decline
  • Single temperature >38.3 or >38 sustained for more than 1 hour

When you think about empiric coverage, consider patients as either high risk or low risk. Here’s a breakdown of high vs. low from Medscape.

High-risk patients are those patients with any one of the following:

  • Anticipated, prolonged (>7-d duration), and profound neutropenia (ANC <100/µL) following cytotoxic chemotherapy
  • Significant medical comorbidities, including hypotension, pneumonia, new-onset abdominal pain, or neurologic changes

Low-risk patients are those with the following

  • Anticipated brief (<7-d duration) period of neutropenia
  • ANC greater than 100/µL and absolute monocyte count greater than 100/µL
  • Normal findings on chest radiograph
  • Outpatient status at the time of fever onset
  • No associated acute comorbid illness
  • No hepatic or renal insufficiency
  • Early evidence of bone marrow recovery
  • Most of the guidelines for neutropenia come from patients with chemotherapy induced neutropenia – these patients are at the highest risk for acute infection due to the combination of both low neutrophil count and mucositis.
  • However, patients with other causes of neutropenia who have had absolute low neutrophils for prolonged periods of time, may be at higher risk for indolent infections.

Infected Subdural Hematomas

  • As HH mentioned most subdural infections represent local extension of paranasal sinusitis or otitis, or are complication of intracranial surgery.
  • Infection of a subdural hematoma is a usual cause of subdural empyema with < 50 cases reported (see article below).
    • May transform in the setting of pre-existing subdural via hematogenous infection (concerning for our patient with new murmur and AMS).
    • Mostly seen in adults > 60 and immunolofic dysfunction (eg neutropenia).
    • Microbiology: Varied considerably. Of the 47 case reports 13 cases reported E. Coli (27%), 8 cases reported Salmonella (17%), Staph aureus in 6 cases (13%) and Streptococcus in 5 cases (10%). The rest were a mix of Klebsiella, Campylobacter or unknown.
  • Signs and symptoms are non-specific and include altered sensorium (depressed level of consciousness), fevers and focal deficits.
  • MRI has become the imaging modality of choice in patients with infected subdural hematoma. It is superior to CT scans for the demonstration of extra axial fluid and rim enhancement, and in the visualization of the presence of pus.
  • Definitive management is surgical: both burr hole and craniotomy.
  • The best surgical option is not well defined, however based on limited data the recurrence rate seems to be lower with craniotomy.

See the following review article for more information.

Cardiology Report Pearls – 1.30.18 – Infective Endocarditis

Thank you to our cards team (Manoj, Noa and Nicole) for presenting the case of an elderly woman with hx of AVR presenting both native and prosthetic valve enterococcus endocarditis involving in the mitral valve and aortic valve. She is awaiting more urgent cardiac surgery given worsening MR and heart failure. A fun case where we learned a ton about endocarditis and HH nailed the organism prior to speciation!


  • In a patient with a positive UA with negative nitrites one should think of gram-positive organisms including enterococcus.
  • Ceftriaxone is not active alone against enterococcus, however ampicillin and ceftriaxone (CTX) are used in conjunction b/c CTX augments the activity of ampicillin.
  • If you have a high concern for endocarditis send 3 sets of blood cultures prior to abx!

Approach to prosthetic valve endocarditis:

  • Early (<30d): often are virulent organisms including S aureus, GNRs. Fungemia is BAD!
  • Late: Similar organisms to native valve endocarditis (staph, step and enteroccus), plus fungal organisms.

Indications for TEE

  1. Evaluation of endocarditis after a poor/unclear TTE study or possible complications (eg, fistula, abscess)
  2. Evaluate for valve disorders pre or post operatively
  3. Evaluation for left atrial/LAA thrombus in a patient with atrial fibrillation/atrial flutter to facilitate clinical decision making regarding anticoagulation, cardioversion, or ablation
  4. Suspected acute aortic pathology (ie, dissection, transsection, intramural hematoma).
  5. Evaluation of source of embolism in a young (<50 years) patient for whom a TEE would be performed if the TTE was normal

Global Indications for Surgery in Valve Endocarditis – (see table below)

  1. Heart Failure
  2. Uncontrolled infection
  3. Persistent Emboli

See more info in this fantastic 2013 NEJM Infective Endocarditis review article by Hoen and Duval. Table 2 is a great summary below.

IE Surgery Capture

Definitions of early surgery

  • There is no consensus as to the optimal timing of early surgery.
  • The ESC guideline classifies surgical indications in IE as emergent (within 24 hours), urgent (within a few days), and elective (after 1-2 weeks of antibiotic therapy).
  • The AHA/ACC guideline defines early surgery as occurring during the initial hospitalization and before completion of a full therapeutic course of antibiotics.

 Favorite PEARL from Anne this am!

  • Early intervention for endocarditis related valve dysfunction is associated with significantly reduced composite end point of death from any cause and embolic events by decreasing risk of systemic embolism. See the NEJM original article here:
  • When advocating for your patients send this to your friendly CT Surgery colleagues 🙂