Infectious Diseases (Opportunistic & Bacteremia)

Criptococcus

young, complain of intense headache without PMH, change in mood/irritable with + sx of infection

Order CSF cryptoccal antigen test!
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Terms in this set (23)
Criptococcus

young, complain of intense headache without PMH, change in mood/irritable with + sx of infection

Order CSF cryptoccal antigen test!
38yr male evaluated for 3 months Hx of malaise and low grade headache and fever with gradual progression of intensity and night sweats. Over the last 2 weeks he reports fullness sensation in both ears and irritability.
Exam shows temp of 100.7F (38.2C). He is oriented to person & place, but not time or date. The neck is stiff and painful with flexion. Fundoscopy reveals papilledema.
CT normal
LP reveals 300WBC
What do you suspect & what test do you order?
Histoplasmosis

fever, weight loss, skin lesion on lip with hepatomegaly and lymphadenopathy

Order a urine culture for H. capsulatum antigen
36y male evaluated for chronic nonproductive cough of 3 week duration, worsening fatigue, malaise and weight loss. Reports fever, chills, night sweats and DOE.

Exam reveals 100F, 101bpm, skin lesion on upper lip, hepatomegaly and lymphadenopathy in left inguinal region.

Lab: pancytopenia and LFT abnormalities
CXR: bilateral diffuse reticulonodular infiltrates
Lymph Bx: yeast budding

What do you suspect and what test to order?
Candidiasis

Fluconazole x14 days
IV until able to swallow
39y HIV male presents with 5 day Hx of mild burning sensation in mouth, increasing dysphagia. PMH reveals HIV Dx was in 1995 and most recent CD4 count was 1 years ago. Not on medications.

Exam= + erythema of hard palate
EGD: lesion and creamy plaque in mid esophagus

What do you suspect and recommend?
Pneumocystis Jirovecii

Bactrim with a steroid to assist breathing with low O2 sats
40y woman presents for eval of gradual onset of fever & respiratory symptoms. Dx HIV 8 years ago and last CD4 was 135 with HIV RNA viral load of 53,120 copies/mL. Has not been taking meds and now presents with 4week fever, fatigue, non-productive cough and DOE.
Exam reveals 20 respiration rate, O2 sat 91%, pH 7.48 (7.35-7.45), CO2 29mmHg (35-45) and pO2 68 mmHg (75-100) with elevated LDH.
CXR show bilateral opacities with interstitial markings.

What do you suspect and recommend?
Cytomegalovirus due to decreased CD4 and vision abnormalities.

CMV <50 CD4
Seek ophthalmologist immediately!
43y HIV-infected woman with CD4 <22 with new visual problems. Describes difficulty seeing out left eye and notices floaters in the same eye. Has not taken medications for HIV, but on Bactrim (TMT-SMX) for pneumocystis pneumonia.

What do you suspect and recommend?
Toxoplasmosis
36y HIV male presented 2-3 week Hx of fever and headache brought to ER with generalized tonic-clonic seizure.
CD4 count was 14 and HIV RNA >500,000. Pt on Bactrim (TMT-SMX) and antiretroviral for 1 year but stopped 9 months ago. PMH Kaposi sarcoma.
Exam: confusion, fever, Kaposi sarcoma
CT: focal mass lesions on brain

What do you suspect?
Coagulase Negative Staphylococcus (45%)
What is the most common bacterial contaminant in blood culture?
The pathogen and the PMH
What are 2 critical factors to know in a bacteremia case?
LPS (endotoxin) binds to macrophages & monocyte receptors
How do Gram - bacteria trigger the immune response?
Peptidoglycans and lipoteichoic acid
Exotoxins (superantigens bypass macrophages/monocytes and target T-cells directly --*streptococcal sp. )
How do Gram + bacteria trigger the immune response?
TLR (Toll-like receptors)What is the most important receptor in triggering the immune response via detection of a foreign agent?IL 1 & 2 activate fever, chills IL6 activate inflammation, fatigue, malaise & loss of appetite (due to block of leptin) In elderly, it reaches the Reticular Activated System and causes deliriumDistinguish between the young and elderly immune response mediated by interleukinsRespiratory Tract Urinary Tract Abdominal Infection Venous CatheterWhich sites does True bacteremia usually seed from?Vital signs (HYPOTN + blood culture = Gram - ABx) Lungs (egophony sounds for pneumonia) CV system (hands & feet for brown spots of necrosis) abdomen skin (edema, erythema unilateral = cellulitis) AMSWhat do you look for in a physical exam if suspect bacteremia?WBC, toxic granulation, thrombocytopenia, lactic acid (ischemia), creatinine UA, CXR, CT abdomen, LPWhat do you check for lab tests?Acute infection causes NO release = vasodilation = perfusion of the kidney = renal injury = elevated CrDescribe the pathophys behind the elevation in creatinine levels with infection1. Fever (>100.4F or 38C) or hypothermia (<36C) 2. HR >90bpm 3. leukopenia (<4k) or leukocytosis (>12k) (5-10) 4. Respiratory Rate >20, PaCO2 <32mmHg (35-45)What are the 4 indications of SIRS?septic shock has HYPOTNWhat is the difference between sepsis and septic shock?shaking chills (80% indicative)What specific clinical sign has the highest indication for bacteremia?Platelets <150,000 or <120,000What values would you expect for platelets in a pt with bacteremia?Major: -suspect endocarditis -temp. >39.4C -catheter line Minor: -Temp. 38.8-39.3 -Age >65 -Chills -Vomiting -SBP <90mmHg -WBC >18k Creatinine >2 Platelets <150kBased on the Shapiro Prediction Rule what are the components of the Major and Minor criteria?ALWAYS order a Trans Esophageal Echocardiogram due to risk of endocarditisWhat should you do if bacteremia cause is Staphylococcus aureus sp.?Sometimes for Streptococci sp. No need for gram - bacteriaIs it necessary to order an Echo for bacteremia caused by streptococci or gram - bacteria?