Infectious Disease Flashcards
Diagnosis:
- Fever
- Leukopenia/thrombocytopenia
- Elevated aminotransferases
- History of tick bite
Ehrlichiosis
Treatment:
Ehrlichiosis
Doxycycline
What disease presents similarly to Rocky Mountain Spotted Fever, but lacks a rash?
Ehrlichiosis
Treatment:
TB in a patient who is pregnant, suffering from malnutrition or has diabetes mellitus
TB treatment plus pyridoxine (Vitamin B6)
Active TB: Isoniazid (INH), rifampin, ethambutol and pyrazinamide for 2 months followed by, INH and rifampin alone for 7 months
Latent TB: Isoniazid only (?)
Why should you add pyridoxine (Vitamin B6) to the medical therapy for TB in a patient who is pregnant, suffering from malnutrition or has diabetes mellitus?
INH-induced peripheral neuropathy
INH binds the active form of pyridoxine and results in renal excretion. This can lead to pyridoxine deficiency in certain at risk patients.
Initial evaluation:
Amebiasis
- Imaging
- Serologic testing for Entamoeba histolytica antibodies
- Empiric treatment with Metronidazole
- Luminal agent (F: to eradicate intestinal colonization)
Treatment:
Amebiasis (Entamoeba histolytica)
Metronidazole + luminal agent to eradicate intestinal colonization
Cyst drainage is not recommended routinely.
Diagnosis:
- Abdominal pain
- Fever
- Leukocytosis
- Liver abscess on imaging
- Hx of dysentery
- Recent travel from Mexico
Amebiasis (Entamoeba histolytica)
Differential:
Bloody diarrhea in the absence of recent travel
- Escherichia coli (EHEC)
- Shigella
- Campylobacter
What is the most common cause of bloody diarrhea in the absence of fever?
E. coli (EHEC)
True or False:
Antibiotics are the mainstay of treatment for Enterohemorrhagic E coli (EHEC).
FALSE! Treatment is generally supportive. Antibiotics may increase the risk of hemolytic uremic syndrome.
How can you confirm the diagnosis of Enterohemorrhagic E. coli (EHEC)?
Stool assay for Shiga toxin
Management:
Suspected Infective Endocarditis
Acute illness: obtain 3 blood cultures from 3 different venipuncture sites over a 1-hour period before beginning empiric antibiotic therapy.
Stable Subacute Illness (malaise without fever): obtain 3 blood cultures from 3 different venipuncture sites over several hours. Wait for cultures to return before starting antibiotic therapy.
What diagnostic tool can be used to make a clinical diagnosis of infective endocarditis?
Modified Duke criteria
What pathogen causes Toxic Shock Syndrome?
Staphylococcus aureus
Diagnosis:
- Fever
- Myalgia
- Marked hypotension
- Diffuse erythematous macular rash (erythroderma)
- Recent history of nasal packing
Toxic Shock Syndrome
TSS is associated with: (1) use of tampons during menstruation (2) nasal packing (3) post-surgical infections.
If left untreated, TSS can lead to multi-organ involvement.
Treatment:
PPX against Mycobacterium avium complex in a patient with HIV
Azithromycin
At what CD4 count is prophylaxis against Mycobacterium avium complex recommended for HIV patients?
CD4 <50
- CD4 <200 = Pneumocystis*
- *CD4 <100 = CMV**
What are the key distinctions between primary HIV and Infectious mononucleosis?
Rash and diarrhea are less common in infectious mononucleosis.
Exudative pharyngitis is less common in HIV.
The febrile illness seen in primary HIV also closely resembles __________.
Infectious mononucleosis
Diagnose:
Infectious mononucleosis
Heterophile antibody test
Treatment:
Splenic abscess
Splenectomy
Antibiotics alone have a high mortality rate (up to 50% in some studies) .
What is the classic triad of splenic abscess?
- Fever
- Leukocytosis
- Left upper-quadrant abdominal pain
Diagnosis:
Signs/Symptoms
- Fever
- Leukocytosis
- Left upper-quadrant abdominal pain
- Left sided pleuritic chest pain
Imaging:
- Left-sided pleural effusion
- Splenic fluid collection
Splenic abscess.
Treatment=splenectomy
List the risk factors for splenic abscess.
- Infection with hematogenous spread (eg infective endocarditis)
- Immunosuppression
- IV drug use
- Trauma
- Hemoglobinopathies
How long do the symptoms of influenza typically last?
<1 week
*Influenza is a self-limited infection. *
What are the systemic and respiratory signs of influenza?
Systemic:
- Fever
- Malaise
- Myalgia
- Headache
Respiratory:
- Rhinorrhea
- Pharyngitis
- Non-productive cough
What patients are at risk for complications of the flu?
- Patients with advanced age (age >65)
2. Patients with chronic illness (eg coronary artery disease, diabetes mellitus)
Differentiate between primary influenza pneumonia and Streptococcus pneumoniae pneumonia/Pseudomonas aeruginosa pneumonia.
Influenza pneumonia:
- Acute worsening of cough and dyspnea
- Leukocytosis, but <15,000
- Hypoxia
- Bilateral, diffuse interstitial infiltrates on CXR
Streptococcus pneumoniae/Pseudomonas aeruginosa pneumonia:
- High fever
- Significant leukocytosis (>15,000)
- Lobar infiltrates on CXR
What are the possible complications of Influenza.
- Pneumonia (primary influenza vs. Strep pneumoniae vs. Pseudomonas aeruginosa)
- Myositis
- Rhabdomyolysis
- Myocarditis
- Pericarditis
- Encephalitis
- Transverse myelitis
