Infectious Diseases Part 2 Flashcards
Regarding Candidiasis, what is shown on a Potassium Hydroxide (KOH) Smear
Budding yeast and pseudohyphae
Symptoms of Candidiasis in the oropharyngeal cavity (Thrush)
-friable, white plaques that leave erythema if scraped
Treatment for Thrush
- Nystatin swish and swallow
- Clotrimazole troches
Intertrigo is a cutaneous infection that is most common in moist, macerated areas. The rash appears beefy, red and distinct scalloped orders and satellite lesions. What is the treatment
Clotrimazole topical, keep area dry
How is Cryptococcis transmitted?
Pigeon and bird droppings inhalation
Risk factors for Cryptococcosis
-Most common in immunocompromised (CD4 < 100)
Symptoms of Cryptococcosis
- Meningoencephalitis: headache and meningeal signs (stiff neck, nausea, vomiting, photophobia)
- Pulmonary: pneumonia
- Skin lesions if disseminated
Diagnostics for Cryptococcosis
- Lumbar puncture: Fungal CSF pattern (increased WBC, decreased glucose, increased protein)
- Cryptococcal antigen in CSF on visualization with encapsulated yeast on India Ink Stain
Treatment for Cryptococcosis
- Amphotericin B + Flucytosine x 2 weeks followed by Oral Fluconazole x 10 weeks
- Fluconazole if prophylaxis needed and if CD4 < 100
What is the biggest risk factor for Histoplasmosis?
Immunocompromised states and people with CD4 < 150
Transmission of Histoplasmosis
- Inhalation of soil containing bat and bird feces in Mississippi and Ohio River Valleys
- Demolition, Spelunkers, Excavators
Symptoms of Histoplasmosis
- Asymptomatic (Most patients)
- PNA (Can Mimic TB)
Diagnostics for Histoplasmosis
- CXR: Pulmonary infiltrates, hilar or mediastinal LAD
- Antigen testing: via sputum (PCR) or urine highly specific
- Cultures: Most specific test
Treatment for Histoplasmosis
- Asymptomatic: No treatment needed
- Mild: Itraconazole
- Severe: Amphotericin B
Risk Factor for Pneumocystis Pneumonia (PCP)
CD4 < 200
Symptoms of PCP
- Classic Triad: progressive dyspnea on exertion, fever, nonproductive cough
- Oxygen desaturation with ambulation
Diagnostics for PCP
- CXR: diffuse bilateral interstitial infiltrates
- Labs: Increased LDH
- Lung Biopsy: Definitive
Treatment for PCP
- Bactrim drug of choice x 21 days
- If HIV +, add Prednisone if hypoxic
If the chest xray is positive with PCP PNA, what will it show?
Bilateral diffuse symmetric finely granular opacities/reticular interstitial airspace disease
PCP Prophylaxis in HIV
CD4 < 200: Bactrim
Risk factor for MAC
CD4 < 50
-Underlying pulmonary disease
Transmission of MAC
-Present in soil and water (not person to person)
Treatment for MAC
-Clarithromycin + Ethambutol + Rifampin
Prophylaxis for HIV patients against MAC
-Clarithromycin or Azithromycin if CD4 < 50
Pathophysiology of TB
After inhalation, Mycobacterium Tuberculosis goes to alveoli, gets incorporated into macrophages, and can disseminate from there
In chronic/latent infection, what three things do you need to show the person is not infectious with TB?
- Positive PPD
- No symptoms of infection
- No imaging findings of active infection
With secondary/reactivation TB, what is seen on CXR?
Apex/upper lobes with cavitary lesions. These patients are contagious
Regarding CXR and TB, explain the differences to each stage of TB
-Primary: middle/lower lobe
-Reactivation: apical (upper lobe)
Miliary TB: small millet-seed nodular lesions
For sputum acid-fast staining, what must you get?
3 samples taken on 2 consecutive days must be negative to rule out TB
However, for TB, what is more sensitive than sputum smears?
NAAT
Management of active TB
Initiate 4-drug therapy: RIPE for 2 months
-Followed by 4 months of RI = 6 month total duration
TB drugs and side effects
- Rifampin: orange colored secretions
- Isoniazid: peripheral neuropathy, hepatitis
- Pyrazinamide: hepatitis and hyperuricemia
- Ethambutol: Optic Neuritis, red/green color blindness
Treatment for Latent TB infection
-INH + Pyridoxine (Vitamin B6) x 9 months OR -RIF X 4 months OR -INH + Rifapentine x 3 months OR -INH x 6 or 9 months
> 5 mm to be positive for TB:________
10 mm to be positive for TB: __________
15 mm to be positive for TB: ________
5: HIV or immunosuppressed, close contact with active TB, CXR with old TB
10: all other high-risk populations
15: everyone else, no risk factors for TB
MC helminth infection in the US
Enterobiasis (Pinworm)
Transmission of Enterobiasis Vermacularis
-Hand-mouth contact with contaminated fomites, fecal-oral contamination in school-aged children
Symptoms of Enterobiasis
- Perianal itching, especially nocturnal (eggs are laid at night)
- Abdominal pain, nausea, vomiting
Diagnostic for Enterobiasis
-Cellophane tape test or pinworm paddle test early in AM to look for eggs under a microscope
Treatment for Enterobiasis
-Albendazole, Mebendazole, or Pyrantel (in pregnancy)
MC intestinal helminth worldwide
-Ascariasis (roundworm)
Diagnostic for Ascariasis
-Stool ova and parasite
treatment for Ascariasis
- Albendazole or Mebendazole
- Pyrantel if pregnant
Trichinosis is transmitted through
Raw or undercooked meat (pork, boar, or bear)
Adult Trichinosis are excreted in the stool and larva penetrate intestinal wall and go where?
Encapsulate in striated muscle tissue
Symptoms of Trichinosis
- GI phase: abdominal pain, nausea, vomiting
- Muscle phase: myositis (weak or painful muscles), subungal splinter hemorrhages
- Cardiac: Myocarditis
What labs are shown with Trichinosis?
- Eosinophilia (hallmark)
- Increased CK and LDH (due to muscle involvement)
Treatment for Trichinosis
-If any CNS, cardiac, or pulmonary involvement, Albendazole or Mebendazole
Hookworm is common in countries where
Hookworm (Ancylostoma duodenale and Necator americanus)
Poor access to adequate water, sanitation, and hygiene
What three conditions must be met to transmit Hookworm? (Ancylostoma duodenale and Necator americanus)
- Human fecal contamination of soil
- Favorable soil conditions for larvae growth
- Contact of human skin with contaminated soil
4 phases of hookworm symptoms
- Skin: pruritic erythematous dermatitis at site or entry
- Transpulmonary: asymptomatic
- GI: N/v, diarrhea, GI bleed rare
- Chronic Nutritional Impairment: daily loss of blood, iron, and albumin
Treatment for Hookworm
- Albendazole or Mebendazole, Pyrantel
- Iron supplementation, multivitamins
