"Other" Infectious Disorders Flashcards
Chronic infection with mycobacterium tuberculosis leading to granuloma formation; high mortality rates in untreated smear positive.
Tuberculosis
Close contact of patient with active TB, health care workers are at an increased risk of _____
Exposure
Immigrants from high-prevalance areas and homeless are at an increased risk of _______
Infection
Immunodeficient patients, such as those with HIV, CRI, DM, IVDA, ETOHics, and those with malignancy are at a high risk of ?
Active TB once infected
Inhalation of air droplets –> Mycobacterium reaches alveoli and is ingested by alveolar macrophages –> Mtb remains viable within macrophage, bypasses or escapes defense –> active infection
Tuberculosis
What are the three different outcomes of a TB infection?
Primary
Chronic (Latent) infection
Secondary (reactivation)
The outcome of initial infection (usually self-limited)
Primary TB
Most exposed people mount an immune response sufficient to prevent further profession from initial infection to clinical illness. T cells and macrophages surround the organism and form a granuloma.
Primary TB
How many people who are infected with TB will develop the disease?
10%
When a person fails to contain the primary TB infection and progresses to active TB
Progressive primary TB
Are patients with primary progressive TB contagious?
YES!
How many patients will contain the TB bacterium without becoming contagious? What is this called?
95%; Latent TB infection (Chronic TB)
Do patients with chronic/latent TB have a positive PPD? Are they contagious?
Yes, usually within 2-4 weeks post infection
Not contagious!
What keeps patients with chronic/latent TB from having a primary TB infection?
Granuloma formation of T cells and macrophages around the bacteria
What is it called when someone has chronic/latent TB that is reactivated by a waning immunity? (Elderly, HIV, steroid use, malignancy)
Secondary reactivation TB
Where is TB usually located in the lungs?
Apex/upper lobes with cavitary lesions
Are patients with reactivation TB contagious?
YES!
What are the two types of TB?
Pulmonary and extra-pulmonary
Classically presents with pulmonary symptoms and constitutional symptoms
Pulmonary TB
Chronic, productive cough, chest pain (pleuritic), hemoptysis in advanced disease; Drenching night sweats, fever/chills, fatigue, anorexia, weight loss
Pulmonary symptoms of TB
What would you expect to see on a physical exam in a patient with pulmonary TB?
Signs of consolidation: Rales or rhonchi near apices/involved areas, rhonchi, dullness.
Which organs can extra-pulmonary TB affect?
Any organ!
Vertebral TB
Pott’s disease
Lymph node TB
Scrofula
Meningitis caused by TB
TB meningitis
Other extra-pulmonary infections caused by TB
Pericarditis, peritonitis, joints, kidney, adrenal, cutaneous infections
What is the change yearly of having a reactivation of LTBI in patients with HIV?
7-10%
For an immunosuppressed patient, a patient who has had close contact with active TB, or a CXR consistent with old or healed TB (granuloma), what is the reaction size of a PPD that would be considered positive?
> /= 5mm
For all other high-risk populations and high prevalence populations, what is the reaction size of a PPD that is considered positive?
> /= 10mm
How do you diagnose suspected TB? What is considered non-infectious?
Acid-fast smears and sputum culture for 3 days
3 negative smears = non-infectious
What is the gold standard for diagnosing TB?
Acid fast bacillus culture
How do you exclude active TB in a patient with a new + PPD?
CXR
CXR shows apical upper lobe fibrocavitary disease
Reactivation
Middle/lower lobe consolidation on CXR
Primary TB
CXR shows small millet0seed like nodular lesions (2-4mm)
Miliary TB
Pleural effusion on CXR
TB Pleurisy
Detected as residual evidence of healed primary TB on CXR
Granuloma
What is the 4 drug regiment to treat an active TB infection?
Isoniazid, rifampin, pyrazinamide, ethambutol OR streptomycin
RIPE: Rifampin, INH, Pyrazinamide, Ethambutol
When are patients considered to no longer be infectious?
2 weeks after initiation of therapy
TB resistant to both INH and rifampin
Multi drug resistant TB
Which TB drug has an adverse side effect of hepatitis and peripheral neuropathy?
Isoniazid
Which TB drug has an adverse side effect of thrombocytopenia and orange colored secretions?
Rifampin
Which TB drug has an adverse side effect of Which TB drug has an adverse side effect of hepatitis and hyperuricemia, GI sx, arthritis, and a photosensitive dermatologic rash?
Pyrazinamide
Which TB drug has an adverse side effect of optic neuritis, scooter, color perception problems, red-green visual changes, and peripheral neuropathy?
Ethambutol
Which TB drug has an adverse side effect of ototoxicity with CN8 and nephrotoxicity?
Streptomycin
Highly contagious infection secondary to bordetella pertussis; Rarely seen due to widespread vaccination Gram negative coccobacillus. Most commonly seen in children under 2 years old.
Pertussis (Whooping cough)
What are the 3 phases of pertussis?
- Catarrhal phase
- Paroxysmal phase
- Convalescent phase
URI symptoms for 1-2 weeks
Catarrhal phase Pertussis
Severe paroxysmal coughing fits (with inspiratory whooping sound after coughing fit) with or without post coughing emesis
Paroxysmal phase Pertussis
Resolving of cough and emesis (Coughing phase may last up to 6 weeks)
Convalescent phase Pertussis
How can you diagnose whooping cough?
Nasopharyngeal swab
Severe lymphocytosis seen on differential
How soon does a nasopharyngeal swab need to be done to diagnose pertussis?
First 3 weeks of symptom onset
What is the mainstay of treatment with pertussis?
Supportive Rx
If you choose to treat pertussis, what are some drugs you could use?
Macrolides or Bactrim (use if allergic to macrolides)
According to the green PANCE book, what is the DOC for pertussis?
Erythromycin (macrolide)
Pneumonia, encephalopathy, otitis media, sinusitis, and seizures are all complications of?
Pertussis
What is treatment of Pertussis aimed at?
Treatment is aimed at stopping transmission
Inflammation of the epiglottis that can interfere with breathing. MEDICAL EMERGENCY!
Epiglottitis
What is the common etiology of epiglottitis? What else could cause it?
Primarily Haemophilus influenzae B
Can be caused by s. pneumoniae, s. aureus, GABHS
What are the “3 D’s” that characterize epiglottitis?
Drooling, distress, dysphagia
What are some addition clinical manifestations of epiglottis other than the “3 D’s?”
Fevers
Odynophagia
Inspiratory stridor
tripoding
If you have a suspicion of epiglottis, what should you never do?
Try to visualize epiglottis –> this can obstruct the airway!
How should you diagnose epiglottitis?
Lateral cervical X-ray: Look for “thumb sign” of swollen, enlarged epiglottis
What is the mainstay of treatment with epiglottitis?
Supportive Rx and maintain airway
use dexamethasone to reduce airway edema
Tracheal intubation for severe cases
What type of abx should you use to treat epiglottitis?
2nd/3rd gen cephalosporins
AKA acute viral laryngotracheobronchitis, commonly affects children 6 months to 5 years. Most common cause is parainfluenza type 1 and 2. RSV, adenovirus, influenza, and rhinovirus are also implicated.
Croup
Symptoms for this disease are a harsh, barking, seal-like cough; inspiratory stridor, hoarseness, aphonia, low-grade fever; and rhinorrhea.
Croup
How do you diagnose croup?
Clinically
What would a PA neck film show in a patient with croup?
subglottic narrowing (steeple sign)
Why should you do a lateral neck film when you diagnose croup?
To differentiate between croup and epiglottitis
How do you treat croup?
Typically does not require treatment; hydrate
What are some things you can give your patient to help them recover from croup?
Humidified air or oxygen, nebulizer epinephrine
When should you hospitalize your patient with croup?
Severe symptoms
Acute respiratory illness caused by influenza A or B viruses with outbreaks mainly in fall/winter; spreads primarily via airborne secretions
Influenza
Which strain of influenza is associated with more severe, extensive outbreaks?
A
What is characteristic about flu symptoms?
They usually have a very abrupt onset
How do you usually diagnose influenza?
Clinically or with a culture
What are the two types of influenza vaccine?
Influenza trivalent vaccine
Intranasal (live attenuated)
Who should always get a flu shot?
everyone! More specifically >50 years of age and those with underlying chronic medical conditions like asthma, sickle cell disease, and COPD
How do you manage the flu?
Best if begun within 48 hours of onset of symptoms:
Acetaminophen or salicylate for symptoms
Antivirals