Infections Flashcards
Patient presents with cough for 2 weeks (no sputum), a little difficulty breathing, and some complains of pain in the chest. No fever. Upon auscultation, you hear rhonchi. CBC shows slightly elevated WBC count.
Acute bronchitis
It’s fall and a patient comes in with a sudden onset of a cough, sore throat, nasal congestion, fever, headache, and myalgia that began abruptly 2 days ago. The patient appears flushed. You notice swollen lymph glands in the neck and swollen part of pharynx between epiglottis and soft palate.
Influenza
Tx for acute bronchitis
Symptomatic.
- NSAIDS, acetaminophen, bed rest
- Don’t use cough suppressants, beta 2 agonists (unless airway obstruction), or mucolytics
- Treat rhinorrhea symptoms if follows URI
Tx for Influenza
Supportive care- bed rest-self limiting so should resolve within a week, analgesics (no aspirin under 18), cough suppressants
- Antiviral therapy for very severe cases, initiated within 2 days- Zanamivir or oseltamivir
- Abx only for secondary bacterial infections
Common causes of Acute Bronchitis
Virus- Influenza A and B, parainfluenza. Bacteria infection uncommon- Mycoplasma pna, chlamydophilia pna, and bordatella pertussis
Common causes of Influenza
Influenza A and B. VERY contagious. Ptns are infectious 24-48 hrs before illness onset and 2 days after symptom onset.
Diagnostic evaluation of Influenza
CBC may show leukopenia or leukocytosis. Rapid detection assay has poor sensitivity. Can do nucleic acid PCR.
Most serious complications of influenza
Reye’s disease and primary influenza pneumonia
What symptoms could Reye syndrome cause
Hepatic failure and encephalopathy.
Prevention of influenza
Vaccine! 3 types available: Live attenuated vaccine, intradermal inactivated vaccine, intramuscular inactivated vaccine. Chemoprophylaxis in high risk patients with oseltamivir or zanamivir prescriptions
Cause of CAP
Usually bacterial- S. pneumoniae most common, then H. Influenza. Viral- Influenza, RSV, adenovirus, etc. In pediatric population less than 5, viral infection more common
How can you differentiate bacterial vs. viral CAP?
Bacterial CAP is more common. Patient will appear ill and more toxic. In viral, patient usually less toxic. Auscultation findings more diffuse and bilateral. Typically will have preceding URI sx.
Patient presents with acute onset of fever, sweats, chills, dyspnea, productive cough with blood, chest discomfort, pleurisy, fatigue, anorexia, headache, and abdominal pain. In the PE, you note an elevated heart rate and increased respiratory rate. Arterial oxygen desaturation as well. Upon auscultation, there is slight wheezing and crackles. Bronchophony, egophony, and whispered pectiriloquy are positive. Decreased, bronchial breath sounds. Decreased? tactile fremitus, and dullness to percussion.
Community Acquired PNA
Diagnostic evaluation of CAP
CXR or CT scan. CBC, acute phase reactants, serum electrolytes, blood and sputum cultures, pleural fluid cultures, nasopharyngeal swabs. Procalcitonin (viral vs. bacterial), Ag testing for different organisms, TB skin testing, serum and urine testing for histoplasmosis. HIV testing in high risk ptnts. Arterial blood gases in hypoxemic ptnts.
Tx of CAP for outpatient adult
Macrolide or doxycycline. For high risk patients, respiratory FQ OR macrolide with beta lactam
Tx of CAP for inpatient (Non-ICU) adult
Respiratory FQ OR macrolide with beta lactam
Tx of CAP for inpatient (ICU) adult
Respiratory FQ plus azithromycin plus beta lactam (anti-strep/anti-pneumococcal)
Tx for outpatient child
Amoxicillin
Tx for inpatient child
3rd generation cephalosporin
Tx for CAP
Supportive care, empiric therapy until culture comes back, smoking cessation
How to decide whether CAP should be treated inpatient or outpatient?
Clinical prediction tools assess severity of illness, ability to maintain oral intake, compliancy of patient, living situation, functional status/cognitive impairment using PSI (Pneumonia Severity Index) or CURB-65
Recovery of CAP
Cough may persist for weeks to months, follow up CXR if persistent or recurrent PNA
Causes of fungal PNA
Cryptococcus, Histoplasmosis, Coccidioides, Blastomyces
Type of pneumonia with wide range of manifestations- can be asymptomatic, flu-like, or present as severe pulmonary infection with associated respiratory failure.
Fungal pneumonia
Diagnosis of fungal PNA
clinical presentation, radiographic imagine (CXR), fungal cultures, body fluid or tissue analysis
What causes atypical pneumonia?
Atypical bacteria- legionella, mycoplasma, or chlamydophilia spp.
Tx for Mycoplasma pneumonia
Macrolides, fluoroquinolones, and/or tetracyclines
Tx for Legionella pneumonia
Macrolides or floroquinolones
Tx for Chlamydophilia pneumonia
Doxycycline
Incubation period for Influenza
1-4 days
Patient with Influenza. They just got it yesterday morning. When can they go back to school, and when will they feel better?
Influenza is contagious for 24-48 hours before symptom onset, and 2 days after. So if they just started to get symptoms yesterday, can probably return to school tomorrow, but do a day after tomorrow just to be safe. Symptoms resolve within a week.
Patient with influenza comes back into office after 5 days with fever that has gotten worse. You do a CBC, and find that elevated levels of Leukocytosis. What do you suspect?
Secondary bacterial infection- complications include acute sinusitis, otitis media, purulent bronchitis, and pneumonia
What is the most deadly infectious disease in the U.S.?
Pneumonia
Patient comes in that had URI last week. They now have CAP. Auscultory findings are more diffuse and bilateral. Bacterial or viral?
Viral. Bacterial is usually more toxic with moderate to severe respiratory distress.
What can cause CAP in children?
measles, varicella, HSV
Evidence of infiltrate on CXR in patient with fever, cough, dyspnea, sweats, chills, chest discomfort.
CAP.
Is F/U necessary with CAP patient after resolution of symptoms?
Yes, follow up after 6-8 weeks, especially in patients >50 years of age and smokers to document resolution of pneumonia and exclude malignancy
Your patient with pneumonia wants to know the complications associated. What do you tell them?
The following are more common to occur as a result of bacterial pneumonia: pleural effusion and empyeme, necrotizing pneumonia, lung abscess, pneumatocele, hyponatremia
Fungus commonly seem to cause pneumonia found in the south (Texas, mexico, central and south america)
Coccidioides spp.
What pneumonia causing fungus is found in soil throughout the world. vs. in moist soil?
Blastomyces- moist soil, cryptococcus- soil throughout the world
Pneumonia causing fungus most likely caused by someone that lives near the mississippi river?
Histoplasmosis
Tx for fungal pneumonia
Resolves on its own or treat with antifungals
What atypical bacteria would you most commonly see in patient under 40?
Mycoplasma
Your 60 year old patient has pneumonia. She just came back from a trip to India where she lived in a village and may have had uncontaminated water. What caused her pneumonia most likely?
Legionella- spread through contaminated water
What is chlamydophilia pneumonia associated with?
Pharyngitis and hoarseness.
Leading cause of death in hospitals due to infection
Nosocomial pneumonia
Contrast CAP with nosocomial pneumonia
caused by different infections, have different abx susceptibility patterns (higher incidences of drug resistance with nosocomial), and more likely to get more severe infection with nosocomial because systems are already compromised
Nosocomial pneumonia cause
S. aureus, Psuedomonas
Tx for nosocomial pneumonia
Start of with broad spectrum combination abx followed by de-escalation of therapy once culture results are available.
What kind of tx would you give for HIV-related pneumonia?
MicrobiCIDAL therapy start asap
Reactivation of virus is common in which pneumonia?
HIV-related. Includes Cytomegella virus, strongyloidiasi
How are bacterial HIV-related pneumonias different from general population?
They are more often preceded by viral URI
Patient presents with dyspnea, cough, and fever. Bilateral, diffuse interstitial infiltrates. What is the diagnosis if you know the cause is a fungal infection.
HIV-related pneumonia, caused by pneumocystis jirovecii. = most common opportunistic infection in patients with HIV.
How is fungal pneumonia in HIV-related patient diagnosed?
Isolation of the organism in respiratory secretions, can’t grow in lab.
Tx for HIV-pneumocystis pneumonia
Supportive therapy, TMP-SMX, and prednisone. Bactrim can be administered as prophylaxis in selected patients if prone to getting pneumonia.
What symptoms would you expect to find in a child with HIV-pneumocystis pneumonia?
Non-specific and insiduous
Tx you would prescribe to newborn with high chance of developing HIV pneumonia
bactrum Prophylaxis after 4-6 weeks of life even if CDR count is more than 200 and continued for 1 year of life
Normal CD4 count
500-1000
HIV-related fungal infections
pneumocystis jirovecci and aspergillus species
What is the most consistent feature of PNA?
Tachypnea
Ages of live attenuated vaccine
2-49
Age of inactivated intradermal vaccine
18-64
When are adults and children suspected of HIV pneumocystis jirovecii
Adults- CD4 counts greater than 200. Infants can get it below or event about 200
Alternative test to diagnose latent TB, (if have receieved BCG vaccine) besides TB skin test
Interferon gamma release assay- don’t use to diagnose active TB
Side effects of ioniazid in tx of TB?
hepatitis and peripheral neuropathy- treat with pyridoxine supplementation
What part of TB does reactivation or progressive primary TB affect?
Apices
