1 - Infectious Disease Flashcards
Infectious Disease - general principles
- normal healthy humans are colonized by __ bacteria
- microbes outnumber human cells __
- vast majority of infections are caused by
50 trillion
10:1
Organisms part of our normal microbiota
Infectious Disease - general principles
- __ leading cause of death worldwide
- deaths disproportionally affect ages
Second-leading
<1 and >70 y.o.
Infectious Disease - history
- exposure (5)
- immunity (2)
Drug-resistant microbes Social history Dietary habits Animal exposures Travel hx
Immunocompromised
Vaccinations
Infectious Disease - physical examinations
- vital signs (2)
- lymphatics
- skin
- foreign bodies
Fever = core temp >/= 38.3 C or 101 F
Heart rate
Lymphadenopthy - localized or generalized
Lesions assoc with systemic disease
IV lines, catheters, etc.
Infectious Disease - physical exam
-splinter hemorrhages (4)
Non-specific
Non-blanching
Linear reddish-brown lesions under nail bed
Usually do NOT extend the entire length of the nail
Infectious Disease - diagnostic testing
- WBC count (2)
- inflammatory markers (3)
Often high - but leukopenia w/ many viral infections
Differential: PMN neutrophils, lymphocytes, eosinophils, etc
ESR = indirect
CRP = direct
Both sensitive, not very specific
Infectious Disease - diagnostic testing
-CSF analysis (6)
Opening pressure Cell counts Gram stain/culture Glucose/protein levels Fluid profiles differentiate diff types of meningitis and encephalitis
Infectious Disease - diagnostic testing
- cultures (2)
- pathogen-specific tests (3)
Mainstay of infectious disease dx
Infected tissue/fluid
Serology
Antigen testing
PCR testing
Infectious Disease - diagnostic testing
-radiology (2)
Lymphadenopthy in non-accessible regions
Evidence of infection of internal organ
Infectious Disease - management
- antibiotics (2)
- infection control (2)
- referrals/consultations (2)
Narrow-spec vs empirical
Infected tissue/fluid
CDC guidelines
Prophylaxis
Specialist for specific area of infection
Infectious diesase specialist
Epstein-Barr virus
- epidemiology
- type of virus
- causes
Very common (>90% adults worldwide) Young children w/ peak in late adolescents
Human herpes virus 4
Infective mononucleosis and assoc with several tumors
Epstein-Barr virus
- transmission
- infects __ of __, then spreads…
Salivary secretions
Infects epithelium of salivary tract, then spreads thru blood stream
Epstein-Barr virus
-symptoms
—young kids
—adolescents
Usually asymptomatic or mild pharyngitis
Prodrome of fatigue, malaise, myalgia
Fever, sore throat, lymphadenopathy (posterior cervical nodes)
Epstein-Barr virus
- lab findings
- complications
Elevated WBC count with lymphocytosis (>10% atypical lymphocytes)
Liver function abnormal in >90%
Most cases self-limiting, but very rare deaths occur due to CNS complications, splenic rupture, upper-airway obstruction, bacterial superinfection
Epstein-Barr virus
- diagnosis
- management
Blood titer of heterophile (Ab) above a certain level in pt with compatible symptoms and atypical lymphocytes is diagnostic for acute infection
Supportive therapy (rest, analgesia) No proven anti-viral or vaccine
Influenza
- symptoms
- virus
- spread
- cells infected
- pandemic in hx
Respiratory illness accompanied by fever, malaise, fatigue
Specific type, many strains
Rapidly via respiratory droplets
Ciliated epithelial cells of respiratory tract
1918 - 50 million deaths
Influenza - clinical manifestations
- primarily a respiratory illness causing (4)
- distinguished from other respiratory illnesses by the degree of (4)
Rhinorrhea
Sore throat (diffuse pharyngeal erythema)
Conjunctivitis
Cough (recurrent, persistent)
Fatigue
Fever
Malaise
Myalgia
Influenza - complications
- respiratory
- extrapulmonary (4)
Pneumonia - primary viral, secondary bacterial, or mixed
-alveolar sacs involved (fill with fluid/pus, causing breathing difficulty)
Myositis (most common) - can lead to renal failure
Post-infectious acute demyelinating encephalomyelitis
Guillain-Barre syndrome
Reye syndrome
Influenza - diagnosis
- confirmed cases
- microbiological dx
- most effectively collected
Only a fraction are lab confirmed
Important for individual pt and public health
Nasopharyngeal specimen via nasal swab
Influenza - management -vaccination -antivirals —limited use due to (2) —current meds
Major intervention to limit illness
Yearly - typically available in september
Intramuscular/dermal/nasal
Few effective drugs
Changing patterns of resistance (amantadine/rimantadine)
Neuraminidase inhibitors limit egress of virus from infected cells
- most effective if given within 48 hours
- symptom resolution 1-2 days sooner
Infectious disease
-implications for ODs (3)
Understanding basic concepts
Recognizing and know how to co-manage common infections
Ocular implications of systemic infection
