Influenza Flashcards
How contagious is the flu
- Highly contagious
*orthomyxovirus
How is seasonal influenza transmitted
Respiratory droplets (small or large)
1. Direct inhalation
2. Self-contamination
3. Direct/indirect contact
4. Small particle transmission
What are the type influenza types
A B C
*AB are usually what infects humans
*A can infect other mammals besides humans
*C is milder
When is seasonal influenza most present
Annual epidemics (fall / winter)
1. Minor antigenic variations
*virus can survive and change in order to survive
What is the incubation period is of seasonal influenza
- 1 to 4 days
*how long it takes to see symptoms
*viral shedding is happening during that time
When are people infectious with the flu
- On day one and then up to 5 to 7 days after symptoms starts
What are the high risk populations for seasonal influenza
- Young/old
- Hospitalized
- Asthma
- Pregnant
How can seasonal influenza cause secondary bacterial infections
- Acute influenza causes necrosis of the respiratory tract epithelium THEN there
- Is increased adherence of bacteria to infected cells and ciliary dysfunction which leads to
- Secondary bacterial infections on top of seasonal influenza infection
What is the most common secondary bacterial infections and most serious
MC : pneumococcal pneumonia
Most serious: staphylococcal pneumonia
What are the Ssx of seasonal influenza
Vary
1. Abrupt onset (especially in unvaccinated patient) of systemic symptoms
2. Fever (100.76)
2. Cough (nonproductive)
4. Confusion, altered mental status, encephalitis
5. GI issue (N/V esp kids)
What are the SSx that have a high possibility of a diagnosis of influenza
- Over 4 years olds
- Fever of 100.76 or higher
- Cough during influenza season
What will be on the PE
- Fever (100.76 or higher)
- Pharyngeal injection
- Flushed face
- Conjunctival redness
- Cervical lymphadenopathy
- Tracheal tenderness
What are the DDx of seasonal influenza
- Parainfluenza
- RSV
- Atypical dengue
- Adenovirus
- Enterovirus
- Coronavirus
- SARS Cov 2
- Acute HIV Vs acute onset of AIDS
What are the diagnostic studies for seasonal influenza
- Rapid influenza diagnostic test (RIDTs)
- Polymerase chain reaction (PCR) technique
What is the Rapid influenza diagnostic test (RIDTs)
- Detects A and B (may not be able to differentiate them)
- Available in under 15 minutes
- Nasal or throat swabs
- Predictive value is dependent on prevalence
*Early in flu season may not be accurate
*late in flue season more accurate