Influenza virus: Difference between revisions

Latest revision as of 13:28, 18 August 2020

Background

Microbiology

Enveloped, single-stranded, negative-sense RNA virus in the Orthomyxoviridae family
Four genera corresponding to influenza A through D
Typed by hemagglutinin (HA) and neuraminidase (NA) proteins
- Antigenic drift refers to small mutations
- Antigenic shift refers to large changes from reassortment

Epidemiology

Worldwide
Seasonal in temperate climates, lasting from fall through spring and peaking in late winter
Antigenic drift usually results in local outbreaks, while antigenic shift can result in epidemic or pandemics

Clinical Manifestations

Fever and respiratory symptoms, especially with myalgias

Management

Neuraminidase inhibitors started within 48 hours of symptom onset are associated with a shorter duration of illness
- Oseltamivir
- Zanamavir
- Peramivir is IV only
Monitor for secondary bacterial pneumonia

Prevention

Annual influenza vaccination is recommended for everyone 6 months of age and older
Chemoprophylaxis with oseltamivir may be indicated as post-exposure prophylaxis or during local outbreaks for all people at risk

@@ Line 1: / Line 1: @@
-== Background ==
+==Background==
-=== Microbiology ===
+===Microbiology===
-* Enveloped, single-stranded, negative-sense RNA virus in the [[Family::Orthomyxoviridae]] family
+*Enveloped, single-stranded, negative-sense RNA virus in the [[Family::Orthomyxoviridae]] family
-* Four genera corresponding to influenza A through D
+*Four genera corresponding to influenza A through D
-* Typed by hemagglutinin (HA) and neuraminidase (NA) proteins
+*Typed by hemagglutinin (HA) and neuraminidase (NA) proteins
-** Antigenic drift refers to small mutations
+**Antigenic drift refers to small mutations
-** Antigenic shift refers to large changes from reassortment
+**Antigenic shift refers to large changes from reassortment
-=== Epidemiology ===
+===Epidemiology===
-* Worldwide
+*Worldwide
+*Seasonal in temperate climates, lasting from fall through spring and peaking in late winter
+*Antigenic drift usually results in local outbreaks, while antigenic shift can result in epidemic or pandemics
+== Clinical Manifestations ==
-* Seasonal in temperate climates, lasting from fall through spring and peaking in late winter
-* Antigenic drift usually results in local outbreaks, while antigenic shift can result in epidemic or pandemics
+* Fever and respiratory symptoms, especially with myalgias
+== Management ==
+* Neuraminidase inhibitors started within 48 hours of symptom onset are associated with a shorter duration of illness
+** [[Oseltamivir]]
+** [[Zanamavir]]
+** [[Peramivir]] is IV only
+* Monitor for secondary bacterial pneumonia
+== Prevention ==
+* Annual influenza vaccination is recommended for everyone 6 months of age and older
+* Chemoprophylaxis with [[oseltamivir]] may be indicated as post-exposure prophylaxis or during local outbreaks for all people at risk
 [[Category:RNA viruses]]