Oseltamivir for Post-Exposure Prophylaxis in Influenza

Indications for Post-Exposure Prophylaxis

The Centers for Disease Control and Prevention recommends post-exposure prophylaxis with oseltamivir for asymptomatic adults and children ≥3 months who are at very high risk of developing complications from influenza, after household exposure to influenza 1, 3
The American Academy of Pediatrics suggests oseltamivir prophylaxis can be considered for unvaccinated adults and children ≥3 months who are household contacts of a person at very high risk of complications from influenza, after exposure to influenza 2, 4

Post-exposure prophylaxis should be administered as soon as possible after exposure, ideally within 48 hours of exposure, as recommended by the Infectious Diseases Society of America 3, 4
The standard duration for post-exposure prophylaxis in a non-outbreak setting is 7 days after the most recent exposure to a close contact with influenza, according to the American Academy of Pediatrics 3, 5

Oseltamivir has demonstrated 82-89% protective efficacy in preventing laboratory-confirmed influenza illness in household contacts, as reported by the Clinical Infectious Diseases journal 7

The Centers for Disease Control and Prevention states that oseltamivir prophylaxis is not a substitute for annual influenza vaccination, which remains the primary means of influenza prevention 6
The Infectious Diseases Society of America recommends that antiviral drugs should not be used for routine or widespread chemoprophylaxis outside of institutional outbreaks 1
The American Academy of Pediatrics suggests that patients receiving prophylaxis should be informed that risk of influenza is lowered but not eliminated while taking medication, and susceptibility returns when medication is stopped 6, 8

For institutional outbreaks, the Centers for Disease Control and Prevention recommends implementing outbreak control measures including antiviral chemoprophylaxis when 2 cases of healthcare-associated laboratory-confirmed influenza are identified within 72 hours of each other in residents or patients of the same ward or unit 4
The Infectious Diseases Society of America recommends that neuraminidase inhibitors (oseltamivir or zanamivir) should be used for prophylaxis rather than adamantane antivirals due to widespread resistance to the latter 2, 8