General Description: Influenza is a frequently debilitating viral infection of the respiratory tract with cough, sore throat, fever, and muscle aches and pains. Influenzal pneumonia and secondary bacterial pneumonia have been reported in otherwise healthy adults. Vaccines for influenza are available; their efficacy is affected by the degree to which the vaccine virus matches up with the virus circulating in the community.
Mode of Transmission: Respiratory tract droplet spread and contact with inanimate objects. In experimental studies, influenza vaccine has survived for 24 to 48 hours on hard nonporous surfaces and <8 to 12 hours on cloth, paper, and tissues. Virus survived on hands for up to 5 minutes after transfer from environmental surfaces.
Efficiency of Transmission/Attack Rate: In general populations, 5 to 20%; in closed institutional populations, 50% or more.
Period of Communicability: Virus shedding is reduced by the third day of symptoms; in most cases, the virus cannot be detected by Day 5.
Effect on LEO Fitness for Duty: The symptoms of influenza can affect stamina, agility, and situational awareness. LEOs with influenza-like illness should assess their functional status before reporting for duty. LEOs should consider receiving influenza vaccine to prevent spreading infection in institutions such as jails, detention centers, and health care facilities.
LEO-specific Clinical Studies and Reports: See Appendix A for CDC guidance on the use of PPE by staff with occupational assignments that expose them to influenza-like illness.