- Safety and Health Topics
- Avian Influenza
In human cases, the signs and symptoms of avian influenza range from fever, cough, sore throat, and muscle aches to diarrhea, eye infections, pneumonia, and severe respiratory disease. Symptoms are often like those associated with human seasonal influenza, but may depend on the avian influenza virus (AIV) causing the infection. The infected worker’s immune status and the presence of secondary illnesses or underlying conditions may also affect the symptoms a worker experiences, the length of illness and the severity of disease.
Healthcare providers must assess exposure history, risk factors, signs, and symptoms of infection when presented with ill workers. Examining job tasks or identifying business travel to areas where AIVs are endemic could indicate an increased risk of exposure to AIVs. For more information relating to clinical evaluation and patient management for workers exposed to AIVs, including strains that are of particular public health concern, see the Centers for Disease Control and Prevention (CDC) Avian Influenza: Information for Health Professionals and Laboratorians page and Interim Guidance on Influenza Antiviral Chemoprophylaxis of Persons Exposed to Birds with Avian Influenza A Viruses Associated with Severe Human Disease or with the Potential to Cause Severe Human Disease.
Because signs and symptoms can vary so much, laboratory testing is required for proper diagnosis of AIV infection in humans. Testing usually involves swabbing the nose or back of the throat and then sending the sample to a clinical laboratory for analysis.
To help healthcare providers evaluate possible avian influenza cases, the CDC published Interim Guidance on Testing, Specimen Collection, and Processing for Patients with Suspected Infection with Novel Influenza A Viruses with the Potential to Cause Severe Disease in Humans.
Even when wearing personal protective equipment, workers potentially exposed to AIV should monitor their health starting on the first day of exposure and for 10 days after the last exposure. The CDC's self-observation instructions, while written for responders to avian influenza outbreaks, may be useful guidance for monitoring other workers potentially exposed to AIVs on the job. Workers should report any signs or symptoms of illness to a healthcare provider. Healthcare providers should report suspected or confirmed cases of AIV to appropriate state or local public health authorities.
At the time of this page's last update, CDC recommends the antiviral drugs oseltamivir, peramivir, or zanamivir for treatment of human infection with AIVs. The CDC also recommends treatment with influenza antiviral medications for all exposed persons. Clinical judgment and consideration of exposure type and complication risk are necessary when making the decision to prescribe influenza antiviral drugs preventively. The CDC's Interim Guidance on the Use of Antiviral Medications for Treatment of Human Infections with Novel Influenza A Viruses Associated with Severe Human Disease is available to guide healthcare providers in treatment of avian influenza infections.
For further recommendations on antiviral treatment, see the World Health Organization Guidelines for pharmacological management of pandemic (H1N1) 2009 influenza and other influenza viruses.
Seasonal influenza vaccination will not prevent infection with AIVs, but can reduce the risk of co-infection with human and avian influenza viruses.
Although at the time of this page's last update, the CDC does not recommend routine vaccination against AIVs, vaccines can protect people during outbreaks of certain AIV strains. For example, the United States government maintains a vaccine stockpile to protect against avian influenza A H5N1. If a similar strain of virus began transmitting easily among humans, the stockpiled vaccine may be useful. See the Strategic National Stockpile page for more information.