Testing Recommendations for Persons with possible infection with Highly Pathogenic Avian Influenza A (H5N1) virus in the United States
Patients who meet both the clinical and exposure criteria described below should be tested for avian influenza A (H5N1) virus infection by reverse-transcription polymerase chain reaction (RT-PCR) assay using H5-specific primers and probes. Decisions on diagnostic testing for influenza using RT-PCR should be made using available clinical and epidemiologic information, and additional persons in whom clinicians suspect avian influenza A (H5N1) virus infection also should be tested. For more information on laboratory testing of persons under investigation for avian influenza A (H5N1) virus infection, please see Information for Health Professionals and Laboratorians. Guidance on testing, treatment, and infection control will be updated by CDC as more information becomes available.
Clinical Illness Criteria
- Patients with new-onset severe acute respiratory illness requiring hospitalization (i.e., illness of suspected infectious etiology that is severe enough to require inpatient medical care in the judgment of the treating clinician).
- Patients for whom no alternative infectious etiology is identified.
- Patients with recent travel (within 10 days of illness onset) to areas where human cases of avian influenza A (H5N1) virus infection have recently become infected1 or where avian influenza A (H5N1) viruses are known to be endemic in animals2.
- Patients who have had recent close contact (within 10 days of illness onset) with suspected3 or confirmed cases of human infection with avian influenza A (H5N1) virus. Close contact may be regarded as coming within about 6 feet (2 meters) or within the room or care area of a person with a suspected or confirmed case while the person was ill (beginning 1 day prior to illness onset and continuing until resolution of illness). Close contacts include healthcare personnel providing care for a person with a suspected or confirmed case, family members of a person with a suspected or confirmed case, persons who lived with or stayed overnight with a person with a suspected or confirmed case, and others who have had similar close physical contact, especially without the use of respiratory protection.
- Persons with an unprotected exposure to avian influenza A (H5N1) virus in a laboratory setting.
1Countries where human cases of avian influenza A (H5N1) viruses have recently (within the previous 24 months) become infected include: Bangladesh, Cambodia, China, Indonesia, Vietnam, and Egypt (Cumulative number of confirmed human cases for avian influenza A(H5N1) reported to WHO, 2003-2013).
2The U.N. Food and Agriculture Organization (FAO) considers 6 countries to have endemic circulation of highly pathogenic avian influenza A (H5N1) virus among poultry: Bangladesh, China, Egypt, India, Indonesia, and Vietnam (Approaches to Controlling, Preventing and Eliminating H5N1 Highly Pathogenic Avian Influenza in Endemic Countries).
3Patients suspected of having infection with avian influenza A (H5N1) virus can include probable cases, cases under investigation for infection with avian influenza A (H5N1) virus, and other patients for whom available clinical and epidemiologic information support a diagnosis of infection with avian influenza A (H5N1) virus.
State health departments are encouraged to investigate potential human cases of avian influenza A (H5N1) virus infection and should notify CDC within 24 hours of identifying a probable or confirmed case of novel influenza A virus infection, including avian influenza A (H5N1) virus infection, and avian influenza A (H7N9) virus infection.