VUMC Pandemic Influenza Preparedness

The Department of Emergency Preparedness in conjunction with the Department of Infection Control & Prevention and the Occupation Health Clinic has developed an online education lecture that provides information on personal and institutional preparedness for pandemic influenza.  The lecture may be accessed on the Department of Emergency Preparedness website (link).

Updated Interim Guidance for Surveillance and Laboratory Testing of Persons with Suspected Infection with Avian Influenza A (H5N1) Virus in the United States

This update provides revised interim guidance for testing of suspected human cases of avian influenza A (H5N1, a.k.a. “bird flu”) in the United States. The epidemiology of H5N1 human infections has not changed significantly since February 2004.  The Centers for Disease Control and Prevention (CDC) recommends maintaining enhanced surveillance efforts to identify patients at increased risk for avian influenza A (H5N1) as noted below.

Testing for avian influenza A (H5N1) virus infection is recommended for:

A patient who has an illness that:

·         requires hospitalization or is fatal; AND

·         has or had a documented fever of ≥38°C (≥100.4° F); AND

·         has radiographically confirmed pneumonia, acute respiratory distress syndrome (ARDS), or other severe respiratory illness for which an alternate diagnosis has not been established; AND

·         has at least one of the following potential exposures within 10 days of symptom onset:

A) History of travel to a country with influenza H5N1 documented in poultry, wild birds, and/or humans, AND had at least one of the following potential exposures during travel:

• direct contact with (e.g., touching) sick or dead domestic poultry;

• direct contact with surfaces contaminated with poultry feces;

• consumption of raw or incompletely cooked poultry or poultry products;

• direct contact with sick or dead wild birds suspected or confirmed to have influenza H5N1;

• close contact (approach within 3 feet) of a person who was hospitalized or died due to a severe unexplained respiratory illness;

B) Close contact of a patient with confirmed or suspected H5N1 influenza;

C) Worked with live influenza H5N1 virus in a laboratory.

VUMC clinicians should contact the Department of Infection Control & Prevention (936-0725) as soon as possible to report any suspected human case of influenza H5N1 in the United States.

Specimen Collection and Testing Guidelines:

·         Oropharyngeal swab specimens and lower respiratory tract specimens (e.g., bronchoalveolar lavage or tracheal aspirates) are preferred because they appear to contain the highest quantity of virus for influenza H5N1 detection. Nasal or nasopharyngeal swab specimens are acceptable, but may contain less virus and therefore not be optimal specimens for virus detection.

·         Detection of influenza H5N1 is more likely from specimens collected within the first 3 days of illness onset. If possible, serial specimens should be obtained over several days from the same patient.

·         Bronchoalveolar lavage is considered to be a high-risk aerosol-generating procedure. Therefore, infection control precautions should include the use of gloves, gown, goggles or face shield, and a fit-tested respirator with an N-95 or higher rated filter. A loose-fitting powered air-purifying respirator (PAPR) may be used if fit-testing is not possible (for example, if the person has a beard).

·         Swabs used for specimen collection should have a Dacron tip and an aluminum or plastic shaft. Swabs with calcium alginate or cotton tips and wooden shafts are not recommended. Specimens should be placed at 4°C immediately after collection.

·         For reverse-transcriptase polymerase chain reaction (RT-PCR) analysis, nucleic acid extraction lysis buffer can be added to specimens (for virus inactivation and RNA stabilization), after which specimens can be stored and shipped at 4°C. Otherwise, specimens should be frozen at or below -70°C and shipped on dry ice. For viral isolation, specimens can be stored and shipped at 4°C. If specimens are not expected to be inoculated into culture within 2 days, they should be frozen at or below -70°C and shipped on dry ice. Avoid repeated freeze/thaw cycles.

·         Influenza H5N1-specific RT-PCR testing conducted under Biosafety Level 2 conditions is the preferred method for diagnosis. All state public health laboratories, several local public health laboratories, and CDC are able to perform influenza H5N1 RT-PCR testing, and are the recommended sites for initial diagnosis.

·         Viral culture should NOT be attempted on specimens from patients suspected to have influenza H5N1, unless conducted under Biosafety Level 3 conditions with enhancements. Please notify the microbiology laboratory and the Department of Infection Control & Prevention prior to collecting specimens for culture.

·         Commercial rapid influenza antigen testing in the evaluation of suspected influenza H5N1 cases should be interpreted with caution. Clinicians should be aware that these tests have relatively low sensitivities, and a negative result would not exclude a diagnosis of influenza H5N1. In addition, a positive result does not distinguish between seasonal and avian influenza A viruses.

Travel Health Notice:

CDC has not recommended that the general public avoid travel to any of the countries affected by H5N1. However, CDC does recommend that travelers to these countries avoid poultry farms and bird markets or other places where live poultry are raised or kept.

More Information:

Department of Health and Human Services: www.pandemicflu.gov

World Health Organization: http://www.who.int