Updated Reporting and Testing Guidelines for Novel Influenza A (H1N1) 

June 2, 2009

PLEASE NOTE: This update provides interim guidance which might change in the weeks ahead as more information becomes available.

Epidemiologic Update

• As of June 1, human cases of H1N1 Influenza, have been identified in all 50 states.
• In Colorado, gradually increasing numbers of confirmed H1N1 cases are being identified.
• To date, H1N1 illness in Colorado and the United States continues to be similar to seasonal influenza, with the vast majority of diagnosed patients having mild illness.
• Nationally, 99% of reported H1N1 cases are less than 65 years of age.
• Influenza H1N1 is currently being detected substantially more frequently than seasonal influenza viruses.

CDPHE's current testing priority is to conduct public health monitoring for more severe illness due to H1N1 Influenza.

• It is neither necessary nor feasible to test for H1N1 in every person with influenza-like illness.
• H1N1 testing is now available through one or more commercial laboratories.
• Persons with uncomplicated influenza-like illness who are not at high risk for influenza complications do NOT need to be seen by a health care provider and do NOT need to be tested for H1N1.
• Persons at high risk for influenza complications who are seen in the outpatient setting can be managed similar to "seasonal" influenza, either empirically or based on rapid influenza testing (which might have either false positive or false negative results).
• CDPHE testing for H1N1 is not intended for diagnosis and clinical management. 

Reporting and Testing Guidelines

HOSPITALIZED Persons with SEVERE Febrile Respiratory Illness <65 Years Old

• Severe febrile respiratory illness is defined as temperature over 38 degrees C AND Pneumonia OR acute respiratory distress.
• Hospitals do NOT need to "screen " for influenza with rapid flu tests 
• If rapid flu testing is performed, DO NOT submit specimens to CDPHE for H1N1 testing if rapid test is Negative or Positive for Type B
• To collect and submit specimens for novel influenza A (H1N1) testing by RT-PCR at the state laboratory - Acceptable specimens include:
  • Nasopharyngeal swab placed in viral transport media (or 1ml of sterile saline), that has not been used in rapid flu testing
  • Nasal wash (in sterile container)
  • Nasal (anterior nares) swab PLUS throat swab placed in viral transport media (or 1ml of sterile saline), that has not been used in rapid flu testing

Wood shaft swabs should not be used

• Patients for whom specimens are being submitted should be reported to CDPHE (303-692-2700). 
• Refrigerate specimens until transport with cold packs to the state laboratory. 
• Personal protective measures should be taken by medical personnel obtaining specimens from patients being tested for novel influenza A (H1N1).
  • for routine specimen collection, use STANDARD plus DROPLET level precautions
  • for specimens collected during aerosolizing procedures (e.g., bronchoscopy, deep open tracheal suctioning), use AIRBORNE level precautions

(see: http://www.cdphe.state.co.us/epr/Public/H1N1/ClinicianGuidance.html)

Respiratory Hygiene

• To prevent the transmission of all respiratory infections in healthcare settings, including novel influenza A (H1N1), Respiratory Hygiene/ Cough Etiquette infection control measures should be implemented at the first point of contact with a potentially infected person. See: http://www.cdc.gov/flu/professionals/infectioncontrol/resphygiene.htm .

More Information About Novel Influenza A (H1N1)

— http://www.cdphe.state.co.us/epr/H1N1.html

— http://www.cdc.gov/h1n1flu/index.htm