Screening & Investigation of Suspect Avian Influenza (H5N1)

1. Screening & Investigation of Suspect Avian Influenza (H5N1) County of San Diego Health & Human Services Agency Public Health Services Nancy Bowen MD, MPH Louise Gresham PhD, MPH Elaine Pierce MD, MPH Lisa Yee Jill Giesick MS, MPH Spring 2006

2. Overview • Goal: To improve case detection and control of avian influenza by educating professionals on the case definition, screening criteria, and investigation of suspect cases. • This presentation includes information about: • Review of case definition • Reporting and confidentiality • Safe specimen collection and processing • Educational messages • Contacting the Public Health Department

3. Case Definition(as of March 2006; may be subject to change) There are two ways to meet the case definition for suspect avian influenza: • Hospitalized patients with: • Radiographically confirmed pneumonia, acute respiratory distress syndrome (ARDS), or other severe respiratory illness for which an alternate diagnosis has not been established • AND within 10 days of symptom onset, the patient had one of the following exposures in an H5N1-affected country: a. Direct contact with domestic poultry* (e.g. touching sick or dead chickens or ducks or well-appearing ducks) b. Consumption of uncooked poultry* or poultry* products c. Direct contact with surfaces contaminated with poultry* feces d. Close contact (within 1 meter) with a known or suspected human case of H5N1 *Poultry is defined as domestic chicken, turkeys, ducks or geese raised for meat or eggs Testing for avian influenza A (H5N1) is indicated in these patients

4. Case Definition, continued (as of March 2006; may be subject to change) • Hospitalized or ambulatory patients with: • Fever >100.4° F (38 ° C) • AND one or more of the following: cough, sore throat, shortness of breath • AND within 10 days of symptom onset, the patient had one of the following exposures in an H5N1-affected country: a. Direct contact with domestic poultry* (e.g. touching sick or dead chickens or ducks or well-appearing ducks) b. Consumption of uncooked poultry* or poultry* products c. Direct contact with surfaces contaminated with poultry* feces d. Close contact (within 1 meter) with a known or suspected human case of H5N1 *Poultry is defined as domestic chicken, turkeys, ducks or geese raised for meat or eggs Testing for avian influenza A (H5N1) should be considered on a case-by-case basis in consultation with local health departments for these patients

5. Reporting Requirements • Report any individuals that meet case definition immediately (24 hours a day, 7 days a week) to the San Diego County Public Health Services (PHS) Community Epidemiology Branch: Monday through Friday, 8AM to 5PM: (619) 515-6620 After business hours and on weekends: Station M (858) 565-5255

6. Confidentiality • We have a responsibility to protect personal data in all forms of communication: • Verbal • Written • Electronic • HIPAA privacy regulations allow the reporting of data with individual identifiers for the purposes of public health investigations

7. How to determine if a patient meets case definition • CADHS Screening Form For Suspect Avian (H5N1) Influenza • Posted on EMAN at http://sdeman.org • San Diego PHS will assist in completing form and is responsible for submitting it to California State DHS

8. Investigation after a patient meets case definition • CADHS Case Report Form For Suspect Avian (H5N1) Influenza • Posted on EMAN at http://sdeman.org • San Diego PHS will assist in completing form and is responsible for submitting it to California State DHS

9. Office Diagnosis: Rapid Antigen Tests • Often the first test to be performed due to its wide availability and 30-minute turnaround time • A positive influenza A rapid antigen test may increase the suspicion of avian flu • A negative rapid antigen test result never rules out avian influenza • Sensitivity and specificity are variable, depending on the brand of test kit used • Sensitivity and specificity may be lower for avian flu than seasonal flu • If a patient meets the case definition and has a negative rapid antigen test, further testing must be performed

10. Laboratory Diagnosis: RT-PCR vs. Viral Culture • Rapid antigen specimens cannot be used for further testing; additional specimen collection using Viral Transport Medium (VTM) is required • When avian (H5N1) influenza is suspected, specimens should be sent to the PH Laboratory, not to commercial laboratories • Preferred specimen collection site(s): • Seasonal influenza – nasopharyngeal specimen optimal • Avian influenza – nasopharyngeal AND oropharyngeal specimens needed

11. Laboratory Diagnosis: RT-PCR vs. Viral Culture (continued) • Choosing a specific test depends on whether seasonal or avian influenza is suspected; therefore, the lab must know what you are thinking before specimen processing • Label the specimen “SUSPECT AVIAN INFLUENZA” • For seasonal influenza: • Viral culture is often performed to confirm the diagnosis • Avian (H5N1) influenza: • The laboratory test of choice is RT-PCRnot culture • Rapid antigen tests and RT-PCR carry a much lower risk of infection to laboratory personnel than viral culture • Only enhanced biosafety level 3 laboratories can safely perform viral culture testing for avian influenza

12. Laboratory Diagnosis: RT-PCR vs. Viral Culture (continued) • The San Diego PH Lab currently has the ability to detect H1 and H3 nucleic acid by RT-PCR • In February 2006, the San Diego PH Lab applied to CDC for the newly FDA-approved RT-PCR primers for H5 • For RT-PCR testing, results should be available within 4-6 hours • Detection of the N1 nucleic acid by RT-PCR will be performed by CDC

13. Specimen Collection for Suspect Avian (H5N1) Influenza Cases • Notify Community Epidemiology before specimen submission • Completed Specimen Collection Form for Suspect Avian (H5N1) Influenza Cases MUST accompany specimens to the PH Lab • Form includes instructions on how to collect specimens using Viral Transport Medium (VTM) • Posted on EMAN at http://sdeman.org

14. Comparison of Diagnostic Process

15. Laboratory Diagnosis: Conclusion • The Take-Home Message: If the clinician and Community Epidemiology agree that the patient should have further testing, Community Epidemiology and the Public Health Laboratory will provide guidance for appropriate specimen submission

16. Educational Messages for Everyone • Practice cough etiquette • Practice hand hygiene

17. Educational Messages for Providers • Encourage the use of seasonal flu vaccine annually for persons without contraindications (especially health care workers): • Helps to prevent co-infection with seasonal and pandemic flu, which could lead to reassortment events • A low community prevalence of seasonal flu reduces confusion in the epidemiologic investigations of possible pandemic flu • Will reduce stress on a healthcare system that may be seriously overburdened by pandemic influenza • Encourage the use of pneumococcal vaccine in those for whom it is indicated: • During previous pandemics, many deaths resulted from secondary bacterial pneumonia

18. County of San Diego Public Health ServicesCommunity Epidemiology Branch Contact Information • Monday through Friday, 8AM to 5PM: (619) 515-6620 • After business hours and on weekends: Station M (858) 565-5255 • Fax: (619) 515-6644

19. References • World Health Organization. Avian Influenza (H5N1) Infection in Humans. NEJM 2005. 353;13:1374 – 1385. Downloadable from http://content.nejm.org/ • For current information on H5N1 cases in animals (click on graph at the top of the page): http://www.oie.int/downld/AVIAN%20INFLUENZA/A_AI-Asia.htm • For current information on H5N1 cases in humans: http://www.who.int/csr/disease/avian_influenza/en/ • General CDC site: http://www.cdc.gov/flu/pandemic/ • Additional references:http://www.cdc.gov/flu/avian/references.htm# • General WHO site:http://www.who.int/csr/disease/avian_influenza/en/index.html • Latest WHO Fact Sheet: http://www.who.int/csr/disease/avian_influenza/avianinfluenza_factsheetJan2006/en/index.html • State of California pandemic influenza site:http://www.dhs.ca.gov/ps/dcdc/izgroup/pandemic.htm • Nongovernmental websites of interest: http://www.promedmail.org/pls/promed/f?p=2400:1000 http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/index.html http://id_center.apic.org/apic/influenza/panflu/biofacts/panflu.html http://www.upmc-biosecurity.org/