Health & Human Services Agency Public Health Division 2344 Old Sonoma Road Building G Napa, CA 94559 www.co.napa.ca.us/PublicHealth Main: (707) 253-4270 Fax: (707) 253-4880 Randolph F. Snowden Agency Director
HEALTH ALERT H1N1 UPDATE
September 15, 2009 To: Napa County Clinicians and Healthcare Facilities From: Karen Smith, MD, MPH Public Health Officer (707) 253‐4270 Updated Recommendations from Centers for Disease Control and Prevention for the Use of Antiviral Medications in the Treatment and Prevention of Influenza for the 2009‐2010 Season Based on global experience to date, pandemic (H1N1) 2009 influenza viruses may be the most common influenza viruses circulating in the coming season. Circulation of seasonal influenza viruses during the 2009‐10 season is also expected. Influenza seasons are unpredictable, however, and the timing and intensity of seasonal influenza virus activity versus pandemic (H1N1) 2009 circulation cannot be predicted in advance. Health facilities that experience unusual activity of respiratory or influenza like illness should contact Napa County Public Health Communicable Disease Control at 299‐1499. Groups at higher risk • Treatment with oseltamivir or zanamivir is recommended for persons with suspected or confirmed influenza who are at higher risk for complications (children < 5 years old [especially children under 2 years], adults 65 years and older, pregnant women, persons with certain chronic medical [chronic pulmonary, cardiovascular, hepatic, renal, hematological , neurologic, neuromuscular or metabolic disorders] or immunosuppressive conditions, and persons younger than 19 years of age who are receiving long‐term aspirin therapy). Antiviral Treatment • Currently circulating pandemic (H1N1) 2009 viruses are susceptible to oseltamivir and zanamivir, but resistant to amantadine and rimantadine; however, antiviral treatment regimens might change according to new antiviral resistance or viral surveillance information.
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Persons with suspected pandemic (H1N1) 2009 influenza or seasonal influenza presenting with uncomplicated febrile illness typically do not require treatment. However, some groups appear to be at higher risk for influenza‐related complications. When anti‐viral therapy is indicated, initiate treatment as early as possible. Studies show that treatment initiated early (i.e., within 48 hours of illness onset) is more beneficial. Treatment with oseltamivir or zanamivir is recommended for all persons with suspected or confirmed influenza requiring hospitalization. Persons not at high risk for complications or not presenting with severe influenza requiring hospitalization do not require antiviral medications for treatment or prophylaxis. However, any suspected influenza patient presenting with warning symptoms (e.g., dyspnea) or signs (e.g., tachypnea, unexplained oxygen desaturation) of lower respiratory tract illness should promptly receive empiric antiviral therapy. Do not wait for laboratory confirmation of influenza to initiate treatment. Laboratory testing can delay treatment and a negative rapid test for influenza does not rule out influenza. Information on dose and dosing schedule for oseltamivir and zanamivir can be located in the complete CDC guidance available at http://www.co.napa.ca.us/publichealth or www.cdc.gov/h1n1. Actions that should be taken to reduce delays in treatment initiation should include: o Inform persons at high risk for influenza complications about signs and symptoms and need for early treatment after onset of symptoms (i.e., fever, respiratory symptoms); o Ensure rapid access to telephone consultation and clinical evaluation for these patients as well as patients who report severe illness; o Consider empiric treatment of patients at high risk for influenza complications based on telephone consult if hospitalization not indicated. Providers may supply patients at high risk for influenza‐related complications (e.g., patients with neuromuscular disease) with prescriptions to be filled at onset of symptoms with or without telephone consultation with provider.
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Chemoprophylaxis • Reserve antiviral chemoprophylaxis for persons at high risk for influenza‐related complications who have had close contact with someone likely to have been infected with influenza during that person’s infectious period (from 1 day before symptoms to 1 day after fever resolves). Testing • Prioritize testing for pandemic (H1N1) 2009 influenza infection with real‐time reverse transcriptase‐ polymerase chain reaction for suspect cases who are hospitalized, healthcare workers, part of a cluster, or have a fatal outcome. Do not delay anti‐viral therapy pending laboratory confirmation.
Vaccination The Napa County Public Health Division will not have the capacity to provide pandemic (H1N1) 2009 vaccine to all persons in Napa County prioritized for vaccination. Medical providers are therefore urged to go to www.calpanflu.org to order vaccine and vaccine supplies, free of charge, to administer to their patients. Public Health will hold mass vaccination clinics with the goal of reaching those who have no medical home, are without insurance or who did not otherwise access vaccines through their primary care providers. For more information see Napa County Public Health Web Site: http://www.co.napa.ca.us/publichealth and click on Information for Healthcare Professionals.