New guidelines for evaluation and treatment Pandemic Influenza A

Influenza Update 7-6-2009: Pandemic H1N1v

Scattered outbreaks of influenza continue throughout California, the US, and worldwide despite the end of the usual "seasonal influenza" in the northern hemisphere. Almost all of the current influenza activity is the H1N1v (Swine variant H1N1). In the southern hemisphere, there are many outbreaks of H1N1v. Based upon clinical experience in the United States so far, this form of influenza appears no more virulent or dangerous than seasonal influenza. Influenza is a potentially serious illness. We recommend treatment with antivirals in persons with severe disease and persons at increased risk of severe disease. Persons at increased risk of complications of "normal" seasonal influenza are also at risk for complications of H1N1v :

          Children age 4 years and younger, especially children younger than age 2 years

          Adults age 65 and over

          Pregnant women

          Persons younger than 19 years of age and receiving chronic aspirin therapy

          Persons with the following conditions: chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematologic (including sickle cell disease) or metabolic disorders (including diabetes), immunosuppression (including HIV and medication induced), disorders of cognition or neuromuscular function which predispose to aspiration

          Residents of institutions such as nursing facilities

Treatment with antiviral influenza medication (oseltamivir, zanamivir) should be considered in persons at risk for complications if they have an influenza like illness :

          Fever >37.8C (100F)

          Sore throat and or cough

          No other explanation for their symptoms.

          onset of illness <48 hours

          Persons with severe disease thought to be influenza

Antiviral treatment is not indicated in persons who are not at risk for complications. Please discuss potential candidates for treatment with Infectious Diseases.

All persons with possible influenza should avoid contact with others until they are improved (usually about 7 days) and observe careful respiratory and hand hygiene . Persons with possible influenza who are seen in the office should avoid exposing other persons by covering mouth/noses with tissues when coughing and sneezing, wearing surgical masks if available, with and careful hand hygiene using alcohol-based gels or soap-and-water 15 second wash. Health care workers should treat suspected influenza patients in the office and in the hospital with "droplet precaution" isolation and should use appropriate protective measures: gown, gloves, protective eyewear, surgical mask (unless otherwise directed by Public Health or Infectious Diseases), and hand hygiene.

Public health departments have recommended viral testing in persons with severe disease or when the diagnosis is in doubt. Routine viral testing for influenza is not indicated at this time. Persons for whom treatment is begun should have nasopharyngeal viral cultures performed for influenza (see attachment for method for nasopharyngeal viral cultures).

Oseltamivir (Tamiflu) and zanamivir (Relenza) remain restricted to consultation with Infectious Diseases . Reports of neuraminidase resistance in H1N1v remain rare, but emphasize the need to treat appropriately.

Jared Spotkov MD

for the SCPMG Regional Infectious Diseases Specialists