October 2009

Commentary Preparing for H1N1

Dear Colleagues,

Virtually all cases of influenza now occurring in Northern California are considered H1NI Influenza A (swine flu). So far, most swine flu cases have been as mild as seasonal flu and have not required antiviral treatment, though it's difficult to predict how swine flu will evolve this winter. The following general precautions to prevent the spread of influenza apply to all personnel who work in patient care settings:

  • All health care workers should be vaccinated against seasonal and H1N1 influenza.
  • Clean your hands frequently with alcohol gel or soap and warm water for at least 20 seconds, especially after you cough or sneeze.
  • Cover your mouth and nose with a tissue or your arm when you cough or sneeze.
  • Use droplet precautions when caring for patients with respiratory symptoms.
  • Add contact precautions for patients with diarrhea of unknown cause.
  • Wear a surgical mask and eye protection when in contact with patients with influenza-like symptoms. (Prescription glasses do not provide sufficient protection.)
  • Everyone, including patients and family members, with fever or cough should wear a surgical mask while in a health care setting. Quickly identify and provide masks to those with influenza-like symptoms to prevent exposure to staff and other patients.
  • Everyone, except patients requiring evaluation and medical care, with influenza-like illness should be instructed to stay home until they have been free of fever for at least 24 hours. Health care workers are encouraged to remain off work for at least seven days from the onset of symptoms.

Criteria for Treatment

Antiviral treatment is not specifically indicated unless patients are hospitalized or at high risk for complications of influenza as outlined below.

Consider triaging normal-risk patients over the phone with instructions to reduce symptoms and fever with Tylenol and to stay at home until they have fully recovered. In most cases, these patients will not require antiviral medications unless their condition worsens.

Antiviral treatment is recommended for the following populations:

  • Children age 4 and younger, especially children younger than age 2.
  • Adults age 65 and over.
  • Pregnant women.
  • Residents of nursing homes and other chronic-care facilities.
  • Patients younger than 19 years of age and receiving long-term aspirin therapy.
  • Those with the following conditions:
    • Chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological (including sickle cell disease) or metabolic disorders (including diabetes)
    • Immunosuppression, including that caused by medications or by HIV infection
    • Any condition (e.g., cognitive dysfunction, spinal cord injuries, severe seizure disorders, or other neuromuscular disorders) that can compromise respiratory function, the handling of respiratory secretions or that can increase the risk of aspiration.
    • Obesity (appears to be a risk factor based on preliminary data).

HINI Influenza Vaccine

H1N1 influenza is expected to evolve in the coming months. Clinicians can expect an increase in patient visits related to the virus. A two-dose H1N1 vaccine should be available at the end of October. Note — A single dose regimen is being evaluated by the Centers from Disease Control and Prevention.

Provider distribution of the vaccine is at the discretion of the local health authority. Groups identified as the highest priority for H1N1 vaccine include pregnant women, patients 6 months to 24 years old, health care workers, household contacts of children less than 6 months of age and those 25 to 65 years old with chronic health conditions or compromised immune systems.

I hope these guidelines help protect you and your patients against the spread of H1N1 influenza.

Thank you for your interest.

Josh Adler, M.D.
Internist and Chief Medical Officer
UCSF Medical Center
UCSF Benioff Children's Hospital

More information about the H1N1 influenza is available at: