2009 New York City Dept of Health and Mental Hygiene

Health Alert #20: Novel H1N1 Influenza Update
May 24, 2009

Novel H1N1 influenza is now widespread in New York City. As expected, since there are more persons infected, hospitalized and critically ill cases are also increasing. Patients presenting with influenza-like illness in New York City health care facilities at this time can be presumed to have novel H1N1 infection, as we are seeing very little seasonal influenza A H3N2. Because it is not possible to prevent community transmission of influenza and mild illness at this time, the Health Department is focusing its efforts on reducing and preventing severe outcomes due to infection with novel H1N1 influenza.

Dear Colleague,

In the context of the novel H1N1 influenza outbreak in New York City, the Health Department has developed the attached one page algorithms to assist providers in emergency department and outpatient settings with managing patients with influenza-like illness or severe acute febrile respiratory illness. We hope they are useful for you. Please see our website at www.nyc.gov/health  for detailed and frequently updated information on the epidemiology of the outbreak, as well as guidance on reporting, testing, infection control and clinical management of suspected cases of novel H1N1 influenza, including treatment and prophylaxis recommendations.

In addition we would like to stress the following points:

• At this time, although seasonal influenza is continuing to circulate, all patients with influenza-like illness (ILI=documented fever 100.4 (38 C) with cough or sore throat) or with otherwise unexplained, acute febrile respiratory illness (fever with ILI, pneumonia, ARDS or respiratory distress) in New York City can be presumed to have novel H1N1 influenza unless proven otherwise since this is the predominant strain of influenza currently circulating in the city.

• Providers should ensure that all people who are below 2 or above 65 years of age, or have asthma, diabetes, emphysema, or other chronic illnesses (see list below) are treated with antiviral medication if they get influenza-like illness. See Treatment and Prophylaxis recommendations on our website for details.

• Asthma is the most common chronic illness among children in New York City, and children with asthma are at higher risk for severe illness if they get influenza.

• In particular providers should make sure that patients with asthma who have flu-like illness, even if it is mild, are treated with antiviral medication (TamifluÒ is recommended, as RelenzaÒ is contraindicated in persons with chronic respiratory disease, such as asthma or COPD).

• Antiviral treatment should be started as soon as possible, ideally within 48 hours after the person first develops symptoms.

• Providers should advise people with mild flu NOT to go to the emergency department.

o Office visits may not be necessary for patients with mild ILI.
o Providers can prescribe antiviral medications over the phone for their patients with mild illness, when indicated.

o Only people with more serious symptoms, such as difficulty breathing, shortness of breath, severe chest or abdominal pain, dizziness or confusion, should go to the emergency department.

• Providers should consider prescribing antiviral prophylaxis for persons who:

o Have an underlying condition listed below, and

o Have household or other close contact with a person with influenza-like illness during that person’s infectious period (one day before to 7 days after symptom onset).

• Children and staff from schools that have been closed due to high or increasing levels of influenzalike illness may be considered to have possibly had exposure to persons with ILI. Such individuals should also be considered for prophylaxis if they have underlying conditions (listed below).

As always, we greatly appreciate your collaboration and cooperation in addressing this outbreak. We will continue to update you with new information as it becomes available,

Sincerely,

The DOHMH Novel H1N1 Investigation Team

Underlying conditions that increase the risk for severe influenza:

1. Age > 65 years
2. Age < 2 years
3. Chronic pulmonary disease, such as asthma or COPD
4. Chronic cardiovascular, renal, or hepatic disease
5. Hematologic disease, such as sickle cell anemia
6. Metabolic disorders, such as diabetes
7. Immunosuppression, including HIV-related or caused by medication
8. Compromised respiratory function and conditions which increase the risk for aspiration
9. Persons with neuromuscular disorders, seizure disorders, or cognitive dysfunction that may compromise the handling of respiratory secretions
10. Pregnancy
11. Persons requiring long-term aspirin therapy for diseases such as rheumatoid arthritis or Kawasaki disease