H1N1 (Swine) Flu

Updated December 27, 2009

In April 2009, a new form of influenza virus was recognized. This virus is called the novel H1N1 flu virus (formerly called swine flu). It causes the same types of symptoms typically seen with seasonal influenza: runny nose, sore throat, cough, fever, body aches, and malaise. Occasionally, vomiting and diarrhea are seen as well.

Over the spring of 2009, the novel H1N1 flu virus, initially recognized in Mexico, spread rapidly to the United States and then throughout the world. The outbreak was described by the World Health Organization as a pandemic, meaning that it had spread very widely and that there was no hope of curtailing the virus's spread throughout the world's population.

As of late December 2009, the rates of new infection with H1N1 are declining throughout the United States. In Massachusetts, the rates of new flu cases have fallen to about 1/2 of what they were in November. No one knows if the rates will begin to increase again in the future. Because we have already had two peaks of H1N1 illness, both in atypical flu seasons (spring and fall), scientists worry that further spikes of disease activity may occur in the future.

The available evidence suggests that H1N1 flu is somewhat more severe for children than the typical seasonal flu. Nonetheless, the vast majority of children who contract H1N1 flu experience only minor illness.

As per guidelines disseminated by the Centers for Disease Control (CDC) and the Massachusetts Department of Public Health (DPH), we make the following recommendations to our patients:

(1) If your child has symptoms that seem typical of the flu but without signs of serious illness, please do not panic. The CDC guidelines advise that you need not be seen by the doctor. Rest, fever control, and fluids are the mainstays of therapy. If you have any questions about how your child's care should be managed, please feel free to contact our office to request telephone consultation with our phone triage nurse.

(2) If you think your child may have the flu, s/he should be kept home, so as to minimize contact with other people in the community, until fever has resolved.

(3) If your child has more severe symptoms (lethargy, respiratory distress, dehydration, or worsening or persistent fevers, for example), please do contact our office. Of course, we will be happy to see your child at any point if you are concerned. If children seem seriously ill, we will help you decide whether referral to the Emergency Department is appropriate.

(4) Routine testing for influenza is not recommended. In general, it's not important to know whether a patient has novel H1N1 flu or some other "flu-like" illness, because the treatment is generally the same. There are some cases, however, in which it is important to know, as with immunocompromised or very sick patients. We do have "rapid flu" diagnostic tests in our office. These tests were designed to recognize seasonal human influenza and provide results within 10 minutes. These tests do have some value in diagnosing the novel H1N1 flu, but there can be false positive and false negative tests.

(5) Antiviral therapy is available for novel H1N1 flu and should be used for severe cases (i.e., children who require hospitalization) and for children with increased risk of complications (for instance, children with immunocompromise). These drugs are only somewhat helpful in routine cases; typically, the duration of illness is shortened by about 1 day. The antiviral drugs can have some unpleasant side effects. Decisions about whether to institute antiviral therapy for children with suspected or confirmed novel H1N1 flu infection will have to be made on an individual basis.