Richard V. Lee
is professor of medicine and an expert on infectious disease proliferation and prevention. He has traveled the globe studying the origins of infectious diseases.
What do we know at this point about the “new flu,” a.k.a “swine flu”?
It is an H1N1 virus with genetic attributes from multiple swine and human influenza viruses. It is a new virus, which means the human population has no immunity, either by natural infection or immunization. The current influenza vaccine does not contain specific antigens for this new flu. There is no evidence that people now acquiring the virus have had contact with pigs: This is a virus that is transmissible between humans.
The extensive media coverage of the flu raises a lot of concern. Should we be worried?
While the (A) H1N1 flu is something to be smart and careful about, this is not a panic situation. It is not a highly virulent virus, unlike the H5N1 Asian avian flu virus, which produces high mortality but is not easily transmitted from human to human. As of late Wednesday afternoon, 23 countries have confirmed cases of the flu. There have been only two deaths outside of Mexico.
What are the symptoms?
The symptoms are the same as the usual human flu: fever, sore throat, headache, muscle aches and cough. The incubation period is about 2-7 days; the acute illness lasts for 4-7 days, and then a week or more for recovery. Secondary bacterial pneumonia can complicate the usual course of influenza. Patients are infectious shortly after acquiring the virus and during the acute illness.
How is this flu treated?
There is no vaccine. However, vaccine production will start if the infection continues to spread. The (A) H1N1 virus is sensitive to Tamiflu, so people with high risk factors—medical conditions like heart disease, diabetes, immune impairment, pregnancy—should be treated within 24-48 hours of the onset of the illness.
Do you agree with the World Health Organization that a pandemic is imminent?
There are documented infections in family members that have not been in Mexico but have been in contact with sick family members traveling from Mexico. Rapid secondary spread from ill travelers returning to their home country and their close contacts will be the feature that indicates this a pandemic. This has not yet happened and it is too early to predict that this will happen. Vaccine production will begin, with a new vaccine available in about six months. In the meantime, public health measures, such as closure of schools and public places, restrictions on travel and quarantine, as well as personal protective measures, will be necessary.