Warning signs of a rare, dangerous complication of the H1N1 flu

Most people who were infected by the H1N1 influenza virus of 2009 and then also came down with the flu only had mild symptoms. They recovered within a week’s time without needing medical attention.

Yet according to the World Health Organization (WHO), a small number of otherwise healthy people did become ill from a severe form of the H1N1 flu (previously also known as “swine flu”), which can be dangerous. These people were typically relatively young – mostly under the age of 50. Yet there are still no standardized and well-studied examination methods that could assist doctors in predicting these severe symptoms.

It is known that pregnant women have a significantly higher risk of experiencing severe symptoms. Data from 2009 show that pregnant women had serious complications of the H1N1 virus and died of the consequences more frequently than did other people who had gotten sick. People who have conditions like chronic respiratory disease are also more susceptible to having severe symptoms.

A sick person who is developing severe symptoms will require medical attention as quickly as possible. The WHO therefore recommends watching for the following warning signs if you are ill from a viral flu:

• High fever lasting for more than 3 days
• Breathlessness, either during exertion or at rest
• Difficulties breathing
• Blue discoloration of the lips or skin
• Sputum (for example, coughed-up phlegm) that is bloody or discolored
• Chest pain
• Changes in consciousness
• Low blood pressure

Warning signs in children also include:

• Rapid or labored breathing
• Listlessness
• Difficulties waking up
• Little or no interest in playing

 

According to the Robert Koch Institute, in Germany about 1 out of every 100,000 people was hospitalized due to an H1N1 virus infection in the winter of 2009. But not all people admitted to the hospital were also seriously ill. Canadian health data provide a more exact point of reference for the frequency of a severe course of illness: according to their numbers, less than a third of hospitalized patients there were actually so seriously ill from the H1N1 flu that they needed to be taken to the intensive care unit for treatment.

Author: German Institute for Quality and Efficiency in Health Care (IQWiG)

Next planned update: January, 2014. You can find out more about how our health information is updated here.

© IQWiG (Institute for Quality and Efficiency in Health Care) Last update of this website: 05/22/2012