Flu and H1N1

Also known as: influenza, seasonal flu, swine flu.

What are flu and H1N1?

Flu is a very common, highly contagious, often severe viral illness that affects the respiratory airways (the breathing passages of the nose and upper and lower bronchial tubes, and lungs), that occurs during the winter months.

The influenza virus has a number of types called A, B and C. A and B cause epidemics, while type C usually causes no or mild respiratory tract symptoms. Influenza viruses continually change (mutate) which means every year many children’s (and adults’) immune systems are not equipped to manage it.

Different subgroups of influenza A (the most dangerous of the group) are named according to the the body’s immune response to their surface glycoproteins called HA and NA, for example: H1N1 (called swine flu), plus another at least 15 different HA and 9 NA subtypes.

What causes flu and H1N1?

Flu is always caused by the influenza virus. However, there are many different strains of influenza, including H1N1.

What are the symptoms of flu and H1N1?

Flu symptoms involve the whole body; common ones include fever, sore throat, runny nose, non-productive cough, headache, body muscle and joint pain, fatigue, vomiting and diarrhea.

Recovery usually takes about 1 week though infected children (and adults) may feel unwell for 3-4 weeks. In some cases, flu can lead to severe complications like pneumonia, dehydration, infections or the worsening of asthma or diabetes. It can be life-threatening.

What are flu and H1N1 care options?

The best defense against the flu is prevention by getting the flu vaccination each late summer or fall. The CDC recommends that every child above the age of 6 months receive the influenza vaccine each year.

Management includes medications to relieve fever and body pains (like acetaminophen or ibuprofen. Aspirin should NOT be given to children unless ordered by your child’s pediatrician), bed rest, and good calorie and fluid intake.

There are antiviral drugs that can lessen the duration and severity of flu, which are typically most effective when taken with early flu symptoms.


Reviewed by: Jose R. Rosa-Olivares, M.D.

This page was last updated on: July 25, 2022 10:32 AM

Infectious Diseases

The Division of Infectious Diseases at Nicklaus Children’s Hospital uses state-of-the-art diagnostic tools to identify acute or chronic viral and bacterial diseases, so that we can treat it effectively as quickly as possible.

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