Guidance

Influenza A(H1N2)v: information for medium category contacts

Updated 19 December 2023

You have been given this information as you have been identified as someone who has had contact with a person who has or probably has influenza A(H1N2)v.

While you are at very low risk of developing an infection, it can take up to 10 days for an infection to develop after you were exposed to influenza A(H1N2)v. You do not need to self-isolate and can continue with your normal activities, unless you develop symptoms during the 10 days after you were exposed to influenza A(H1N2)v.

You will have been given a designated contact number to phone. If you do not have this number, contact your local health protection team. If you develop symptoms, you should phone your designated contact and self-isolate until further advice is given. It is important that you report any symptoms that develop to your designated contact during these 10 days.

If you become seriously unwell, phone 999 and mention that you have had exposure to influenza A(H1N2)v.

Influenza A(H1N2)v

Influenza A(H1N2) is a virus which normally infects pigs. A human infection (influenza A(H1N2)v) has recently been detected for the first time in the UK. Similar to seasonal flu, influenza A(H1N2)v infection appears to be mild to moderate, causing flu-like symptoms that typically last for 3 to 5 days. More serious complications, such as pneumonia, are possible but rare. At this stage, we don’t yet know exactly who may be more at risk of more severe infection. However, people who are offered an annual flu vaccine because they are in a high-risk category for seasonal flu, are also likely to be at higher risk of becoming more seriously ill from influenza A(H1N2)v.

When someone with a respiratory viral infection breathes, speaks, coughs or sneezes, they release small particles that contain the virus which causes the infection. These particles can be breathed in or can come into contact with the eyes, nose, or mouth. The particles can also land on surfaces and be passed from person to person via touch.

The current seasonal flu vaccine protects against the human flu viruses and is not likely to provide protection against this influenza A(H1N2)v virus. However, the treatments for flu are likely to be effective against influenza A(H1N2)v.

Actions to take

You can go about your daily life as usual. However, the following actions are important for the health and safety of you, your family and anyone else that you may have contact with. These actions will reduce the spread of infection to others and ensure that if you develop the infection it can be identified quickly.

If you develop any of the symptoms listed below, phone your designated contact, and self-isolate until further advice is given. If you become seriously unwell, phone 999 and mention that you have had exposure to influenza A(H1N2)v.

Use the nose and throat swab provided to you to test if you have developed an infection on days 1, 3, 5, 8 and 10 after you were last exposed to the case. If you were given the swabs longer than 1 day after you were exposed, then use your first swab as soon as you receive it. Then continue with swabbing on correct days. For example, you may receive your swabs on day 4 and use the first one on day 4. You would then take your day 5, 8, and 10 swab as normal. You may only have received some of these swabs. In this case, you should use the swabs you have on the days instructed.

You may be offered medication to help prevent an infection or to reduce the severity of your symptoms if you were to become ill.

You may be asked to take blood tests to help understand and control the spread of  influenza A(H1N2)v.

Symptoms

The symptoms of influenza A(H1N2)v infection are likely to be similar to seasonal flu. They may include one or more of:

• continuous cough
• high temperature, fever or chills
• loss of, or change in, your normal sense of taste or smell
• shortness of breath
• unexplained tiredness, lack of energy
• muscle aches or pains that are not due to exercise
• not wanting to eat or not feeling hungry
• headache that is unusual or longer lasting than usual
• sore throat, stuffy or runny nose
• diarrhoea, feeling sick or being sick
• conjunctivitis

If you become ill in the 10 days after you were exposed

If you develop any of the symptoms listed above phone your designated contact so that further assessment and testing can be arranged. If you do not have this number, contact your local health protection team. You should self-isolate at home until given further advice unless you become very unwell.

It is important that you report to your designated contact any symptoms you develop during the 10 days after you were last exposed, however mild. Individuals with influenza A(H1N2)v can be infectious to others from the day before the onset of symptoms, so it is important to report any of these symptoms so that we can arrange for you to be assessed quickly and appropriately.

If you are seriously unwell, phone 999 and mention that you have been exposed to someone with influenza A(H1N2)v.