Guidance

Influenza A(H1N2)v: information for high 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 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.

To help limit the spread of influenza A(H1N2)v and to protect others that you come into contact with, you should self-isolate until at least 10 days after you were last in contact with the person who has or probably has influenza A(H1N2)v. Your self-isolation period will end if you receive a negative test result for all of the nose and throat swabs you take during your isolation period, including the last swab which you will take on day 10.

You will have been given a designated contact number to phone. If you do not have this number, contact your local health protection team. Report any symptoms that develop to your designated contact up to 10 days following your last exposure.

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 should take the following actions to protect the health and safety of you, your family and anyone else that you may have contact with. These actions will reduce the spread of virus to others and ensure that if you develop the infection, it can be identified quickly.

As a precautionary measure, you should self-isolate at home for at least 10 days from when you were last exposed. This means you should stay at home and not go to work, school or public areas. You may end your self-isolation period if you receive a negative test result from the swab you will take on day 10 of your self-isolation period, and if all of your other test results have also been negative.

If you live on a farm with pigs, keep pigs as pets, or attend pigs as a vet or pig industry worker, you should avoid any contact with them during your isolation period if you can.

If it is not possible for you to avoid contact with pigs, wear a face covering, and follow your usual measures for biosecurity on pig farms. Make sure you clean your hands with alcohol gel or soap and water before and after contact and change your footwear and outer clothing from that used while caring for the animals. Your face covering should cover your nose and mouth and fit well without gaps between the covering and your face.

Try to maintain distance from people living in the same household during your self-isolation period. If possible, stay in separate rooms from other household members.

If you use shared facilities, like the kitchen or bathroom, during your self-isolation period, avoid using them at the same time as other people and use a separate towel. Use them after everyone else, wear a face covering and clean surfaces after use. Your face covering should cover your nose and mouth and fit well without gaps between the covering and your face.

Clean surfaces in your home often. Pay particular attention to surfaces that are touched frequently, such as handles, light switches, work surfaces and electronic devices such as remote controls.

Maintain good ventilation of rooms by opening windows and leaving them open for at least 10 minutes after leaving rooms, particularly in shared rooms.

If you have to be in the same room as others during your self-isolation period, try to maintain good ventilation of the room, keep at least 2 metres away from others, and wear a face covering. Follow the advice given in the guidance on ventilation to reduce the spread of respiratory infections, including COVID-19.

Clean your hands regularly with alcohol gel or soap and water, especially before using shared rooms and after coughing, sneezing or blowing your nose.

Any non-essential medical or dental treatment should be postponed during your isolation period. You should discuss any essential treatment required with your designated contact before attending a healthcare facility.

Do not invite or allow social visitors, such as friends and family, to visit at home during your isolation period.

On days 1, 3, 5, 8 and 10 of your isolation period, use the nose and throat swab provided to you to test if you have developed an infection. If you were given the swabs later 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 only end your isolation period if you receive a negative test result for all of the swabs you take during isolation period. This means you must wait until you receive the result of your day 10 test before you know whether you can end isolation.

Inform your designated contact point daily of any of the symptoms listed below within 10 days of your last exposure.

During your self-isolation period, 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

Let your designated contact know if you develop any of the symptoms listed above so that further assessment and testing can be arranged. If you do not have this number, contact your local health protection team. You should continue to 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 your self-isolation period, however mild. Individuals with influenza A(H1N2)v can be infectious to others from the day before the onset of their symptoms, so it is important to report any of these symptoms so that you can 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.