Introduction

What is the H3N2v virus?

H3N2v is an influenza A virus that infects  pigs, making them a type of swine flu virus. When these viruses infect humans, they are known as variant viruses.¹

Transmission of H3N2v

Origin and spread of H3N2v virus

Influenza A viruses are viruses that are present in pigs from all around the world. So, when the influenza virus is found in a person, it is called a variant influenza virus. There are a few subtypes of influenza viruses that are found in pigs and can infect humans and these include H1N1, H1N2, and H3N2. 

H3N2v had an outbreak in various parts of America in 2012, and this is because they found cases linked to the exposure of pigs at agricultural fairs, or to people who raised pigs and worked on farms that could have had infected pigs .^1,2

Modes of transmission (direct and indirect)^2,3

• Through direct contact – pig to person by virus entering through eyes, mouth and nose. Person to pig transmission also occurs by entering through eyes, mouth and nose
• Through indirect contact – the flu virus can spread through surface contact and enter mouth , eyes and nose of either the person or the pig 
• Flu virus can spread through the air – droplets or dust 

Factors influencing transmission rates

Being in close proximity to the infected pigs or by visiting certain locations such as agricultural fairs. 

Symptoms and complications^1,2,3,4

Common symptoms of H3N2v infection 

The symptoms and how severe H3N2v virus are very similar to a seasonal flu, where people may experience:

• Cough
• Runny nose
• Fever 
• Body aches
• Vomiting
• Diarrhea
• Headache
• Fatigue
• Chills

Vulnerable populations at higher risk

People who are at a higher risk of developing flu are children less than the age of five, those 65 years of age and older, pregnant women, and those with any chronic illness such as diabetes, heart disease, and asthma. If you think you have developed any of the flu symptoms after having direct or indirect contact with swine, do contact your local GP!

Diagnosis and treatment⁴

Diagnostic methods for H3N2v infection

A swab test of the throat and nose is taken, processed in the lab.  Rapids influenza tests are also available. 

Treatment options for H3N2v

Depending on how severe your symptoms are, your doctor can decide to prescribe certain antivirals (oseltamivir, zanamivir) to act on influenza A viruses and reduce the severity of the flu.

Antiviral medications and their effectiveness

Since the symptoms for H3N2v resemble a common flu, the antiviral medication that is used to treat a seasonal flu can treat H3N2v in adults and children. 

Prevention strategies^3,4

Vaccination against H3N2v

According to the CDC, early steps to develop a vaccine specific to target H2N2v have been carried out, however currently there are no decisions of mass production of the vaccine.

Hygiene practices to prevent transmission

• Avoid touching eyes, nose and mouth
• General hygiene measures, such as regular washing of hands before and after touching any sick animals
• Avoid contact with pigs or animals if you have flu-like symptoms
• Wearing personal protective clothing, like gloves and mask to cover your mouth and nose, in cases where the animal looks to be ill.
• For vulnerable people, it is important take the flu jab, to avoid any severe symptoms of flu

Surveillance and monitoring⁵

Importance of surveillance for H3N2v

Since influenza viruses are constantly mutating, the World Health Organisation urges the importance of global surveillance for detecting virological, clinical, and epidemiological changes that are related to the existing influenza virus, which can have an effect on the health of the population and the animals.

Public health implications^4,6

The Centre for Disease Control and Protection (CDC) aims in communicating on a regular basis with the different states. The different states also have increased their surveillance and laboratory activities for detecting human cases for this virus. CDC also is in close monitoring of the outbreak and working with different laboratories. The influenza division of the CDC is examining the genes of the variant to make sure there are no changing differences in the variant. 

Conclusion

H3N2v is a virus that affects pigs, and has recently been able to become a variant that infects humans. The symptoms are not different to a seasonal flu, so regular seasonal flu medication is able to relieve the symptoms, but it is important to seek medical help if you think you have the flu-like symptoms. This can help the healthcare industry to monitor and control the outbreak whilst working with the CDC.