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Influenza H7N7
Overview / History
Avian influenza H7N7 is a subtype of the influenza A virus, which belongs to the Orthomyxoviridae family. Both low and highly pathogenic avian influenza H7N7 are known to affect poultry and wild birds.
In 2013, poultry workers in Italy with conjunctivitis were diagnosed with highly pathogenic bird flu H7N7. An outbreak was recorded among humans in Netherlands in 2003. Poultry workers and their families were affected during an outbreak in animals. A single case was detected in the United Kingdom, where a woman acquired the infection from her pet duck in 1996. In 1959, the United States recorded an imported case. Most cases were mild.
Mode of spread
- Animals
Transmission
Humans usually catch avian flu from birds. People who raise, slaughter, prepare or live with poultry are at a higher risk of getting infected. Humans appear to become infected by touching, then ingesting or inhaling infected faeces. In very rare cases, people have also gotten the virus from sick family members. So far, bird flu is not able to easily spread from person-to-person. However, the virus can undergo genetic changes that make it easy to spread between people.
Symptoms
Like other bird flu, H7N7 also resembles ordinary flu. Patients may experience a sudden fever, cough, sore throat and muscle pain. Redness of the eyes (conjunctivitis) has also been recorded in cases of H7N7. Although H7N7 has not caused serious illness in humans, severe lower respiratory tract infection, and even pneumonia are seen to develop with other strains of avian flu. Gastrointestinal symptoms, such as diarrhoea, may occur. Neurologic symptoms, such as headache and convulsions, have been described.Complications are not known to occur in H7N7. However, other avian flu strains may lead to severe pneumonia and respiratory distress. They can cause multiple organ failure leading to death.
Diagnosis
A medical professional may suspect someone has avian flu based on their symptoms and the likelihood they've been exposed to birds, or to someone sick with bird flu. Information will be collected about the individual's travel history, occupation, accommodation, and other recent activities. Avian flu can be diagnosed with samples collected from a patient's nose and throat, which are then analysed by a special laboratory. In some cases, especially in areas with fewer resources, this testing may not be available.Treatment
Some antiviral drugs have proven to be effective against the H5N1 virus if a person takes them in the early stages of infection. Laboratory data on the H7N9 flu virus shows it may also be treatable with antivirals. However, as this virus strain is new to humans, there's not much information on actual infected people being treated.
Vaccination
No vaccine is available for humans.
Prevention
You should avoid contact with birds and other animals, and their environment.
- Do not go to live animal markets, poultry farms or pig farms.
- Do not handle any birds, even if they appear well. Prevent children from doing so.
- Avoid touching any surfaces that may be contaminated by bird droppings. Do not swim in any body of water that is used by birds.
Always maintain high levels of personal hygiene.
- Frequent hand washing is very important. Wash hands before and after food preparation and before eating.
- Thoroughly cook all poultry and poultry products, including eggs.
Consider having an influenza vaccination. Although it will not protect you against bird flu, it reduces your risk of a "co-infection" with human influenza.
Risk to travellers
Travellers who avoid live poultry markets and direct contact with birds are at very low risk.
