What is the issue?
Agriculture Victoria has confirmed that AI H7N7 has been detected at an additional egg farm in the Golden Plains Shire, and AI H7N6 has been detected at an emu farm near Kerang in the Gannawarra Shire. AI H5N2 was detected in poultry at a property in Lethbridge, and another near Bairnsdale. A total of six farms have been affected by AI since the first farm detection on 31 July 2020.
On rare occasions, H7N7 avian influenza has been known to infect and cause disease in humans who have had close contact with infected poultry. Most people have only mild disease. Spread from humans to humans has been documented mostly in close contacts of confirmed cases. No human cases of AI H5N2 or H7N6 have ever been reported.
Staff and other persons who may have been exposed to infected poultry are being contacted by the Department of Health and Human Services and provided with relevant information to monitor their health and seek medical assistance if they develop symptoms.
Agriculture Victoria has ensured that movement controls are in place and the affected properties have been quarantined. These controls prohibit the movement of birds, equipment and products within and out of the restricted area until further notice.
What is avian influenza?
Avian influenza (AI) viruses are common in birds throughout the world. For the most part, AI viruses circulate harmlessly in these birds, however AI outbreaks among poultry occur worldwide from time to time.
On rare occasions, some strains of AI virus can infect and cause disease in humans. Australia has had a number of small outbreaks of other strains of AI on poultry farms.
Who is at risk?
Only people who come into close contact with infected birds or their secretions or are close contacts of confirmed cases are considered at risk.
Symptoms and transmission
Most people who are infected with H7N7 show no symptoms or mild conjunctivitis or flu-like illness. No human cases of AI H5N2 or H7N6 have ever been reported.
Symptoms generally appear between 2 and 10 days following exposure.
AI viruses can infect people following close contact with infected poultry or materials contaminated with poultry infection feathers, faeces or other waste from poultry facilities.
Humans infected with an AI virus do not easily transmit the infection to others. When this has occurred, it seems to have been due to close contact with a sick person over several days.
Eating properly cooked poultry products including chicken or eggs does not result in AI.
Consider testing for AI in people who have been in contact with infected poultry. Collect combined nose and throat swabs (usually from adults) or nasopharyngeal aspirates (usually from children) and place in viral transport medium. Collect conjunctival swabs from patients presenting with conjunctivitis. Sputum is strongly recommended wherever possible. Bronchoalveolar samples and lung biopsy should also be sent if available. clearly identify samples as requiring urgent testing for avian influenza and separate from non-urgent specimens.
Gloves, gown, P2 mask and eye protection should be worn as a minimum when collecting samples from patients. If a negative pressure room is unavailable, the patient should be placed in a single room with the door closed.
Doctors and laboratories must notify people with suspected AI to the Department of Health and Human Services on 1300 651 160 - select option 2 (urgent diseases).
Should human cases be suspected, the department will work with the patient, the treating doctors, and the laboratory to confirm the diagnosis.
Anyone exposed to potentially infected birds or contaminated products should be vaccinated with the seasonal human influenza vaccine. Although the seasonal human influenza vaccine will not protect against AI, it may avoid simultaneous infection with both human and AI. There is a small possibility that if a person is infected with both these viruses, the viruses could share genetic material (reassortment) to produce a new and highly infectious virus that would pose a threat to the wider community.
Having the human influenza vaccination will also protect workers from the usual human seasonal influenza and help avoid diagnostic confusion if workers develop influenza-like symptoms.
Treatment and prophylactic antivirals
Oseltamivir (Tamiflu) can be used in treatment of confirmed cases and prophylactic oseltamivir could be considered for people who have had close contact with AI-infected birds, in particular for people exposed without wearing appropriate PPE.
Decisions should be based on clinical judgement, with consideration given to the type of exposure and whether the exposed person is at high risk for complications from influenza.
Avian influenza (bird flu)
Better Health Channel - Bird flu (avian influenza)
For more information please contact the Communicable Disease Prevention and Control section at the Department of Health and Human Services on 1300 651 160 (24 hours) and select option 2 (urgent diseases).