(This article first appeared in the E-newsletter of BirdLife South Africa in July 2018 - Ed.)
We’ve all had ‘the flu’. The disease is synonymous with the sniffles, winter, warm layers, blankets and soup. A simple vaccination helps us humans to beat the virus, but there is currently no cure for avian influenza. In early 2018 an outbreak of the disease in wild seabirds was cause for concern, and a report by the state veterinarian on the progression of the flu until May 2018 was recently released. It is summarised here, with the addition of some pertinent information.
The second half of 2017 was a difficult time for the South African poultry industry. H5N8, a strain of highly pathogenic avian influenza (HPAI; commonly referred to as bird flu or avian flu), was diagnosed in commercial chickens in June. In testament to the strain’s volatility, the poultry industry reported a loss of 70% of commercial layer chickens by October, and two-thirds of all ostrich farms were under quarantine. The outbreak slowed, but by then the disease had spread to other species, with a Helmeted Guineafowl being the first wild bird to test positive. In late December, the first reports of abnormally high rates of tern mortality began to come in, heralding a new wave of birds affected by this virus.
Avian influenza is a viral respiratory disease spread through direct contact with infected birds or contaminated materials. The virus can persist in bird guano and mucous discharges. This strain is harmless to humans, although humans can spread the disease through contact with infected birds. The disease causes birds to become very weak and have flu-like symptoms such as fever, chills, nasal discharges and headaches. Visual signs of the disease include cloudy eyes, bright green guano and neurotic behaviour such as rocking back and forth, turning in circles and nodding the head.
If you find a live bird showing these symptoms, please report it to SANCCOB in Cape Town or your nearest seabird rehabilitation centre. The disease is transferred through contact, so avoid touching the bird unnecessarily and use disposable gloves or newspaper to transfer the bird to a box for safekeeping. Be sure to call ahead for instructions, as some species such as Swift Terns are not being admitted due to poor rehabilitation success. Dead birds are best removed and incinerated or buried.
Seabird species most affected by this latest outbreak include Swift Terns and Cape Gannets (both with more than 1000 suspected cases as of May 2018), Common Terns, African Penguins and Cape Cormorants (all with more than 100 suspected cases). Other species of gulls, terns, cormorants and even a handful of African Black Oystercatchers have also tested positive, though the numbers of suspected cases are still very low.
The state veterinarian report has stressed that the data presented are limited. It is prohibitively expensive to test every single suspected case and it is likely that there are undiscovered or unreported cases that have not been factored in. The Department of Environmental Affairs is concerned about the outbreak and has instigated measures to try limit its spread and effect. However, as these are wild birds that move many hundreds of kilometres on a regular basis, this is not an easy task. We ask that members of the public are responsible in the way that they share information about avian flu. Unnecessary panic is counterproductive and the outbreak as it stands is not threatening the survival of any species. It is important to remember that disease is also a natural and normal part of life and occasional outbreaks are to be expected.