Agent

Suttonella ornithocola is a recently discovered bacterium in the family Cardiobacteriaceae.

Species affected

Suttonella ornithocola infection has been most commonly observed in blue tit (Cyanistes caeruleus); however, other birds within the tit families (Paridae and Aegithalidae) are also susceptible to infection, such as coal tit (Periparus ater), long-tailed tit (Aegithalos caudatus) and great tit (Parus major). Suttonella ornithocola infection has not yet been diagnosed in the other groups of British garden bird species.

Pathology

Suttonella ornithocola causes lung disease in affected tits. Microscopic examination of lung tissues typically reveals a “pneumonia-like” condition associated with S. ornithocola infection. However, this bacterium has been isolated from several organs, suggesting a widespread or systemic infection can occur.

Signs of disease

Birds affected by S. ornithocola infection tend to show non-specific signs of ill health, for example lethargy and fluffed-up plumage. In addition, they may show breathing difficulties such as gasping. Wild birds suffering from a variety of conditions can exhibit similar signs of disease and there are no characteristic signs of S. ornithocola infection that allow it to be diagnosed without specialist veterinary examination. Affected birds are often thin, indicating that the disease may progress over the course of several days.

Disease transmission

Relatively little is known about S. ornithocola in British tit species. Since the bacterium causes a lung infection, aerosol or air-borne infection (i.e. cloud or mist of infectious agent released by coughing or sneezing) is thought to be the most likely route of transmission between birds. The length of time that S. ornithocola can survive in the environment, and whether this is important in the disease transmission, is unknown.
Since blue tits are involved in the majority of S. ornithocola mortality incidents to date, it has been suggested that this species may play an important or key role in the disease life-cycle.

Disease patterns

In the spring of 1996, eleven mortality incidents involving a range of tit species were reported with a wide distribution across England and Wales. Blue tits were most frequently affected but signs of ill health were also observed in long-tailed tit, coal tit and great tit. The number of affected birds varied in each incident (between one and ten) therefore localised disease outbreaks affecting multiple birds can occur. Suttonella ornithocola was isolated from birds from multiple sites; this was the first time the bacterium had been seen; therefore, it was considered a new and perhaps emerging disease of British wild birds.
Surveillance since 2005 has identified a small number of S. ornithocola infection incidents (ranging from none to two per year) which have occurred with a widespread distribution across Great Britain. Blue tits remain the species most commonly affected and outbreaks typically occur in spring. These findings suggest that S. ornithocola infection is well-established (i.e. endemic) in the British tit population.
Suttonella ornithocola infection was confirmed for the first time in South and Central Finland in spring 2017: three incidents involving blue tit and coal tit mortality were reported. The following year, in April 2018, S. ornithocola-associated mortality of tits was described for the first time in Germany: four tit mortality incidents were investigated in southern North Rhine-Westphalia, again with blue tits, coal tits and great tits affected.
In spring 2020, an epidemic primarily involving blue tits was reported in northwestern Germany: over 20,000 suspicious reports of sick and dead tits were received by NABU (The Nature And Biodiversity Conservation Union), the national ornithological organisation in Germany, that year.  Recurrent seasonal mortality of tit species occurred to a lesser extent in 2021 but has not been observed in more recent years. Population monitoring data of blue tit indicated a regional population decline in areas of greatest disease occurrence, raising the possibility that this reduction was caused by the disease outbreak, however, other factors may also have contributed.

Risk to human and domestic animal health

Whilst S. ornithocola was first isolated in 1996, it was not fully identified as a novel bacterium until 2005; therefore, relatively little is known about the bacterium and the range of species which can be infected. Nevertheless, there are no known reports of infection with this bacterium in humans or any mammal. To date, only birds within the tit family in Britain have been confirmed with the infection; the extent to which other bird species may be susceptible is unknown.
Garden birds in the UK may carry other infectious agents (for example Campylobacter, Chlamydia psittaci, Escherichia albertii  and Salmonella bacteria) that can affect people and pets.
We recommend following sensible hygiene precautions as a routine measure when feeding garden birds and handling bird feeders and tables. Following these rules will help avoid the risk of any infection transmitting to people and help safeguard the birds in your garden against disease.
  • Clean and disinfect feeders and feeding sites regularly. Suitable disinfectants that can be used include a weak solution of domestic bleach (5% sodium hypochlorite) and other specially-designed commercial products (See Further information). Always rinse thoroughly and air-dry feeders before re-use.
  • Brushes and cleaning equipment for bird feeders, tables and baths should not be used for other purposes and should not be brought into the house, but be kept and used outside and away from food preparation areas.
  • Wear rubber gloves when cleaning feeders and thoroughly wash hands and forearms afterwards with soap and water, especially before eating or drinking. Avoid handling sick or dead birds directly. For instance, use disposable gloves or pick the bird up through an inverted plastic bag.

Diagnosis

Diagnosis of S. ornithocola infection in garden birds relies on post-mortem examination. The signs of the disease at post mortem are subtle and non-specific therefore additional laboratory tests are used to confirm the diagnosis of the disease. The bacterium is fastidious (i.e. difficult to grow in the laboratory) and requires special culture conditions therefore a molecular test has been developed to assist with its detection.
If you wish to report finding dead garden birds, or signs of disease in garden birds, please visit www.gardenwildlifehealth.org. Alternatively, if you have further queries or have no internet access, please call the Garden Wildlife Health vets on 0207 449 6685.

Control

Whilst medicines are available which may help treat S. ornithocola infection in captive birds, effective and targeted dosing of free-living birds is not possible.
Where a problem with S. ornithocola infection exists, general measures for control of disease in wild bird populations should be adopted:
  • Ensure optimal hygiene at garden bird feeding stations, including disinfection (as described above).
  • Ensure that water provided for garden birds is fresh and clean on a daily basis.
  • Feeding stations (such as bird tables and hanging feeders) encourage birds to congregate, sometimes in large densities, thereby increasing the potential for disease to spread between individuals when outbreaks occur.  If many birds in your garden are affected, we recommend that you consider significantly reducing the amount you feed, or stop feeding for a period (2-4 weeks). The reason for this is to encourage birds to disperse, thereby minimising the chances of new birds becoming infected at the feeding station. Gradually reintroduce feeding, whilst continuing to monitor for further signs of ill health (See Further information).

Prevention

Following best practice for feeding garden birds is recommended to help control and prevent transmission of disease at feeding stations all year round (See Further information):
  • Routine good table hygiene. Clean away uneaten food and droppings before putting out fresh food and disinfect feeders/ feeding sites on a regular basis.
  • Provision of clean and fresh drinking water on a daily basis.
  • Provision of fresh food from accredited sources.
  • Rotate positions of feeders in the garden to avoid build-up of contamination in any one area and pay particular attention to clearing food remains that fall on the ground.

Further information

Best feeding practices should be followed at all times to help ensure that the birds visiting your garden remain healthy.  More information can be found on the Garden Wildlife Health website www.gardenwildlifehealth.org.

Scientific publications

Martín-Maldonado B & Esperón F (2024) Can Suttonella ornithocola entail a potential hazard to songbirds? A systematic review. European Journal of Wildlife Research, 70(2), p.29 doi.org/10.1007/s10344-024-01785-4
Leitzen E, Peters M, Merbach S, Wohlsein P, Baumgärtner W (2022) Suttonella ornithocola detected within lesions of tit birds (Paridae) from epidemic death episodes in Germany, 2018–2020. Frontiers in Veterinary Science 9 doi.org/10.3389/fvets.2022.977570
Nature and Biodiversity Conservation Union (NABU) (2020) Suttonella ornithocola bacterium causes blue tit deaths [Accessed April 22nd 2020] https://www.nabu.de/news/2020/04/27990.html
Merbach S, Peters M, Kilwinski J, Reckling D (2019) Suttonella ornithocola-associated mortality in tits in Germany, Berliner und Münchener Tierärztliche Wochenschrift, 132(9/10), p.459-463doi.org/ 10.2376/0005-9366-18065
Finnish Food Safety Authority (EVIRA) (2017) Suttonella ornithocola infection associated with mortality in Finnish tits (Paridae). European Wildlife Disease Association Newsletter Summer 2017, http://ewda.org/ewda-newsletter-summer-2017/
Peniche G, Rodriguez-Ramos Fernandez J, Durrant C, John SK, Macgregor SK, Cunningham AA (2017) Nested PCR for Suttonella ornithocola reveals widespread infection in British Paridae species. European Journal of Wildlife Research 63:50 doi.org/10.1007/s10344-017-1105-6
Lawson B, Malnick H, Pennycott TW, Macgregor SK, John SK, Duncan G, Hughes LA, Chantrey J, Cunningham AA (2011) Acute necrotising pneumonitis associated with Suttonella ornithocola infection in tits (Paridae). The Veterinary Journal 188: 96-100. doi.org/10.1016/tvji.2010.03.010
Kirkwood JK, Macgregor SK, Malnick H, Foster G (2006) Unusual mortality incidents in tit species (family Paridae) associated with novel bacterium Suttonella ornithocola. Veterinary Record 158: 203-205. doi.org/10.1136/vr.158.6.203
Foster G, Malnick H, Lawson PA, Kirkwood J, MacGregor SK, Collins MD (2005) Suttonella ornithocola sp. nov., from birds of the tit families, and emended description of the genus Suttonella. International Journal of Systematic and Evolutionary Microbiology 55: 2269-2272. doi.org/ 10.1099/ijs.0.63681-0

Acknowledgements

Current funding for the GWH comes in part from Defra, the Welsh Government and the Animal and Plant Agency (APHA) Diseases of Wildlife Scheme (DoWS) http://apha.defra.gov.uk/vet-gateway/surveillance/seg/wildlife.htm; and from the Esmée Fairbairn Foundation, the Universities Federation for Animal Welfare and the Garfield Weston Foundation.

Disclaimer

This fact sheet was produced by Garden Wildlife Health (GWH) for information purposes only. The GWH will not be liable for any loss, damage, cost or expense incurred in or arising by reason of any person relying on information in this fact sheet.

Date of factsheet update

October 2024