E.Gull – A Toxic Tern

Seagulls have always been commonplace in coastal towns and cities but today they are continuing to move inland with an increasing presence in urban areas. In terms of health risks seagulls provide a highly effective vector for several infections, and of all the organisms carried by gulls the most pressing health concern is perhaps their carriage of Escherichia coli (E.coli). However, seagulls are also responsible for spreading many other diseases including Psittacosis, Histoplasmosis, and Cryptococcosis a potentially fatal fungal infection.These diseases are spread via bacteria and fungus in the birds’ droppings which, over time, dry out, solidify and turn to dust resulting in particles being blown into the air and inhaled by passers-by.

In terms of environmental damage the built environment is now being more frequently exposed to seagull droppings, and this interaction with manmade materials can often result in degradation through chemical damage or corrosion which may ultimately compromise the serviceable lifespan of buildings. Twenty percent of the chemical composition of seabird droppings generally comprise uric acid, proteins, ammonia and nitrite which collectively may degrade and damage structural metalwork, concrete and stonework. Seagull droppings are acidic and over time can cause extensive structural damage to infrastructure, but when seagull droppings dry out and become solidified excrement their chemical pH drops thereby increasing their corrosiveness toward certain metals.

The phrase 'you are what you eat' came from the 1826 work entitled ‘The Physiology of Taste’ by the French author Jean Anthelme Brillat-Savarin who wrote ‘Tell me what you eat and I will tell you what you are.’ Hence it is important to recognise the eating habits of gulls. Snatching food is a behaviour seagulls have developed over many years and its detrimental effects are compounded each and every time the birds are fed by members of the public. It is imperative therefore that such feeding is discouraged, but gulls are attracted to urban areas due to the abundance of littering, heaps of discarded rubbish and food waste. These negligent and irresponsible acts regarding waste disposal compromise physical, mental and social well-being and place increasing pressure upon local authorities to provide safe and secure waste handling facilities. But such troubling instances involving gulls are worsened throughout their nesting season when the birds are rearing their young. During these periods gulls often exhibit aggressive behaviour whilst searching for food and/or protecting their chicks that have not yet fledged and remain unable to protect themselves.

Such episodes create a public nuisance but are increasingly exposing local populations to personal injury risks from disease and infirmity. However, dealing with troublesome gulls is in itself tricky. The Wildlife & Countryside Act 1981 protects all animals, plants and habitats in the UK and defines a wild bird as any bird, in a wild state, of a species which is resident in or is a visitor to the European Territory of any member country. Seagulls fall under this definition and are therefore protected. Consequently, like all wild birds, seagulls, their eggs and nests are protected under law and it is illegal to intentionally or recklessly injure or kill any gull or damage or destroy an active nest or its contents. Gulls cannot be killed unless they are being controlled under the terms of licences issued by Natural England orNatural Resources Wales. In Scotland and Northern Ireland it is also illegal to prevent birds from accessing their nest or to disturb any nesting bird. Conditions specified on each licence must be followed and intentionally killing or injuring a seagull is a criminal offence, with offences against wildlife often carrying a penalty fine in the order of £5,000 or even a jail term.

Unfortunately, seagulls provide a highly effective vector for several infections. They can carry scabies mites, which cause a perennial intensely itchy nightmare in places where people live in close quarters, for example in hostels and nursing-homes. Perhaps not hugely risky for most people, the fungal pneumonias Histoplasmosis and Cryptococcosis are commonly implicated in mortality at the extremes of life and in immunocompromised individuals, for example those infected with HIV or transplant patients. Patients can suffer fevers, breathing difficulties and septicaemia leading to meningitis and organ failure. Thankfully systemic illness is rare in people with a competent immune system. Immunocompromised people, that is, those with poor immunity secondary to disease, advanced age or deliberately weakened immune systems to cope with some inflammatory illnesses, are however growing in number and so these fungal infections will be an ever-more important consideration.

Disease-causing pathogenic bacteria spread by seagulls tend to be much more virulent than the fungi and do frequently affect healthy individuals. Psittacosis, from the inhalation of droppings, feather dust or respiratory secretions of birds, is a respiratory illness that is very difficult to distinguish from the usual bugs that cause chest-infections but it is resistant to most of the antibiotics used for the more common-or-garden respiratory pathogens. Gastroenteritis spread by gulls, caused by Salmonella, Campylobacter or E.coli is much more frequently encountered than pneumonia though and causes fevers, chills, nausea, vomiting, diarrhoea, stomach cramps, and headache. Serious complications like meningitis may ensue. These facts therefore warrant a discussion regarding the protection of wildlife versus claims for personal injury due to contamination.

Salmonella bacteria thrive in similar conditions to E.coli and have become widespread and increasingly found in contaminated food, soil and water. These contaminations have originated from a wide range of animal hosts including gulls, with most associated infections being attributed to the ingestion offood contaminatedby faeces.Wildlife can become infected with Salmonella through a variety of routes including direct contact, the ingestion of contaminated food or water, or by exposure to contaminated soil or faeces. Whilst the usual symptoms of infection from this species are diarrhoea and dehydration, severe cases can even lead to sepsis, organ failure, and death.

Of all the aforementioned organisms carried by seagulls, the most pressing health concern is perhaps their carriage of E.coli. This is a rod-shaped coliform, a bacteria that lives in the digestive tracts of all mammals and birds. As seagulls expand their habitat in-land, their aggressive nature and adaptability to avoid and ignore deterrents like scarecrows, ‘bird bangers’ and gas guns makes them a particular concern with regard to the spread of E.coli. Seagulls show a strong predilection for landfill sites and the distribution of E.coli infection is associated with migratory seagulls that have eaten refuse containing sewage or medical waste.

E.coli is not always a danger. The commensal, or ‘good bacteria’, form of E.coli helps the host organism to break down carbon compounds in the gut. Pathological forms, however, can cause serious illness even if only very small amounts are ingested, even in healthy patients. It is the commonest cause of urinary tract infection in humans and in the top five bacterial culprits for gastroenteritis. Strains resistant to various antibiotics i.e. ‘superbugs’ are now endemic and seen every day in medicine. These pose a grave public health concern. It is now standard procedure to send a urine sample off for culture and a sensitivity profile, so as to be confident a prescription will be effective. Toxin-producing strains of E.coli, most notoriously 0157, can withstand highly acidic environments, meaning they can survive passage through the human stomach and on to wreak havoc in the colon, causing blood and fluid loss, frequently leading to fatal renal failure.

This heavy burden of E.coli on the health service, comprising mostly urinary tract infection or gastroenteritis, means this bacterium is responsible for a good proportion of antibiotic prescriptions which itself brings about selection of resistant, more virulent strains through a process of Darwinian natural selection whereby resistant strains survive whilst susceptible ones are killed by antibiotics. This looming public health emergency is further sped along by ‘horizontal’ gene transfer, this being the ability of E.coli to transfer genetic material between neighbours, as opposed to ‘vertical’ transfer from parent to child. In this way genes that confer resistance to antibiotics spread particularly quickly in this organism compared to other bacteria. Avian droppings disseminate these resistant organisms which subsequently persist within soil, as evidenced by 95% of shoe sole swabs proving positive for E.coli.

In terms of dissemination there is an imperative to highlight potential transmission paths from source to receptor i.e. from infective contaminants to humans. In its simplest form this can comprise transmission through manual interaction with faeces-contaminated objects such as handrails, street furniture, parked cars and playground apparatus. What solutions are available? The RSPB suggests that methods to deter seagulls from continuing to move inland could include rendering potential nesting sites inaccessible, reducing the amount of organic waste taken to landfill sites, and preventing street littering in urban areas. Such measures will not always be easy or practicable, but culling should only be considered if there remains an ongoing serious problem, as non-lethal solutions to gull problems are always deemed preferable. Nevertheless, research has revealed that over a fifteen year period the number of urban gull colonies in the UK and Ireland has actually doubled.

In summary, severe health and environmental risks emanate from scavenging gulls that feed from the carcasses of dead animals, scraps of food, or roadkill, and from those gulls that eat just about anything by regularly gathering on refuse tips where it is easier to wait for food to be dropped on the ground rather than flying around in search of it. Hence, the fundamental dilemma is balancing ‘environmental protection’ against the risks to ‘personal injury’. Seagulls can be carriers of disease, with bacteria and infectious matter found in their droppings presenting severe biological hazards with appreciable dangers. Any resulting infections may potentially develop into life threatening diseases to which the most susceptible members of the community are likely to be the over 60’s and young children under the age of 5 years. Therefore a legal quandary remains: To what extent should society and legislation protect gulls, whilst they pose real and severe threats from personal injury?

Robert Jackson is the Mouchel Parkman Professor Emeritusand former Associate Head of the School of Computing, Science & Engineering,at the University of Salford.As a Forensic Engineering Expert he is a Law Society Checked Expert and an Association of Personal Injury Lawyers 1st Tier Expert.

Fred Newton is a GP and Senior Partner at Grove Road Surgery in Wallasey, Merseyside. He is the practice lead for Dermatology and Endocrinology and is a member of the Wirral Local Medical Committee and a Fellow of the Royal College of General Practitioners.