Firstly this short list is not designed to frighten you, just make you aware of some of the diseases that can cross between our hens and onto us. I as a nurse have always felt that if you know about it, you can deal with it. In the case of these infections PREVENTION is the key.
Domestic chickens can transmit diseases to us in two ways. The first and the most common way is for a sick chicken or a sick chicken's faeces to come into contact with the hen keeper or vet. The other way is for a disease to live in a sick chicken's eggs which someone then goes onto eat and they also become ill.
This is commonly known as "bird flu" and is the most serious chicken-to-human disease currently known, as humans have no immunity to it. The only way to contract this disease is through contact with live, sick chickens. It is a disease of birds caused by the influenza virus and is closely related to human influenza viruses. Transmission to humans in close contact with poultry or other birds occurs rarely and only with some strains of avian influenza.
Avian tuberculosis is caused by bacteria in food. The only way a person can get it is to come in contact with the faeces of a sick bird. A bird with the disease will show progressive weight loss though maintain a good appetite. It will become increasingly depressed, have diarrhoea, increased thirst, and respiratory symptoms. Once the disease appears, it is impossible to eliminate. Eventual death of the bird is often the outcome. It is treatable in humans but as with most forms of TB, its very difficult to grow cultures in the labs for definite diagnosis and treatment can be long.
The most common chicken-to-human disease is salmonella. Our hens contract it by eating contaminated food. People can get it by eating the eggs of sick chickens or coming into contact with their faeces. The illness usually lasts 4–7 days, and most people recover without treatment. However, in the very young and the elderly, and in cases when the bacteria enter the bloodstream, there is often the need for antibiotics. That said the salmonella bacteria is very complexed and not all types(over 2,000) can be tranferred to humans. Since the vaccination of breeding & laying flocks, incidence has fallen sharply.
Let me firstly state that this is a rare illness but one that you should be aware of, there are only about 100 cases reported annually in the UK. It is a bacteria disease which largely affects parrots, parakeets, cockatoos and lories. It is also found in other avian species, those that are often kept as pets, canaries, budgies and pigeons. It can also affect domesticated fowl such as turkeys and ducks. Major outbreaks of the disease are now rare due to strict import controls on birds and increased knowledge. Infection occurs through inhalation of bacteria from avian faeces and feather dust. There have been cases reported following oral contact with birds (e.g. giving resuscitation). Psittacosis can survive for several months in dander or faeces. If people catch this disease they can be left feeling very ill indeed, tiredness, headaches with pneumonia like symptoms, it can often be misdiagnosed as pneumonia, if all the facts aren’t known. Following treatment, the sufferer if usually told not to keep birds.
How to prevent becoming infected is fairly simple, good hygiene and wearing face masks when causing dust to be stirred that you will breath in.