farmer's lung disease is due to
Answers
Answer:
People can get Farmer's Lung by breathing in dust containing the spores of special, heat-tolerating bacteria or moulds often found on moldy crops. Spores from two types of bacteria, "Micropolyspora faeni" and "Thermoactinomyces vulgaris", and certain types of moulds called "Aspergillus" are the major causes of Farmer's Lung.
In areas where crops are harvested in wet or rainy weather, crops usually undergo self-heating while in storage. When this happens, heat-tolerating bacteria and moulds grow rapidly and cause spoilage. As spoiled hay dries, it darkens, crumbles easily, and is extremely dusty. This dust that contains bacteria and mould spores is extremely fine. People can breathe these spores into the innermost regions of the lungs (alveoli) where the problem begins.
The spores that cause Farmer's Lung are not infectious. Instead, they trigger an allergic reaction. Allergic reactions are produced by the immune system, the body's defence system that normally protects against infectious diseases. The immune system reacts when special substances called "antigens" enter the body. Antigens are usually found on germs such as infectious bacteria or viruses. The immune system reacts to neutralize these germs and prevent infections. Antigens are also found on harmless material such as mould spores. Sometimes the immune system will react against these by producing a harmful reaction (e.g., an allergic reaction) against an antigen attached to material like a spore that is otherwise harmless.
Farmer's Lung develops in two steps, as other allergic reactions do. The first time a person inhales a large amount of dust and spores from moldy hay, the immune system often responds by producing specific antibodies against the antigens. Antibodies are chemicals that circulate in the blood and attack specific antigens. Once the body has produced these antibodies, there is a chance that further exposure to moldy dust can generate a hypersensitive type of allergic reaction. This reaction is typical of Farmer's Lung.
A hypersensitive reaction is triggered when antigens in the lungs react with antibodies that circulate in the blood; this sets off a complicated reaction normally intended to protect the lungs from infections. Certain types of white blood cells move into the lungs to attack the antigens. Then, other types of white blood cells move into the lungs, releasing chemicals and poisons that increase blood flow and kill lung tissue close to the antigens. This response causes swelling, inflammation and damage to lung tissue, resulting in noticeable breathing problems