Post by Na9er on Oct 20, 2012 12:04:26 GMT -5
Infectious diseases are caused by the transmission of pathogens, which are microorganisms such as bacteria and viruses. Pathogens can be transmitted by direct contact - horizontal and vertical transmission - and by indirect contact - vehicle-borne transmission and vector-borne transmission.
Pathogens
Pathogens are microorganisms that cause infectious disease. Pathogens are mostly bacteria but some are viruses, fungi and protoctists.
Bacteria
Bacteria come in many shapes and sizes, but even the largest are only 10 micrometres long (10 millionths of a metre).
Bacteria are living cells and, in favourable conditions, can multiply rapidly. Once inside the body they release poisons or toxins that make us feel ill.
Viruses
Viruses are many times smaller than bacteria. They are among the smallest organisms known and consist of a fragment of genetic material inside a protective protein coat.
Viruses can only reproduce inside host cells, and they damage the cell when they do this. A virus can get inside a cell and, once there, take over and make hundreds of thousands of copies of itself. Eventually the virus copies fill the whole host cell and burst it open. The viruses are then passed out of the body in the bloodstream, the airways, or by other routes.
There's more info about "Infectious Diseases" so please try to post as much as you can.
Pathogens
Pathogens are microorganisms that cause infectious disease. Pathogens are mostly bacteria but some are viruses, fungi and protoctists.
Bacteria
Bacteria come in many shapes and sizes, but even the largest are only 10 micrometres long (10 millionths of a metre).
Bacteria are living cells and, in favourable conditions, can multiply rapidly. Once inside the body they release poisons or toxins that make us feel ill.
Viruses
Viruses are many times smaller than bacteria. They are among the smallest organisms known and consist of a fragment of genetic material inside a protective protein coat.
Viruses can only reproduce inside host cells, and they damage the cell when they do this. A virus can get inside a cell and, once there, take over and make hundreds of thousands of copies of itself. Eventually the virus copies fill the whole host cell and burst it open. The viruses are then passed out of the body in the bloodstream, the airways, or by other routes.
There's more info about "Infectious Diseases" so please try to post as much as you can.