INFECTION ,INFECTIOUS DISEASES SPREAD , PREVENTION AND CONTROL
ROUTES OF TRANSMISSION
Infectious or contagious diseases are all caused by some infectious agents - such as bacteria, viruses, fungi or parasites. Some infectious diseases can be transmitted from one person to next. Some is transmitted by the bites of insects and animals. Others are acquired from eating contaminated food or water or other environmental exposures.
Transmission of infectious or contagious diseases may also include a vector. Vectors may be mechanical or biological. A mechanical vector contains an infectious agent outside the body and sends it passively. There is an example of mechanical vector is a fly that landed on the cow manure, pollution of the annexes for the bacteria in the stool, and then landed in the food before consumption. The pathogen never enters the body of the flies.
The relationship between virulence and transmission is complex and has important implications for long-term evolution of a pathogen. Since it takes several generations for a microbe and a host of new species co-evolution, an emerging pathogen may hit its first victims particularly difficult. It usually occurs in the first wave of a new disease mortality rates are higher. If a disease is rapidly fatal, the host may die before the microbe can be that way to another host. However, this cost could be overwhelmed by short-term benefit of higher infectiousness if transmission is linked to virulence, as in the case of cholera (the explosive diarrhea helps bacteria to find new hosts) or many infections respiratory (sneezing and coughing for creating infectious aerosols).
PREVENTION AND CONTROL
ROUTES OF TRANSMISSION
Infectious or contagious diseases are all caused by some infectious agents - such as bacteria, viruses, fungi or parasites. Some infectious diseases can be transmitted from one person to next. Some is transmitted by the bites of insects and animals. Others are acquired from eating contaminated food or water or other environmental exposures.
A contagious (infectious ) disease can be transmitted from one source. Definition of transmission plays an important role in understanding the biology of an infectious agent, and in the fight against the disease it causes. Transmission can be through several mechanisms. Respiratory diseases and meningitis are often acquired through contact with aerosol droplets spread by sneezing, coughing, talking, kissing or even sing. Gastrointestinal diseases are often acquired through contaminated food and water. Sexually transmitted diseases are acquired through contact with bodily fluids, generally as a result of sexual activity. Some contaminants can be spread through contact with an infected person, inanimate object (known as a vector liabilities) as a coin passed from one person to another, while others penetrate the skin diseases directly.
Transmission of infectious or contagious diseases may also include a vector. Vectors may be mechanical or biological. A mechanical vector contains an infectious agent outside the body and sends it passively. There is an example of mechanical vector is a fly that landed on the cow manure, pollution of the annexes for the bacteria in the stool, and then landed in the food before consumption. The pathogen never enters the body of the flies.
In contrast, biological vectors of pathogens in their body and deliver pathogens actively in new hosts , usually a bite. Biological vectors are often responsible for serious blood diseases such as malaria, viral encephalitis, Chagas disease, Lyme disease and African sleeping sickness. Biological vectors are usually but not exclusively, arthropods such as mosquitoes, ticks, fleas and lice. Vectors are often necessary in the life cycle of a pathogen. A common strategy to fight against the infectious disease vectors is to interrupt the life cycle of a pathogen by killing the vector.
The relationship between virulence and transmission is complex and has important implications for long-term evolution of a pathogen. Since it takes several generations for a microbe and a host of new species co-evolution, an emerging pathogen may hit its first victims particularly difficult. It usually occurs in the first wave of a new disease mortality rates are higher. If a disease is rapidly fatal, the host may die before the microbe can be that way to another host. However, this cost could be overwhelmed by short-term benefit of higher infectiousness if transmission is linked to virulence, as in the case of cholera (the explosive diarrhea helps bacteria to find new hosts) or many infections respiratory (sneezing and coughing for creating infectious aerosols).
PREVENTION AND CONTROL
Methods of prevention of infection depends on the source and route of transmission.
- Eradication of reservoir : There is no provision in the tank to an unusual disease to humans are the only natural reservoir of infection, it may be possible to eliminate the disease through intensive screening, treatment and vaccination. What has been done in cases of smallpox there. If an animal or a complete eradication of the reservoir environment is unlikely, but local control methods can reduce the risk of human infection (eg kill rodents to control fever, leptospirosis and other diseases) .
- For arthropode - vector - borne infections : Destroys the carrier (which can be quite certain cases). Act to avoid biting (eg, insect repellent spray, mosquito nets).
- For food borne infection : Improve food handling and preparation is less contamination during processing, transportation or preparation. naturally present in foods can kill the body preparation and cooking. Improve supervision and regulation of food and better health education for the public need.
- For faeco-oral infections : Improvement in water supply and sanitation. About 30% ( thirty percent ) of the world's population have no access to adequate safe drinking water ,and over half have no adequate sanitation.
- For blood borne infections : Prevention of blood transfusion and handling of contaminated medical equipment which is use during transfusion .And routine testing of donated blood for infectious disease or infection even in most developed countries.
- For infections spread by airborne and direct contact: In some respiratory infections which is caused by some air-borne infectious agents or microorganisms and some infections which is spread by direct contact ,we can control it by isolating the patients. Isolation is so useful but it is impractical in patients .In severe immunodeficient patients ,it could be useful to protect them from infectious agents which is responsible for infection.
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