Infectious disease is human illnesses caused by microorganisms (microscopic life forms) or their poisonous by products.Disease- causing microorganisms reproduce in humans and have evolved to live in all human environments.
Several types of microorganisms can cause infectious disease:
1) Viruses
2) Bacteria and bacteria like organisms
3) Protozoa
4) Parasites
5) Fungi
6) Microscopic worms
7) Rickettsia
These microorganisms produces a vast array of illness -form the short lived, minor nuisance of the common cold or stomach "flu" to fetal episodes of Malaria, Cholera, Tuberculosis, and Ebola infection
Some disease causing microorganisms live only in humans. As they reproduce, they can spread from person to person directly through sneezing, coughing, touching, or sexual activity, in some cases an infected pregnant woman can infect her developing fetus in the womb. Microorganisms can also spread indirectly when an infected person contaminates an environmental surface or products (such as food) and the other people touch the surface or products. Some microorganisms can be spread when infected blood, or sometimes other infected body fluids, are exchanged with another person.
Many disease-causing microorganisms also live with animals or other parts of the environment. These microscopic disease agents can be spread to humans through contaminated food, beverages, surface, or object. Some can be breathed in from the air, or transmitted into the blood by an insect bite or the bite of a sick animal.
Emerging infectious disease are those that have appeared in a population within the past two decades or threaten to increase in the near future.
"New" infectious disease can emerge from genetic changes in existing organisms and appear suddenly in new populations. At least 30 new disease agents have been identified over the past two decades, and new agents are being added with disquieting regularity. (E.g. Lyme disease, legionnaire's disease; hepatitis C, AIDS)
Infectious disease viewed as afflictions of a bygone era are also making a comeback. Termed "reemerging infectious disease," these are illness from well-understood microorganisms that were ones under control but are now resistant to common antimicrobial drugs (ex: Malaria; Tuberculosis; Gonorrhea) or have gained new footholds in the populations (ex: Cholera).
Once thought to be on the verge of being eliminated as a public health problem, infections disease remains the leading cause of death worldwide. Of the nearly 52 million deaths in the world each year, infectious disease accounts for more than 17 million or one in three . Infectious disease is also the leading cause of death among children.
Simple principles of food and water safety, community hygiene, safe sex appropriate use of antibiotics, and immunization could prevent millions of death and illness from infectious disease each year. In the developing world, however, most of these practices have yet to be widely implemented, due to lack of resources.
Infectious disease thwarts the economic development of many of the world's poorest countries and strain already overburdened health- care infrastructures.
Many factors or combination of factors is making it easier for infectious disease to become an even bigger problem in the future.
1) The simple genetic makeup of many infectious microbes allows them to change their genetic makeup quickly and often , resulting in "new," more deadly strains against which humans have limited resistance.
2) Civil strife and poverty around the world result in mass migrations and the influx of refugees who carry infectious diseases into new areas.
3) Global air travel is increasing, and well people are travelling to areas where they get infected and bring new disease home with them.
4) Unchecked population growth and movement has led to the development of massive urban slums lacking in clean water and basic sanitation.
5) Population growth and shits have disturbed natural habitats and increased human contact with remote environments and poorly understood ecosystems that hide many previously unknown, dangerous microorganisms
6) Irrigation projects, deforestation, and other changes in land use upset the local ecology and create new habitats for parasite-carrying insects and animal hosts.
7) The globalization of world commerce means that potentially disease-carrying insects and contaminated foods,plants, and other products, cross country borders every day.
8) Because of years of misuse and overuse, once-dependable antibiotics such as penicillin and tetracycline are losing their ability to combat common infections. Disease agents have been "forced" to change their genetic makeup to adapt to antibiotics, and many disease-causing microorganisms have succeeded in becoming resistant to our most powerful modern drugs.
9) Changes in human behavior, such as new eating habits, risky sexual activity, and increased substance abuse, have expedited the spread of infectious agents. child-care centers play a role in substance abuse, have expedited the spread of infectious agents. child-care centers play a role in spreading contagious respiratory illnesses, middle ear infections, and intestinal ailments in susceptible children and their families.
Several types of microorganisms can cause infectious disease:
1) Viruses
2) Bacteria and bacteria like organisms
3) Protozoa
4) Parasites
5) Fungi
6) Microscopic worms
7) Rickettsia
These microorganisms produces a vast array of illness -form the short lived, minor nuisance of the common cold or stomach "flu" to fetal episodes of Malaria, Cholera, Tuberculosis, and Ebola infection
Some disease causing microorganisms live only in humans. As they reproduce, they can spread from person to person directly through sneezing, coughing, touching, or sexual activity, in some cases an infected pregnant woman can infect her developing fetus in the womb. Microorganisms can also spread indirectly when an infected person contaminates an environmental surface or products (such as food) and the other people touch the surface or products. Some microorganisms can be spread when infected blood, or sometimes other infected body fluids, are exchanged with another person.
Many disease-causing microorganisms also live with animals or other parts of the environment. These microscopic disease agents can be spread to humans through contaminated food, beverages, surface, or object. Some can be breathed in from the air, or transmitted into the blood by an insect bite or the bite of a sick animal.
Emerging infectious disease are those that have appeared in a population within the past two decades or threaten to increase in the near future.
"New" infectious disease can emerge from genetic changes in existing organisms and appear suddenly in new populations. At least 30 new disease agents have been identified over the past two decades, and new agents are being added with disquieting regularity. (E.g. Lyme disease, legionnaire's disease; hepatitis C, AIDS)
Infectious disease viewed as afflictions of a bygone era are also making a comeback. Termed "reemerging infectious disease," these are illness from well-understood microorganisms that were ones under control but are now resistant to common antimicrobial drugs (ex: Malaria; Tuberculosis; Gonorrhea) or have gained new footholds in the populations (ex: Cholera).
Once thought to be on the verge of being eliminated as a public health problem, infections disease remains the leading cause of death worldwide. Of the nearly 52 million deaths in the world each year, infectious disease accounts for more than 17 million or one in three . Infectious disease is also the leading cause of death among children.
Simple principles of food and water safety, community hygiene, safe sex appropriate use of antibiotics, and immunization could prevent millions of death and illness from infectious disease each year. In the developing world, however, most of these practices have yet to be widely implemented, due to lack of resources.
Infectious disease thwarts the economic development of many of the world's poorest countries and strain already overburdened health- care infrastructures.
Many factors or combination of factors is making it easier for infectious disease to become an even bigger problem in the future.
1) The simple genetic makeup of many infectious microbes allows them to change their genetic makeup quickly and often , resulting in "new," more deadly strains against which humans have limited resistance.
2) Civil strife and poverty around the world result in mass migrations and the influx of refugees who carry infectious diseases into new areas.
3) Global air travel is increasing, and well people are travelling to areas where they get infected and bring new disease home with them.
4) Unchecked population growth and movement has led to the development of massive urban slums lacking in clean water and basic sanitation.
5) Population growth and shits have disturbed natural habitats and increased human contact with remote environments and poorly understood ecosystems that hide many previously unknown, dangerous microorganisms
6) Irrigation projects, deforestation, and other changes in land use upset the local ecology and create new habitats for parasite-carrying insects and animal hosts.
7) The globalization of world commerce means that potentially disease-carrying insects and contaminated foods,plants, and other products, cross country borders every day.
8) Because of years of misuse and overuse, once-dependable antibiotics such as penicillin and tetracycline are losing their ability to combat common infections. Disease agents have been "forced" to change their genetic makeup to adapt to antibiotics, and many disease-causing microorganisms have succeeded in becoming resistant to our most powerful modern drugs.
9) Changes in human behavior, such as new eating habits, risky sexual activity, and increased substance abuse, have expedited the spread of infectious agents. child-care centers play a role in substance abuse, have expedited the spread of infectious agents. child-care centers play a role in spreading contagious respiratory illnesses, middle ear infections, and intestinal ailments in susceptible children and their families.
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