Introduction to medical Microbiology.

Public Health and Medical Microbiology.

Public health is the protection and improvement of the health of entire populations through a communitywide action;primarily by government agencies.Public health clinics routinely scree patients for a number of infectious diseases.one branch of public health,epidemiology,studies the incidence of disease in the large population.

Epidemiologist and other public health officials attempt to break the chain of disease transmission by notifying people who may be the risk for contracyion an infectious disease.When epidemiologist learth that a resturant worker has infectious diesease,they place announcement in local media,such as radio and newspapers,urging people who ate at that resturant in recent weeks to be checked for the disease and to seek treatment so that they will no longer risk infecting others.vaccination reduces the incidence of several epidemics but vaccination is not available for all diseases.

Goals of public Health are;

• prevent human disease,injury, and disability.
• orotect people from envirnomental health hazards.
• promote behaviours that lead to good physical and mental health.
• assure availabilty of high-quality health services and
• Educate the oublic about health.

Terms related to public health.

Epidemic.

A disease is said to be epidemic when it occurs in an unusually high number of individuals in a population involving an extensive geographical area.

Among the disease that has occured in epidemic proportions throughout the history and bubonic plague,influenxa,smallpox,typhoid fever,tuberculosis, and cholera.Occasionly,choldhood disease such as mumps and German measlesbecome epidemic.

Epidemics can often be prevented or controlled by immunization,improved sanitation,and by other public health measures such as the use of pesticides to wipe out disease-carrying insects.

Endemic.

An endemic disease is one that is constantly present within a given geographic area or population group without importation from outside.An endemic disease can burst into an epidemic when conditions are favourable for example hepatitis A and typhoid fever.

Pandemic.

Pandemic is an epidemic affecting a large proportion of population occurring over a wide geographic area such as an entire nation or a whole continent of the world.

The 1918-1919 Influenza pandemic was the most destructive in recorded history.It caused 20million deaths,Twenty-four year after the first cases of a new deadly disease were diagnosed in the US,the AIDS pandemic had become one of the most devasting examples in human history.Worldwide,more than 40million people are infected with HIV.

Sporadic.

The term sporadic means "scattered about" i.e disease occurring occasionally at intervals that have no apparent position,The cases occur irregularly,haphazardly from time to time,and generally frequently.

Faecal-oral transmission.

Microorganism enters thebody through ingestion of contaminated food and water.Inside the digestive system, these microorganisms multiply and are shed from the body in faeces.If proper hygenic and sanitation practises are not in place,the microorganisms in the faeces may contaminate the water supply through inadequate sewage treatment and water filtration.Fishes that swim in contaminated water can be used ad food surces.If the infected individual is waiter,cook or food handler then inadequate hand washing may result in food being contaminated with microorganisms.

Vector-borne Transmission.

Vectors are animals that are capable of transmitting diseases.examples of vectors are flies, mites, ticks,rats and dogs.The most common vactor for dusease is the mosquito.It transfers the disease through the saliva which comes in the contact with their hosts when they are withdrawing blood.Mosquitoes are vectors for malaria,dengue fever, and yellow fever.Biting is not only the way vectors can transmit diseases.Diseases may be spread through the faeces of a vector.

Hospital Acquired Infection.

hospital acquired infection can be also known as nosocomial infection,Nosocomial infection is defined as an infection developed in patients or other due to their stay at the hospital which was neither present nor in incubation at that time at their entry of hospital.The prevalence of hospital-acquired infection has been reported by WHO(1992) as 3-21% with a mean of 8.4%

Antibodies.

Antibodies are also called immunoglobin.They are protective protein produced by the immune system in response to the presence of the foreign substance,called an antigen.Antibodies recognize and bind antigens in order to remove them from the body.A wide range of substances is regarded by the body as antigens,including disease-causing organisms and toxic materials such as insects.

The binding of an antibody to a toxin can neutralize the poision simply by changing its chemical composition;such antibodies are called Antitoxin.Once begun,antibody production continues foresveral days untill all antigenmolecule are removed.Antibodies remain in circulation for several months,providing extended immunity against that particular antigens.

Antigens.

Antigens are foreign substances which when introduced into the body react with the components of immune response responsible for antobodies and T cell receptor protein.Antigens include molecules found on invading microorganisms,such as viruses,bacteria,protozoans and fungi as well as molecules located on the surface of foreign substances,such as pollen,dust or transplanted tissue.

Reference.

C.H.Collins. (1995). Microbiological Methods. Oxford Univ Press.

D.Greemwood, R. S. (2002). Medical Microbiology. London: Churchill Livingstone.

M.J.Pelezar. (1993). Microbiology. Tata McGraw hill.

M.T.Madigan, J. a. (1997). Biology of microorganisms. London: Prentice hall International Inc.

R.N.Atlas. (1984). Fundamentals and Applications. NewYork: MacMiHiam Publishing Co.