Microbiology: Chapter 14

Signs

A change due to a disease that a person can observe and measure. Objective changes, ec: tumors, lesions, etc.

Symptom

A change in body function that is felt by a patient as a result of a disease.Changes in body functions, ex: Pain, malaise (a vague feeling of body function).

Bacteremia

A condition in which there are bacteria in the blood.

Epidemic disease

A disease acquired by many hosts in a given area in a short time. Greatly increased incidence of the disease within a defined area.

Latent disease

A disease characterized by a period of no symptoms when the pathogen is inactive. Remains inactive for a period of time (Shingles)

Acute disease

A disease in which symptoms develop rapidly but last for only a short time. Associated with high fever, elevated WBC, very sick, quick recovery.

Endemic disease

A disease that is constantly present in a certain population. Common Cold

Contagious Disease

A disease that is easily spread from one person to another (host to host).

Noncommunicable disease

A disease that is not transmitted from one person to another but microbe introduced into body will cause disease, ex: tetanus (Clostridium Tetani).

Sporadic disease

A disease that occurs occasionally in a population. Typhoid fever (Salmonella Typhi)

Subacute disease

A disease with symptoms that are intermediate between acute and chronic.(Subacute Bacterial Endocarditis)

Opportunistic pathogen

A microorganism that does not ordinarily cause a disease but can become pathogenic under certain circumstances. ex. E. Coli harmless while in the gut, by potentially fatal if invades another part of body.

Syndrome

A specific group of signs or symptoms that accompany a disease.

Parasitism

A symbiotic relationship in which one organism (the parasite) exploits another (the host) without providing any benefit in return. One benefits, other is raped (harmed, damaged or killed). Many disease-causing bacteria are parasites.

Commensalism

A symbiotic relationship in which two organisms live in association and one is benefited while the other is neither benefited nor harmed.

Focal infection

A systemic infection that began as an infection in one place. Can arise from infections in areas such as teeth, tonsils, or sinuses.

Mutualism

A type of symbiosis in which both organisms or populations are benefited. eg. E. coli synthesizes Vitamin K and B complex. Host used the vitamins, host provided a stable environment for bacteria to live.

Disease

An abnormal state in which part or all of the body is not properly adjusted or is incapable of performing normal functions; any change from a state of health. occurs when

Primary infection

An acute infection that causes the initial illness.

Pandemic disease

An epidemic that occurs worldwide.

Secondary Infection

An infection caused by an opportunistic microbe after a primary infection has weakened the host's defenses.

Local Infection

An infection in which pathogens are limited to a small area of the body.

Subclinical infection

An infection that does not cause a noticeable illness; also called inapparent infection.

Systemic (generalized) infection

An infection throughout the body. microorganisms or their products are spread throughout the body by the blood or lymph.

Communicable Disease

Any disease that can be spread from one host to another. (directly or in directly)

Predisposing Factors

Conditions which affect disease occurrence: Gender Genetic makeup Climate and Weather Lack of proper nutrition Age Amount of rest of lack or Lifestyle Occupation Pre-Existing illness Chemotherapy Emotional State

Microbial Antagonism or Competitive Exclusion

Growth of some microbes prevents the growth of other microbes (ow:Competition among microbes which prevent the over growth of any one specific microbe.) Normal microbiota protect the host against colonization by potentially pathogenic microbes by competing for nutrients, producing substances harmful to the invading microbes, and affecting conditions such as pH and available oxygen.

Prodromal Period

Short period, early symptoms, characterized by aches and pains.

Chronic disease

Slow onset, low or absent fever, slow recover (TB). Disease is likely to continue or recur for long periods.

Koch's Postulates Exceptions

Some microbes cannot be grown on artificial media, ex: Legionnaire's disease. Some do not produce specific sign and symptoms Some cause several disease, S. pyogenes Ethical considerations - some pathogens will only grow in humans

Prevalence

The fraction of a population having a specific disease at a given time. Number of people within a population

Incidence

The fraction of the population that contracts a disease during a particular period of time.

Infection

The invasion or growth of microorganisms in the body. May exist in the absence of detectable disease

Symbiosis

The living together of two different organisms or populations. Relationship between the normal microbiota and the host. One organism is dependent on the other.

Pathogenesis

The manner in which the disease develops

normal microbiota

The microorganisms that colonize a host without causing disease; also called normal flora.

Herd Immunity

The presence of immunity in most of a population. When enough individuals within a population are immune to a specific disease, the transmission will be slowed or stopped from spreading to the non-immune portion of the population.

Toxemia

The presence of toxins in the blood.

Viremia

The presence of viruses in the blood.

Septicemia

The proliferation of bacteria in the blood, accompanied by fever; sometimes causes organ damage. Also called blood poisoning, is a systemic infection arising from the multiplication of pathogens in the blood.

Pathology

The scientific study of disease Is concerned with the structural and functional changes brought about by disease and with their final effects on the body.

Etiology

The study of the cause of a disease

Incubation period

The time interval between the actual infection and first appearance of any signs or symptoms of disease. Can be specific or variable time frame. Variables affects incubation time are ;specific microbe, virulence, number of microbes, resistance of host (predisposing factors).