solutionvova.blogg.se - Transmit definition physiology

#Transmit definition physiology skin#

Rabies is carried by many domestic and wild mammals.ģ.

The reservoir of plague, for example, is usually the rodent population.

Mosquitos are responsible for transmitting many diseases as well.

Pigs and ducks serve as reservoir for the transmission of influenza virus.

There are more than 100 zoonotic diseases.

The disease which are transmitted from animal to man are called zoonotic diseases, e.g.

The animal reservoir may also be case or carrier.

In typhoid fever, urinary carrier is more dangerous than an intestinal carrier.

Therefore, there are urinary carrier, intestinal carriers, nasal carrier etc.

Carriers are also classified according to the portal of exit to the infectious agents.

Some chronic carriers excrete the infectious agents intermittently and some continuously.

The longer the carrier state, the greater is the risk to the community.

Chronic carriers excrete the infectious agents for indefinite period of time.

Incubatory, convalescent and healthy carriers are temporary carriers.

They are those who shed the infectious agents for short period of time.

Thus a person maybe an endogenous reservoir of his/her own infectious disease.

Opportunistic infection also may occur in persons with normal defences following autoinoculation, the transfer of microbes indigenous to one area of the body to another arear where they may cause disease.

For ex- poliomyelitis, salmonellosis and diphtheria.

These are subclinical cases which have developed carrier state without suffering from disease and shed the disease agent.

Convalescent carriers pose threat to the unprotected household member for example Typhoid fever in which patients may excrete the bacilli for 6-8 weeks.

These carriers continue to shed the infectious agents during recovery.

Example: measles, polio, influenza, hepatitis B etc.

They are capable of infecting others before the onset of disease.

They shed the infectious agents during the incubation period of disease.

Classification of carriers: basis of classification.

Shedding of the disease agents in the excretions.

Absence of noticeable signs and symptoms of disease.There must be the presence of disease agent in the body.The Typhoid Mary is an example of a carrier.Epidemiologically, carriers are more infectious because they are not recognized and live as normal in community.A carrier is defined as ‘ an infected person or animal that harbors a specific infectious agent in the absence of the clinical disease and serve as a potential source of infection for others’.The host does not shed the infectious agent in latent infection.

#Transmit definition physiology skin#

Subclinical infection can be detected by lab test, isolation of micro-organisms, antibody assay, biochemical and skin sensitivity tests.They are important source of infection because they do not show any signs and symptoms of disease and shed infectious agent continuously.The subclinical cases are also called inapparent cases.The mild cases are more important source of infection as compared to severe cases.The clinical case may be mild or moderate, typical or atypical, severe or fatal.The cases maybe clinical, sub-clinical or latent.The cases are identified by clinical, biochemical and laboratory tests.A case is defined as ‘ a person in the population or study group detected as having the particular disease, health disorder or condition under investigation.’.Human himself is the important source or reservoir of infections.In tetanus, the reservoir and source are the same, which is the soil.In hookworm infection, the reservoir is a man, but the source of infection is the soil contaminated with infective larvae.Example: in typhoid fever the reservoir of infection is human but the source of infection may be faeces or urine of patients or contaminated food or water.Reservoirs is the natural habitat in which the microorganisms metabolizes and replicates.Reservoirs may be either animate or inanimate.Reservoirs are sites in which viable infectious agents remain alive and from which infection of individuals may occur.A source of infection is defined as the person, animal, objects or substance from which an infectious agent passes or is disseminated to the host.The medical model of infectious disease transmission consists of three interlinked chains. Diseases are transmitted from the source of infection to susceptible host.Dynamics of disease transmission: Reservoir, Mode of transmission and Susceptible host