Infectious Disease

Contagious disease

Acontagious diseaseis a subset category of transmissible HYPERLINK "https://en.wikipedia.org/wiki/Diseases" \o "Diseases" diseases(can transmit from person to another), usually HYPERLINK "https://en.wikipedia.org/wiki/Infection" \o "Infection" infectionsor some non-infection diseases, which are transmitted to other persons, either by physical contact (hence the name-origin) with the person suffering the disease, or by casual contact with their secretions or objects touched by them or airborne route among other routes. HYPERLINK "https://en.wikipedia.org/wiki/Contagious_disease" \l "cite_note-1" [1]
Thenon-contagiouscategory of infections usually require a special mode of transmission between persons or HYPERLINK "https://en.wikipedia.org/wiki/Host_(biology)" \o "Host (biology)" hosts. These include need for intermediate vector species ( HYPERLINK "https://en.wikipedia.org/wiki/Mosquito" \o "Mosquito" mosquitoesthat cause HYPERLINK "https://en.wikipedia.org/wiki/Malaria" \o "Malaria" malaria) or by non-casual transfer of bodily fluid (such as HYPERLINK "https://en.wikipedia.org/wiki/Blood_transfusion" \o "Blood transfusion" transfusions, HYPERLINK "https://en.wikipedia.org/wiki/Needle_sharing" \o "Needle sharing" needle sharingor HYPERLINK "https://en.wikipedia.org/wiki/Sexual_intercourse" \o "Sexual intercourse" sexual contact). They can also be inherited from parents or caused by environmental or behavioral factors.
The boundary between contagious and non-contagious infectious diseases is not perfectly drawn, as illustrated classically by HYPERLINK "https://en.wikipedia.org/wiki/Tuberculosis" \o "Tuberculosis" tuberculosis, which is clearly transmissible from person to person, but was not classically considered a contagious disease. In the present day, most sexually transmitted diseases are considered contagious, but only some of them are subject to medical isolation.

Disease

Adiseaseis a particular abnormal condition, a disorder of a structure or function, that affects part or all of an HYPERLINK "https://en.wikipedia.org/wiki/Organism" \o "Organism" organism. The causal study of disease is called HYPERLINK "https://en.wikipedia.org/wiki/Pathology" \o "Pathology" pathology. Disease is often construed as amedical conditionassociated with specific HYPERLINK "https://en.wikipedia.org/wiki/Symptom" \o "Symptom" symptomsand HYPERLINK "https://en.wikipedia.org/wiki/Medical_sign" \o "Medical sign" signs. HYPERLINK "https://en.wikipedia.org/wiki/Disease" \l "cite_note-1" [1]It may be caused by factors originally from an external source, such as HYPERLINK "https://en.wikipedia.org/wiki/Infectious_disease" \o "Infectious disease" infectious disease, or it may be caused by internal dysfunctions, such as HYPERLINK "https://en.wikipedia.org/wiki/Autoimmune_disease" \o "Autoimmune disease" autoimmune diseases., "disease" is often used more broadly to refer to any condition that causes HYPERLINK "https://en.wikipedia.org/wiki/Pain" \o "Pain" pain, HYPERLINK "https://en.wikipedia.org/wiki/Abnormality_(behavior)" \o "Abnormality (behavior)" dysfunction, HYPERLINK "https://en.wikipedia.org/wiki/Distress_(medicine)" \o "Distress (medicine)" distress, HYPERLINK "https://en.wikipedia.org/wiki/Social_problems" \o "Social problems" social problems, or HYPERLINK "https://en.wikipedia.org/wiki/Death" \o "Death" deathto the person afflicted, or similar problems for those in contact with the person, it sometimes includes HYPERLINK "https://en.wikipedia.org/wiki/Injury" \o "Injury" injuries, HYPERLINK "https://en.wikipedia.org/wiki/Disability" \o "Disability" disabilities, HYPERLINK "https://en.wikipedia.org/wiki/Disorder_(medicine)" \o "Disorder (medicine)" disorders, HYPERLINK "https://en.wikipedia.org/wiki/Syndrome" \o "Syndrome" syndromes, HYPERLINK "https://en.wikipedia.org/wiki/Infection" \o "Infection" infections, isolated HYPERLINK "https://en.wikipedia.org/wiki/Symptom" \o "Symptom" symptoms,.
Death due to disease is called HYPERLINK "https://en.wikipedia.org/wiki/Death_by_natural_causes" \o "Death by natural causes" death by natural causes. There are four main types of disease: pathogenic disease, deficiency disease, hereditary disease, and physiological disease
The termdiseasebroadly refers to any condition that impairs the normal functioning of the body. For this reason, diseases are associated with dysfunctioning of the body's normal homeostatic process. HYPERLINK "https://en.wikipedia.org/wiki/Disease" \l "cite_note-4" [4]Commonly, the termdiseaseis used to refer specifically to HYPERLINK "https://en.wikipedia.org/wiki/Infectious_disease" \o "Infectious disease" infectious diseases, which are clinically evident diseases that result from the presence of HYPERLINK "https://en.wikipedia.org/wiki/Pathogenic" \o "Pathogenic" pathogenicmicrobial agents, including viruses, HYPERLINK "https://en.wikipedia.org/wiki/Bacteria" \o "Bacteria" bacteria, fungi, protozoa, multicellular organisms, and aberrant proteins known as HYPERLINK "https://en.wikipedia.org/wiki/Prion" \o "Prion" prions. An HYPERLINK "https://en.wikipedia.org/wiki/Infection" \o "Infection" infectionthat does not and will not produce clinically evident impairment of normal functioning, such as the presence of the normal HYPERLINK "https://en.wikipedia.org/wiki/Gut_flora" \o "Gut flora" bacteria and yeasts in the gut, or of a HYPERLINK "https://en.wikipedia.org/wiki/Passenger_virus" \o "Passenger virus" passenger virus, is not considered a disease. By contrast, an infection that is asymptomatic during its HYPERLINK "https://en.wikipedia.org/wiki/Incubation_period" \o "Incubation period" incubation period, but expected to produce symptoms later, is usually considered a disease. HYPERLINK "https://en.wikipedia.org/wiki/Non-infectious_disease" \o "Non-infectious disease" Non-infectious diseasesare all other diseases, including most forms of HYPERLINK "https://en.wikipedia.org/wiki/Cancer" \o "Cancer" cancer, HYPERLINK "https://en.wikipedia.org/wiki/Heart_disease" \o "Heart disease" heart disease, and HYPERLINK "https://en.wikipedia.org/wiki/Genetic_disease" \o "Genetic disease" genetic disease.

What is Infectious Disease?

An infectious disease or communicable disease is caused by a biological agent such as by a virus, bacterium or parasite.Infectious diseases are the invasion of a host organism by a foreign replicator, generally microorganisms, often calledmicrobes, that are invisible to the naked eye.Microbes that cause illness are also known as pathogens. The most common pathogens are variousbacteriaandviruses, though a number of other microorganisms, including some kinds offungiandprotozoa, also cause disease.An infectious disease is termedcontagiousif it is easily transmitted from one person to another.
How are infectious diseases diagnosed?Diagnosis is initially by medical history and physical examination, and imaging (such as X-rays), but the principal tool in infectious disease is the microbiological culture.
A microbiological culture, or microbial culture, is a method of growing a microbial organism to determine what it is often used a tool to determine the cause of infectious disease by letting the agent multiply (reproduce) in predetermined media in laboratory. In a culture, a growth medium is provided for a particular agent. After inoculation of a specimen of diseased fluid or tissue onto the medium, it is determined whether bacterial growth occurs.
What's the difference between infectious and contagious
Infectiousdiseases are caused by microscopic germs (such as bacteria or viruses) that get into the body and cause problems. Some but not all infectious diseases spread directly from one person to another. Infectious diseases that spread from person to person are said to becontagious.
Some infections spread to people from an animal or insect, but are not contagious from another human. Lyme disease is an example: You can't catch it from someone you're hanging out with or pass in the street. It comes from the bite of an infected tick.
Contagious diseases (such as the flu, colds, or strep throat) spread from animal to animall in several ways. One way is through direct physical contact, like touching who has the infection. Another way is when an infectious microbe travels through the air after someone nearby sneezes or coughs.
Infection
invasionandmultiplicationofmicroorganismsinbodytissues,asinaninfectiousdisease.Theinfectiousprocessissimilartoacircularchainwitheachlinkrepresentingoneofthefactorsinvolvedintheprocess.Aninfectiousdiseaseoccursonlyifeachlinkispresentandinpropersequence.Theselinksare(1)thecausativeagent,whichmustbeofsufficientnumberandvirulencetodestroynormaltissue;(2)reservoirsinwhichtheorganismcanthriveandreproduce;forexample,bodytissuesandthewastesofhumans,animals,andinsects,andcontaminatedfoodandwater;(3)aportalthroughwhichthepathogencanleavethehost,suchastherespiratorytractorintestinaltract;(4)amodeoftransfer,suchast


hehands,aircurrents,vectors,fomites,orothermeansbywhichthepathogenscanbemovedfromoneplaceorpersontoanother;and(5)aportalofentrythroughwhichthepathogenscanenterthebodyof(6)asusceptiblehost.Openwoundsandtherespiratory,intestinal,andreproductivetractsareexamplesofportalsofentry.Thehostmustbesusceptibletothedisease,nothavinganyimmunitytoit,orlackingadequateresistancetoovercometheinvasionbythepathogens.Thebodyrespondstotheinvasionofcausativeorganismsbytheformationof HYPERLINK "http://medical-dictionary.thefreedictionary.com/Antibody" antibodiesandbyaseriesofphysiologicchangesknownas HYPERLINK "http://medical-dictionary.thefreedictionary.com/Inflammation" inflammation.
acute infection
Aninfectionthatappearssuddenlyandmaybeofbrieforprolongedduration.
airborne infection
Aninfectioncausedbyinhalationofpathogenicorganismsindropletnuclei.
apical infection
Aninfectionlocatedatthetipoftherootofatooth.
bacterial infection
Anydiseasecausedbybacteria.Bacteriaexistinavarietyofrelationshipswiththehumanbody.Theycolonizebodysurfacesandprovidebenefits,e.g.,bylimitingthegrowthofpathogensandbyproducingvitaminsforabsorption(inasymbioticrelationship).Bacteriacancoexistwiththehumanbodywithoutproducingharmfulorbeneficialeffects(inacommensalrelationship).Bacteriamayalsoinvadetissues,damagecells,triggersystemicinflammatoryresponses,andreleasetoxins(inapathogenicorinfectiousrelationship).
See: HYPERLINK "http://medical-dictionary.thefreedictionary.com/bacterium" bacteriumfortable

blood-borne infection

Aninfectiontransmittedthroughcontactwiththeblood(cells,serum,orplasma)ofaninfectedindividual.Thecontactmayoccursexually,throughinjection,orviaamedicalordentalprocedureinwhichablood-contaminatedinstrumentisinadvertentlyusedafterinadequatesterilization.Examplesofblood-borneinfectionsincludehepatitisBandCandAIDS.
 HYPERLINK "http://medical-dictionary.thefreedictionary.com/injury" needle-stick injury;
breakthrough infection
Aninfectionthatoccursdespitepreviousvaccination.
chronic infection
Aninfectionhavingaprotractedcourse.

morbidity rate

thespeedorfrequencywithwhichaneventorcircumstanceoccursperunitoftime,population,orotherstandardofcomparison.
.,theproportionofpersonswhoareexposedtothediseaseduringtheoutbreakwhodobecomeill.
Theproportionofpatientswithaparticulardiseaseduringagivenyearpergivenunitofpopulation.
thenumberofcasesofaparticulardiseaseoccurringinasingleyearperaspecifiedpopulationunit,asxcasesper1000.

Mortality rate

Mortality rate, ordeath rate, HYPERLINK "https://en.wikipedia.org/wiki/Mortality_rate" \l "cite_note-Porta-2014-death-rate-1" [1]is a HYPERLINK "https://en.wikipedia.org/wiki/Measurement" \o "Measurement" measureof the number of HYPERLINK "https://en.wikipedia.org/wiki/Death" \o "Death" deaths(in general, or due to a specific cause) in a particular HYPERLINK "https://en.wikipedia.org/wiki/Statistical_population" \o "Statistical population" population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of deaths per 1,000

Prevalence

Prevalencein HYPERLINK "https://en.wikipedia.org/wiki/Epidemiology" \o "Epidemiology" epidemiologyis the proportion of a population found to have a condition (typically a disease or a risk factor). It is arrived at by comparing the number of animals found to have the condition with the total number of animals studied, and is usually expressed as a fraction, as a percentage or as the number of cases per 10,000 or 100,000 people.Point prevalenceis the proportion of a population that has the condition at a specific point in time.Period prevalenceis the proportion of a population that has the condition at some time during a given, and includes people who already have the condition at the start of the study period as well as those who acquire it during that period.Lifetime prevalence(LTP) is the proportion of a population that at some point in their life (up to the time of assessment) have experienced the condition. HYPERLINK "https://en.wikipedia.org/wiki/Prevalence" \l "cite_note-Rothman2012-1" [1]
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