Medical Microbiology

104 2 BasicPrinciplesofImmunology

Table2. 9 BalancebetweenInfectionandHostImmunity:EffectontheDisease

Infectious agent

Cytopatho- genicity ofagent

Efficiencyofimmuneresponse Early start

Later start

Noimmune response

Extracellularbacteria Meningococci Staphylococci

High Recovery Death Death

Facultativelyintracellularbacteria Listeria High Recovery Death Death Tuberculosisbacilli Moderate Recovery Immuno- pathological inflamma- tion

Miliarytuberculo- sis(earlydeath) Landouzysepsis (veryearlydeath) Leprosybacilli Verylow Recovery Tuberculoid leprosy

Lepromatous leprosy(late death)

Viruses Smallpoxvirus High Recovery Death Death(early) LCMV(lymphocytic choriomeningitis)

Verylow Recovery Immuno- pathological disease

Healthycarrier

HepatitisBvirus Verylow Recovery Aggressive hepatitis

Carrier(verylate livercarcinoma) HIV Low(?) Recovery AIDS Healthycarrier (occultinfection) (?)

Unrecognizedand unknowninfections, viruses,bacteria, andendogenous retroviruses

Low? Auto- immunity

“Healthy”or occultcarrier (althoughinfec- tiousagentis unknown)

Clinical symptoms

None Chronic disease

Variabledisease symptoms,some- timesdelayedor asymptomatic

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