Medical Microbiology

Corynebacterium,Actinomyces,OtherGram-PositiveRodBacteria 257

Epidemiologyandprevention.Humansarethesolepathogenreservoirfor

diphtheria.Infectionsourcesincludeinfectedpersonsandcarriers(rare).

Thediseaseisusuallytransmittedbydropletinfection,orlessfrequentlyin-

directlyviacontaminatedobjects.Theincubationperiodistwotofivedays.

IncidencelevelsincentralEuropearelow.From 1975 to 198 4,only 113 cases

werereportedinGermany.Incidencelevelsarehigherinothercountries

(Russia).Protectiveimmunizationwithdiphtheriatoxoidisthemostimpor-

tantpreventivemeasure(seeTable 1. 13 ,p.33).Exposureprophylaxisinvolves

isolationofinfectedpersonsuntiltwoculturesfromspecimenstakenatleast

24 hoursapartarenegative.

NoseandThroat(Nasopharyngeal)Diphtheria

Fig.4. 10 aHemorrhaging

of the nasal mucosa

(endothelialdamage).Pro-

nounced cervical adeno-

pathyandswelling,creating

abullneckappearance.

b Thick coating (mem-

brane) onhighly swollen

tonsils(so-calleddiphtherial

pseudomembrane), caus-

ingrespiratorystridor.

4

Kayser, Medical Microbiology © 2005 Thieme