Medical Microbiology

DNAViruses 417

&Animportantaspectoftheintestinalinfectionsisthattheprimarygas-

troenteritisformsarecausedbytheviralstrains 40 and 41 ,whicharedifficult

toculture.

Adenovirusescanpersistformonthsintheregionallymphnodesortonsils

untiltheyarereactivated.

Diagnosis.Antibodyassaysinpatientserumarethemainapproachtakenin

respiratoryadenovirusinfections.Serologyisunreliableintheeyeandintes-

tinalinfections,sincehardlyanyantibodiesareproducedinresponsetosuch

highlylocalizedinfections.Itispossibletoisolatethevirusesthatcausere-

spiratoryinfectionsbyinoculatingcellcultureswithpharyngealmaterialor

bronchialsecretionandwithconjunctivalsmearsineyeinfections.Enteral

adenoviruses,ontheotherhand,arehardtoculture.Thebestapproachto

detectingthemisthereforetosubjectstoolspecimenstoelectronmicro-

scopy,enzymeimmunoassay,orpassiveagglutinationmethods.

Epidemiologyandprevention.Humansarethesourceofinfection.Suscep-

tibilityistherule.Generalizedcontaminationofthepopulationbeginsso

earlyinchildhoodthatadenovirusinfectionsplayamoresignificantrole

inchildrenthaninadults.Transmissionofrespiratoryadenovirusesispri-

marilybydropletinfection,butalsoassmearinfectionssincethevirusis

alsoexcretedinstool.Eyeinfectionscanbecontractedfrombathingwater

or,inthecaseofadenovirustype 8 inparticular,iatrogenicallyfrominsuffi-

Adenoviruses

500 nm

Fig.8. 3 Viralcrystalsinthenucleusof

thehostcell(TEM).

8

Kayser, Medical Microbiology © 2005 Thieme