Medical Microbiology

RNAviruses 455

CombinationTreatmentsofHIVInfections:

ToavoiddevelopmentofresistantHIVvariants,acombinationofatleastthree

drugsfromatleasttwosubstanceclassesisusuallyadministered.Thefollowing

combinationsarecurrentlyestablishedpractice:

a)OnePIandtwoNRTIs

b)OneNNRTIandtwoNRTIs

c)TwoPIsandoneortwoNRTIs

d)OnePIandoneNNRTI,alternativelywithoneortwoNRTIsaswell;

e)ThreeNRTIs

a)andb)appeartoproducethebestlong-termresults.

Standardvaccinescanbeusedtopreventotherinfections,forexample

opportunisticinfectionsinHIV-positivepersons,especiallychildrenshowing

nosymptoms.Thedeadvaccinetypeisrecommendedforpolio.Livevaccine

materialsshouldgenerallynotbeusedinpersonsshowingAIDSsymptoms.

PrecautionsforHealthcareStaff

AllpersonnelinmedicalprofessionsshouldknowthatHIVisnothighlycontagious

andthatprecautions,astheyapplytohepatitisB,areconsideredsufficient:wear

protectiveglovesinallsituationsinvolvingpossiblecontactwithblood.Ifblood

dropletscouldbespatteredorsprayed,masksandgogglesshouldalsobeworn.

Ifexposurehasoccurreddespiteprecautions(accidentalinjection,stabwound,

contaminationofawoundormucosawithmaterialcontainingHIV),immediate

commencementofacombinationtherapywithonePIandtwoNRTIsfortwoto

fourweeksisindicatedinadditiontoathoroughwoundtoiletanddisinfection.

ViruseswithDouble-StrandedRNAGenomes

Reoviruses

&Reovirusespossessasegmented,double-strandedRNAgenome.Among

thereoviruses,therotavirusesarethemostsignificanthumanpathogens.

Theycausediarrheainsmallchildrenandtheelderlyandcanalsoproduce

severesequelaeinimmunosuppressedpatients.

Diagnosis: reovirus—isolation;rotavirus—antigen detection or electron

microscopy.Isolationofthisviraltypeincellculturesisnotaroutine

method. &

8

Kayser, Medical Microbiology © 2005 Thieme