Medical Microbiology

Drugresistance.Theresistanceofmalariaplasmodiatocertainantimalarial

drugsisagrowingproblem.ResistanceisclassifiedfromRI(lowgrade)toRIII

(highgrade)andappliesparticularlytomalariatropica.Table9. 7 andFig.9. 19

provideinformationonregionsinwhichresistantP.falciparumstrainshavede-

veloped.Selectionofdrugsandtheirdosageintherapyandpreventionmusttake

thisproblemintoaccount.In-vitromethodsareavailableforresistancetesting.

Prevention.Travelerstomalariousareasshouldbeinformedwellaheadof

timeconcerningtheriskofinfectionattheirdestinationandthenecessary

prophylacticmeasures.Thisinformationisavailablefromspecialistsand

institutionsinthefieldoftropicalmedicine,healthoffices,etc.,aswellas

ontheinternet(WHO:www.who.int;Austria:www.reisemed.at;Germany:

http://www.dtg.mwn.de;Switzerland:www.safetravel.ch).Itisimportanttore-

memberthatupdatedinformationisrequiredbecauserecommended

malariapreventionmeasuresvaryfromcountrytocountryandaresub-

jecttosuddenchanges.

Prophylacticmeasuresarenecessaryfortravelerstomalariousareasin

Africa,CentralandSouthAmerica,andAsia.Sub-SaharanAfricainpartic-

ularmustbeconsideredahigh-riskarea.Withinamalariousarea,theriskof

infectionmayvarywidelydependingontheseason,locality,andlengthof

stay.Prophylacticmeasuresmusttakethisvariationintoconsideration.

Thefollowingmethodscanbeusedtopreventamalariainfection:

— mosquitobiteprevention,

— chemoprophylaxis,

— emergencystand-bytherapy.

534 9 Protozoa

MalariaProphylaxisbyAreas

A

C C

A

B C

B

A

C

A

Fig.9. 19 SeeTable9. 7 forexplanation(accordingto:InternationalTraveland

Health.Geneva:WorldHealthOrganization;2000).

9

Kayser, Medical Microbiology © 2005 Thieme