malaria – as an imported disease
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MALARIA – AS AN IMPORTED DISEASE. Javed Sethi. Which type of malarial plasmodium is the most common? What is the incubation period ? Is the antimalarial prophylaxis on NHS prescriptions? Which antimalarial is safe in pregnancy?. Travelling. - PowerPoint PPT PresentationTRANSCRIPT
MALARIA – AS AN IMPORTED DISEASE
Javed Sethi
Which type of malarial plasmodium is the most common?
What is the incubation period?
Is the antimalarial prophylaxis on NHS prescriptions?
Which antimalarial is safe in pregnancy?
Travelling70 million trips in 2007 compared to 30
million in 1987
6% fall in visits abroad, but yet large numbers travel
1 in 10 seek medical advice
EpidemiologyAt risk areas include Africa, South America,
Indian Subcontinent, Far East1600 cases per year of malaria notified
between 2003 to 2008 in travellers returning to UK
Visiting family or friends > holiday makers83% have not taken prophylaxis
MalariaMost common imported tropical disease85 deaths from 2000 to 2008Our role as GPs – in care of the acutely illand in promoting health and preventing
disease
MalariaPlasmodium, by a mosquito bite- AnophelesMultiplies in liver and then attacks the RBCsFever, nausea, shivering, headache and may
result in multi-organ failure or even deathDormant in liver for months
Causes
Risk assessmentOur responsibility under GMSPreventative measures – identify risks and
those at riskAssessment with a questionnaire and face to
face appointmentTravel to visit family accounts 18%Destination, length of stay, accomodation,
healthcare, budget and insuranceAge, comorbidities, cultural beliefs
Post assessment adviceGeneral and specific adviceExplain disease transmissionChemoprophylaxisPrevention adviceEnsure understandingSign post travellers to www.travax.nhs.uk,
www.fitfortravel.nhs.uk
Clinical featuresIntermittent fever with rigors and sweatingHeadache, malaise, myalgia and anorexiaFlu like symptomsChildren can present with vague symptomsIncubation period is 6 daysMay manifest in 6 months or suspect for upto
12 months in travellers from high risk areasComplications occur with parasitaemia (> 2%
blood cells parasitized)
ComplicationsImpaired conciousnessSeizuresRenal impairmentAcidosisHypoglycaemiaPulmonary oedemaDIC, HaemoglobinuriaShock
InvestigationsDiscuss with microbiologistThick and Thin blood filmsRepeat in 12 to 24 hours3 negative films make diagnosis unlikelyMalarial parasitic antigenFBCNotifiable diseaseMalaria reference laboratoryRelatives/travelling group should be informed
that they may be at risk
TreatmentFalciparum malariaUncomplicated:Quinine and doxycycline for 5 to 7 daysAtovaqoune-proguanil for 3 daysComplicated:IV quinineMefloquine (side effects)Chloroquine (resistance)
TreatmentNon falciparum malariaChloroquine for 3 days thenPrimaquine for 14 days to treat hypnozoite
stage
PreventionRisk of exposure versus side effects of
chemoprophylaxis.Awareness of riskPrevention of BitesChemoprophylaxisDiagnosis and treatment
Prevention of BitesBite from dusk to dawn, peak at 02:00 amRepellants - Diethyltoluamide 50%Advisory Committee on Malaria Prevention
recommend it in pregnancy, breast feeding, children
Insecticides Mosquito netsClothing, Electric heated devices
Drug Advantages
Disadvantage
Dose Side effects
Proguanil Well tolerated
Resistance 200 mg 1 wk before and 4 wks after
GI upset
Chloroquine Pregnancy and breast feeding
Exacerbate Myasthenia,Psoriasis
300mg wkly and 4 wks later
GI upset and headache
Mefloquine 2nd and third trimester, weekly dose
CI in depression and epilepsy
250mg weekly begin 3 wks before til 4 wks
Neuropsychiatric problems
Doxycycline Cheap, started close to departure
Photosensitivity, CI in <12
100mg OD 2 days before and 4 wks later
Oesophagitis, photosensitivity
Atovaquone/proguanil
Short course
Expensive 250/100mg, 2 days before til 7 days after
GI upset and headache
ChemoprophylaxisPrimaquine:Effective prophylactic against hynozoite
stageNot recommended by ACMPHaemolysis in patients with G6PD deficiency
ProphylaxisCausal prophylaxis is against liver stage as it
takes 7 days to developTo be taken for 7 days afterSuppressive prophylaxis is against the red
cell stage and is taken 4 weeks after Give travellers written informationNot on NHSTo buy over the counter or private
prescription
Precautions in special conditions with antimalarialsPregnancy, BreastfeedingEpilepsyAnticoagulantsG6PD deficiencyImmunosuppressionSickle cell diseaseLiver disease, Renal impairmentPorphyria
MYTH: I used to live in Africa so I am immune to Malaria
FACT: Nobody is 100% immune and partial immunity fades