Javed Sethi. Which type of malarial plasmodium is the most common? What is the incubation period? Is the antimalarial prophylaxis on NHS prescriptions?

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