Malaria in Pregnancy - GT 54a and 54b Flashcards
How many cases/year of malaria are reported in the UK?
1500
What % of cases are due to Plasmodium falciparum?
75%
What is the overall mortality rate from malaria?
0.5-1%
What is rosetting in malaria?
Adherence of non-infected RBCs interfering with microcirculatory flow
What is the hallmark of Falciparum infection in pregnancy?
Sequestration of parasites in the placenta - evade splenic filtering and processing
Does not happen in benign types of malaria
From what do the adverse effects of malaria in pregnancy result?
- Systemic infection, i.e. the same as any severe febrile illness in pregnancy
- Parasitisation itself - FGR/LBW, mat anaemia,interaction with HIV, infant susceptibility to malaria
Which subtype of malaria is not as benign as previously thought?
Plasmodium vivax
At what % parasitised blood cells should women be treated as severe malaria?
> 2% (otherwise - uncomplicated malaria if less and no signs of severity)
What are the clinical manifestations of severe malaria?
- Prostration
- Impaired consciousness/convulsions
- Resp distress/pul oedema**
- Circulatory collapse
- DIC
- Jaundice
- Haemoglobinuria (without G6PD deficiency)
What are the lab tests with severe malaria?
- Hb <8
- Thrombocytopenia
- BM <2.2**
- pH <7.3, raised lactate
- Oliguria or Creat >265
- Hyperparasitaemia >2%
- Gram neg septicaemia**
Should perform LP to exclude meningitis
What is algid malaria?
Associated with gram neg septicaemia
Often involves GI viscera
How is malaria in pregnancy diagnosed?
Microscopy - thick and thin blood films (gold standard)
Rapid diagnostic test - may miss low parasitaemia
What is the fatality rate from severe malaria in pregnant and non-pregnant?
Pregnant - 50%
Non-pregnant- 15-20%
Where should patients be admitted with malaria in pregnancy?
Uncomplicated - to hospital
Severe - to ITU
What is the treatment for severe falciparum malaria in pregnancy?
IV artesunate 2.4mg/kg at 0, 12, 24 then OD
Then when well PO/IM artesunate + clindamycin
IV quinine if not available (but doesn’t kill sequestered parasites)
What is the treatment for uncomplicated falciparum (or combined) malaria in pregnancy?
Quinine 600mg TDS and clindamycin 450mg TDS PO for 7/7
Give IV if vomiting ++
What is the treatment for P vivax, ovale or malariae?
PO chloroquine
Which antimalarial should be avoided in pregnancy and why?
Primaquine
Can induce methaemoglobinaemia and haemolysis in the fetus
Which antimalarial is associated with severe recurrent hypoglyacaemia in late pregnancy?
Quinine
What are the alternative antimalarials for falciparum malaria?
Riamet
Malarone (Atovaquone-proguanil)
What is chinconism and which drug causes it?
Quinine 7/7
Tinnitus, headache, nausea, diarrhoea, altered auditory acuity and blurred vision
When does most recurrence occur with malaria?
Day 28-42 but can see late recurrence unique to pregnancy - 85-121 days
Therefore weekly blood films until delivery
What is the treatment for recurrence of malaria in pregnancy?
Atovaquone-proguanil (Malarone)
Dihydroartemisinin-piperaquine
Particularly if quinine/clinda failed as first line
What is the treatment of severe anaemia in severe malaria in pregnancy?
Slow blood transfusion
Ideally with 20mg frusemide IV
What should be suspected if a patient with severe malaria becomes hypotensive?
Secondary bacterial infection
Which antimalarials should be used to prevent relapse during and after pregnancy?
During - Chloroquine 300mg PO weekly
After- postpone 3/12 and after G6PD testing (provides resistance)
What are the obstetric complications of malaria?
Preterm labour
FGR
Fetal heart rate abnormalities
Thrombocytopenia if acute
When should placental histology be sent in malaria?
Peripartum malaria
Also send cord and baby blood film
What antenatal care should be given following an episode of malaria in pregnancy?
Regular Hb
Platelets
Glucose
Growth scans
When does vertical transmission occur in malaria?
Either during pregnancy or at time of birth
How often should a neonate be screened if malarial parasites are identified in the placenta?
Weekly until 28/7
By how much does IV artesunate reduce mortality compared to quinine?
35%
Not resistance - but kills the sequestered parasites
What is premunition?
The degree of naturally acquired host immunity to malaria - low in UK residents and high susceptibility
Depends on repeated exposure to infectious anopheline bites
What is the risk of contracting malaria without chemoprophylaxis during a 1 month stay in:
1 Oceania
2 Subsaharan Africa
3 Indian subcontinent/southeast Asia?
1 Oceania 1:20
2 Subsaharan Africa 1:50
3 Indian subcontinent/southeast Asia 1:500
In what % of cord bloods was DEET detected following application in pregnancy?
8% no apparent adverse effects
How long should chemoprophylaxis be continued after leaving an endemic area for malaria?
If causal Rx - 7/7 (eg Malarone)
If suppressive Rx - 4/52 (e.g. Mefloquine)
What is the recommended chemoprophylaxis for malaria in pregnancy?
T2/T3 Mefloquine; may be justified in T1
Caution re: neuropsychiatric effects
Atovaquone and proguanil (Malarone®) potentially good but insufficient safety data
Which malarial chemoprophylaxis is contraindicated in pregnancy?
Doxycycline - bone growth, teeth discoloration in T3, congenital cataract
Primaquine - haemolysis especially in G6PD deficiency
