By Dr Frans Cronje (Divers Alert Network Southern Africa) & Dr Albie De Frey (Worldwide Travel Medical Consultants)
DAN receives many inquiries from members regarding malaria. Indeed, malaria has become an increasing problem due to drug resistance. As divers venture deeper into the African tropics they incur increasing risk of contracting malaria. Lack of medical facilities, transportation and communication add additional complexity to managing this medical emergency. Three DAN members have required evacuation by air over the last three years due to malaria. Understanding malaria prophylaxis and general preventative measures is therefore of the utmost importance. The following section covers the most important considerations in selecting and using malaria prophylactic measures and medications. The treatment of malaria, which is complex and requires close medical supervision, falls outside the scope of this document. If you think that you may have malaria or are concerned about unexplained symptoms after visiting a malaria area, contact DAN immediately on 0800 020111 or +27(0)11 254 1112.
The Three Commandments of malaria prevention and survival are :
- Do Not Get Bitten
- Seek Immediate Medical Attention If You Suspect Malaria
- Take "The Pill" (Anti-Malaria Tablets / Prophylaxis)
- DO NOT GET BITTEN
- Stay indoors from dusk to dawn
- If you have to be outside between dusk and dawn - cover up : Long sleeves, trousers, socks, shoes (90%) of mosquito bites occur below the knee)
- Apply DEET containing insect-repellent to all exposed areas of skin, repeat four-hourly
- Sleep in mosquito-proof accommodation :
- Air-conditioned, proper mosquito gauze
- Buildings / tents treated with pyrethrum-based insect repellent / insecticide
- Burn mosquito coils / mats
- Sleep under an insecticide impregnated (Permacote® / Peripel®) mosquito net (very effective)
- SEEK IMMEDIATE MEDICAL ATTENTION IF YOU SUSPECT MALARIA
- Any flu-like illness starting 7 days or more after entering a malaria endemic area is malaria until proven otherwise.
- The diagnosis is made on a Blood smear or with an ICT finger prick test,
- One negative smear / ICT does NOT exclude the diagnosis (Repeat smear / ICT until diagnosis is made, another illness is diagnosed or the patient recovers spontaneously - e.g. from ordinary flu)
- TAKE "THE PILL"
- Prophylaxis does not make the diagnosis more difficult
- It does protect against the development of cerebral malaria
- Is not 100% effective - hence the importance of avoiding bites
- Not all anti-malarials are safe with diving
- Malaria is often fatal - making prophylaxis justified
- Anti-malaria drugs, like all drugs, have potential side-effects, but the majority of side-effects decrease with time.
- Serious side-effects are rare and can be avoided by careful selection of a tablet or combination of tablets to suit your requirements (region and season).
There are several dangerous myths regarding malaria prophylaxis. Please note that:
THE FOLLOWING DRUGS ARE AVAILABLE FOR THE PREVENTION OF MALARIA
- Chloroquine (Nivaquine® or Daramal® or Plasmaquine®):
- Proguanil (Paludrine®):
- Doxycycline (Vibramycin® or Cyclidox® or Doryx®, etc.):
- Mefloquine (Lariam® or Mefliam®) :
- Pyrimethamine / Dapsone (Maloprim® or Deltaprim® / Malazone®):
- Sulfadoxine & Pyrimethamine. (Fansidar®):
- Quinine (Lennon-Quinine Sulphate®):
- Arthemeter (Cotexin®):
- Halofantrine (Halfan):
Contains only chloroquine. Must be taken in combination with Proguanil (Paludrine®)
Dosage: 2 tabs weekly starting one week before exposure until 4 weeks after leaving the malaria endemic area.
Contra-indications: Known allergy, epilepsy
Side effects: Headache, nausea & vomiting, diarrhoea, rashes; may cause photosensitivity (sunburn; prevention - apply sun block)
Use in Pregnancy: Safe. (Note: SCUBA diving is not considered safe during pregnancy)
Must be taken in combination with Chloroquine (Nivaquine® or Daramal® or Plasmaquine®)
Dosage: 2 Tablets every day starting one week prior to exposure until 4 weeks after.
Contra-indications: Known allergy to Proguanil. Interactions with Warfarin (an anti-coagulant -- that is incompatible with diving)
Side-effects: Heartburn (Tip: take after a meal, with a glass of water & do not lie down shortly after taking Proguanil); mouth ulcers (Tip: Take Folic acid tablets 5mg per day if this occurs); loose stools (self limiting - no treatment required)
Use in Pregnancy: Safe - but must be taken with Folic acid supplement: 5mg per day. (Note: SCUBA diving is not considered safe during pregnancy)
The combination of Chloroquine & Proguanil is about 65% effective. It is DANs second choice for malaria prophylaxis in areas of resistant malaria and a first choice in areas of low or absent resistance due to the benign side-effect profile of the drugs.
Used extensively in the prevention of resistant malaria. About 99% effective. Used alone or in combination with chloroquine. Not officially recommended for use in excess of 8 weeks for malaria prevention, but it has been used for as long as three years with no reported adverse effects. Offers simultaneous protection against tick-bite fever and cholera.
Dosage: 100mg daily starting 1 - 2 days before exposure until 4 weeks after exposure.
Side effects: Nausea, vomiting, diarrhoea, allergy, photosensitisation. May cause vaginal thrush infections and reduces the efficacy of oral contraceptives.
Use in Pregnancy: Unsafe (as is SCUBA DIVING). Also avoid during breast feeding and in children < 8 years
Doxycycline is DANs first choice recommendation for divers diving in areas with chloroquine resistance / resistant malaria.
About 90% effective. Dosage: One tablet /week.
Side effects: May cause drowsiness, vertigo, joint aches and interfere with fine motor co-ordination (making it difficult to exclude DCI in some cases).
Pregnancy: Probably safe in early pregnancy and may be used with confidence after the first trimester of pregnancy. May be used in breast feeding and babies weighing more than 5kg.
Lariam is considered unsafe for divers & pilots. It is contra-indicated in Epilepsy but is a good first choice for other travellers.
No longer regarded as effective. Still recommended in Zimbabwe.
No longer used as prophylactic. Used as first-line treatment in mild malaria as a single dose in isolated areas while en route to definitive care. Efficacy is variable. Contra-indicated in known sulphonamide allergy.
Not used for prophylaxis but is the backbone in the treatment of moderate and severe malaria. Serious side-effects are not uncommon during treatment.
The "Chinese drug". Available in some areas of Africa. Not for prophylaxis. Used in combination with other drugs in the treatment of mild to moderate malaria but it is not registered in South Africa at present.
Not used for prophylaxis. Can cause serious Interactions with other anti-malarials. Efficacy variable.