Malaria prevention and prophylaxis

AdobeStock_23489585

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.

The three commandments of malaria prevention and survival are:
1. Do not get bitten
2. Seek immediate medical attention if you suspect malaria
3. Take “the pill” (anti-malaria tablets/propftylaxis)

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 diagnosis is made, another illness is diagnosed or the patient recovers spontaneously – i.e. from ordinary influenza)

Take “the pill”

There are several dangerous myths regarding malaria prophylaxis:

  • 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-malaria medication is safe for 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 (Country, region and season)

The following drugs are available for the prevention of malaria:

Doxycycline (Vibramycin® or Cyclido or Doryx®)

Used extensively in the prevention of Chloroquine resistant malaria. About 99% effective. 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 side effects. Offers simultaneous protection against tick-bite fever.

Dosage: 100mg after a meal daily starting 1 to 2 days before exposure until 4 weeks after exposure. Doxycycline should be taken with plenty of non-alcholic liquid.

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 younger than 8 years of age.

Doxycycline is DAN’s first choice recommendation for divers in areas with choloquine resistance/”resistant malaria”.

Chloroquine (Nivaquine ® or Daramal ® or Plasmaquine ®):

Contains only chloroquine. Must be taken in combination with Proguanil (Paludrine ®)

Dosage: 2 tablets weekly starting one week before exposure until 4 weeks after leaving the 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)

Proguanil (Paludrine®)

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 incompatible with diving)

Side-effects: heartburn (tip: take after a meal, with a glass of water and 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 falciparum malaria. Although not a first choice, its relative safety and limited side effects may justify its use in certain individuals.

Atovaquone / Proguanil (Malarone ® ; Malanil ®)

Registered in South African as a causal prophylaxis in February 2004. Safety in diving has not been established. Preliminary data suggests it may be safe for pilot and divers.

Effective against Malaria isolates that are resistant to other drugs.

Controlled studies have shown a 98% overall efficacy of Atovaquone / Proguanil in the prevention of P. falciparum malaria

Dosage: 1 Tablet daily for adults, starting 24 – 48 hours prior to arrival in endemic area, during exposure in endemic areas and for 7 days after leaving the endemic area only.

Dose should be taken at the same time each day with food or a milky drink.

Contra-indications: Known allergy to Proguanil or Atovaquone or renal impairment (i.e., significant renal disease is likely to be incompatible with diving). Safety in children < 11kg has not been established.

Side-effects: Heartburn (Tip: Take after a meal, with a glass of water & do not lie down shortly after taking Proguanil); mouth ulcers. To date Atovaquone has been well tolerated and the most common adverse reaction being headache.

Use in Pregnancy: Safety in pregnancy and lactating women has not been established. (Note: SCUBA diving is not considered safe during pregnancy)

The safety of Malanil has not been confirmed in diving. Accordingly, even though preliminary data suggests that it may be safe, we are not able to recommend it. Doxycycline remains the first choice for divers diving in Africa where there is resistance to chloroquine.

Mefloquine (Lariam® or Mefliam®)

About 90% effective Dosage: one tablet per 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.

Mefloquine is considered unsafe for divers and pilots. It is contra-indicated in epilepsy but us a good first choice for other travellers

Pyrimethamine/Dapasone (Maloprim® or Deltaprim®/Malzone®)

No longer regarded as effective but still recommended in Zimbabwe

Sulfadoxine and Pyrimethamine (Fansidar®)

No longer used as a prophylactic.

Quinine (Lennon-Quinine Sulphate®)

Not used for prophylaxis but is the backbone in the treatment of moderate and severe malaria. Serious side-effects are not uncommon during treatment.

Arthemeter (Cotexin®)

fte “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.

Halofantrine (Halfan)

Not used for prophylaxis and best avoided for treatment.

Recommended malaria drug prophylaxis in DAN Southern African region (Africa and Indian Ocean islands)

malaria

* In situations where the risk of contracting malaria is low, (e.g. in cities, air conditioned hotel or when rainfall has been low, etc.) the traveller may be advised to take no drug prophylaxis but stand-by treatment mus t be carried unless medical care is readily available. Personal protection against bites must be adhered to at ALL TIMES.

# high risk people include babies and children under 5 years, pregnant woman, elderly people (and greater than 65 years), people with suppressed immunity (e.g. diabeties, etc)

Notes:

  1. The above mentioned recommendations were compiled from material supplied by the National Department of Health and Worldwide Travel Medical Consultants.Prohpylaxis significantly reduces the incidence of malaria and slows the onset of serious symptoms of malaria
  2. All anti-malaria drugs excluding Mefloquine are considered compatible with diving
  3. Like with all other medications, anti-malaria drugs should be tried and tested on land well in advance
  4. If unpleasant side-effects occur, please consult your diving doctor
  5. Whether or not you take prophylaxis, be paranoid about malerial Malaria can presrnt in many ways varying from fever or diarrhoea to flu-like symptoms. Always inform your doctor that you have been in a malaria area. Symptoms can start within 7 to 14 days from first exposure until 30 days (and rarely even months) after leaving a malaria area.
  6. No single medication is 100% effective and barrier mechanisms (personal protection against bites e.g. mosquito repellents, nets, protective clothing, not going outdoors from dusk to dawn) must be
  7. Any strange symptom occurring during or within 6 weeks of leaving a malaria area should be regarded with suspicion and requires medical

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)11 242 0112.

Frans J Cronjé, MBChB(Pret), BSc(Hons) Aerosp Med
Albie De Frey, MBChB(Pret)
Hermie C Britz, MBChB(Pret), BSc(Hons) Aerosp Med

error: Content is protected !!