Chief Medical Officer
Many people including aid workers, missionaries, students and health-care workers are travelling to live and work in remote rural communities, where malaria is endemic. The estimated rate of severe infection associated with falciparum malaria (the type most commonly found in sub-Saharan Africa) in non-immune travellers is up to 5%, and therefore preventive measures must be taken very seriously.
Long-term travellers have a higher risk of malaria than short-term travellers for a number of reasons, not just because their potential time of exposure is greater. They tend to underuse personal protective measures and adhere poorly to continuous anti-malarial prophylaxis. There is often a perceived low risk of malaria reinforced by misinformed advice from local colleagues. Commonly cited reasons for poor adherence include fear of long-term adverse effects, actual adverse events from medication, conflicting advice, and complicated regimens or daily medications. Developing malaria while taking anti-malarial drugs (ie, “breakthrough” malaria) or having febrile illnesses misdiagnosed as malaria also reduce confidence in anti-malarials.
A number of strategies are used during long-term stays:
- Discontinuation of anti-malarial medication after the initial period (often the first 6 months when the medication from the home country runs out)
- Moving from one form of anti-malarial to another in a self-devised sequential rotation
- The alternative use of stand-by emergency self-treatment
- Seasonal anti-malarial medication targeting high-incidence periods or locations.
All these strategies have advantages and drawbacks. Counterfeit drugs sold in countries endemic for malaria also pose serious concern for long-term travellers who purchase their medications overseas.
10 malaria prevention steps for HR to fulfil their duty of care to the traveller or expatriate
#1 Offer specialist travel medicine advice – prior to travel it is important that details of the destination, nature of travel, availability of medical care, duration of stay, general health of the traveller are all considered in order that a risk rating can be made and applied, and an acceptable plan for malaria prevention can be agreed. Specialist considerations need to be taken for small children and pregnant women in particular.
#2 Anti-malarial tablets – appropriate malaria prophylaxis medication needs to be obtained prior to travel and the benefits and side effects explained to the traveller. It is important to identify a reliable source of anti-malarials in-country or the means to acquire them externally.
#3 Take your tablets before you travel – some tablets need to be taken just one to two days before entering the malaria endemic region while others need to be taken weeks before, in order to provide protection. It is important to check which it is, in advance.
#4 DEET insecticide spray – anti-malarial tablets do not provide 100% protection against malaria and therefore bite prevention must be observed alongside medication. DEET insecticides (20-40%) for personal use should be sprayed on exposed skin when likely to be exposed to mosquitoes.
#5 Permethrin impregnated clothing – long-sleeved, loose light clothing and long trousers should be worn outdoors in order to cover any exposed skin as much as possible but this can be supplemented by spraying permethrin onto the clothing to further deter the mosquito. Aftershaves and perfumes should also be avoided.
#6 Insecticide-treated bed nets (ITNs) – the majority of bites that occur indoors occur during the sleeping hours. Sleeping under an ITN can reduce contact between mosquitoes and humans by providing both a physical barrier and an insecticidal effect. And window screens will help to stop mosquitoes entering from outside and hanging around waiting for an opportune moment to bite. Air conditioning also helps to deter the mosquito.
#7 Room spraying – this has been found to be one of the most effective means of tackling the mosquito that has already found its way indoors. Mosquitoes tend to rest on the walls and therefore by spraying the walls, the mosquito absorbs the paralysing insecticide. Indoor residual spraying (IRS) with insecticides is another powerful way to rapidly reduce malaria transmission, typically done once or twice a year.
#8 Minimise outdoor time from dusk until dawn – though it may be nice to sit out and watch the sun go down or sit outside for a drink in the early evening, this is the feeding time for the mosquitoes and so it is wise to avoid sitting out at dusk and dawn- pyrethroid coils can be used outside to help deter mosquitoes.
#9 Finish course of anti-malarials – it is, of course, important to take your medication every day or every week, as prescribed, but it is equally important to continue to take the medication after leaving the malaria endemic region – with some tablets this is for a week but with others it can be for up to four weeks – this is in order to break the long life-cycle of the malaria parasite.
#10 Be aware of symptoms when back home – malaria may occur at any time from weeks to months after leaving the endemic region. It is important to always be aware that malaria may be the cause of a high temperature, for example, when seeking medical attention.
General guidelines for malaria prevention should be adopted by all employers sending staff to high risk zones, but the support for long-term travellers must be individualised and should be provided by travel medicine specialists.
Personal protective measures are paramount. Identification of reliable medical facilities at destinations is crucial for long-term travellers regardless of their malaria prevention strategies – these should be identified prior to outbound travel. And crucially, long-term travellers should always ensure they have evacuation insurance for medical emergencies.