Travelling to a tropical region is a fantastic life experience, but it isn’t without its risks. Taking preparatory measures to protect against indigenous illnesses in such areas is crucial. Among these are typhoid, dengue fever, yellow fever and, of course, malaria.

Those who know anything about malaria will likely have heard about its formidable symptoms (headache, fever, diarrhoea, sickness and muscular pain to name a handful), the fact that it can cause lasting health complications and, if not treated, even be fatal.

As you’ll read elsewhere on this site, the condition is transmitted by mosquito bites, and caused by a parasite (called plasmodium). There are five main types which cause the disease to occur in people, of which the P. falciparum variety is the most aggressive.

Once someone is bitten by a mosquito carrying the parasite, it spreads through the body by taking over blood cells, before eventually attacking the vital organs and central nervous system.

Generally, treatment is very effective when the infection is caught early. However, the harmful nature of the disease, combined with the likelihood that emergency health facilities may not be accessible in more remote areas, makes preventative treatment (what we term ‘prophylaxis’) essential.

No effective vaccination against malaria is available yet, although in 2016 WHO reported that more than 30 potential candidates were either going or about to go through clinical assessment.

For this reason, preventative treatment is a must when visiting a malarious destination.

There are several different types of antimalarial, and the one you use depends on the area you’re visiting.

Areas affected by malaria

Below, we’ve put together a malaria world map based on the estimated risk of malaria as defined by the US Centers for Disease Control and Prevention:

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(The data in this malaria world map is correct as of July 2018)

It should be noted that even where the CDC state that the risk of malaria is ‘none’ (such as in Argentina) or there is no data available (Algeria) the disease may still be present in remote areas of the country.

Before travel, you should also check the NHS Fit For Travel website for specific, up-to-date health guidance on the destination you are visiting.

Below you can find a map displaying the different levels of risk present in different countries, according to Fit For Travel, as of July 2018. (However, you should still visit the Fit For Travel site for detailed information, as risk classifications vary in different areas within countries, and can change.)

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Where is malaria most common?

According to WHO, Nigeria had the highest number of estimated cases of any country, with 57,300,000 in 2016; the number of reported confirmed cases in Nigeria at health facilities was 9.3 million, and there were a little over 3 million confirmed cases at community level.

Mali had the highest number of estimated cases per head: 7.9 million cases, out of a population of 17.8 million. (However, this figure should not be taken to mean that 44% of people were estimated to have the infection in 2016, as in many cases one person may have contracted the infection on several occasions.)

Malaria risk by country

Using data from WHO, below we have compiled a list of countries where malaria is thought to be present, along with how many estimated cases there were in 2016. 

To provide a sense of the scale of the risk, we have also included population data for each country from the CIA World Factbook. 

Despite there being different levels of risk in different countries, the threat of the disease should always be taken seriously when visiting any malarious region, be it low, moderate, variable or high risk.

Again, this data was correct as of July 2018; but you should still check the CDC and NHS Fit for Travel sites for the most up-to-date information.

Africa: Estimated malaria cases and risk

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Caribbean, Central and South America: Estimated malaria cases and risk

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Europe, Central Asia and the Middle East: Estimated malaria cases and risk

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South and East Asia and Pacific: Estimated malaria cases and risk

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Is malaria prevalence rising or falling?

According to WHO, the number of malaria cases between 2000 and 2014 declined globally by 37%. However, in their World Malaria Report published in 2017, they noted that there was a slight rise between 2015 and 2016, from 211 million to 216 million.

They also note that Sub-Saharan Africa is the region most affected by the disease. The African continent accounts for almost 9 in 10 of global malaria cases.

When global rates were declining between 2000 and 2014, the number of cases in Africa increased. Rising temperatures and climate change have been cited as possible causes of the rise observed in African countries, as warmer weather enables plasmodium-carrying mosquitoes to survive at higher altitudes in these regions.

What prevention measures should I take?

When preparing for your trip, the basics are an essential requirement in addition to prophylactic medicine. Even in those areas where resistance is very low, it’s advisable to wear insect repellent (be it a spray containing an active ingredient like DEET, or a wristband), trousers and long-sleeved garments to reduce the likelihood of bites.

Sleeping under a mosquito net is essential too; make sure one is provided in your hotel room when booking.

Which antimalarial should I use?

It really depends on a number of factors, including:

  • the region you’re travelling to
  • the length of your trip
  • and your medical profile.

Many countries (and sometimes even regions within countries) may contain varieties of the parasite that are resistant to certain types of antimalarial, so it’s important to do your research first. The CDC has detailed information on where known resistance to certain drugs is present, and which drugs are the prefered method of prophylaxis.

Some treatments may also need to be commenced up to three weeks prior to travel, so it’s vital to make preparations well in advance. The closer you get to your travel date, the fewer antimalarial options you’ll have. It may be necessary to continue taking these treatments for some weeks upon your return.

The main candidates are:

Chloroquine is an older antimalarial and consequently more susceptible to resistance, and is generally becoming less recommended for use. 

During consultation, a doctor will ask which area the patient is travelling to in order to supply the most suitable treatment.

How do they work?

Once bitten, the malaria parasite enters the body through the bloodstream then journeys to the liver. Here, the parasite replicates itself before exiting the liver to return to the bloodstream in greater numbers.

When used as a prophylactic prior to exposure, antimalarials work in the liver to destroy the parasite before it can duplicate itself and spread through the body.

However, in patients where infection has passed beyond this stage, the parasite will become more robust, necessitating urgent medical attention, and often antimalarial medicines given at higher doses. These will attack the parasite once it has re-entered the bloodstream in order to prevent it from multiplying and spreading through the body.

In summary, malaria is a condition which is much simpler to prevent than it is to treat. For this reason, it’s always better to be prepared than take the risk.

You can find out more on the above treatments, including information on possible side effects, by referring to our medicine pages.