If you are planning an overseas trip to the tropics, you are probably getting ready for white sand beaches and lazing in the sun. But it’s important to factor in some preventive health plans too. Malaria is common in these regions. In addition to avoiding mosquitoes, one of the best strategies available is taking regular anti-malarial tablets.
Malaria is a devastating disease – worldwide, more than 600,000 people die from the infection annually. And it’s most dangerous for those who haven’t been exposed to malaria before.
Having worked in rural Angola, I’ve seen first-hand just how sick people can be. A few weeks after the start of the rainy season, we saw dozens of small children brought to our health centre with life-threatening anaemia. In another part of the country where malaria transmission levels were slightly lower, a medical colleague saw many slightly older kids with seizures due to complications in the brain.
Australian travellers to malarious areas are also at risk.
In this post, we will be looking at the common questions around malaria. Which countries have malaria? Which preventive medications are available for malaria? Which anti-malarial tablets are right for me? There will be tips for travelling with and taking malaria medications.
So if you’re wondering, ‘do I need anti-malarial tablets for my overseas trip?’ here is the answer to all your questions.
Contents
What types of Malaria are there?
What are the Symptoms of Malaria?
Is There Malaria at My Destination?
Do I need Anti-Malarial Tablets?
Which Anti-Malarial Tablet is Best for Me?
Tips for Travelling with Anti-Malarial Medications.
When Should I Start Taking Anti-Malarial Tablets?
When Should I Stop Taking Anti-Malarial Tablets?
Can I Get Malaria while Taking Anti-Malarial Tablets?
What types of Malaria are there?
Malaria is a parasitic infection transmitted by the bite of an infected female Anopheles mosquito. Several species of malaria infect humans. For all of these, the parasites spread from the mosquito bite through the bloodstream to the liver, where they lie dormant for up to four weeks, depending on the species. This is known as the incubation period. After this, parasites are released into the blood stream, where they cause successive cycles of infection of the red blood cells. This is when symptoms begin.
Plasmodium falciparum malaria
Falciparum malaria is the most dangerous form. In addition to parasitising red blood cells, this species of malaria causes a range of complications in different organs. This ranges from severe anaemia, to kidney failure, to a build-up of fluid in the lungs called pulmonary oedema. Metabolic complications like high-levels of acid in the blood or low levels of glucose can develop. Cerebral malaria is caused by parasitised red blood cells sticking in the blood vessels of the brain.
Any of these complications can be rapidly life-threatening. And people can develop several complications at once. It can be just a matter of hours between the first symptoms, severe illness and death.
Falciparum malaria is found in many parts of the tropics and is the predominant form of malaria found in Africa.
Plasmodium vivax, Plasmodium ovale and Plasmodium malariae
While vivax, ovale and malariae cause infection in the red blood cells, complications in other organs are rare. When complications do occur, they are generally in older people. The case fatality rate for these three species of malaria is low.
Vivax malaria occurs in the tropics, with a greater predominance in Asia and other tropical countries outside Africa. Ovale malaria is found more commonly in Africa. Liver forms of vivax and ovale malaria can lie dormant for months. This means that after the initial illness, relapses can occur several months later. These relapses can be prevented by some anti-malarial medications.
While Plasmodium malariae is found in many tropical regions, it is less common than falciparum, vivax and ovale.
Plasmodium knowlesii
Knowlesii malaria is a more recently discovered form of malaria in humans. It occurs in Southeast Asia. Complications, similar to those seen for falciparum malaria can occur.
What Are the Symptoms of Malaria?
After the incubation period, symptoms of fever, fatigue, muscle aches and headaches begin. Nausea and vomiting can be a feature. Abdominal pain and diarrhoea can develop. Other symptoms related to complications can occur, mainly in falciparum malaria. These include drowsiness and seizures in cerebral malaria, breathlessness when fluid builds up in the lungs and extreme fatigue related to anaemia.
Is There Malaria at My Destination?
Malaria can extend within the habitat of the insect that carries it. Anopheles mosquitoes live in tropical areas below 1500 to 2000 metres in altitude. Whether a particular destination has malaria or not can change. So the best way to assess this ahead of you trip is to check the American Centres for Disease Control webpage which has a comprehensive list of malaria information by country.
At the time of writing, malaria is present in Bali, outside the main resort areas. Most of the surrounding islands, like Lombok, also have malaria. Most Southeast Asian countries, like Thailand, Cambodia, and Vietnam also have areas with malaria.
While at the time of writing, Fiji was malaria-free, other Pacific Island destinations like Vanuatu and the Solomon Islands have malaria present in all parts.
India is a malarious country and the parasite is present in metropolitan areas of Mumbai and Delhi. The risk varies by region with no malaria above 2000m.
As the situation changes constantly, the best way to assess whether your destination has malaria is to check the CDC website.
Do I Need Anti-Malarial Tablets?
Anti-malarial tablets, otherwise known as malaria prophylaxis, are recommended for almost everyone travelling to an area with malaria. Malaria prophylaxis forms an important part of the overall strategy for reducing the health risks of malaria.
Insect avoidance, in this case the Anopheles mosquito, is also important. This mosquito bites between dusk and dawn, so staying indoors between these times helps to reduce the risk. Sleeping indoors, in airconditioned rooms or under an insecticide-treated mosquito net is also advisable. The use of insect repellent, containing DEET, Picardin or oil of lemon eucalyptus is a proven way to reduce the risk of insect-borne infections including malaria.
For those travelling to an area with malaria, a pre-travel medical consultation is highly recommended to get advice on all aspects of reducing malaria risk. In almost all cases, this will be an opportunity to discuss malaria prophylaxis and obtain a prescription for your chosen medication. Travelling to an area with malaria without taking malaria prophylaxis is something that should only be contemplated in close consultation with a doctor experienced in travel medicine.
It’s a common misconception that if you have grown up in a region with malaria, you are immune to the infection. The truth is that any partial immunity you developed in the malarious area is lost only a few months after leaving. So those travelling home to a region with malaria to visit family and friends are also at risk. Anti-malarial tablets are recommended for the vast majority of people in this situation.
Those who are pregnant are at risk of additional complications like maternal anaemia, fetal growth restriction, premature labour and fetal loss. The options for anti-malaria tablets are also more limited. So travel to a malarious area is best avoided while pregnant.
Which Anti-Malarial Tablet is Best for Me?
Assessing your options for anti-malarial tablets starts with an assessment of the species of malaria present at your destination and whether drug-resistance is present. This information is available on the CDC website.
From the anti-malarial options which are active against the relevant types of malaria, the decision between them comes down to an assessment of the dosing regimen, the risks of the various possible adverse effects and the cost.
Doxycycline
Doxycycline needs to be taken daily. While the medication is usually well tolerated, it’s recommended to take it with food and avoid lying down for 30 minutes afterwards to reduce the risk of gastrointestinal upset, oesophagitis and, rarely, oesophageal ulceration.
Another potential side effect is a sensitivity to sunlight, so extra care is required with sunscreen to avoid sunburn. In addition to being an antiparasitic agent, doxycycline is also an antibiotic. This means it can occasionally result in vaginal thrush. A standby treatment for this can be carried with you in case it’s needed.
Doxycycline can’t be taken by children under eight or pregnant women. At around $30 to $40 for eight weeks of tablets, it is one of the least expensive options for malaria prophylaxis. The tablets need to be continued for four weeks after leaving the affected area.
Mefloquine
Mefloquine has the advantage of being a once weekly tablet. So for longer trips this may be preferable to taking a daily medication.
Most people tolerate mefloquine well. Potential side effects include gastrointestinal upset, light headedness and headaches. Mefloquine can sometimes cause difficulty concentrating, mood swings and strange dreams. More serious neuropsychiatric reactions like anxiety, depression, paranoia and others also occasionally occur. And psychosis and seizures occur with a frequency of about one in 10,000 people taking the medication.
People who have had recent anxiety or depression should avoid taking mefloquine. As should all those who have had seizures or major psychiatric disorders in the past. People with heart arrhythmias and those taking certain medications also cannot take mefloquine. Your travel doctor can advise if this is relevant to you. Mefloquine can be taken in all trimesters of pregnancy.
The cost of mefloquine usually works out as a little more than doxycycline. It should be taken for four weeks after leaving the malarious region.
Atovaquone-Proguanil (Malarone)
Among the anti-malaria tablets, atovaquone-proguanil has one of the best side effect profiles. Occasional adverse effects tend to be mild and limited to gastrointestinal upset like nausea. Insomnia, headache, rash and mouth ulcers can also occasionally occur.
Atovaquone-proguanil is a once daily medication. It has the added advantage of being active against liver forms of the malaria parasite. So, unlike many of the others, you only need to take it for a week after leaving the malarious region.
People with some kidney problems can’t take atovaquone-proguanil. It also needs to be avoided during pregnancy or breastfeeding and it can’t be given to very young infants.
Atovaquone-proguanil is one of the more expensive anti-malarials. For shorter trips, the increased cost is partially offset by the shorter duration of the tablets after leaving the affected region. A recent pharmacy enquiry revealed that for a two-week trip, the total cost ranged from $60 to $120.
Tafenoquine
Tafenoquine is a relatively new anti-malarial agent, having been approved for use by the Therapeutic Goods Association in 2018. It is one of the few medications active against the dormant stages of the parasite in vivax and ovale malaria. So, unlike most of the others, it will also prevent the relapses that occasionally occur months after leaving an area with these forms of the infection.
Tafenoquine is generally well tolerated. The most common side effects include gastrointestinal upset, dizziness and headaches. It’s necessary to have a blood test prior to being prescribed tafenoquine for a rare biochemical deficiency known as G6PD deficiency. Women who are pregnant need to avoid tafenoquine, as do those with a psychiatric history. The medication can’t be given during breastfeeding unless G6PD deficiency has been excluded in the baby.
After daily doses for three days, tafenoquine is taken weekly. The tablets should be taken with food. As it is active against all forms of the malaria parasite it only needs to be taken for a week after your return to Australia. Tafenoquine prophylaxis can’t be taken for more than six months. Tafenoquine is one of the more expensive anti-malarials. The cost can be comparable to atovaquone-proguanil.
Choloroquine
As resistance to chloroquine is now widespread among the various malaria species, the use of chloroquine is now more limited. It can still be used in parts of Central America and the Caribbean but very few other locations.
In Australia, chloroquine is available as hydroxychloroquine. This is a once weekly tablet which is taken with food to alleviate gastrointestinal side effects. Other occasional side effects include dizziness, blurred vision and headaches. Itchy skin can also occur, as can flares of an autoimmune condition called psoriasis.
Chloroquine can be used in pregnancy and during breastfeeding. It should be taken for one to two weeks prior to travel and for four weeks after. Chloroquine is the least expensive of the antimalarial options.
Tips for Travelling with Anti-Malarial Medications
Like all prescription medications, it’s wise to carry a letter from your doctor which states that your anti-malarial medications have been prescribed by a doctor for your own personal use, or for the use of an immediate family member for whom you are caring. This documentation can be useful when moving through customs at your destination.
The Therapeutic Goods Association advises you keep prescription medications in their original packaging and carry them in your hand luggage on the plane.
It’s worth obtaining you anti-malarials before leaving Australia. This ensures you are protected during your entire stay. It also avoids the risk of lower quality or counterfeit medication which is an issue in many overseas countries.
When Should I Start Taking Anti-Malarial Tablets?
You should begin your malaria prophylaxis before you arrive at the malarious area. The medications take time to reach the right levels in your bloodstream.
It can also be a good idea to start the tablets earlier to assess for any adverse effects. If these develop you will need to have enough time to see your doctor to switch to a different type of medication. For mefloquine, as it is a once weekly dose, a good time to begin would be two or three weeks ahead of your trip. For the daily medications, beginning several days before is reasonable.
When Should I Stop Taking Anti-Malarial Tablets?
Most anti-malarial tablets should be continued for four weeks after your return to Australia. Exceptions to this include atovaquone-proguanil and tafenoquine, which can be discontinued one week after you get back.
The reason for this is that most tablets act against the blood forms of the parasite. These forms can take up to four weeks to emerge from your liver after you have been bitten by an infected mosquito. For atovaquone-proguanil and tafenoquine the medication acts against the liver forms of the parasite, so can safely be stopped earlier.
Can I Get Malaria while Taking Anti-Malarial Tablets?
Yes. While anti-malaria tablets are highly effective they do not reduce your risk of malaria infection to zero. If you experience fever or any other symptom of malaria while you are travelling or within four weeks of your return it’s vital you seek immediate medical attention.
Summary
A knowledge of the health risks at your destination is an important part of staying safe during your trip. Once you understand the different types of malaria and their risks, the next step is to find out which types of malaria are present where you’ll be travelling. After you’ve learned whether resistance to anti-malarial medications is an issue, you will then know which are the available options for your preventive therapy.
Exploring each of the relevant anti-malaria medications in more detail will put you in a good position to speak with your doctor regarding which one is best for you. With a prescription for the right medication, instructions on when to start and stop taking the medication, advice regarding insect avoidance and an awareness to seek immediate medical care for fever, you are well on your way to keeping yourself as safe as possible from malaria while you’re away.