Malaria and the motorcycle traveller

I decided to write this article after a brief conversation with Grant following repeated postings on the HUBB from various people that have caused controversy. I have no vested interest in any particular drug or pharmaceutical company and have extensive experience and formal training in developing world medicine. Malaria is a serious illness, not part of the adventure and can rapidly be fatal. There are myths and misunderstandings floating around on the internet and together with Grant, I hope this article will help forum members and lurkers travel more safely in the future. Armed with the right knowledge, it is easy to protect yourself from mosquito borne illnesses and I hope this article will help you do that. It should be noted that even taking the right precautions, the risk of getting a mosquito borne disease can only be reduced, not eliminated. In addition, I would add that pills are the icing on the cake – the most important step is avoiding being bitten. It should also be noted that even if one takes all the precautions and right medicines for prevention one could still get malaria.

I would like to point out that I have written this article for the layperson. I am well aware that there are many health professionals on the site – those that want more detail can find it on the usual websites such as that of the CDC in Atlanta or the Health Protection Agency in the UK. Although written for a lay audience, the information is up to date and reflects contemporary medical thinking.

In this article, I am going to deal with the causes of malaria, the symptoms, prevention and treatment and then I am going to try and dispel a few myths. Finally, I will address how one might address infection whilst travelling.

Malaria is caused by a parasite of the species plasmodium. There are many different types but four major ones, malariae, ovale, vivax and falciparum. Of these, the deadliest is falciparum, although all can be fatal. Two of the four can exist in the human body by hiding in a dormant form in the liver for many years after infection if not treated properly (ovale and vivax).

Humans are infected by the bite of specific kind of mosquito, the female anophalene; these feed at night and dusk/dawn; don’t worry, day biting mosquitoes can infect you with other nasty diseases which will be covered in a later article.

When feeding on human blood, the mosquito, itself infected by plasmodium parasites that replicate in its body, injects the parasites into the bloodstream. Once in the body, the parasite reproduces and causes illness by bursting blood cells and clogging blood vessels. This in turn can cause respiratory, cardiac and kidney failure and brain damage and death.

There are two important points to note about the plasmodium species:

1. Distribution varies around the tropics, so, for example, falciparum may be found only in certain areas.
2. The drugs used to treat and prevent infection may be ineffective in certain areas due to resistance of the strain in that area; hence treatment and prevention must be tailored to area of travel and adjusted for the roaming traveller according to risk.

The symptoms that one might experience after infection include fevers recurring at intervals, classically 2-4 days, sweats, headaches, muscle aches and pains and diarrhoea; the urine turning black is a classic symptom of falciparum infection associated with bursting of the blood cells in the circulation – ‘blackwater fever’. Often mistaken for viral infections and colds/flu, a good rule of thumb is that someone who has been travelling in a malaria area who has a fever has malaria until proven otherwise.

In terms of prevention, there are two broad strategies to reduce the risk of contracting malaria:

1. Bite avoidance.
   1. Clothing - wear long sleeves and trousers (ha ha ha! – it’s the tropics, but that is the advice); dip clothing in permethrin rinse to repel mosquitoes; lasts about six weeks.
   2. Use of mosquito repellents on skin – use after swimming, copious sweating and washing.
   3. Use of insecticide treated mosquito nets to sleep under, mosquito screens for doors and windows.
2. Chemoprophylaxis – use of medication to kill parasites that might enter the bloodstream.

There are several things to note about this voluminous topic; the choice of agent is dictated by the area of travel, local resistance patterns, side effect profile, interaction with the health of the traveller and other medications and of course, cost. My advice is to see a doctor at a travel clinic to sort this out, as generalized rules are not much use, it is such an individual subject. Popular drugs in use include Malarone, Mefloquine and Chloroquine/Proguanil and doxycycline, depending on area of travel. One myth that often comes up is that using nothing is better than using Larium (mefloquine). With the exception of people not taking it for medical reasons, this is just that – a myth. Notwithstanding the observation that most side effects occur with treatment doses rather than prophylactic doses, if you are not contraindicated from using it for medical reasons, it is a good drug. Once weekly too, rather than daily, like malarone.

Treatment

In some cases the same drugs as used for prophylaxis are used, in others, different, more potent drugs are required. For serious cases, intensive care or individual organ support may be required to preserve life and/or function. I have left this part deliberately vague so as not to encourage self-treatment and to emphasize that people must be treated as individuals by a qualified doctor who can see the whole picture. If you think you have malaria, you need to see a doctor, full stop.

I will doubtless now get comments from ‘hard care’ adventurers about how they treated themselves or sought the help of the local witch doctor and were healed with a teaspoon three times a day of boiled goat dung – save your breath – I don’t care. My advice is what it is and you are free to take it or leave it. Just know that malaria kills millions – millions – of people every year.

A note on drugs.

One topic that always raises it’s head on the HUBB is that of either buying drugs in third world countries or second-hand from other travellers. I personally think that both are bad ideas for the following reasons:

1. Drugs bought second-hand have probably not been stored in optimal conditions; this may lead the drug to degrade and be ineffective. Caveat emptor. Sellers may find themselves liable for considerable sums. It is illegal to supply prescription only medicines without the proper certification.
2. In third world countries there is a booming trade in expensive drugs that happen to be counterfeit. Up to 40% of the artemisinin derivative type drugs in SE Asia on sale have been found to be fake. For this reason, I generally suggest that people buy their drugs before they go in a first world country from a reputable pharmacy. You may get lucky and get a bargain abroad, but then again, you may not. Pharmacy is big business in the third world and you have no way of checking whether or not you are being ripped off. It is an avoidable risk.

The choice with drugs, ladies and gents, is yours, but these are the facts and risks.

What to do if you get sick in out of the way places.

If access to a doctor is genuinely restricted by time or distance, it is certainly possible to take a treatment dose of drugs if you happen to have them. However, if you are sick despite the prophylaxis, it may be that those drugs are not effective. One should also drink plenty of fluid to avoid dehydration, rest and get to a medical facility. Don’t mess with malaria – it can kill you.

Those travellers in range of Nelson, BC, can consult me for travel preparation and prescription. I would also be happy to answer any queries by email or via the HUBB.

I also have interests, experience and training in Pre-hospital trauma care, Emergency Room medicine, Aviation medicine and tropical diseases.

Safe travels all.

Dr Sean Wachtel
MRCP (UK), MRCGP (UK), DTM&H, LMCC