Malaria in Uganda

The warm, tropical climate in Uganda is favorable not only for human beings, but also a variety of disease-causing germs and their vectors. The most notorious one is the anopheles mosquito that transmits malaria, a disease scattered all over the country. This is the biggest health concern of anybody travelling into the country from the northern hemisphere.

However, man is the master of all living things on earth. These germs and their vectors can be tamed. With information and the necessary facilities, you won’t have to live in fear.

The World Health Organization (WHO) in its Year 2001 international travel and health publication, recommends that visitors to a malaria zone should be aware of the problem and take precautions.

  • Protect yourself from mosquito bites by sleeping under a mosquito net. An insecticide-treated net costs about $5 in Kampala. Protect your skin with insect-repellent creams especially when outdoors between dusk and dawn. Use according to manufacturer’s recommendations. If possible remain indoors at night, with doors and windows closed as early as 6.00 p.m. Spray indoors with anti-mosquito sprays.
  • If travelling from a malaria-free zone, take prophylaxis as recommended by the doctor. Start 2 – 3 weeks before departure and continue for another four weeks after you return home.
  • There is a possibility of getting malaria even if you take prophylaxis. Take other precautions in addition and seek immediate assistance in case of any illness.
  • Know the symptoms of malaria. These include fever with or without headache, muscle aches, weakness, vomiting, diarrhea and cough. Seek medical assistance promptly. Malaria can kill if treatment is delayed.
  • Where prompt medical help is not available (as is often the case in many parts of Uganda), take antimalarial drugs for stand-by emergency treatment according to medical advice. Malarial resistance to chloroquin and sulfadoxine-pyrimethamine has been reported in parts Uganda. Travellers to areas where resistance is reported are advised to use a combination rather than any one of the two drugs.
  • Some anti-malarial drugs can cause serious side effects. Seek immediate medical help if this occurs.
  • If you suffer from malaria or suspect it while in Uganda, see a doctor on arrival back home.

Malaria. Killer or nuisance?

Uganda is in the tropics. Most people coming here expect to see tropical diseases. In fact they probably will not. You expect to see typhoid, yellow fever and leishmaniasis. In fact you are more likely to get in-growing toenails, ‘flu and a bad back, all the routine things you went through life with in Europe or America. Most people will get an awful lot of coughs and colds and frequent attacks of diarrhoea in their first few months or years here. After that you will be immune to most of what’s around and you will be back to the toenails, bad backs and haemorrhoids.

One of the tropical diseases we do see is malaria. Is malaria a potentially fatal disease or similar to a bad flu? Killer or nuisance?

Malaria in expatriates is not very common. Most 2 year contract workers never get it, most long term residents haven’t had it for years and none of my family have had malaria in the past 15 years. Yet some people claim they have had malaria dozens of times. They recognize the early symptoms, take treatment and get better in a day. How come?
Simple. Read on: they have never had malaria. Some studies have indicated that about 90% of people who have been told they have malaria do not have malaria. They get better because it wasn’t there.

To understand how to avoid, prevent, treat and survive malaria you need to know a bit about it’s life cycle.

Our local species of anopheles Mosquito is a picky little creature. Doesn’t like lakes, swamps, contaminated water, tin cans or toilet cisterns. It has plenty of culex and aedes cousins to breed in such places and bite us at night: but they don’t transmit malaria.

Heaven to an anophylene is a shallow muddy puddle to breed in, a nearby house with lots of warm bodies to bite, and a nice quiet dark place to rest in after her meal. The average muzungu house is isolated, painted, not very crowded and no nice puddles outside. Why leave the wet, overcrowded housing estate at the bottom of the hill and fly all the way up to the top to bite one muzungu?

If there are anophylene breeding and biting in your compound, who else have they bitten? If they haven’t bitten someone recovering from malaria, they cannot transmit malaria.

That is why I’ve not had malaria for 15 years or more: I have not been bitten by an infected anophylene.

The only important type of malaria in most of Uganda is falciparum. The others are rare and much less severe. The following applies to falciparum only.

Life cycle

When an infected anophylene bites someone, the invisible parasites are injected into the blood in the mosquito’s saliva. They disappear into liver cells and multiply for about 5 days. Now 30,000 times as many, they break out of the liver cell and invade a red blood cell each. They grow in the red cells for 2 days, and then the cells stick to the blood vessel wall in the deeper organs such as liver, spleen lungs or brain. There they divide into up to 32 new parasites. The cell ruptures, releasing the new parasites and all the toxins produced by their growth. These toxins released into the circulation are what give the fever, headache, nausea and other symptoms of malaria. About 10 of these very small new parasites successfully invade a new red cell each and start to grow. The patient than feels better, as the live parasite growing inside the red cell doesn’t cause any symptoms. During the about 12 hours when the cells are stuck in the deep organs and the new ones are still too small to be seen they will not be visible in a blood slide.

The parasites then grow for 2 days and repeat the cycle.
The patient will probably have no symptoms first round as the parasites are too few, and the level of toxins too low. 2nd round there will be fever, nausea headache etc. then you may feel better for a day. Next round there will be 10 times as many parasites and there will be correspondingly far worse illness.

What happens next depends on the immune status of the host.
In a semi immune (i.e brought up in a malarial area, who has had malaria continually for years) the immune system, mostly the spleen, stops the parasites from developing, eats the red cell host and destroys the parasite. Because the parasites are having a hard time, some stop the cycle of division and growth and instead become male and female gametes. These are sucked up by a mosquito and if it happens to be an anophylene, the gametes “hatch” in the stomach, male and female meet, mate and produce thousands of babies, which make their way to the salivary gland ready to be injected into the next host about a week later.

If you are not immune, or have weak immunity, the cycle of division and growth continues, giving you about 10 times as many parasites each time. A person will normally get symptoms at about 1 parasite in 15 to 20,000 red cells. After 2 days without treatment there will be 1 per 2,000. After 4 days 1 parasite in 200 cells. You will now be fairly seriously ill. After 6 days there will 1 in 20, i.e. more than 1% and this is when trouble starts. When the 2-day-old parasites stick in the blood vessels, they also stick to other parasitized cells, forming rosettes. These get stuck in the small capillaries, block it, and cause any organ cells served by the vessel to run out of blood and die. If it happens in the kidneys you may get signs of renal failure. If it happens in the lungs, pulmonary oedema. If in the brain, cerebral malaria, resulting in permanent or fatal brain damage. These complications usually happen if around 5% of your cells have a parasite, which would normally be around the 10th day of a neglected malaria attack. If it gets up to 25% then death is probably inevitable.

This description of the life cycle in immunes and non-immunes explains the symptoms, signs and outcome of malaria in the 2 groups.

In the semi immune Ugandans, malaria is a mild disease, rarely fatal after the age of 5 years, and responds to most anti-malarial drugs. Chloroquin, fansidar, short courses of quinine, all will slow the parasite down enough for the immune system to gobble them up. Many get better without treatment: if this were not true, then there would be no healthy gamete producers in the community to infect the mosquitoes. The children grow big spleens and many will have a few parasites in the blood most of the time, with no real symptoms.

The non-immune expatriate or Ugandan visiting from a non-malarial area has a very different disease, with almost certain death after 2 weeks without effective treatment. However he does not produce gametes and does not infect mosquitoes!

So, Malaria is only a nuisance, but also a potentially fatal disease, depending on who you are and what you do.

Malaria in Expatriates
Most of us are non immune. We do not get malaria because in Kampala we do not get bitten by infected anopheles. That is why most people we see with malaria have been up country, particularly notorious places of high transmission such as Murchison falls.

When you get malaria the first time, you may get mild symptoms from the rupture of the first round of parasites. A blood slide may show no parasites, as they are too few: some are stuck in the deep vessels dividing, and the new generation are too small to be seen. It doesn’t matter. They are too few to hurt you, and a repeat slide tomorrow when they are all released and growing fatter will show them easily enough if they are there. A Malaria rapid or parasite F test kit are very good indeed for those going up-country. They can pick up malaria at a concentration of 1 in 25000. The test is tripped by the presence of a protein molecule only found in falciparum malaria, and produces a red line on the test strip, very like a home pregnancy test. It does not need a live parasite as the protein is released by the ruptured cell, and therefore can be picked up even when no parasites are visible. It can remain positive up to 10 days after treatment. However if there are very few parasites, the level of protein may be too low to trip the test. Sometimes clear parasites are seen in a film with a negative test. However if there are enough to cause symptoms, the test will certainly be positive the next day, making it a trustworthy and very useful kit to take up country. We sell a kit of 25 tests for 65,000/=.

There is no point in taking anti-malarial drugs for every little fever hoping to cut malaria short. Most fevers are not malaria. Other causes of fever especially respiratory and gut infections are much more common in expats. Malaria is not going to hurt you in the first day or 2 of symptoms, so it is worth waiting for a positive diagnosis.

Positive blood slides
Laboratory technicians in Uganda know that malaria can be serious in non-immunes. They are frightened of missing it. There is also a culture of calling every fever malaria. In many languages the word for malaria is the same as the word for fever or even ill. You cannot translate “you have a fever but it is not malaria” into some languages! This explains why every blood slide is “positive”. I have seen reports of positive blood slides in people who have been in the country 3 days, totally impossible. Some expats up country have also found that about 1 in 10 people diagnosed as malaria actually have a positive protein test. As the other 9 get better with no treatment, this could not be real malaria.

So be very wary of “positive” blood slides in some clinics and labs. If you are not very ill there is no harm in waiting another day and repeating the test if you still have a fever.

The medicine we recommend is Artenam. It kills the parasites very quickly. The cell hosting the parasite ruptures and the toxins are released, just as in the natural grow and divide cycle. So 4 hours after taking artenam you will get a new wave of malaria symptoms, high fever, nausea, probably vomiting, aching, a lot more ill then before treatment. If you do not, then it was probably not malaria.

You are likely to still feel very unwell for 2 days after starting treatment. Those who say they had malaria and took whatever and they were better the next day probably did not have malaria. The symptoms of malaria always get worse after effective treatment.

Artenam has no important side effects, is very safe and is tasteless. Artenam kills only the parasites in the blood, not any new generation coming through the liver. So we always give doxycyclin with it one a day for 10 days to prevent a relapse. We have seen no treatment failures in those taking the full course of Artenam plus 10 days of doxycyclin.

Quinine is also effective but much more slowly, and it is very unpleasant. We no longer use it.

Atovoquone (malarone) is effective, hideously expensive, and tastes nasty. So why bother?

Chloroquin and fansidar are effective in immunes, but not likely to work in expats. Most of the disasters I’ve seen are in expats treated with chloroquin or fansidar.

Most people do not get malaria living in Kampala. However you are likely to get all sorts of niggling infections causing fever when you first arrive so why risk malaria as well? Most long-term residents take nothing unless they go to one of the notorious areas, but almost all cases of malaria we see are in those taking nothing.

I advise all travelers to take prophylaxis, all newcomers for the first year or two, and anyone going to the coast or out of town. We have been here 20 years, but my family takes chloroquin and paludrine when we go to the coast or a game park where we might meet mosquitoes that have bitten immunes.

Expensive, very effective, but 10% of people will get unpleasant psychiatric side effects. First bad dreams, not sleeping well, mood swings, then paranoia, panic attacks even frank psychosis. Not worth the risk unless you know you are one of the 90% who can tolerate it.

Useless for treatment but we find it is still effective as a prophylaxis. It is concentrated in the liver and hangs around for months. It stops the parasites from developing and is much more effective if taken with paludrine. Your leaflet may say chloroquin is useless in chloroquin resistant areas, but it still seems better than nothing.

Chloroquin and Paludrine
Our recommended combination. No significant side-effects, though plenty of rumours. Safe in pregnancy and babies. We hardly ever see malaria in people taking paludrine and chloroquin, and in those few it has been mild. No point in continuing after leaving a malarial area, take your last dose as you get on the plane or come home from Murchison.

Effective. It will clear up your acne too. Has to be taken with food, can cause ulcers and thrush in ladies. Needs to be continued for 10 days after leaving. Not for children below 8 yrs, pregnant or breast feeding women.


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