Article by: Dr. Dick Stockley

Prevention Part 2

And now some philosophy. If something works most of the time, but isn’t 100%, is it a good option? The Pakwatch school boy gets bitten every night by 3 or 4 infected mosquitoes, so he always has malaria. This makes him immune, so he may be a bit tired most of the time, and he gets a clinical attack of malaria every now and again when he gets a cold or bad diarrhoea due to lowering his immune threshold. Preventing malaria will probably make him healthier, cleverer, and bigger, and has been shown that he is less likely to die from pneumonia and diarrhoea as getting rid of his malaria strengthens his immune system. BUT, and this is a big But. (Oops, pun not intended.)

Now he sleeps under a net. So for a year or 2, or 3, he doesn’t get malaria and he is fitter, bigger and cleverer. Then the system fails. He gets up for a pee in the middle of the night and gets bitten for the first time in 3 years. His immunity has now waned. So he gets a really awful attack of malaria, and without treatment he is going to be like the non-immune mzungu, multi-organ failure and dead in 2 weeks. And as he doesn’t have immunity, or at least a lot less immunity then before, he needs full total treatment, not partial. See last month. Just a thought for the health planners - If we are serious about prevention, we had better do it properly or not at all!

And now the Biggy! DDT One lecturer at the Liverpool School of Tropical Medicine, where clever doctors go, used to swallow a teaspoon full of DDT powder in front of the students to demonstrate how safe it is. Yes I agree with “Silent Spring”, but hey, that was millions of tons of the stuff sprayed on crops indiscriminately every year. So as we all know it builds up in the food chain and birds lay soft eggs. But a tiny amount sprayed on the walls is as safe as houses. Maybe the vultures may get a little too much when they eat us, but as long as we are buried, I don’t think it matters!! Now I am not daft, I know the real issue is that the EU and USA have zero tolerance for organophosphates in fish and coffee. OK. So what about their tolerance for mercury in tuna? Could it possibly be that European and American fishermen catch poisoned Tuna from European and American pollution,

but not tilapia with one part per million of DDT? I don’t know much about politics, but do I smell hypocrisy? I also know that if the District health officer has a few drums full of DDT for perfectly safe spraying on house walls to save a lot of lives, then it is very tempting to spray a bit of it on his tomatoes or his cotton too, and sell a bit to his mates as well. Dangerous!! I also know that if the poor old farmer simply leans his bag of coffee beans against the sprayed wall, it will pick up the one in a million parts of DDT that will get our whole crop rejected by the EU. So the programme needs a lot of honesty and a lot of education. The challenge is on! However to me the biggest challenge is, destroy the immunity built up over years, and everything about malaria changes. When the Pakwatch schoolboy does get malaria he is going to need far more vigorous treatment than he used to.

Enough Philosophy, on with the drugs.
There are many each with pros and cons.

Malarone
Excellent drug, 100% effective, there is no record of proven malaria in Africa in someone taking Malarone correctly. It is the only drug that works in the liver, actually preventing malaria from developing at all, and in the blood killing it if it escapes from the liver. For this reason it only needs to be started the day you arrive and for 5 days after you leave. It probably has more side effects than the others, none particularly dangerous. Your hair may fall out, you may get mouth ulcers, you may be dizzy and sick, you may get diarrhoea, but then who doesn’t? Prove it is the Malarone! However the main side effect is the very serious effect on your wallet. The stuff is ridiculously expensive. It is great for a weekend away, as you only need to take it for 5 days but costs a fortune if you are here for 3 months. Maybe that is another way that it works: once you have bought the Malarone, you can’t afford to go to Murchison! If you miss a dose it doesn’t matter, probably works if you take a dose alternate days, though I wouldn’t try it! If you are leaving the country we will buy any leftover Malarone from you at 4,000/= a tablet.

Mephloquin
This is a great drug for 90% of us. Another 100% effective drug in Africa, i.e. no proven case in those with adequate blood levels, but 10% of people get serious psychiatric side effects. Don’t let this put you off: the drug has a very long half life of 3 weeks, and hangs around for 7 weeks; it builds up slowly, so you get some warning. If after 3 tablets you start to get bad dreams, wake up at night screaming with emotional swings and paranoia, (they are out to get you, but you’re not supposed to know) then stop the drug. The full blown picture of psychosis, and laughing and crying at the same time, comes slowly over the first few weeks. If you have taken over 4 tablets and start to get mild problems, then reduce the dose to 3 a month, i.e. skip a dose and skip the last Sunday every month. And the skipping will make you fit, too. Good option for those who can tolerate it for long term use, not really useful for weekends away as you need 3 doses to begin to get an effective blood level.
It obviously doesn’t matter if you forget to take a dose, and you only have to take one more dose after you leave, as it lasts for 3 weeks. It works only in the blood, not in the liver, so although it kills all species, Vivax can still come out of the liver and get you up to a year later. It is now the CDC recommended drug for pregnant women.

Doxycyclin
Like Mephloquin, Doxycyclin works only on the blood stages, so you can develop some immunity to malaria without ever getting sick if you live in an area of high transmission. Unfortunately it is no longer 100% effective for everyone; we have seen a few cases of malaria from some areas of the country even in those taking it properly. However it slows the malaria down, so instead of getting the classical alternate day rigors and fever getting worse every cycle, the few patients we have seen have been vaguely ill with little fevers coming and going, but mostly just ill and tired for weeks. It is very difficult to find in such cases, the slide is negative, even the malaria rapid the first few days, but usually the urine is dark, and that is a good clue. Treatment is the same, with ACT’s, but do carry on with the doxy, it is still mostly effective.

It is a great drug, with few side effects, and very cheap, about 2$ a month. Main problem is that blue eyed blondes and the Irish can get terrible sunburn. The sensible option is try it and see. The most important warning is take it standing up with a lot of water or followed by food. If it sticks half way down your oesophagus, it will make an ulcer and give you pain swallowing for 10 days. 2 of my children have managed to do that!! It can give ladies thrush, but only for the first few weeks, then the lactobacillus gets resistant to it and it doesn’t happen again. Ditto the “pill doesn’t work” story. Oestrogen absorption depends on a bacteria killed by antibiotics, but again it gets resistant after a week or 3, and anyway the progesterone component isn’t affected. Have you ever seen anyone get pregnant on the pill while taking doxy? I haven’t!
It is safe in pregnancy. If taken in the last 4 months, the baby teeth may be stained brown. It won’t happen if taken for a weekend away. It works only on the blood stage, so needs to be taken for at least 2 weeks after leaving the malaria area. If used to cover the Entebbe night flight scenario, take it for a full 2 weeks, and when you stop, if you do have a grumbling chronic malaria, it will now take off as a classic full blown malaria attack, so a fever a week after stopping doxy must be properly assessed.

Primaquin
This is a great drug - its very cheap and costs about 3 dollars a month. Trials show pretty good efficacy, but not enough yet to know the full picture. I have never seen a case of malaria in Uganda on someone taking Primaquin. Like Malarone, it works in the liver, actually preventing malaria rather then killing it in the blood after it comes out. Also like Malarone it kills Vivax, so if taken on departure, you will not get a dose of Vivax a month after coming home. The only significant side effect is that it causes haemolysis in people with G6PD deficiency. Er….it does what? Don’t worry about it! If you are of true northern European descent, it is safe for you! However if you, or the father of your unborn baby, is genetically from the Mediterranean, Africa, the middle and Far East, then you may have the gene for this fairly rare blood group, and if you take Primaquin or half a dozen or more other drugs, then there is a risk of the blood self-destructing. Simple. If you are at risk, get a cheap blood test done before you take Primaquin.

It is an excellent weekend away drug as you only need to take it for 5 days, if you forget a dose it doesn’t matter, and a good choice for pregnant women as long as you know who the father is!

Summary
Read the other 6 articles online so you know what I am talking about. Get a map, so you know where Makindye is People living up country, travellers, Kampala residents going away for the weekend, or taking a night flight out of Entebbe should take prophylaxis. The drugs work, if you are told you have malaria be very suspicious.