Kampala is a city built on 7 rumours and 8 of them are about health. Bilharzia is no exception, and some guide books give the most extraordinary advice. Regular Eye readers will know my summary of staying healthy in Uganda: don’t drink and drive, wear a seat belt and keep your knickers on.

So here goes with my simple advice. Lake Vic is the biggest fresh water lake in the world, it is pretty well free of any real health threatening pollutants, is warm and safe, and water sports are fun, cheap and an excellent way of keeping fit. It is difficult to smoke a cigarette while water skiing. So go white water rafting, sailing, water skiing, canoeing, wind surfing and even wild midnight skinny dipping parties, and don’t worry about Bilharzia. Heresy? The truth shall make you free, so read on.

Bilharzia is a common disease that has indeed caused serious health and economic problems in and around many of Africa’s fresh water lakes and rivers. Do not minimize it; it can cause a huge range of multi-organ disease including infertility, renal failure, quadriplegia, epilepsy and even death. It is also easy to diagnose and easy to treat, as long as you are sensible. The life cycle is as always crucial to understanding the risks, symptoms, diagnosis and treatment, so let’s start with faeces. Our local Bilharzia is Schistosoma Mansoni and the eggs are found in faeces. The eggs are washed into the lake or rivers, hatch out and penetrate the foot of snails. Not any snail, only one species for each human type, and the ph of the water, copper content and temperature determine if the right snail is there. That is why Bunyoni, Naivasha and the soda lakes have no Bilharzia.

The infected snails then produce about 10,000 little larvae called cercaria every day for the rest of their lives. These are short lived, cannot swim far and mostly die in about half an hour.

So you cannot get Bilharzia from water unless you are in contact within half an hour of the water leaving the lake or river. The cercaria somehow wriggle through intact skin and change their names to a schistosomule, though they probably don’t know that. They do not get in through sores, cuts, or by drinking, but directly through healthy skin. They finish up in the liver, where the males and females meet. As far as I know no-one has yet worked out how.

Probably in an intrahepatic disco, which explains why teenagers play extremely loud and very bad music all night long after white water rafting in a futile attempt to confuse the little boys and girls and stop them meeting. However where there’s a will there’s a way and the shistosomules meet and mate for life until death do them part. It really is very sweet. They grow up together, the male has muscles, (don’t we all?) the ladies are a long egg laying tube (no comment) and he wraps himself round her and swims down the veins to the terminal venules of the gut, mostly in the pelvis. There they spend their entire lives in permanent copulation and finally die, probably from exhaustion, mostly after 8 to 10 years. The mature flukes are about 2 cms long and as thin as string. They don’t do any harm, they are covered in our antigens so are

invisible to the immune system, and they don’t eat much. But they lay eggs. If you, and the egg, are lucky it works its way through the intestinal lining and into the bowel where they are passed in faeces, wash into the lake and go off to torment another snail for a few months. So why the big deal?

The eggs. Many don’t make it, get stuck in the tissues, and set up an intense immune reaction. Basically little inflammatory tumours form around the eggs which can grow big enough to cause serious damage in the wrong places. Not all the flukes finish up in the terminal venules of the bowel, some get lost. Many finish up in or around ovaries, tubes, uterus, or prostate if you have one or other small parts most of us are rather fond of. Even worse they can drift up the wrong veins completely and finish up in the brain or spinal cord. Those eggs have no hope of escape and every one causes an inflammatory granuloma which rapidly grows bigger every day as new eggs are added. Hence the paralysis and the “brain tumours”.

So what are the symptoms of Bilharzia?
When first infected there are no symptoms at all. After 4 to 6 weeks the first females mature and start laying eggs, and there is a rapid immune reaction causing general systemic symptoms. Fever is common, often a rash called “safari itch” and joint pains, headache, almost any vague symptoms but mostly just tired. Children become irritable, difficult and tired all the time. Teenagers become, er… teenagers. Without treatment most people get better and are simply tired all the time for the next 10 years.

Many people get organ specific problems, mostly vague bad guts, but sometimes acute dysentery or chronic diarrhoea. Some get diagnosed as appendicitis and get an operation, and thank the surgeon profusely for saving their lives. 3 months later they are still tired, and still have vague recurrent abdominal pain. Many women get gynae symptoms of all types, and finish up with a diagnosis of ovarian cysts, tubal infections, endometriosis, etc. Men get told they have prostate cancer or chronic prostatitis. Most people get vague liver symptoms, and unfortunately the chemical tests show a raised GT and they are told they drink too much.

One good friend who had a “full medical” in UK retorted “Ï drink less than my doctor” and came back here for a proper diagnosis and treatment. I know one American girl who saw 3 gynaecologists and had 3 different diagnoses and a laparoscopy. She then saw a surgeon, who removed her appendix, found her whole large bowel stuck down with inflammatory tissue into the paravertebral gutter, and was flummoxed. So 2 years after leaving Uganda she emailed with her long and expensive history, and got better a week after taking the tablets.

So how do we diagnose Bilharzia?
It is actually very easy! Simple rule of thumb. If you have been in the water and you don’t feel well, think “Bilharzia”.

All rivers and lakes in Uganda have Bilharzia except the dead soda lakes, Bunyoni and possibly Nabugabu. White water rafting is low risk, but the slow water bathing and camping areas are all high risk. Most of the most notorious places for transmission are advertised as “Bilharzia free”, which means the Bilharzia is free; you don’t have to pay for it. All of Lake Victoria is very high risk, especially the shallow first few metres around the edge, right out in the deep water is most likely OK.

Where you have been is important, because the easiest way to diagnosis Bilharzia is “symptoms + exposure = treat. Next issue will look at treatment and prevention.