So you asked me to say a little bit about worms or helminths and we kind of divide them up clinically into the roundworms and the flatworms. And the roundworms that we see here are Ascaris and hookworm. There's also trichuris, which was more common in children. So these are traditionally known as the roundworms. Most of those have their cycle through the oral route, except hookworm actually goes into your feet. So, and the worm finally, the final resting place for the worm is in your small bowl, your intestine, usually your upper small bowel. And Necator americanus, Necator duodenale, they're very famous for one thing, is that each hookworm feeds on a certain amount of blood from your intestine per day. So cumulatively, if the worm load is high and is there for a long time, you will become deficient in blood and particularly iron. And this gives rise to the main clinical presentation of hookworm is the iron deficiency, anemia. Now traditionally, those worms are associated with people who have been exposed to soil, because the entry's to their feet. So you can imagine, then, that with urbanization, they almost disappear. But if you consider that 80% of Tanzania and, well, 90% of Tanzania, comprise of farmers who are working in the soil. So if we see a non-deficiency anemia coming from somebody in the farming community, we will think of hookworm. They're easily identified under a microscope looking at a stool sample, and they're easily treated with a broad spectrum anthelmintic drug like Bendazol, often as a single dose. And you can replace the iron with ferrous sulfate tablets. Ascaris is a much bigger roundworm that lives in your intestine, usually the small bowel. And they tend to cause problems more in children, when the worm load can get very big and will cause abdominal pain and they're easily identified by their eggs in the stool. And they would be what we call worms in children and it's the same oral-fecal root of transmission, so that man is the definition of host for these worms. So there isn't intermediate host, it's just between you and the worm, and its lifecycle. So, and Trichuris, we see sometimes reported by the microscopist from the laboratory. So, generally speaking, these are called the helminths, the roundworms, and there they're in your intestine. If you go to some parts of rural Tanzania and rural Uganda, you may find that the worm load and the percentage of the population infected with worms can get up as high as 50%. In other words, it's almost living as a commensal with humans. And there's some very interesting research coming out now suggesting that worms from Uganda, and this is prospective studies, looking at the effect of early worm infection on the unborn neonate, the unborn child, and mother. And the studies are suggesting that possibly, there is some protection against what we call diseases associated with allergies of the skin, and that would be eczema and also asthma. And there is some evidence suggesting that early infection of the mother during pregnancy, when she's carrying the baby, and of the baby during its first years of life is protective later on against this big epidemic of what we call common diseases now in the west, the eczemas and asthma, which are increasing. That's an example of possibly humans living with worms historically for thousands of years, and evolving a coexistence, maybe even a protection. The other worm then that we do see from time to time are the flatworms, or what we call the tapeworms. And usually the beef tapeworm it's called, man is a definitive host for the worm and then the intermediate hosts are cows. And then the life cycle is completed if man ingests undercooked beef, these worms can be up to a meter long. And they're very famous because they come out in your back passage when you're passing urine. Or you may see the postage stamp size or less of the actual worm in the stool in segments and segments and they excrete these in the stool, full of eggs but the worm doesn't die. And they're associated with big abdominal pain. Usually the saginata doesn't cause too much symptoms apart from vague, nonspecific symptoms. But the solium or the pig one does cause symptoms. And the way that may cause symptoms is that, again, man's definitive host, pig is intermediate host. And the way that lifecycle is transmitted is the pig ingests feces, and the worm insists in the pig's muscle, which becomes measly, or what we call full of cysticerci, that's what they're called, little encysted, and then man ingests undercooked pork, and the life cycle is completed. But if man intervenes, and gets contaminated orally with somebody's stool which carries the taenia saginata over, then he becomes intermediate host, and he develops a disease called cysticercosis. Now cysticercosis are the very same cysts that the pig should develop. Man is developing those in his muscles and maybe in his brain. And this is where the pig tapeworm in Africa is responsible for a sizable proportion of epileptic seizures in areas endemic for the disease. The method of prevention, of course, is hygiene, defecation in toilets, that would immediately break the cycle. The other way would be not to have pigs, free range pigs. In other words, the possibility of ingesting human feces. And of course, the last possibility to pick up infection is from somebody who's infected with the worm, who isn't hygienic handing your food. And that means vegetarians can pick up the disease. The adult worm is amenable to treatment with anti-larva sides or anthelmintic drug, but the actual cystic form is very difficult to treat. It's estimated that there may be as many as 50 million people in sub-Saharan Africa actually exposed to cysticercosis. And has been responsible for the burden of epilepsy, it's estimated that it could be responsible for 10, 20% of all the epilepsy in that community. So you can see then that cysticercosis has a significant morbidity, and there is mortality with it as well. Some patients don't survive the disease in their brain. It's an old disease, and it's been around as long as humans have been around, living with animals. And it's of interest that, historically, the pig has been a creature that religions have chosen not to eat for different reasons, and it may well be, that some of that may have emanated from their understanding their role in epilepsy, and that's just hypothesis. But, it's of interest. The last of these tapeworms I want to discuss is the Echinococcus granulosus. And in this case, the human is not the definitive host for the worm. The dog is, usually the dog or some canines like foxes or jackals. But the one that we pick the disease from is the dog. And usually the dog carries the adult worm, it excrete the offal in stool, then cows ingest the offal, they become the intermediate host. The worm develops in the muscles of the cow, usually the mesentery, the intestine, sometimes in the brain, and then the dog eats the offal or the mesentery, and the life cycle is continued. So along comes a human, especially the animal husbandry, the Maasai, who have dogs and deal with cattle, they're the group that will get the disease. It's called hydatid disease, and of course, they become the intermediate host by accidentally touching, or ingesting dogs feces, and now you become the intermediate host. So, you develop the cysts, and these cysts may grow in your intestine, your liver, your lung, and occasionally in the brain, or spinal cord. And you can imagine, the cysts grow as big as oranges and they are very difficult to treat. They have to be surgically drained and drugs have minor if any role. So hydatid disease then is one of the diseases we see. It's endemic in certain traditional communities, the Maasai, the Turkana in Northern Kenya. And the Karamojong in northern Uganda, they're all what we call nomadic pastoralists with cattle and dogs, and these are the epicenters then, of the of hydatid disease across sub-Saharan Africa. Thank you.
