context: As a kid, you may have heard that only dirty people get worms. In fact, you can get pinworms and tapeworms no matter how often you take a bath. But most of the time, these parasites are easy to get rid of. Pinworms are also called âthreadworms.â They're the most common type of intestinal worm infection in the U. S., and one of the most common in the world. They're thin and white, and about one-quarter to one-half inch long -- about as long as a staple. Tapeworms are flat worms that look a bit like ribbons. Their bodies are made up of segments, and each segment is about the size of a grain of rice. Adult tapeworms can grow to be 30 feet -- almost as long as the average school bus. Fortunately, infections caused by them are rare in the U. S. Pinworms are spread from feces to the mouth. It can happen directly, like when your dirty fingers touch your mouth or food. It can also happen indirectly, like when you touch an object that's contaminated with eggs. Tiny pinworm eggs can live on surfaces -- toys, bathroom fixtures, school desks, or bed linens -- for up to 3 weeks. Once inside your body, pinworms make a home in your colon and rectum. At night, female worms come outside to lay eggs in the skin around your anus. If you scratch the area, the eggs get on your fingers or under your nails, then wipe off on the next thing you touch. This is why pinworms are spread so easily among young children. Tapeworms can live outside for months, waiting for a host to come along. You're most at risk if you work around livestock or travel to a country where hygiene is poor. You can also be infected if you eat or drink something that contains tapeworm eggs or larvae, like raw or undercooked beef or pork. Once inside your body, the tapeworm head attaches to the wall of your intestines. It uses the food you eat to grow new segments. The older segments, which contain eggs, then break off and leave your body with your poop. Most of the time, there aren't any. You might have anal itching, especially at night. You could also have stomach pain, nausea, or vaginal itching. Sometimes pinworms can be seen around your anus or on your underwear or bed sheets about 2 to 3 hours after you've gone to bed. Most of the time, pinworms don't cause major problems. But in rare cases, they can cause infections of the vagina and uterus. If you have a tapeworm infection, you may not have any symptoms. But some people have nausea, stomach pain, weakness, or diarrhea. You might notice a change in appetite (eating more or less than usual). And since the tapeworm keeps your body from absorbing nutrients from food, you may lose weight. If you get tapeworm from eating pork (it's actually called the pork tapeworm), the eggs enter your blood stream and hatch in your tissues. There, they form fluid-filled cysts, which doctors call âcysticercosis.â This can cause a wide range of possible symptoms, depending on where the cysts develop and how much inflammation they cause. Some of these may include vision changes, lumps on the skin, neurologic changes, or seizures. If your doctor suspects you have pinworms, he may ask you to do a âtape test.â As soon as you wake up in the morning, you'll place a piece of clear tape around your anus, then gently peel it off. Any pinworm eggs will stick to the tape, which your doctor can see under a microscope in a lab. A tapeworm infection is usually diagnosed by finding eggs or tapeworm segments in the stool. Your doctor may ask you to bring in a sample so a lab can look for eggs, larvae, or tapeworm segments. A blood test can spot antigens, harmful substances that let your doctor know your body is trying to fight the infection. Sometimes, an MRI or CAT scan can find cysts formed by the pork tapeworm. Some over-the-counter medicines kill pinworms. Your doctor also could prescribe you an anti-parasite medicine. The most common one is albendazole. Everyone in your family should be treated -- even if they don't have symptoms. Two doses are often needed to ensure the infection is gone for good. Sometimes you don't need to do anything about a tapeworm. It could leave your body on its own. But if your doctor finds it, he can prescribe a medicine like praziquantel or nitazoxanide. These will either kill the adult worms or cause you to poop them out. But they won't kill the eggs, which can still cause infections. You'll likely need to give your doctor a stool sample for a few months to make sure all the worms are gone. It's harder to treat an infection caused by tapeworm cysts. In addition to the medicine that kills the tapeworm, you may need medicine to reduce inflammation or other symptoms, like seizures, that you're having. Depending on where your cysts are and how many you have, you may need surgery to remove them. To avoid being infected with either pinworms or tapeworms, it's crucial that you wash your hands with soap and water before eating or handling food and after going to the bathroom or changing diapers. Here are some other ways to prevent them: Keep your fingernails clipped short. Take a shower or bath every day (in the morning is best). Try not to scratch around your anus or between your legs. Wash your clothes and bed linens often. To help prevent tapeworms, try these things: Don't eat raw or undercooked beef, pork, or fish. If you have a dog with tapeworm, treat it right away.