Re: What is the biggest thing that causes an infection

Hi Susan.

It often seems like when we get sick, or have an infection, that the cause is something that we never see. Right now I'm recovering from the flu and I really wish that virus was big enough to see with my eyes because I could of seen it and stayed away from it. Unfortunately, as you know viruses are so small we can�t see them just with our eyes. But just because we can't see them does not mean they are not there. Some scientists even have ways to look at viruses and bacteria using different types of microscopes. Here is a picture of the type of virus that gave me the flu. The picture was taken with a special microscope called the electron microscope.

There are other causes of disease, besides viruses and bacteria, that may be much bigger even big enough to see with our own eyes. Would you believe me if I told you that it is possible to become infected by something that is 30 feet long? That is five times taller than me. Surely someone could avoid getting sick by something that big? But it's really true that there is a worm, a tapeworm, called Diphyllobothrium latum that can live in our belly and grow as long as thirty feet. Unfortunately, it does not grow that long until it gets into our belly so we can't see it to avoid it. People become infected by the worm by eating insufficiently cooked fish in which a small stage of the tapeworm, called a larvae, can live. This is a picture of what the tapeworm looks like:

The biggest thing that causes an infection is a tapeworm. Actually the longest animal in the world is also a tapeworm that can be over 130 feet long. Lucky for us that tapeworm, called Polygonoporus, infects whales and not people. Don't get worried about getting sick by a tapeworm because they are not very common in the U.S. and most people do not even feel sick when they are infected. Doctors can also easily detect these tapeworms when someone is infected even when it is hidden in our belly. To avoid getting infected by a tapeworm people need to make sure that the meat they eat is cooked well.

I hope that this helped to answer your question.