Common causes of worms in humans may include eating raw or undercooked meat or fish, catching the parasites from your pet, poor hygiene and more. Here is an overview of our parasite cleanse protocol. In addition to its effectiveness, special consideration was given for safety. Worms 'N' Us: A look at 8 parasitic worms that live in humans. Take a trip through Scientific American's Worm Gallery and meet the charming, slinky creatures that turn your innards into their home.

1. What Causes Worms In Humans

For many people, parasites are the stuff of nightmares. These organisms take up residence in their human hosts and feed on the nutrients of the person, causing both minor ailments as well as serious and sometimes life-threatening illness.

Many people think parasites may be acquired only in developing and third-world countries or as a parting gift on an exotic vacation. However, a new report from the Centers for Disease Control and Prevention finds these buggers are very much alive in the U.S. Millions of Americans develop parasitic infections and symptoms often go unnoticed or are misdiagnosed. These microscopic creatures are typically picked up through food and water. An infection can lead to serious health problems, including seizures, blindness, pregnancy complications, heart failure and even death.

Thankfully, however, it's possible to prevent and treat infections caused by these unwanted guests. Parasites can usually be detected with a blood test or through stool analysis, and treated with anti-parasitic drugs or antibiotics.

Here are five of the most common parasitic infections in the U.S., according to the CDC:

Chagas disease

More than 300,000 American are infected with Trypanosoma cruzi, the parasite that causes Chagas disease, and more than 300 infected babies are born every year. Chagas disease is transmitted through a bite from the triatomine bug, which then deposits its feces in the skin opening. Chagas disease can cause long-term digestive, cardiac and neurological complications. Death from the infection is often caused by heart attack. However, if caught early, the condition is easily cured with medication.

Cysticercosis

This parasitic infection, caused by the taenia solium tapeworm, makes its home in human tissues such as the brain and muscles. Larval cysts from the parasite form in the body and can cause a number of complications, including seizures. There are at least 1,000 hospitalizations for cysticercosis per year in the U.S. This tapeworm infection is often the result of eating uncooked pork that contains larval cysts.

Toxocara

Approximately, 13.9 percent of the U.S. population has antibodies against this parasitic infection. Sadly, the rest of us are at risk for for acquiring it through roundworms often found in the intestines of dogs and cats. About 14 percent of Americans have had exposure to toxocara, and at least 70 people die from the infection each year. According to the CDC, most of the infections are in children and many suffer blindness due to related eye disease.

Toxoplasma gondii

What Causes Worms In Humans

Toxoplasma is often called the 'cat poop parasite,' since it's frequently caused by close contact with a friendly feline. In the U.S., more than 60 million people are chronically infected with toxoplasma gondii. The parasite is also found in undercooked meat and even some unwashed fruits and vegetables. Health experts say toxoplasma can put pregnant women at risk for birth defects. Symptoms of this parasitic infection include swollen lymph nodes, muscle aches and eye complications. If left untreated these problems can become chronic.

Trichomoniasis

In the U.S., trichomonias is an incredibly common and curable sexually transmitted disease, though it can also increase one's risk for developing other STDs. The protozoan parasite affects 3.7 million people in the United States. However, only about 30 percent of people will actually develop symptoms, which can include itching and burning in the genital area, pain during urination and discharge. The parasitic infection is treated successfully with prescription antibiotics.

A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.

Protozoa are microscopic, one-celled organisms that can be free-living or parasitic in nature. They are able to multiply in humans, which contributes to their survival and also permits serious infections to develop from just a single organism. Transmission of protozoa that live in a human’s intestine to another human typically occurs through a fecal-oral route (for example, contaminated food or water or person-to-person contact). Protozoa that live in the blood or tissue of humans are transmitted to other humans by an arthropod vector (for example, through the bite of a mosquito or sand fly).

Entamoeba histolytica is a protozoan. A microscope is necessary to view this parasite. Credit CDC.

The protozoa that are infectious to humans can be classified into four groups based on their mode of movement:

• Sarcodina – the ameba, e.g., Entamoeba
• Mastigophora – the flagellates, e.g., Giardia, Leishmania
• Ciliophora – the ciliates, e.g., Balantidium
• Sporozoa – organisms whose adult stage is not motile e.g., Plasmodium, Cryptosporidium

An adult Ascaris lumbriocoides worm. They can range from 15 to 35 cm. Credit CDC.

Helminths are large, multicellular organisms that are generally visible to the naked eye in their adult stages. Like protozoa, helminths can be either free-living or parasitic in nature. In their adult form, helminths cannot multiply in humans. There are three main groups of helminths (derived from the Greek word for worms) that are human parasites:

• Flatworms (platyhelminths) – these include the trematodes (flukes) and cestodes (tapeworms).
• Thorny-headed worms (acanthocephalins) – the adult forms of these worms reside in the gastrointestinal tract. The acanthocephala are thought to be intermediate between the cestodes and nematodes.
• Roundworms (nematodes) – the adult forms of these worms can reside in the gastrointestinal tract, blood, lymphatic system or subcutaneous tissues. Alternatively, the immature (larval) states can cause disease through their infection of various body tissues. Some consider the helminths to also include the segmented worms (annelids)—the only ones important medically are the leeches. Of note, these organisms are not typically considered parasites.

An adult louse. Acutal size is about as big as a sesame seed. Credit CDC.

Although the term ectoparasites can broadly include blood-sucking arthropods such as mosquitoes (because they are dependent on a blood meal from a human host for their survival), this term is generally used more narrowly to refer to organisms such as ticks, fleas, lice, and mites that attach or burrow into the skin and remain there for relatively long periods of time (e.g., weeks to months). Arthropods are important in causing diseases in their own right, but are even more important as vectors, or transmitters, of many different pathogens that in turn cause tremendous morbidity and mortality from the diseases they cause.

Parasitic infections cause a tremendous burden of disease in both the tropics and subtropics as well as in more temperate climates. Of all parasitic diseases, malaria causes the most deaths globally. Malaria kills approximately 660,000 people each year, most of them young children in sub-Saharan Africa.

The Neglected Tropical Diseases (NTDs), which have suffered from a lack of attention by the public health community, include parasitic diseases such as lymphatic filariasis, onchocerciasis, and Guinea worm disease. The NTDs affect more than 1 billion people—one-sixth of the world’s population—largely in rural areas of low-income countries. These diseases extract a large toll on endemic populations, including lost ability to attend school or work, retardation of growth in children, impairment of cognitive skills and development in young children, and the serious economic burden placed on entire countries.

However, parasitic infections also affect persons living in developed countries, including the United States.