The dwarf tapeworm or Hymenolepis nana is the most common tapeworm infection diagnosed in the in the United States and throughout the world. Infection is diagnosed in children, in persons living in institutional settings, and in people who live in areas where sanitation and personal hygiene is inadequate.

Causes

One can get infected by accidentally ingesting tapeworm eggs. This can happen by ingesting fecally contaminated foods and water, by touching your mouth with contaminated fingers, or by ingesting contaminated soil.

Adult tapeworms are very small in comparison with other tapeworms and may reach 15-40 mm (up to 2 inches) in length. The adult tapeworm is made up of many small segments, called proglottids (pro-GLOT-ids). As the tapeworm matures inside the intestines, these segments break off and pass into the stool. An adult tapeworm can live for 4-6 weeks. However, once you are infected, the dwarf tapeworm may cause auto infection (the tapeworm may reproduce inside the body) and continue the infection.

Eggs are infectious (meaning they can re-infect you or infect others) immediately after being shed in feces.

Symptoms

Most people who are infected do not have any symptoms. Those who have symptoms may experience nausea, weakness, loss of appetite, diarrhea, and abdominal pain. Young children, especially those with a heavy infection, may develop a headache, itchy bottom, or have difficulty sleeping. Sometimes infection is misdiagnosed as a pinworm infection.

Contrary to popular belief, a tapeworm infection does not generally cause weight loss. You cannot feel the tapeworm inside your body.

Diagnosis

Diagnosis is made by identifying tapeworm eggs in stool. Your health care provider will ask you to submit stool specimens collected over several days to see if you are infected.

Treatment

A prescription drug called praziquantel is given. The medication causes the tapeworm to dissolve within the intestines. Praziquantel is generally well tolerated. Sometimes more than one treatment is necessary.

Prevention

• Wash hands with soap and water after using the toilet, and before handling food.
• If you work in a childcare center where you change diapers, be sure to wash your hands thoroughly with plenty of soap and warm water after every diaper change, even if you wear gloves.
• When traveling in countries where food is likely to be contaminated, wash, peel or cook all raw vegetables and fruits with safe water before eating.

References

CDC