Tapeworms are parasitic flatworms that can inhabit human intestines. They survive by absorbing nutrients from their host. While a tapeworm infection can be concerning, it is often treatable with medication and preventable through proper practices.
How Tapeworms Are Acquired
Humans primarily acquire tapeworm infections by consuming raw or undercooked meat or fish containing larval cysts. The beef tapeworm (Taenia saginata) is contracted from undercooked beef, and the pork tapeworm (Taenia solium) from undercooked pork. The fish tapeworm (Diphyllobothrium latum) is found in raw or undercooked freshwater fish, such as salmon. When consumed, these larval cysts develop into adult tapeworms within the human intestine.
Another route of infection involves ingesting tapeworm eggs directly, which can lead to a more severe condition known as cysticercosis. This occurs through contact with contaminated food, water, or poor hygiene, especially with Taenia solium eggs. For instance, if an infected person has poor hand hygiene, eggs can spread to food or surfaces, leading to accidental ingestion by others. Ingested eggs hatch into larvae that migrate from the intestines to form cysts in various tissues, including muscles, eyes, or the brain.
Identifying a Tapeworm Infection
Many individuals with an intestinal tapeworm infection experience no symptoms or only mild gastrointestinal discomfort. When symptoms do occur, they can include abdominal pain, nausea, diarrhea, a feeling of weakness, or changes in appetite. Unexplained weight loss may also occur.
The most distinctive sign is the visible passage of tapeworm segments, known as proglottids, in stool or around the anus. These segments often resemble small, white grains of rice and may even be observed moving. If larval cysts migrate to other tissues, less common but more serious symptoms can arise, such as headaches or seizures if the brain is affected (neurocysticercosis).
Diagnosis and Treatment
Diagnosing an intestinal tapeworm infection involves laboratory analysis of stool samples. Healthcare providers examine these samples to identify tapeworm eggs or proglottids. Multiple stool samples may be required because egg and segment release can be intermittent.
If larval cysts are suspected outside the intestines, blood tests can detect antibodies. Imaging techniques like MRI or CT scans may also locate and assess the extent of cysts in organs or tissues. Treatment for intestinal tapeworms primarily involves oral anthelminthic medications. Praziquantel is frequently used, often as a single dose, and is highly effective at killing the adult worms. For larval infections in tissues, albendazole or praziquantel may be prescribed, sometimes with corticosteroids to manage inflammation.
Preventing Infection
Preventing tapeworm infection centers on proper food preparation and hygiene. Thoroughly cooking meat and fish to recommended internal temperatures kills tapeworm larvae or eggs. Whole cuts of meat should reach at least 145°F (63°C), while ground meat should reach 160°F (71°C). Fish should be cooked until opaque and flaking.
Practicing good personal hygiene, especially handwashing with soap and water, is another preventive measure. Wash hands diligently after using the restroom and before handling or eating food. Ensuring access to clean, safe drinking water and washing fruits and vegetables before consumption also helps prevent infection from contaminated sources.