Author(s): Susan Montgomery, Sharon Roy

Infectious Agents

Taenia spp., including T. asiatica, T. saginata (beef tapeworm), and T. solium (pork tapeworm), cause human taeniasis.

Transmission

Transmission occurs through eating raw or undercooked contaminated beef (T. saginata) or pork (T. asiatica, T. solium).

Epidemiology

Taeniasis prevalence is greatest in Africa, Latin America, and South and Southeast Asia. Taeniasis has been reported at lower rates in Eastern Europe and the Iberian Peninsula (Portugal and Spain). Tapeworm infections are unusual in travelers.

Clinical Presentation

The incubation period is 8–16 weeks for T. asiatica, 10–14 weeks for T. saginata, and 8–10 weeks for T. solium. Symptoms can include abdominal discomfort, anorexia, diarrhea, insomnia, nausea, nervousness, perianal pruritus, weakness, and weight loss. Symptoms are less likely for T. solium infection than for T. saginata infection.

Diagnosis

Diagnosis is made by detecting eggs, proglottids (segments), or tapeworm antigens in the feces or on anal swabs. Differential diagnosis of Taenia spp. is based on morphology of the scolex and gravid proglottids. Clinicians can obtain diagnostic assistance and confirmatory testing from the Centers for Disease Control and Prevention’s Division of Parasitic Diseases and Malaria DPDx laboratory (dpdx@cdc.gov) and from the Parasitic Diseases Hotline for Healthcare Providers (404-718-4745; parasites@cdc.gov).

Treatment

Praziquantel is the drug of choice for taeniasis, except for symptomatic neurocysticercosis (see Sec. 5, Part 3, Ch. 6, Cysticercosis). Niclosamide is an alternative but is not as widely available.

Prevention

Travelers should practice safe food precautions and especially avoid eating raw or undercooked meat.

CDC website: Taeniasis