Diphyllobothriasis

This code represents an infection caused by adult tapeworms of the genus Diphyllobothrium, commonly known as fish tapeworms. Humans acquire this parasitic infection by consuming raw or undercooked freshwater fish containing the larval stage of the parasite. The adult worms reside in the small intestine, where they can grow to significant lengths.

Use this code when documentation confirms a diagnosis of diphyllobothriasis, specifically indicating the presence of adult worms in the gastrointestinal tract. This typically follows laboratory identification of Diphyllobothrium eggs or proglottids in stool samples. Clinical scenarios include patients presenting with abdominal discomfort, diarrhea, or megaloblastic anemia due to vitamin B12 deficiency, with confirmed parasitic infection.

• Differentiate carefully between adult worm infection (diphyllobothriasis) and larval infection (sparganosis), which is coded separately.
• Ensure the documentation specifies the adult stage of the parasite; otherwise, query the provider for clarification.
• Consider co-occurring conditions like vitamin B12 deficiency (E53.8) or anemia (D51.0) and code them appropriately as secondary diagnoses.