does it cause any disease?
Yes, specially in birds.
Apororhynchus
These worms exclusively parasitize birds by attaching themselves around the cloaca using their hook-covered proboscis. The bird hosts are of different orders, including owls, waders, and passerines. Infestation by an "Apororhynchus" species may cause enteritis and anemia.
what is apororhynchus? It a genus of small parasitic spiny-headed  worms.
wiki:14444412
Apororhynchus [SEP] Introduction
This genus contains six species that are distributed globally, being collected sporadically in Hawaii, Europe, North America, South America, and Asia. These worms exclusively parasitize birds by attaching themselves around the cloaca using their hook-covered proboscis. The bird hosts are of different orders, including owls, waders, and passerines. Infestation by an "Apororhynchus" species may cause enteritis and anemia.