Unusual cases of Taenia crassiceps cysticercosis in naturally infected animals in the Czech Republic

Abstract

The tapeworm Taenia crassiceps has an indirect life cycle. Occasionally, metacestode stages have been reported from aberrant hosts as dogs, cats, lemurs and humans. This study describes an unusual series of serious cysticercosis cases: an 18-month-old male Yorkshire terrier dog with pleural cysticercosis accompanied by a cough, a 10-year-old male Shih Tzu dog with subcutaneous cysticercosis as well as a Cape ground squirrel and a Senegal bushbaby, both with generalised cysticercosis. Surgery was successful only in the Shih Tzu. The Yorkshire terrier died a few hours after surgery, while the Cape ground squirrel was euthanised and the Senegal bushbaby died before surgery. Cysticerci from the four cases were identified morphologically and using molecular methods. Fragments of genes coding for cytochrome oxidase subunit 1 were sequenced for each of the four isolates. Their affiliation to T. crassiceps was confirmed by comparison with the sequence data of other isolates available in the GenBank database. In general, the comparison of sequences of all isolates showed low variability in nucleotide composition (at most five positions). The cases from captive zoo animals represent the first findings of T. crassiceps in the Cape ground squirrel and Senegal bushbaby. The optimal treatment of cysticercosis caused by T. crassiceps remains unclear. Successful attempts usually include extensive surgical interventions and prolonged anthelmintic treatment. Chemotherapeutic options are limited. Although regular deworming targeting intestinal helminths of dogs is not effective against T. crassiceps cysticerci, it may help to prevent contamination of the environment by tapeworm eggs contained in dog faeces and reduce the risk of infection for susceptible animals and humans.