Tapeworm Infection Diagnosed after Campylobacter jejuni-induced Enteritis

Abstract

A 35-year-old man with fever and diarrhea visited our hospital because of white string-like fecal excretion. Based on a morphological examination of the excreted object, a Diphyllobothrium infection was suspected. Additionally, Gram staining of a fecal sample revealed Campylobacter infection. After the intraduodenal administration of meglumine/diatrizoate sodium, the tapeworm was excreted. A polymerase chain reaction-based DNA sequence analysis demonstrated that the tapeworm excreted in this case was Diphyllobothrium nihonkaiensis. This report presents a rare case of coinfection with Diphyllobothrium nihonkaiensis and Campylobacter jejuni. Therefore, it is important to consider the coexistence of other intestinal infections when diagnosing parasitic infections in patients with fever.

Keywords: Campylobacter; Diphyllobothrium nihonkaiensis; gastrografin; tapeworm.

Figure 1.

(A) The tapeworm segment brought by the patient. (B) Low-power field and (C) high-power field microscopic examination of a fecal sample demonstrated oval eggs with an operculum (operation: arrow) and thick eggshell. Scale bars: 1 mm (B) and 50 μm (C).

Figure 2.

Gram staining of the fecal sample showed Campylobacter jejuni appearing as Gram-negative, small spiral rods (arrows). Scale bar: 100 μm.

Figure 3.

Small bowel follow-through using meglumine/diatrizoate sodium (gastrografin) showed a long tapeworm in the ileum (arrow).

Figure 4.

(A) Macroscopic evaluation of the excreted tapeworm after the administration of gastrografin. (B) The tapeworm was excreted along with its scolex.

Figure 5.

Molecular identification of D. nihonkaiensis species by restriction fragment length polymorphism analysis using PCR-amplified cob gene fragments. Lanes: 1: PCR with a mouse tail sample as a negative control; 2: PCR with DNA from D. nihonkaiensis as a positive control; 3: PCR with DNA from the patient’s sample; M: molecular marker. The diagnostic fragment (1,500 bp) was clearly amplified in the positive control and patient samples.