Praziquantel Could Be the Appropriate Choice for the Diagnostic Treatment of Schistosomiasis.

To the Editor We read the article entitled, “Schistosomiasis Diagnosed using Laparoscopy and Colonoscopy,” by Koizumi et al. in the Internal Medicine 58: 2495-9, 2019 (1). We appreciate the authors' contribution to medical progress in the fight against such neglected tropical diseases, which are widespread in developing countries. The authors' detailed description reminds us of this important hepatic and colorectal pathogen, on which we seldom see laparoscopic findings or a colonoscopic view with narrow-band imaging.

However, we would like to address three issues related to this patient's care and clinical course.

First, the fecal smear test has high specificity but low sensitivity. Therefore, the negative result of a fecal smear is not surprising. Second, was an invasive laparoscopic liver biopsy necessary for a definitive diagnosis? We ask since we consider the presence of parasite eggs in the lamina propria obtained by colonoscopy sufficient to make a diagnosis. In addition, high-modality imaging studies, such as magnetic resonance imaging (MRI), can provide highly specific diagnostic value in the modern era (2). Did the medical team try to perform MRI of the liver? Finally, the most appropriate treatment option for this patient may be “diagnostic treatment with praziquantel”, as this anti-helminth medicine has a low rate of adverse effects with no evidence of resistance in Schistosoma japonicum, which would have been a suspected diagnosis in this patient due to the geographical distribution (3, 4). Did the medical team consider such diagnostic treatment with praziquantel in the earlier stage of the clinical course?

The authors state that they have no Conflict of Interest (COI).