title: Therapeutic failure of praziquantel in the treatment of Schistosoma haematobium infection in Brazilians returning from Africa.
abstract: Several cases of therapeutic failure of praziquantel used for the treatment of urinary schistosomiasis have been reported. Alternative drugs, like niridazol and metrifonate, have shown a lower therapeutic effect and more side effects than praziquantel. Twenty-six Brazilian military men (median age of 29 years) with a positive urine parasitological exam who were part of a United Nation peace mission in Mozambique in 1994 were treated with 40 mg/kg body weight praziquantel, single dose. They swam in Licungo river (Mocuba city, Mozambique) during the weekends. After this, they presented haematuria, dysuria, polakiuria, and lumbar pain. Control cystoscopy examinations carried out between 6 and 24 months after each treatment (including two additional treatments at a minimum interval of 6 months) revealed the presence of viable eggs. Granulomas in the vesical submucosa were observed in 46.2% (12/26) of the individuals. A vesical biopsy confirmed the presence of granulomas in all of these patients and the presence of viable eggs in 34.3% (9/26) of individuals who no longer excreted eggs in urine. The eggs filled with miracidia showed characteristics of viability. Histopathological examination using different strains demonstrated therapeutic failure and the need for repeated treatment. In this study, we demonstrated a low efficacy of praziquantel in the treatment of schistosomiasis haematobia, and the necessity of the urinary bladder biopsy as criterion of cure.
authors.affiliation: Divisão de Ensino e Pesquisa, Instituto de Biologia do Exército, 20911-270 Rio de Janeiro, RJ, Brazil. silva.iran@ig.com.br
authors.forename: Iran Mendonça da
authors.initials: IM
authors.lastname: Silva
authors.forename: Roberto
authors.initials: R
authors.lastname: Thiengo
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Conceição
authors.forename: Luis
authors.initials: L
authors.lastname: Rey
authors.forename: Henrique Leonel
authors.initials: HL
authors.lastname: Lenzi
authors.forename: Edson
authors.initials: E
authors.lastname: Pereira Filho
authors.forename: Paulo César
authors.initials: PC
authors.lastname: Ribeiro
mesh_terms: D000328:Adult; D000349:Africa; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use*; D001938:Brazil; D003558:Cystoscopy; D006099:Granuloma / Q000469:parasitology / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D010270:Parasite Egg Count; D011223:Praziquantel / Q000627:therapeutic use*; D012553:Schistosomiasis haematobia / Q000188:drug therapy* / Q000473:pathology / Q000652:urine; D014195:Travel; D017211:Treatment Failure; D001743:Urinary Bladder / Q000469:parasitology* / Q000473:pathology
chemical_list: D000871:Anthelmintics; D011223:Praziquantel