Five-year impact of repeated praziquantel treatment on subclinical morbidity due to Schistosoma japonicum in China

Abstract

We report the 5-year impact (1996)(1997)(1998)(1999)(2000)(2001) of repeated praziquantel chemotherapy on subclinical morbidity related to Schistosoma japonicum infection. We repeated stool examinations and hepatosplenic ultrasonography in a cohort of 120 individuals living on an island with endemic infection in Dongting Lake, China. Prevalence of schistosome infection fell by 43% and intensity (geometric mean eggs per gram) declined by 80% over the 5 years. However, transmission persisted at a dangerously high rate of 13% per year for re-infection or new infection in the cohort. The prevalence of left-lobe enlargement and dilated portal vein fell significantly (P < 0.01) to about half initial levels although a few patients progressed during the study period. At study endpoint, infection was nearly twice as common if the portal vein was dilated (23% versus 13%, respectively), but this association was not statistically significant (P > 0.05). However, endpoint infection was even more strongly associated with left-lobe enlargement (57% versus 15%, P < 0.01). The proportions of subjects with improved parenchymal and periportal tibrosis were much higher than the proportions of subjects that progressed (P < 0.05). Reduction of prevalence and intensity of infection, and improvement of subclinical morbidity, were benefits of repeated treatments. Further research is needed to understand why some patients developed fibrosis despite substantial reductions in egg counts and to evaluate the functional importance of residual subclinical morbidity after chemotherapy-based control in the lake and marshland area of China.

Effect of Chemotherapy with Praziquantel on the Production of Cytokines and Morbidity Associated with Schistosomiasis Mansoni

“…In addition, the lack of a characteristic pattern of fibrosis reversal emphasizes the need for further in-depth analyses of the factors involved. The lack of complete reversion following chemotherapy has already been described in reports of human studies (12,23,33) and mouse studies (3,4). Comparison of old and young patients with respect to the time factor related to fibrosis regression among the treated cases was not considered, because in our study only 4.4% of subjects were less than 20 years of age.…”

Severe hepatosplenic schistosomiasis: clinicopathologic study of 102 cases undergoing splenectomy

“…All patients were symptomatic for schistosomiasis and had splenomegaly (Hackett criteria ≥II) according to published classification criteria [3,[10][11][12]. A medical questionnaire was used to obtain details of medical history and demographics for each patient.…”

Use of Ultrasonography to Evaluate Schistosoma japonicum-Related Morbidity in Children, Sichuan Province, China, 2000–2007

“…8 Several longitudinal community-based surveys look at the use of ultrasonography to evaluate S. japonicum -related liver morbidity. 15,25,26 Our study is unique in its long followup period and focus on a cohort of Chinese children living in an area where there have been large reductions in infection prevalence.…”

“…Those that exist are from over a decade ago and do not have as long of a follow-up period as our study. 15,25,26 Another strength of our study is its specific focus on Chinese children, which are an at-risk group that needs to be evaluated differently than adults because of their growth and development. Also, our study provides useful recommendations for schistosomiasis control and surveillance.…”