Resolution and Resurgence ofSchistosoma haematobium–induced Pathology After Community‐based Chemotherapy in Ghana, as Detected by Ultrasound

Abstract

Community-based treatment is recommended for endemic populations with urinary schistosomiasis; however, the optimal target group for treatment and retreatment interval have not been established. Using ultrasound, this study identified subpopulations whose lesions were most likely to respond to treatment and characterized resurgence of pathology. Ultrasound examination of 1202 infected patients was followed by chemotherapy with praziquantel. A sample of 698 patients was followed for 18 months after treatment. Nearly all types of bladder pathologies resolved after treatment, regardless of patient's age or intensity of initial infection. However, many patients' upper urinary tract pathologies (62.5%) did not resolve. During the 18-month follow-up period, reappearance of severe bladder pathologies was rare, and <10% of persons had resurgence of mild bladder pathologies. For this population, retreatment is not needed annually but might be cost effective if given several years later. Confirmation from other areas is required before general policies can be formed.

The WHO ultrasonography protocol for assessing hepatic morbidity due to Schistosoma mansoni. Acceptance and evolution over 12 years

“…(Ouma et al 2005;Tohon et al 2008;Ramarakoto et al 2008;Ekwunife et al 2009;Qazi et al 2012;Strahan et al 2013). Unfortunately, none of the two studies on reappearance of lesions following therapy in re-exposed people referred to the Niamey protocol (Campagne et al 2001;Garba et al, 2004) However, since there is a number of studies where evolution of pathology has been assessed using the former Cairo protocol it is likely to be applicable in this respect, too (Hatz et al 1998;Wagatsuma et al 1999;Richter 2000, Hatz 2001Richter 2003a;Richter 2003b). By the modifications of the Niamey protocol as proposed above, the assessment of the regression and subsequent reappearance of lesions in constantly exposed individuals might be evaluated more properly.…”

Case–Control Study of Posttreatment Regression of Urinary Tract Morbidity Among Adults in Schistosoma haematobium–Endemic Communities in Kwale County, Kenya

“…In a study by Delegue and others 34 in Senegal, in which 24% of the subjects were over the age of 25, urinary tract lesions were said to regress significantly in the cohort at large 4 months after PZQ therapy, but an age-specific breakdown of outcomes was not given. In a large study in Ghana, Wagatsuma and others 36 confirmed that all types of S. haematobiumassociated bladder pathology resolve after treatment regardless of patient's age (whether adults or children) and initial intensity of infection. However, many (73%) of their subjects above age 15 who had upper urinary tract pathology did not resolve ureteral and/or kidney abnormalities by 18 months after PZQ therapy.…”

“…16,[29][30][31][32][33][34][35][36][37][38] However, these studies have been primarily focused on responses among children and not adults. Doehring and others documented improvement of bladder lesions associated with schistosomiasis among children within 2 months, 29 and found reversibility of urinary tract obstructive findings within 1 year after treatment.…”

“…34,35 Our results confirm that bladder lesions regress quickly, even in adults, whereas upper tract lesions tend to regress more slowly, if at all. 31,36 Although some of our adult subjects were egg negative, the study was performed in an area where nearly all residents experience significant S. haematobium infection by the age of 15. 41 Our subjects' ultrasound findings were typical of schistosomiasis haematobia, 17,35 and it is clear that structural urinary tract disease can persist after active infection subsides.…”

Therapeutic failure of praziquantel in the treatment of Schistosoma haematobium infection in Brazilians returning from Africa

“…Post-treatment follow-up is generally performed by noninvasive methods such as ultrasound of the urinary tract, which, however, do not identify treatment failure (Hatz et al 1998, Wagatsuma et al 1999. Although studies have reported the persistence of pathological alterations and even the development of complications identified by ultrasound in treated patients, no histopathological evidence exists regarding the persistence of viable eggs after long post-treatment periods.…”