Spatial distribution of Schistosoma mansoni infection before and after chemotherapy with two praziquantel doses in a community of Pernambuco, Brazil

Abstract

Praziquantel chemotherapy has been the focus of the Schistosomiasis Control Program in Brazil for the past two decades. Nevertheless, information on the impact of selective chemotherapy against Schistosoma mansoni infection under the conditions confronted by the health teams in endemic municipalities remains scarce. This paper compares the spatial pattern of infection before and after treatment with either a 40 mg/kg or 60 mg/kg dose of praziquantel by determining the intensity of spatial cluster among patients at 180 and 360 days after treatment. The spatial-temporal distribution of egg-positive patients was analysed in a Geographic Information System using the kernel smoothing technique. While all patients became egg-negative after 21 days, 17.9% and 30.9% reverted to an egg-positive condition after 180 and 360 days, respectively. Both the prevalence and intensity of infection after treatment were significantly lower in the 60 mg/kg than in the 40 mg/kg treatment group. The higher intensity of the kernel in the 40 mg/kg group compared to the 60 mg/kg group, at both 180 and 360 days, reflects the higher number of reverted cases in the lower dose group. Auxiliary, preventive measures to control transmission should be integrated with chemotherapy to achieve a more enduring impact

Efficacy and side effects of praziquantel in the treatment of Schistosomiasis mansoni in schoolchildren in Shesha Kekele Elementary School, Wondo Genet, Southern Ethiopia

“…These values are in general within the usual cure rate ranges (63-95%) of PZQ against S. mansoni reported in different epidemiological settings [4,[26][27][28] . Some previous studies have reported efficacy higher than 85% for PZQ [29][30][31][32][33][34] , while others have reported lower (<63%) efficacy for the drug [13][14][15][16][17][18][19][20][21]35,36] . Such variations might be attributable to differences in the number of treatment, factors related to the host, parasite, and drugs or to the methodology.…”

Predicting the spatial distribution of Biomphalaria straminea, a potential intermediate host for Schistosoma mansoni, in China

“…It is an important intermediate host for S. mansoni transmission in South America especially Brazil (Paraense and Corrêa, 1989;Melo et al, 2006;Fernandez and Thiengo, 2010). Reports of natural infection of this snail species with S. mansoni were recorded from different parts of Brazil (Malek, 1985;Fernandez and Thiengo, 2010;Galvão et al, 2010;Barboza et al, 2012). Although it is less important for S. mansoni transmission in areas where its distribution overlaps with B. glabrata (Carvalho, 1992), it has been implicated in disease transmission in some Brazilian states, i.e.…”

Assessment of schistosomiasis in the semi-arid Northeast region of Brazil: the São Francisco River large-scale water transposition project

“…All of the Natural snail breeding sites, preferably near schools in the five selected municipalities, were surveyed in July and October 2010, May and November 2011, and October 2012. The geographic coordinates of both the school address and breeding sites of the Biomphalaria snails were captured using a handheld Global Positioning Systems (GPS) receiver (Garmin Etrex Vista) and imported into a Geographic Information System (GIS) for visualization of their spatial distribution (8) .…”