Efficacy of praziquantel and reinfection patterns in single and mixed infection foci for intestinal and urogenital schistosomiasis in Cameroon
We present the results of our study on the efficacy of praziquantel and reinfection patterns in single and mixed infection foci of intestinal and urogenital schistosomiasis. This study was motivated by the increased overlapping of the schistosome species distribution, and expansion of mass treatment...
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| Published in: | Acta tropica Vol. 128; no. 2; pp. 275 - 283 |
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| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Netherlands
Elsevier B.V
01-11-2013
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | We present the results of our study on the efficacy of praziquantel and reinfection patterns in single and mixed infection foci of intestinal and urogenital schistosomiasis. This study was motivated by the increased overlapping of the schistosome species distribution, and expansion of mass treatment for disease control. The results showed the diversity of reinfection patterns and dynamics across transmission settings.
•Praziquantel is highly effective against Schistoma mansoni and S. haematobium in individuals with mixed infections.•Praziquantel was more effective against S. mansoni than S. haematobium.•Reinfection patterns post-treatment are influenced by the dynamics of schistosomiasis transmission.
The regular administration of the anthelminthic drug praziquantel (PZQ) to school-aged children (and other high-risk groups) is the cornerstone of schistosomiasis control. Whilst the performance of PZQ against single schistosome species infections is well-known, performance against mixed species infections is less so, as are patterns of re-infection following treatment. To address this, a study using a double treatment with PZQ, administered at 40mg/kg spaced by 3 weeks, took place in two mixed intestinal-urogenital schistosomiasis foci in northern Cameroon (Bessoum and Ouro-Doukoudje) and in one single intestinal schistosomiasis infection focus (Makenene). A total of just under 1000 children were examined and the Schistosoma-infected children were re-examined at several parasitological follow-ups over a 1-year period posttreatment. Overall cure rates against Schistosoma spp. in the three settings were good, 83.3% (95% confidence interval (CI)=77.9–87.7%) in Bessoum, 89.0% (95% CI=79.1–94.6%) in Ouro Doukoudje, and 95.3% (95% CI=89.5–98.0%) in Makenene. Interestingly, no case of mixed schistosome infection was found after treatment. Cure rates for S. mansoni varied from 99.5% to 100%, while that for S. haematobium were considerably lower, varying from 82.7% to 88.0%. Across transmission settings, patterns of re-infection for each schistosome species were different such that generalizations across foci were difficult. For example, at the 6-month follow-up, re-infection rates were higher for S. haematobium than for S. mansoni with re-infection rates for S. haematobium varying from 9.5% to 66.7%, while for S. mansoni, lower rates were observed, ranging between nil and 24.5%. At the 12-month follow-up, re-infection rates varied from 9.1% to 66.7% for S. haematobium and from nil to 27.6% for S. mansoni. Alongside these parasitological studies, concurrent malacological surveys took place to monitor the presence of intermediate host snails of schistosomiasis. In the two northern settings, three species of Bulinus (intermediate host snail of S. haematobium) were collected; i.e. Bulinus truncatus, B. globosus and B. senegalensis, however, Biomphalaria pfeifferi (intermediate host snail of S. mansoni) was much rarer despite repeated and intensive searching and was suggestive of limited local transmission potential of S. mansoni during this time. While this study highlights that performance of PZQ was satisfactory in this region, with somewhat greater impact upon intestinal than urogenital schistosomiasis, the dynamics of local transmission are shown, however, to be complex. |
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| Bibliography: | http://dx.doi.org/10.1016/j.actatropica.2013.06.007 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0001-706X 1873-6254 |
| DOI: | 10.1016/j.actatropica.2013.06.007 |