1 Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet2 Ministry of Health3 Makerere University, Faculty of Agriculture, Kampala, Uganda4 Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet
BACKGROUND: The current recommended control strategy for schistosomiasis is annual treatment using 40 mg/kg of praziquantel. However, praziquantel is only effective on adult worms and giving a second dose may increase its efficacy. We assessed the effect of one versus two doses of praziquantel on cure rate and re-infection with Schistosoma mansoni in a high endemic community along Lake Victoria, Uganda. METHODOLOGY: To investigate the effect of the two regimens, 395 infected people were randomised into two groups; one received a single standard dose of praziquantel (Distocide® 600 mg, Shin Poong Pharmaceuticals, Seoul, Republic of Korea), 40mg/kg body weight, while the other group received a second dose 2 weeks later. Cure rate and infection intensity were assessed 9 weeks after the first treatment using standard parasitological procedures. Re-infection levels were monitored 8 and 24 months after treatment. RESULTS: Those who received two doses were more likely to be cured (69.7%) compared to those who received a single dose (47.9%) (¿(2) = 18.5, p <0.001). Geometric mean intensity (GMI) of infection at 9 weeks (eggs per gram of faeces [epg]) was 12.0 epg (CI95: 8.9-16.1) for individuals who received 2 doses and 22.1 epg (CI95: 16.9-28.8) for those in the single dose arm. Eight months after treatment, prevalence of re-infection for individuals in the double dose arm (61.6%, CI95: 50.2-73.1) was not significantly different from that of those in a single dose arm (68.3%, CI95: 59.9-76.8). The difference in GMI of re-infection for individuals in the single dose arm (33.8 epg, CI95: 23.2-49.3) and those in the double dose arm (34.5 epg, CI95: 24.7-48.1) was not significant. Twenty four months after treatment, prevalence of re-infection was not significantly different. The difference in GMI of re-infection for those in the single dose arm (57.5 epg, CI95: 33.9-97.5) and those in the double dose arm (42.2 epg, CI95: 29.9-59.6) was also insignificant. CONCLUSION: Our results suggest that a second dose of praziquantel given 2 weeks after the first dose improves cure rate and reduces S. mansoni infection intensity. However, there is no added advantage on reduction of S. mansoni re-infection by administering two doses of praziquantel. CLINICAL TRIALS.GOV IDENTIFIER: NCT00215267.
Royal Society of Tropical Medicine and Hygiene. Transactions, 2013, Vol 107, Issue 6, p. 397-404