Abstract:
Aim: The aim of this study was to determine efficacy, safety and morbidity of increased dosage of praziquantel (PZQ) of 60 mg/kg compared to the standard dosage of 40 mg/kg of PZQ in the treatment of S. mansoni in school going children in Kirinyaga County, Kenya.
Background: Chemotherapy with PZQ has been the core treatment strategy for schistosomiasis. Due to recent concerns on tolerance and resistance to praziquantel, efficacy studies of up-scaled dosage are warranted. Socio-economic activities in Kirinyaga County exposes the community to fresh water snails that harbour the schistosome parasite. Various studies have reported the increased prevalence and high infection intensity in the area despite ongoing mass drug administration (MDA) interventions.
Methods: Study area was in Kirinyaga County, Kenya where the prevalence of schistosomiasis in school going children was first determined. A sample size of 192 subjects of 4-17 year old infected with S. mansoni were randomly allocated in Group A (40 mg/kg) and Group B (60 mg/kg). Stool samples were examined by Kato Katz technique to determine baseline infection intensity. Cure rate and egg reduction rate were also determined at 21 days post-treatment in both groups. Comparison of the frequency and severity of adverse events (AE) at 4 and 24 hrs post-treatment were also determined. Peripheral blood was collected to study disease morbidity by measuring haemoglobin (Hb) and eosinophil levels.
Results: Prevalence of S. mansoni infection was 52.8%. Baseline intensity of infection was 40% representing light infection while 41.58% and 18.42% representing modereate and heavy infections respectively. Cure rates at 21 days post-treatment were 92% for 40 mg/kg while that of 60 mg/kg was at 94%, a slight variation which did not represent any significant difference between the two treatment groups (p˃0.05). Mean haemoglobin levels for male and female at 21 days post-treatment were 11.26 g/dl and 11.34 g/dl respectively representing a non-significant difference (p>0.05). Eosinophil levels implied a significant decrease after treatment in both treatment groups although no difference was observed between the treatment groups (p>0.05). Adverse events recorded in the 60 and 40 mg/kg groups showed that mild abdominal pain was the most frequent AE for the 2 dosages while anoxia was the least occurring AE at 4 hrs and 24 hrs post-treatment.
Conclusion: The upscaled dosage of 60 mg/kg PZQ offers substantial cure to S. mansoni infected individuals. Efficacy tests in comparison with 40 mg/kg showed the difference in cure rates to be insignificant. The 60 mg/kg dosage was also associated with slightly higher mild adverse events.