Prevalence and Reinfection Rates of Schistosoma mansoni and Praziquantel Efficacy against the Parasite among Primary School Children in Sanja Town, Northwest Ethiopia

Abstract

Background. Schistosomiasis is among the most widespread chronic infections in the world. The magnitude of the infection may show variations across different areas with respect to time. Praziquantel is a first line drug of choice for the treatment of schistosomiasis although its low cure rate has been reported in different parts of the world. Thus, an assessment of the magnitude of the diseases, the efficacy of currently available drugs, and reinfection rates is crucial. Objective. Our principal objective is to determine the prevalence and reinfection rates of Schistosoma mansoni and to evaluate the efficacy of PZQ against Schistosoma mansoni. Method. A school-based cross-sectional study was conducted on Sanja Elementary Schools, Sanja town, northwest Ethiopia. Stool specimens were examined using Kato-Katz method. Schoolchildren who tested positive for intestinal schistosomiasis and fulfilled the inclusion criteria took part in the efficacy and reinfection study. Positive participants were treated with 40 mg/kg of Praziquantel. Cure and egg reduction rates were evaluated three weeks after treatment. The intensity of infection was determined following the WHO’s guideline. Moreover, the reinfection rate of those who were cured was evaluated after a six-month posttreatment period. Data were analyzed using SPSS version 20. Results. At baseline, 130 (35%) of the 372 schoolchildren were found infected with Schistosoma mansoni. Out of the 130 infected schoolchildren, 112 (86.2%) had moderate infection intensity. Among the S. mansoni positive schoolchildren, 80 were included as study participants for the evaluation of PZQ efficacy, based on the inclusion criteria established by WHO. The cure and egg reduction rates were found to be 90% (72/80) and 99.5%, respectively. Of the seventy-two schoolchildren considered for the determination of reinfection rate, after 6 months of posttreatment, 13.9% were found to be reinfected. Conclusion. The schoolchildren in the three primary schools of Sanja are at moderate risk of the infection caused by S. mansoni. Although the therapeutic potency of PZQ at 40 mg/kg was efficient against S. mansoni, a high rate of reinfection was reported in the study site, suggesting the need for integrated schistosomiasis control measures.

Persistent Urogenital Schistosomiasis and Its Associated Morbidity in Endemic Communities within Southern Ghana: Suspected Praziquantel Resistance or Reinfection?

“…This demonstrates, somewhat, the efficacy of praziquantel. In this study, the ERR of 86.5%, observed in the third week post-treatment, was slightly lower compared to a recent report by Woldegerima et al [31] who observed egg reduction rates of 99.5% in S. mansoni. The difference in the species of Schistosoma and the study sites between the current study and that of Woldegerima et al [31] could probably have accounted for the slight difference in the reduction rates.…”

“…In this study, the ERR of 86.5%, observed in the third week post-treatment, was slightly lower compared to a recent report by Woldegerima et al [31] who observed egg reduction rates of 99.5% in S. mansoni. The difference in the species of Schistosoma and the study sites between the current study and that of Woldegerima et al [31] could probably have accounted for the slight difference in the reduction rates. However, the relatively low egg reduction rates, between 64% and 80%, observed in South Africa [30] were attributed to low drug absorption and high levels of catabolism, but not resistance [30].…”

“…Parameters such as the egg reduction rate [30,34,38] and viability [33] which had been used by other researchers [29,31,33,37] and were then adapted as tools during the follow-up assessment for suspecting resistance in this study, gave consistent results. The egg reduction rates (ERR) recorded in this study (with the egg count pattern) from the second week to the twelfth week (76.3% to 100%) agrees with a study conducted at Abeokuta in Nigeria with an ERR between 57% and 100% by the twelfth week [37].…”

“…This reinfection percentage (10.4%) corroborates similar work done by Senghor et al [29] and Kabuyaya et al [30], who also reported reinfection rates of 12.6% and 8.1%, respectively. Woldegerima et al [31] also reported a reinfection rate of 13.9%, after 6 months of post-treatment, although this was in S. mansoni. Meanwhile, a high reinfection percentage of 58% was reported by Oniya and Odaibo [15].…”

Can Early Diagnosis of Varices, Regular Praziquantel, and Reduction of Hepatitis Coinfection Reduce Mortality among Patients Attended for Periportal Fibrosis in Northwestern Tanzania? A Case-Control Study

“…Moreover, the diagnosis of S. mansoni based on rectal snips could have included even those participants with nonviable ova in a study from Zambia [17]. Otherwise, PPF patients attending endoscopy unit for endoscopic variceal ligation are usually put on biannual praziquantel at Bugando [20], and probably those found with active S. mansoni infection represent a subgroup of patients with Schistosoma reinfection since this is a frequent phenomenon reported elsewhere following mass drug administration [21,22].…”