Efficacy and safety of praziquantel preventive chemotherapy in Schistosoma mansoni infected school children in Southern Ethiopia: A prospective cohort study

Abstract

Background: The World Health Organization recommends efficacy and safety surveillance of anti-helminths used in mass drug administration campaigns. We evaluated the effectiveness of single-dose praziquantel against Schistosoma mansoni infection, and the safety of praziquantel plus albendazole preventive chemotherapy (PC) in Schistosoma mansoni infected school children (n = 512) in Southern Ethiopia.Method: Stool examinations were done using thick smear Kato-Katz at baseline, week-4, and week-8 of post-Mass drug administration (MDA) to assess praziquantel efficacy. Participants were followed for MDA-associated adverse events up to day 7 of post-MDA. The primary and secondary study outcomes were praziquantel efficacy (parasitological cure and egg reduction rates) and MDA-associated adverse events (AEs), respectively.Result: The overall cure rates at week-4 and week-8 were 89.1% (95%CI = 86.1–91.7) and 87.5% (95%CI = 83.6–90.8), respectively. Cure rates among moderate-to-heavily infected children were significantly lower (p = 0.001) compared to those with light infection at week-4 (84.4% vs. 91.1%, p = 0.03) and week-8 (78.6% vs. 91.9%, respectively). Older children had a higher cure rate than younger ones at week-8 (90.1% vs. 79.5%, p = 0.01). Among those who were Schistosoma egg-free (cured) at week 4, 7.8% became egg-positive at week 8. The overall egg reduction rate (ERR) at week-4 and week-8 were 93.5% and 91.3%, respectively, being lower among the 5–9 years old age groups (p = 0.01) at week-8. The proportion of children who remained schistosoma egg-positive throughout the study follow-up period was 4.6%, and their ERR at week-4 and week-8 was 50% and 51%, respectively, which is below the 90% World Health Organization threshold for efficacy. The incidence of experiencing at least one type of MDA-associated AEs were 17.0% (95%CI = 13.8%–20.5%); abdominal pain, headache, and vomiting were the most common. The proportion of mild, moderate, and severe AEs was 63.2%, 26.3%, and 10.5%, respectively. Females experienced more AEs than males (p = 0.03).Conclusion: Single-dose praziquantel is still effective for the treatment of intestinal schistosomiasis. Praziquantel and albendazole preventive chemotherapy is safe and tolerable, and associated AEs are mostly mild-to-moderate and transient. However, the reduced PZQ effectiveness in moderate-to-heavy infection and observed AEs in about one-fifth of infected children underscores the need for better treatment strategies and surveillance for early detection of parasite resistance and management of AEs.

Efficacy and safety of prazequantel for the treatment of Schistosoma mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia

“…The CR was nearly equal to the upper limit of the standard CR of 60%-90% set by the WHO for single-dose PZQ treatment [ 35 ]. The present finding is in line with earlier results [ 22 , 36 – 42 ]. The CR in the present study was higher than previous reports from Ethiopia [ 43 ] and other SSA countries [ 20 , 44 – 46 ].…”

“…mansoni mono-infections. However, STH co-infection was not associated with CR (p > 0.05) which was in line with a previous study in southern Ethiopia [ 36 ]. The number of co-infected participants in the present study was small, which makes it difficult to draw a definitive conclusion.…”

“…As measured by the KK method, participants with light infection at baseline had the highest CR, while the lowest CR was reported among participants with heavy infection (95.7% vs. 64.3%; p = 0.002). Similar findings were reported from southern Ethiopia [ 36 ]. In cases of moderate and heavy infections, few adults might escape from the action of PZQ, contributing to a reduced CR as compared to light infections.…”

Endemic status of urogenital schistosomiasis and the efficacy of a single-dose praziquantel treatment in unmapped rural farming communities in Oyo East Local Government Area, Oyo State, Nigeria

“…The significant egg reduction among heavily infected individuals, in this study, would impact positively on the severe morbidity and disease transmission in the Ajagba community. Generally, in sub-Saharan Africa, praziquantel treatment has drastically reduced morbidity and transmission of schistosomiasis [ 17 , 47 – 49 ]. The single-dose of praziquantel at 40 mg/kg body weight, in this study, appeared to be more effective against heavy infections than the light infections.…”

Mechanisms of Arachidonic Acid In Vitro Schistosomicidal Potential

“…Notably, PZQ 40 mg/kg dose does not prevent infection as it is rapidly metabolized in the liver, with a half-life of less than 10 h, − and thus, may not be available for killing invading larvae within days or weeks. The term “preventive” chemotherapy for the ongoing programs should be revisited, especially that it is documented that PZQ administration does not prevent reinfection even after complete cure. ,, Additionally, total cure is often not achieved even after multiple treatments, , which may elicit severe health problems. ,, …”