Efficacy and side effects of praziquantel treatment in a highly endemicSchistosoma mansoni focus at Lake Albert, Uganda

Efficacy and safety of single-dose artesunate plus sulfalene/pyrimethamine combined with praziquantel for the treatment of children with Schistosoma mansoni or Schistosoma haematobium in western Kenya: a randomised, open-label controlled trial

BACKGROUND

Reliance on praziquantel for the treatment and control of schistosomiasis is likely to facilitate the emergence of drug resistance. Combination therapy targeting adult and juvenile schistosome worms is urgently needed to improve praziquantel efficacy and delay the potential development of drug resistance. We assessed the efficacy and safety of single-dose praziquantel combined with single-dose artesunate plus sulfalene-pyrimethamine in the treatment of Kenyan children with schistosomiasis.

METHODS

This was an open-label, randomised clinical trial involving 426 school-aged children (7-15 years old) diagnosed with Schistosoma mansoni (by Kato-Katz) or S. haematobium (by urine filtration). They were randomly assigned (1:1:1) to receive a single dose of praziquantel (40 mg/kg), a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate) or combination therapy using a single dose of praziquantel (40 mg/kg) combined with a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate). The primary outcome was cure and egg reduction rates at 6 weeks post-treatment in the available case population. Adverse events were assessed within 3 h after treatment.

RESULTS

Of the 426 children enrolled, 135 received praziquantel, 150 received artesunate plus sulfalene-pyrimethamine, and 141 received combination therapy. Outcome data were available for 348 (81.7%) children. For S. mansoni-infected children (n = 335), the cure rates were 75.6%, 60.7%, and 77.8%, and the egg reduction rates were 80.1%, 85.0%, and 88.4% for praziquantel, artesunate plus sulfalene-pyrimethamine, and combination therapy, respectively. For S. haematobium-infected children (n = 145), the corresponding cure rates were 81.4%, 71.1%, and 82.2%, and the egg reduction rates were 95.6%, 97.1%, and 97.7%, respectively. Seventy-one (16.7%) children reported mild-intensity adverse events. The drugs were well tolerated and no serious adverse events were reported.

CONCLUSIONS

A single oral dose of praziquantel combined with artesunate plus sulfalene-pyrimethamine cured a high proportion of children with S. haematobium but did not significantly improve the treatment efficacy for either urinary or intestinal schistosomiasis. Sequential administration of praziquantel and artesunate plus sulfalene-pyrimethamine may enhance the efficacy and safety outcomes.

A cross-sectional pilot household study of Schistosoma mansoni burden and associated morbidities in Lake Albert, Uganda

OBJECTIVES

Schistosomiasis is persistent in Lake Albert, Uganda, but local data are limited. This study aims to describe the local burden of moderate-to-heavy infection and associated morbidity in all ages and identify factors associated with these outcomes to guide further research.

METHODS

This cross-sectional pilot study was conducted in July-August, 2022 in four village sites (Walukuba, Rwentale, Kyabarangwa and Runga) of the Praziquantel in Preschoolers (PIP) trial. Residents (approximately four per household) of any age of households of PIP participants were eligible, but individuals <10 years were only enrolled if no older individuals were available. Socio-demographic information, household location, single stool Kato-Katz and hepatic ultrasound results were obtained for a convenience sampled subset of trial households. The primary outcome, moderate-to-heavy infection (≥100 eggs per gram of faeces), was analysed using mixed-effects logistic regression, with a household random effect. Univariate analyses were used for the secondary outcome, periportal fibrosis (Niamey protocol ultrasound image pattern C-F).

RESULTS

Of 243 participants with a median age of 22 (interquartile range 12-33) years from 66 households, 49.8% (103/207 with a Kato-Katz result) had moderate-to-heavy infection and 11.2% (25/224 with ultrasound data) had periportal fibrosis. Moderate-to-heavy infection clustered by household (intraclass correlation coefficient = 0.11) and, in multivariable analysis, varied by village (Walukuba vs. Kyabarangwa adjusted odds ratio [aOR] 0.11, 95% CI 0.02-0.71), was highest in participants aged 10-15 years (vs. 5-9 years aOR 6.14, 95% CI 1.61-23.38) and lower in those reporting praziquantel treatment in the past year (aOR 0.39, 95% CI 0.18-0.88).

CONCLUSIONS

In this setting, schistosome infection and morbidity are pervasive in all age groups. More intensive interventions are needed, for example more frequent praziquantel treatment, under investigation in the PIP trial and improved water and sanitation. More research is needed to understand local treatment barriers and optimal control strategies.

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

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 of Praziquantel for the Treatment of Human Schistosomiasis in Ethiopia: A Systematic Review and Meta-Analysis

BACKGROUND

Schistosomiasis is one of the neglected tropical diseases causing a serious human health problem in Ethiopia. Praziquantel is the only drug that has been used for the treatment of human schistosomiasis in the country. In line with this, the efficacy of praziquantel has been evaluated in a few interventional studies in the country, but there is a lack in systematically gathered and analyzed information for policymakers. The aim of this systematic review and meta-analysis was to provide a summary of the efficacy of praziquantel for the treatment of human schistosomiasis in Ethiopia.

METHODS

We conducted a literature search from ScienceDirect, PubMed/Medlin, and Google Scholar databases. A total of 140 articles published in English from 1980 to June 2021 were accessed and 15 of them were eligible for this meta-analysis. The meta-analysis was conducted using Stata 14 software, "metan command." The heterogeneities among studies were evaluated using I 2 test.

RESULTS

A total of 140 articles were reviewed, but only 15 of them fulfilled the inclusion criteria. The polled cure rate of 40 mg/kg praziquantel was 89.2% (95% CI: 85.4-93.1) and 93.6% (95% CI: 80.6-106) among Schistosoma mansoni and S. haematobium, respectively. Similarly, the mean egg reduction rates of 40 mg/kg praziquantel were 90.2% and 85% among S. mansoni and S. haematobium infected subjects, respectively. The common adverse events observed after receiving praziquantel include abdominal pain, vomiting, headache, diarrhea, and bloody stool.

CONCLUSION

This systematic review and meta-analysis has indicated that praziquantel is still an appropriate drug for the treatment of human schistosomiasis in Ethiopia.

High Egg Reduction Rate but poor clearance of Circulating Cathodic Antigen three weeks after Praziquantel treatment among school children on Ijinga Island, north-western Tanzania

Traditionally, efficacy of Praziquantel (PZQ) is monitored using Parasitological Cure Rates and Egg Reduction Rates applying Kato Katz (KK) technique. This parasitological technique has a number of limitations. Recently, the Point-of-Care Circulating Cathodic Antigen (POC-CCA) rapid test which is a highly sensitive technique, has emerged as a promising candidate to be used for evaluating the efficacy of PZQ. A prospective longitudinal study was conducted among 399 school children aged 7-17 years on Ijinga Island, north-western Tanzania. At baseline and three weeks after treatment, stool and urine samples were collected from participating school children and screened for S. mansoni infection using the KK technique as well as POC-CCA test. All S. mansoni infected children at baseline were treated with 40mg/kg of PZQ and followed up after three weeks. At baseline, the overall prevalence of S. mansoni infection was 56.6% (95%CI: 51.7-61.4) and 99.7% (95%CI: 98.2-99.9) (considering trace as positive) using KK technique and POC-CCA test, respectively. Three weeks after treatment, the prevalence of S. mansoni was 0.92% using the KK technique and 97.7% when applying the POC-CCA test. The parasitological cure rates based on KK technique and POC-CCA were 99.1% (95%CI: 97.5-99.8) and 2.3% (95%CI: 1.2-4.5). Egg Reduction Rate was 99.1%. Based on WHO guidelines using the KK technique, at three weeks point, the efficacy of PZQ is satisfactory. However, the assessment of the efficacy of PZQ using POC-CCA tests needs further evaluation.

Change in schistosomiasis-related liver disease with repeated praziquantel treatment in school children in rural Zambia

Repeated praziquantel treatment for schistosomiasis is an effective method to reduce disease burden. Ultrasonographic methods were used to assess the severity of schistosoma mansoni-related liver disease and demonstrate improvement following treatment. We compared data from 733 children in 2010 and 972 children in 2018 to determine the effect of repeated praziquantel treatment on prevalence of liver disease. Three age groups were compared across three liver disease classifications (normal, mild, severe). From 2010 to 2018, there was a significant reduction in prevalence of severe liver disease in all age groups (P = 0.03 for 5-10 years, P < 0.001 for 11-15 years and 16-20 years). In both male and female students, the proportion having a normal liver significantly increased (P < 0.001) from 2010 to 2018, in the 11-15-year-olds and 16-20-year-olds, demonstrating that liver disease significantly reduced in these age groups. This study demonstrates a reduction in schistosomiasis-related morbidity with repeated praziquantel treatment.

Eugenol, a potential schistosomicidal agent with anti-inflammatory and antifibrotic effects against Schistosoma mansoni, induced liver pathology

Introduction

Schistosomiasis is one of the most prevalent parasitic infections in developing countries. Although chemotherapy is one of the main strategies in controlling the disease, it is less effective in reversal of schistosome-induced pathology especially in the chronic and advanced stages of schistosomiasis. New strategies and prospective therapeutic agents with antifibrotic effects are needed. Eugenol has a wide anti-inflammatory effect. In the present study, we investigated the possible antischistosomal effect of eugenol on Schistosoma mansoni.

Materials and methods

The murine model of S. mansoni was established in three groups of adult male Balb-c mice; group I (infected non-treated group) and groups II and III (infected groups) treated orally with eugenol and praziquantel (PZQ), respectively. The expression of the sensitive immunohistochemical marker α-smooth muscle actin (α-SMA) in schistosome-infected tissues was determined. In addition, parasitological, biochemical, and histological parameters that reflect disease severity and morbidity were examined.

Results

Eugenol treatment showed significant reduction in total worm burden by 19.2%; however, the oogram pattern showed no marked difference compared to that of the PZQ group. Yet, eugenol significantly reduced the serum levels of hepatic enzymes: aspartate aminotransferase and alanine aminotransferase. Histopathological examination revealed a significant reduction in both numbers and diameters of hepatic granulomata, which was consistent with reduction in collagen fiber deposition. Additionally, the antifibrotic effect of eugenol was validated by its considerable reduction in the expression of the sensitive marker α-SMA in both eugenol- and PZQ-treated groups.

Conclusion

Although eugenol could not totally eradicate adults of S. mansoni, the significant amelioration of liver enzymes and hepatic fibrosis potentiate eugenol’s role as a promising antifibrotic and a complementary antischistosomal agent.

High Efficacy of Praziquantel in Schistosoma haematobium-Infected Children in Taraba State, Northeast Nigeria: A follow-up study

Objectives

This study aimed to assess the efficacy of praziquantel in reducing urinary schistosomiasis prevalence, parasite burden and morbidity rates among a previously reported sample of Schistosoma haematobium-infected children. In addition, predisposing factors for reinfection one year post-treatment were also determined.

Methods

This prospective follow-up study was conducted between March 2014 and February 2015 among 675 previously reported children with urinary schistosomiasis in the Murbai and Surbai communities of Ardo Kola, Taraba State, Nigeria. A single dose of 40 mg/kg of praziquantel was administered to each infected child, with a second dose administered one month later if necessary. The number of S. haematobium eggs in urine samples was calculated at baseline and post-treatment.

Results

At four weeks post-treatment, the overall cure rate was 98.1%. Among children with low and heavy parasite burdens at baseline, egg reduction rates (ERRs) were 100% and 96.5%, respectively. The vast majority of children with microhaematuria (98.7%) and proteinuria (98.6%) at baseline were cured at follow-up. Following a second dose, the ERR, overall and morbidity cure rates increased to 100%. At one year post-treatment, 272 infected children (40.3%) were re-assessed; of these, 51 children (18.8%) were reinfected. Close proximity to bodies of water (odds ratio [OR] = 1.23, 95% confidence interval [CI]: 0.998-1.530; P = 0.05) and fishing (OR = 2.23, 95% CI: 0.828-6.040; P = 0.01) were significant factors that predisposed children to reinfection.

Conclusion

A moderate rate of reinfection was noted. Governmental and nongovernmental organisations in Nigeria should collaborate on mass treatment and health education campaigns to reduce the incidence of urinary schistosomiasis reinfections.

Rapid clearance of Schistosoma mansoni circulating cathodic antigen after treatment shown by urine strip tests in a Ugandan fishing community - Relevance for monitoring treatment efficacy and re-infection

Schistosomiasis control and elimination has priority in public health agendas in several sub-Saharan countries. However, achieving these goals remains a substantial challenge. In order to assess progress of interventions and treatment efficacy it is pertinent to have accurate, feasible and affordable diagnostic tools. Detection of Schistosoma mansoni infection by circulating cathodic antigen (CCA) in urine is an attractive option as this measure describes live worm infection noninvasively. In order to interpret treatment efficacy and re-infection levels, knowledge about clearance of this antigen is necessary. The current study aims to investigate, whether antigen clearance as a proxy for decreasing worm numbers is reflected in decreasing CCA levels in urine shortly after praziquantel treatment. Here CCA levels are measured 24 hours post treatment in response to both a single and two treatments. The study was designed as a series of cross-sectional urine and stool sample collections from 446 individuals nested in a two-arm randomised single blinded longitudinal clinical trial cohort matched by gender and age (ClinicalTrials.gov Identifier: NCT00215267) receiving one or two praziquantel treatments. CCA levels in urine were determined by carbon-conjugated monoclonal antibody lateral flow strip assay and eggs per gram faeces for S. mansoni and soil-transmitted helminths by Kato-Katz. Significant correlations between CCA levels and S. mansoni egg count at every measured time point were found and confirmed the added beneficial effect of a second treatment at two weeks after baseline. Furthermore, presence of hookworm was found not to be a confounder for CCA test specificity. Twenty-four hours post treatment measures of mean CCA scores showed significant reductions. In conclusion, removal of CCA in response to treatment is detectable as a decline in CCA in urine already after 24 hours. This has relevance for use and interpretation of laboratory based and point-of-care CCA tests in terms of treatment efficacy and re-infection proportions as this measure provides information on the presence of all actively feeding stages of S. mansoni, which conventional faecal microscopy methods do not accurately reflect.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00215267.

The Efficacy of Single-Dose versus Double-Dose Praziquantel Treatments on Schistosoma mansoni Infections: Its Implication on Undernutrition and Anaemia among Primary Schoolchildren in Two On-Shore Communities, Northwestern Tanzania

Administering more than one treatment may increase Praziquantel cure and egg reduction rates, thereby hastening achievement of schistosomiasis transmission control. A total of 431 S. mansoni-infected schoolchildren were randomized to receive either a single or repeated 40 mg/kg Praziquantel dose. Heights, weights, and haemoglobin levels were determined using a stadiometer, weighing scale, and HemoCue, respectively. At 8 weeks, cure rate was higher on repeated dose (93.10%) compared to single dose (68.68%) (p < 0.001). The egg reduction rate was higher on repeated dose (97.54%) compared to single dose (87.27%) (p = 0.0062). Geometric mean egg intensity was lower among those on repeated dose (1.30 epg) compared to single dose (3.18 epg) (p = 0.036) but not at 5 (p > 0.05) and 8 (p > 0.05) months with no difference in reinfection rate. No difference in the prevalence of stunting was observed between the two treatment regimens (p > 0.05) at 8 months, but there was an increase in the prevalence of wasting among those on repeated dose (p < 0.001). There was an increase in the mean haemoglobin levels at 8 months with no difference between the two arms (p > 0.05). To achieve reduction of transmission intensity and disease control in highly endemic areas, repeated treatments alone may not be sufficient. This trial was registered with PACTR201601001416338.

Knowledge, attitude, and practices on intestinal schistosomiasis among primary schoolchildren in the Lake Victoria basin, Rorya District, north-western Tanzania

BACKGROUND

Globally school-age children, adolescents and young adults bear the highest burden of schistosomiasis. When developing a specific intervention to improve community's knowledge, attitudes, and practices (KAPs), existing KAPs must be taken into account. Therefore, this study was designed to determine schoolchildren's KAPs on schistosomiasis in the study area.

METHODS

A cross-sectional study was conducted in Busanga and Kibuyi villages involving 513 schoolchildren. A pre-tested questionnaire was used to collect socio-demographic data and to assess KAP on schistosomiasis among primary schoolchildren in the study area.

RESULTS

Of the 488 interviewed children, 391 (80.12%) reported to have heard of schistosomiasis, with the majority 289 (73.91%) citing school as the source of this knowledge. Swimming in the lake, worms, witchcraft, and mosquitoes were mentioned to be the cause for intestinal schistosomiasis. Fishing in the lake, drinking unboiled lake water, walking bare footed, and shaking hands were reported to be practices that may lead to contracting schistosomiasis. Only 156 (39.90%) of the study respondents reported to know the signs of intestinal schistosomiasis. Avoiding swimming in the lake, drinking unboiled water and eating unwashed fruits were mentioned as preventive measures. Nearly 85% (412) reported understanding that there was a disease known as schistosomiasis; additionally, 419 (85.86%) considered schistosomiasis as a dangerous disease and 418 (85.66%) believed that schistosomiasis was treatable. Fishermen and schoolchildren were reported to be groups most at risk of schistosomiasis infection. Visiting the lake (for swimming and other gatherings) was a common practice among study participants 471 (96.52%).Nearly 93% (451) of participants mentioned using lake water for domestic chores, and, although 407 (84.61%) reported to own a toilet at home, only 229 (55.31%) reported to always use a toilet for sanitation purposes.

CONCLUSION AND RECOMMENDATION

Despite a high rate of awareness among schoolchildren regarding schistosomiasis, there was a persistent gap amongst the children regarding the causes, modes of transmission, symptoms, and preventive measures for the disease. Therefore, an appropriate health education intervention is needed in order to inculcate better knowledge, attitudes, and practices amongst schoolchildren regarding its transmission, control, and prevention as part of a successful schistosomiasis campaign.

Identification of Heterobilharzia americana infection in a dog residing in Indiana with no history of travel

CASE DESCRIPTION

A 1-year-old castrated male dog residing in Indiana was examined because of intermittent vomiting of 4 months' duration.

CLINICAL FINDINGS

The dog's condition did not resolve with medication. Diagnostic imaging revealed a possible partial obstruction at the ileocecal junction. An exploratory laparotomy was performed. The jejunum contained diffusely distributed, nodular, intramural lesions; 2 biopsy specimens were collected from representative lesions. The pancreas was grossly swollen, and pancreatitis was presumed present. No other abnormalities were observed in the abdomen. Histologic examination of the submitted biopsy specimens revealed infection with Heterobilharzia americana.

TREATMENT AND OUTCOME

After diagnosis, the dog was treated with fenbendazole suspension (48 mg/kg [21.8 mg/lb], PO, q 24 h) for 10 days. This treatment was subsequently repeated 11 and 80 days later. One week after the end of the last fenbendazole treatment, several H americana eggs were detected in a fecal sample via saline sedimentation, and the dog was given praziquantel (25 mg/kg [11.4 mg/lb], PO, q 8 h) for 2 days. No gastrointestinal signs were evident 4 months after that treatment.

CLINICAL RELEVANCE

The dog described in this report was the first autochthonous canine case of H americana infection in Indiana, to the authors' knowledge; this case has confirmed that the distribution of this parasite in the Midwestern United States is broader than previously known. Increased awareness of the distribution of H americana should aid veterinarians in early, noninvasive diagnosis and appropriate treatment of affected animals. Repeated treatments and recheck fecal examinations may be necessary when managing these cases.

Schistosoma mansoni Infections, Undernutrition and Anaemia among Primary Schoolchildren in Two Onshore Villages in Rorya District, North-Western Tanzania

BACKGROUND

Undernutrition and anaemia remains to be a major public health problem in many developing countries, where they mostly affect children. Intestinal parasitic infections are known to affect both growth and haemoglobin levels. Much has been reported on the impact of geohelminths on anaemia and undernutrition, leaving that of Schistosoma mansoni not well studied. Therefore this study intended to determine the association between S.mansoni infections, anaemia and undernutrition among schoolchildren in Rorya district, Northwestern Tanzania.

METHODOLOGY

A cross-sectional study was carried among schoolchildren in two onshore villages namely Busanga and Kibuyi in Rorya district. Single stool specimens were collected from 513 randomly selected schoolchildren and processed for microscopic examination using the Kato-Katz method. Nutritional status was determined by anthropometry. Blood samples were also collected and examined for malaria parasites and haemoglobin levels using the Giemsa stain and HaemoCue methods, respectively. A pretested questionnaire was used to collect socio-demographic data and associated factors.

RESULTS

The prevalence of S. mansoni infection and malaria was 84.02% and 9.16%, respectively. Other parasites found were Ascaris lumbricoides (1.36%) and Hookworm (1.36%). The prevalence of stunting and wasting was 38.21% and 14.42%, respectively. The prevalence of anaemia was 29.43%, whereby 0.58% had severe anaemia. S. mansoni infection was not found to be associated with undernutrition or anaemia (p>0.05). The risk of stunting and wasting increased with increasing age (p<0.001). Anaemia was associated with age, sex and village of residence (p<0.05).

CONCLUSIONS

S.mansoni, undernutrition and anaemia are highly prevalent in the study area. The observed rates of undernutrition and anaemia were seen not to be associated with S.mansoni infection suggesting possibly being a result of poor dietary nutrients. This study suggests that policy makers should consider Rorya district for inclusion into national schistosomiasis control and school feeding programmes.

Intestinal Schistosomiasis among Primary Schoolchildren in Two On-Shore Communities in Rorya District, Northwestern Tanzania: Prevalence, Intensity of Infection and Associated Risk Factors

In Tanzania, Schistosoma mansoni is of great public health importance. Understanding the prevalence and infection intensity is important for targeted, evidence-based control strategies. This study aimed at studying the prevalence, intensity, and risk factors of S. mansoni among schoolchildren in the study area. A cross-sectional study was conducted in Busanga and Kibuyi villages. Sampled 513 schoolchildren provided stool specimens which were examined using kato-katz method. Pretested questionnaire was used to collect sociodemographic data and associated risk factors. The prevalence of S. mansoni infection was 84.01%, with geometric mean egg intensity of 167.13 (95% CI: 147.19–189.79) eggs per gram of stool (epg). Other parasites detected were Ascaris lumbricoides (1.4%) and hookworms (1.4%). The geometric mean infection intensity in Busanga and Kibuyi were 203.70 (95% CI: 169.67–244.56) and 135.98 (95% CI: 114.33–161.73) epg, respectively. Light, moderate, and heavy infection intensities were 34.11%, 39.91%, and 25.99%, respectively. Village of residence, parent's level of education, toilet use, and treatment history were predictors of infection. The high prevalence and infection intensity in this study were associated with village, parent's level of education, inconsistent toilet use, and treatment history. To control the disease among at-risk groups, these factors need to be considered in designing integrated schistosomiasis control interventions.

Reduced Efficacy of Praziquantel Against Schistosoma mansoni Is Associated With Multiple Rounds of Mass Drug Administration

Background. Mass drug administration (MDA) with praziquantel is the cornerstone of schistosomiasis control in sub-Saharan Africa. The effectiveness of this strategy is dependent on the continued high efficacy of praziquantel; however, drug efficacy is rarely monitored using appropriate statistical approaches that can detect early signs of wane.

Methods. We conducted a repeated cross-sectional study, examining children infected with Schistosoma mansoni from 6 schools in Uganda that had previously received between 1 and 9 rounds of MDA with praziquantel. We collected up to 12 S. mansoni egg counts from 414 children aged 6–12 years before and 25–27 days after treatment with praziquantel. We estimated individual patient egg reduction rates (ERRs) using a statistical model to explore the influence of covariates, including the number of prior MDA rounds.

Results. The average ERR among children within schools that had received 8 or 9 previous rounds of MDA (95% Bayesian credible interval [BCI], 88.23%–93.64%) was statistically significantly lower than the average in schools that had received 5 rounds (95% BCI, 96.13%–99.08%) or 1 round (95% BCI, 95.51%–98.96%) of MDA. We estimate that 5.11%, 4.55%, and 16.42% of children from schools that had received 1, 5, and 8–9 rounds of MDA, respectively, had ERRs below the 90% threshold of optimal praziquantel efficacy set by the World Health Organization.

Conclusions. The reduced efficacy of praziquantel in schools with a higher exposure to MDA may pose a threat to the effectiveness of schistosomiasis control programs. We call for the efficacy of anthelmintic drugs used in MDA to be closely monitored.

The cytotoxicity study of praziquantel enantiomers

Praziquantel (PZQ) is prescribed as a racemic mixture (racemic-PZQ, rac-PZQ), which is composed of (R)-PZQ and (S)-PZQ. In this work, the cytotoxicity of rac-PZQ and its two enantiomers (R)-PZQ and (S)-PZQ on eight cell lines (L-02, HepG2, prf-plc-5, SH-SY5Y, HUVEC, A549, HCT-15, Raw264.7) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazolium bromide and lactate dehydrogenase assays. The morphology of apoptotic cells was studied by fluorescence microscope using Hoechst 33342 staining, and the cytotoxicity of the compounds was also tested by lactate dehydrogenase assay. Results revealed that (R)-PZQ had negligible cytotoxicity against L-02, SH-SY5Y, HUVEC, A549, HCT-15, and Raw264.7 cells but selectively inhibited tumor cell lines (prf-plc-5 and HepG2). However, in contrast to (R)-PZQ, the (S)-isomer showed higher cytotoxicity against L-02 cells and lower inhibition on prf-plc-5 and HepG2 cells. Besides, (R)-PZQ showed lower cytotoxicity on SH-SY5Y cells than (S)-PZQ. Meanwhile, (R)-PZQ at <80 μM concentration could promote proliferation of macrophage cells (Raw264.7). Our research revealed that (R)-PZQ has lower cytotoxicity than (S)-PZQ and has similar cytotoxicity with rac-PZQ. (S)-PZQ is the principal enantiomer to cause side effects on human definitive hosts. These findings gave the reasonable reasons for World Health Organization to produce (R)-PZQ as a replacement for rac-PZQ for the treatment of schistosomiasis.

Reduced uptake of mass treatment for schistosomiasis control in absence of food: beyond a randomized trial

Background

Sustaining high uptake of praziquantel is key for long-term control of schistosomiasis. During mass treatment in 2013, we randomized 12 primary schools into two groups; one group received education messages for schistosomiasis prevention for two months prior to mass treatment, while the other, in addition to the education messages, received a pre-treatment snack shortly before mass treatment. The uptake of praziquantel in the snack schools was 94 % compared to 79 % in the non-snack schools. During mass treatment in 2014, no snack was provided. We compared the uptake of praziquantel in 2014 to that in 2013 and attempt to explain the reasons for the observed differences.

Methods

Serial cross sectional surveys were conducted among a random sample of children from the 12 primary schools, 1 month after mass treatment in 2013 and 2014 to measure uptake of praziquantel, reported side effects attributable to praziquantel and prevalence and intensity of schistosomiasis infection. Differences in the demographic and descriptive variables between the 2013 and 2014 samples were compared using chi squared tests for categorical variables and student’s t-test for geometric mean intensity of S. mansoni infection.

Results

Uptake of praziquantel reduced from 93.9 to 78.0 % (p = 0.002) in the snack schools but was unchanged in the non-schools 78.7 and 70.4 % (p = 0.176). The occurence of side-effects attributable to praziquantel increased from 34.4 to 61.2 % (p = 0.001) in the snack schools but was unchanged in the non-snack schools; 46.9 and 53.2 % (p = 0.443). Although the prevalence of S. mansoni infection increased in both the snack and non-snack schools, the differences did not reach statistical significance;1.3 and 7.5 % (p = 0.051) and 14.1 and 22.0 % (p = 0.141), respectively. Similarly, the difference in the geometric mean intensity of S. mansoni infection in both the snack and non-snack schools was not statistically significant; 38.3 eggs per gram of stool (epg) and 145.7 epg (p = 0.197) and 78.4 epg and 322.5 epg (p = 0.120), respectively.

Conclusion

Our results show that in absence of food, uptake of praziquantel reduced and the side-effects of the drug increased. However, the reduced uptake did not affect the prevalence and intensity of schistosomiasis among school children. Rescinding of the provision of the snack is what probably caused the reduction in uptake of treatment in the subsequent mass treatment cycle.

Antischistosomal Activity of Two Active Constituents Isolated from the Leaves of Egyptian Medicinal Plants

In this paper, we investigate the role of two active constituents isolated from the leaves of Egyptian medicinal plants. D-mannitol a naturally occurring sugar isolated from the leaves Ixora undulata Roxb., and the pectin a linear chain homogalacturonan (HG) polysaccharide isolated from the leaves of Linum grandiflorum Desf. (scarlet flax). Both are evaluated for their therapeutic effect against schistosomiasis with biochemical and histochemical evaluations and compared with praziquantel, a reference drug. Biochemical studies of hepatic glucose, the glycogen content, and total serum protein were carried out, and histochemical evaluations through serum protein fractions separated by polyacrylamide gel electrophoresis with different molecular weights (260-10 kDa) were made in all groups, in addition to liver and body weight. D-mannitol and pectin show a remarkable effect in enhancing liver and kidney functions through enhancing most protein fractions in the serum of mice infected with Schistosoma mansoni. Also, the glucose and glycogen content in injured liver tissues improved, in addition liver and body weight in the infected groups. Thus they may be of therapeutic potential in the treatment hepatoxicity and nephrotoxicity.

Single Versus Double Dose Praziquantel Comparison on Efficacy and Schistosoma mansoni Re-Infection in Preschool-Age Children in Uganda: A Randomized Controlled Trial

BACKGROUND

Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda.

METHODOLOGY/PRINCIPAL FINDINGS

Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially all children were treated with a single standard oral dose 40 mg/kg body weight of PZQ. Two weeks later a second dose was administered to children in the double dose treatment arm. Side effects were monitored at 30 minutes to 24 hours after each treatment. Efficacy in terms of CRs and ERRs for the two treatments was assessed and compared 1 month after the second treatment. Re-infection with S. mansoni was assessed in the same children 8 months following the second treatment. CRs were non-significantly higher in children treated with two 40 mg/kg PZQ doses (85.5%; 290/339) compared to a single dose (83.2%; 297/357). ERRs were significantly higher in the double dose with 99.3 (95%CI: 99.2-99.5) compared with 98.9 (95%CI: 98.7-99.1) using a single dose, (P = 0.01). Side effects occurred more frequently during the first round of drug administration and were mild and short-lived; these included vomiting, abdominal pain and bloody diarrhea. Overall re-infection rate 8 months post treatment was 44.5%.

CONCLUSIONS

PZQ is efficacious and relatively safe to use in preschool-age children but there is still an unmet need to improve its formulation to suit small children. Two PZQ doses lead to significant reduction in egg excretion compared to a single dose. Re-infection rates with S. mansoni 8 months post treatment is the same among children irrespective of the treatment regimen.

Uptake of mass drug administration programme for schistosomiasis control in Koome Islands, Central Uganda

Introduction

Schistosomiasis is one of the neglected tropical diseases targeted for elimination in Uganda through the Mass Drug Administration (MDA) programme. Praziquantel has been distributed using community resource persons in fixed sites and house-to-house visits; however the uptake is still below target coverage. In 2011/2012 MDA exercise, uptake stood at 50% yet WHO target coverage is 75% at community level. We assessed the uptake of MDA and the associated factors in Koome Islands, Central Uganda.

Methods

In March 2013, we conducted a mixed methods cross sectional study in 15 randomly selected villages. We interviewed a total of 615 respondents aged 18 years and above using semi structured questionnaires and five key informants were also purposively selected. Univariate and multivariate analysis was done. MDA uptake was defined as self reported swallowing of praziquantel during the last (2012) MDA campaign. We conducted key informant interviews with Ministry of Health, district health personnel and community health workers.

Results

Self reported uptake of praziquantel was 44.7% (275/615), 95% confidence interval (CI) 40.8–48.7%. Of the 275 community members who said they had swallowed praziquantel, 142 (51.6%) reported that they had developed side effects. Uptake of MDA was more likely if the respondent was knowledgeable about schistosomiasis transmission and prevention (adjusted odds ratio [AOR] 1.85, 95% CI 1.22–2.81) and reported to have received health education from the health personnel (AOR 5.95, 95% CI 3.67–9.65). Service delivery challenges such as drug shortages and community health worker attrition also influenced MDA in Koome Islands.

Conclusions

Uptake of MDA for schistosomiasis control in Koome was sub optimal. Lack of knowledge about schistosomiasis transmission and prevention, inadequate health education and drug shortages are some of the major factors associated with low uptake. These could be addressed through routine health education and systematic drug supply for the successful elimination of schistosomiasis on the islands.

Efficacy and side effects of praziquantel in the treatment of Schistosomiasis mansoni in schoolchildren in Shesha Kekele Elementary School, Wondo Genet, Southern Ethiopia

OBJECTIVE

To evaluate the efficacy and side effects of praziquantel (PZQ) in the treatment of schistosomiasis in Ethiopia.

METHODS

In a cross-sectional study, stool specimens were collected from randomly selected 299 school children in Shesha Kekele Elementary School, Wondo Genet, Southern Ethiopia, in April 2010. Stool specimens were examined using a single Kato-Katz thick smear for Schistosoma mansoni (S. mansoni) ova. Children who were found positive for S. mansoni were treated with a single oral dose of PZQ at 40 mg/kg bw and interviewed for treatment-related symptoms 24 hours after drug administration. Four weeks post-treatment, stool specimens were collected from the same children and examined following the same procedure as in the pre-treatment. Drug efficacy was determined based on cure and egg reduction rates.

RESULTS

Pre-treatment prevalence of S. mansoni infection was 74.9% with geometric mean egg count of 268. The evaluated generic PZQ produced an overall cure rate of 73.6% (P<0.000 1, OR: 8.33, CI: 5.3-13.1) and egg reduction rate of 68.2% (P=0.03, F=0.64). The cure rate showed significant association with age (χ(2)=11, P=0.004), the highest rate being observed in the 15-22 age group. 83% of S. mansoni infected children showed various treatment-related symptoms, the most frequent being headache, nausea, and abdominal pain. These symptoms were associated with age (P<0.001) and pre-treatment intensity of infection (P<0.05).

CONCLUSIONS

The present observations revealed relatively lower cure and egg reduction rates of the PZQ evaluated as compared to previous reports for other PZQ brands in Ethiopia. Hence, in depth studies are recommended to clarify whether the present relatively lower cure rate is the actual cure rate of the praziquantel evaluated, treatment failure, or reduced susceptibility of the parasite. Treatment-related side effects observed were transient and tolerable.

Clinical efficacy and tolerability of praziquantel for intestinal and urinary schistosomiasis-a meta-analysis of comparative and non-comparative clinical trials

BACKGROUND

Extensive use of praziquantel for treatment and control of schistosomiasis requires a comprehensive understanding of efficacy and safety of various doses for different Schistosoma species.

METHODOLOGY/PRINCIPAL FINDINGS

A systematic review and meta-analysis of comparative and non-comparative trials of praziquantel at any dose for any Schistosoma species assessed within two months post-treatment. Of 273 studies identified, 55 were eligible (19,499 subjects treated with praziquantel, control treatment or placebo). Most studied were in school-aged children (64%), S. mansoni (58%), and the 40 mg/kg dose (56%); 68% of subjects were in Africa. Efficacy was assessed as cure rate (CR, n=17,017) and egg reduction rate (ERR, n=13,007); safety as adverse events (AE) incidence. The WHO-recommended dose of praziquantel 40 mg/kg achieved CRs of 94.7% (95%CI 92.2-98.0) for S. japonicum, 77.1% (68.4-85.1) for S. haematobium, 76.7% (95%CI 71.9-81.2) for S. mansoni, and 63.5% (95%CI 48.2-77.0) for mixed S. haematobium/S. mansoni infections. Using a random-effect meta-analysis regression model, a dose-effect for CR was found up to 40 mg/kg for S. mansoni and 30 mg/kg for S. haematobium. The mean ERR was 95% for S. japonicum, 94.1% for S. haematobium, and 86.3% for S. mansoni. No significant relationship between dose and ERR was detected. Tolerability was assessed in 40 studies (12,435 subjects). On average, 56.9% (95%CI 47.4-67.9) of the subjects receiving praziquantel 40 mg/kg experienced an AE. The incidence of AEs ranged from 2.3% for urticaria to 31.1% for abdominal pain.

CONCLUSIONS/SIGNIFICANCE

The large number of subjects allows generalizable conclusions despite the inherent limitations of aggregated-data meta-analyses. The choice of praziquantel dose of 40 mg/kg is justified as a reasonable compromise for all species and ages, although in a proportion of sites efficacy may be lower than expected and age effects could not be fully explored.

Efficacy of praziquantel in the treatment of Schistosoma haematobium infection among school-age children in rural communities of Abeokuta, Nigeria

Background

Chemotherapy with praziquantel (PZQ) has been the cornerstone of schistosomiasis control over the last two decades. Being the only available drug for the treatment of over 200 million people worldwide, continuous monitoring of PZQ efficacy under the pressure of widespread use is therefore advocated.

Methods

The efficacy of taking two doses of oral PZQ for the treatment of Schistosoma haematobium was examined among school children in Nigeria. Urine specimens were collected from 350 school children and examined using the filtration technique. Blood was collected for packed cell volume (PCV) estimation, and the weight and height of each child were estimated. S. haematobium egg positive pupils were treated with two oral doses of PZQ at 40 mg/kg with a four-week interval in between. Drug efficacy was determined based on the egg reduction rate (ERR).

Results

Among 350 school children, 245 (70.0%) – of which 132 were males and 113 were females, with an age range of 4 to 15 years – were diagnosed with S. haematobium. All the 245 infected children received a single oral dose of 40 mg/kg PZQ twice with a four-week interval in between and were followed up for 12 weeks. At four, eight and twelve weeks post treatment, the ERR was 57.1%, 77.6% and 100%, respectively. The ERR was significantly higher among the children with a light infection compared to those with a heavy infection. One hundred and twenty-one children were egg negative at four weeks post treatment, among which 1 (6.3) and 120 (52.4%) had heavy and light infections, respectively. Following the second round of treatment, the cure rate at eight weeks and twelve weeks was 85.3% and 100%, respectively.

Conclusion

This study demonstrated the efficacy of taking two doses of oral PZQ for the treatment of urinary schistosomiasis among school children in Nigeria.

Chromatographic fingerprint analysis and effects of the medicinal plant species Mitracarpus frigidus on adult Schistosoma mansoni worms

The aims of this work were to evaluate the in vitro and in vivo schistosomicidal properties of the methanolic extract of the aerial parts of Mitracarpus frigidus (MFM) and to determine its HPLC profile. For the in vitro experiment, four pairs of adult worms, obtained from infected mice, were exposed to different concentrations of MFM (100 to 400 μg/mL) for 24 and 48 h and analyzed under an inverted microscope. For the in vivo experiment, mice were inoculated with cercariae and, 20 days after infection, MFM (100 and 300 mg/kg) was administered orally for the following 25 days. Mice were euthanized after 60 days. MFM showed in vitro schistosomicidal activity, exhibiting the opening of the gynaecophoral canal of some male schistosomes, the presence of contorted muscles, vesicles, and the darkening of the paired worms skin. In vivo experiments showed that MFM treatments significantly reduced total worm count, as praziquantel, showing a decrease in liver and spleen weight. Also, a significant reduction in granuloma density was observed. MFM treatment did not cause alterations in the liver function of either infected or noninfected mice. The HPLC chromatogram profile showed the presence of kaempferol-O-rutinoside, rutin, kaempferol, psychorubrin, and ursolic acid.

Effectiveness of a pre-treatment snack on the uptake of mass treatment for schistosomiasis in Uganda: a cluster randomized trial

BACKGROUND

School-based mass treatment with praziquantel is the cornerstone for schistosomiasis control in school-aged children. However, uptake of treatment among school-age children in Uganda is low in some areas. The objective of the study was to examine the effectiveness of a pre-treatment snack on uptake of mass treatment.

METHODS AND FINDINGS

In a cluster randomized trial carried out in Jinja district, Uganda, 12 primary schools were randomized into two groups; one received education messages for schistosomiasis prevention for two months prior to mass treatment, while the other, in addition to the education messages, received a pre-treatment snack shortly before mass treatment. Four weeks after mass treatment, uptake of praziquantel was assessed among a random sample of 595 children in the snack schools and 689 children in the non-snack schools as the primary outcome. The occurrence of side effects and the prevalence and mean intensity of Schistosoma mansoni infection were determined as the secondary outcomes. Uptake of praziquantel was higher in the snack schools, 93.9% (95% CI 91.7%-95.7%), compared to that in the non-snack schools, 78.7% (95% CI 75.4%-81.7%) (p = 0.002). The occurrence of side effects was lower in the snack schools, 34.4% (95% CI 31.5%-39.8%), compared to that in the non-snack schools, 46.9% (95% CI 42.2%-50.7%) (p = 0.041). Prevalence and mean intensity of S. mansoni infection was lower in the snack schools, 1.3% (95% CI 0.6%-2.6%) and 38.3 eggs per gram of stool (epg) (95% CI 21.8-67.2), compared to that in the non-snack schools, 14.1% (95% CI 11.6%-16.9%) (p = 0.001) and 78.4 epg (95% CI 60.6-101.5) (p = 0.001), respectively.

CONCLUSIONS

Our results suggest that provision of a pre-treatment snack combined with education messages achieves a higher uptake compared to the education messages alone. The use a pre-treatment snack was associated with reduced side effects as well as decreased prevalence and intensity of S. mansoni infection.

TRIAL REGISTRATION

www.ClinicalTrials.gov NCT01869465

Understanding low uptake of mass treatment for intestinal schistosomiasis among school children: a qualitative study in Jinja district, Uganda

Despite attempts to control intestinal schistosomiasis through school-based mass drug administration (MDA) with praziquantel using school teachers in Uganda, less than 30% of the school children take the treatment in some areas. The aim of the study was to understand why the uptake of praziquantel among school children is low and to suggest strategies for improved uptake. This was a cross-sectional qualitative study in which 24 focus group discussions and 15 key informant interviews were conducted 2 months after MDA. The focus group discussions were held with school children in twelve primary schools and the key informant interviews were held with school teachers, sub-county health assistants and the District Vector Control Officer. The study shows that the low uptake of praziquantel among school children is a result of a complex interplay between individual, interpersonal, institutional, community and public policy factors. The individual and interpersonal factors underpinning the low uptake include inadequate information about schistosomiasis prevention, beliefs and attitudes in the community about treatment of schistosomiasis and shared concerns among children and teachers about the side-effects of praziquantel, especially when the drug is taken on an empty stomach. The institutional, policy and community factors include inadequate preparation and facilitation of teachers and the school feeding policy, which requires parents to take responsibility for providing their children with food while at school, yet many parents cannot meet the cost of a daily meal due to the prevailing poverty in the area. It is concluded that strategies to improve uptake of praziquantel among school children need to be multi-pronged addressing not only the preparation and motivation of teachers and health education for children, but also the economic and political aspects of drug distribution, including the school feeding policy.

Increasing teacher motivation and supervision is an important but not sufficient strategy for improving praziquantel uptake in Schistosoma mansoni control programs: serial cross sectional surveys in Uganda

BACKGROUND

Realization of the public health benefits of mass drug administration (MDA) for the control of schistosomiasis depends on achieving and maintaining high annual treatment coverage. In Uganda, the uptake of preventive treatment for schistosomiasis among school-age children in 2011 was only 28%. Strategies are needed to increase uptake.

METHODS

Serial cross-sectional surveys were conducted at baseline (after MDA in 2011) and at follow-up MDA in 2012 where teacher motivation was provided and supervision strengthened in Jinja district of Uganda. Uptake of praziquantel was assessed in 1,010 randomly selected children from 12 primary schools during the baseline survey and in another set of 1,020 randomly selected children from the same primary schools during the follow-up survey.

RESULTS

Self-reported uptake of praziquantel increased from 28.2% (95% CI 25.4%-30.9%) at baseline to 48.9% (95% CI 45.8%-52.0%) (p < 0.001) at follow-up. Prevalence and intensity of Schistosoma mansoni infection were unchanged and moderate on both occasions; 35.0% (95% CI: 25.4%-37.9%) and 32.6% (95% CI: 29.6%-35.5%) (p = 0.25) and 156.7 eggs per gram of stool (epg) (95% CI: 116.9-196.5) and 133.1 epg (95% CI: 99.0-167.2) (p = 0.38), respectively. There was no change in the proportion of children reporting side effects attributable to praziquantel at baseline (49.8%, 95% CI 43.8%-55.8%) and at follow-up (46.6%, 95% CI 42%.1-51.2%) (p = 0.50) as well as in the proportion of children with correct knowledge of schistosomiasis transmission and control between the baseline (45.9%, 95% CI 42.7%-73.7%) and follow-up (44.1%, 95% CI 41.0%- 47.2%) (p = 0.42).

CONCLUSION

Although teacher motivation and supervision to distribute treatment increased the uptake of praziquantel among school-age children, the realized uptake is still lower than is recommended by the World Health Organization (WHO) and apparently too low to affect the prevalence and intensity of schistosomiasis among the children. Additional measures are needed to increase uptake of praziquantel if school-based MDA is to achieve the objective of preventive chemotherapy.

Evidence-based treatment of schistosomiasis in pregnancy

Schistosomiasis is a parasitic infection that causes significant morbidity and mortality, especially in pregnant women originating from developing countries. Prompt diagnosis and treatment can improve pregnancy and infant outcomes. Currently, there are no formal guidelines for treatment in this population, which makes schistosomiasis in pregnancy a challenge to treat.

Efficacy and safety of two closely spaced doses of praziquantel against Schistosoma haematobium and S. mansoni and re-infection patterns in school-aged children in Niger

The aim of this study was to assess the efficacy and safety of two closely spaced doses of praziquantel (PZQ) against Schistosoma haematobium and S. mansoni infection in school-aged children, and to characterise re-infection patterns over a 12-month period. The study was carried out in five villages in western Niger: Falmado, Seberi and Libore (single S. haematobium infection foci), and Diambala and Namarigoungou (mixed S. haematobium-S. mansoni infection foci). Parasitological examinations consisted of triplicate urine filtrations and triplicate Kato-Katz thick smears at each visit. Two 40mg/kg oral doses of PZQ were administered 3 weeks apart. Adverse events were monitored within 4h after dosing by the survey team and 24h after treatment using a questionnaire. Our final study cohort comprised 877 children who were infected with either S. haematobium, or S. mansoni, or both species concurrently and received both doses of PZQ. Follow-up visits were conducted 6 weeks, 6 months and 12 months after the first dose of PZQ. At baseline, the geometric mean (GM) infection intensity of S. haematobium ranged from 3.6 (Diambala) to 30.3eggs/10ml of urine (Falmado). The GM infection intensity of S. mansoni ranged from 86.7 (Diambala) to 151.4eggs/g of stool (Namarigoungou). Adverse events were reported by 33.0% and 1.5% of the children after the first and second doses of PZQ, respectively. We found cure rates (CRs) in S. haematobium-infected children 3 weeks after the second dose of PZQ ranging between 49.2% (Falmado) and 98.4% (Namarigoungou) and moderate-to-high egg reduction rates (ERRs) (71.4-100%). Regarding S. mansoni, only moderate CRs and ERRs were found (51.7-58.8% in Diambala, 55.2-60.2% in Namarigoungou). Twelve months post-treatment, prevalence rates approached pre-treatment levels, but infection intensities remained low. In conclusion, PZQ, given in two closely spaced doses, is efficacious against S. haematobium, but the low ERR observed against S. mansoni raises concern about mounting PZQ tolerance.

Praziquantel treatment of school children from single and mixed infection foci of intestinal and urogenital schistosomiasis along the Senegal River Basin: monitoring treatment success and re-infection patterns

Following major water development schemes in the 1980s, schistosomiasis has become a serious parasitic disease of children living in the Senegal River Basin. Both urogenital (Schistosoma haematobium) and intestinal (Schistosoma mansoni) schistosomiasis can be highly prevalent in school-aged children, with many individuals infected with both parasites. In order to investigate the transmission and re-infection dynamics of both parasite species, single and mixed infection foci at three villages (Nder and Temeye; S. mansoni and S. haematobium foci and Guia; S. haematobium focus) were studied. In each focus infected children were identified and selected for a 12-month study involving two treatments with praziquantel (40mg/kg) three weeks apart at the beginning of the study and again 6 months into the study. Urine and stool samples were examined for schistosome eggs before and at 6 weeks and 6 months after chemotherapy. Prevalence and intensity of infection were recorded for each child at each time point. Before treatment, in all three villages, the prevalence and intensity of infection was extremely high for both S. mansoni (79-100%) and S. haematobium (81-97%). With the first round of chemotherapy sufficient cure rates (CRs) of both species were achieved in all villages (38-96%) with high egg reduction rates (ERRs) (97-99%). The data show that high and rapid re-infection rates occur, especially for S. mansoni, within a six-month period following treatment. Re-infection must be highly linked to ecological and seasonal factors. The persistence of S. mansoni in Nder could raise concern as levels of infection intensity remain high (geometric mean intensity at baseline 653epg changed to 705epg at 12 months) after four rounds of chemotherapy. This phenomenon could be explained by extremely rapid re-infection dynamics or a sub-optimal efficacy of praziquantel against S. mansoni in this village. High intensities in mixed infections may influence disease epidemiology and control warranting further studies. The disease situation in the SRB must be monitored closely and new treatment regimes should be designed and implemented to control schistosomiasis in the school-age population.

Efficacy of Praziquantel against Schistosoma haematobium in Dulshatalo village, western Ethiopia

Background

Praziquantel (PZQ) is the drug of choice for treatment of all human schistosomes. It is used in population based targeted or mass deworming strategies in several countries. The effect of PZQ on S. hematobium has not been studied in Ethiopia. The objective of this study was to determine the efficacy of PZQ against S. haematobium in Dulshatalo village, western Ethiopia.

Methods

A prospective study was conducted from October to December, 2007. Urine samples from 341 residents were collected and screened for haematuria and proteinuria using urinalysis dipstick. S. haematobium eggs were detected and quantified using filtration techniques. The participants who were positive for haematuria were treated with a standard dose of PZQ (40 mg/kg). Data on pre and 24 hours post treatment symptoms were collected via questionnaire. Urine samples were also collected 7 weeks after treatment and examined to assess the cure and the egg reduction rates.

Results

The prevalence of S. haematobium among the study participants was 57.8% (197/341). Haematuria was detected in 234 (68.6%) of the study participants. For PZQ efficacy asessment, 152 of the treated participants were considered. The presence of S. haemetaobium eggs showed statistically significant association (p < 0.05) with haematuria and proteinuria. Seven weeks post treatment, the extent of haematuria and proteinuria decreased from 100% to 40.8% and 94.07% to 48.7%, respectively. The cure and the parasitological egg reduction rates seven weeks post treatment were 86% and 85%, respectively. Post treatment symptoms revealed a wide range of side effects including straining, abdominal pain, nausea and headache.

Conclusions

There were marked cure and egg reduction rates, together with mild and short lived side effects of PZQ for treatment of S. haematobium, in this study.

Potential cost-effectiveness of schistosomiasis treatment for reducing HIV transmission in Africa--the case of Zimbabwean women

Background

Epidemiological data from Zimbabwe suggests that genital infection with Schistosoma haematobium may increase the risk of HIV infection in young women. Therefore, the treatment of Schistosoma haematobium with praziquantel could be a potential strategy for reducing HIV infection. Here we assess the potential cost-effectiveness of praziquantel as a novel intervention strategy against HIV infection.

Methods

We developed a mathematical model of female genital schistosomiasis (FGS) and HIV infections in Zimbabwe that we fitted to cross-sectional data of FGS and HIV prevalence of 1999. We validated our epidemic projections using antenatal clinic data on HIV prevalence. We simulated annual praziquantel administration to school-age children. We then used these model predictions to perform a cost-effectiveness analysis of annual administration of praziquantel as a potential measure to reduce the burden of HIV in sub-Saharan Africa.

Findings

We showed that for a variation of efficacy between 30–70% of mass praziquantel administration for reducing the enhanced risk of HIV transmission per sexual act due to FGS, annual administration of praziquantel to school-age children in Zimbabwe could result in net savings of US$16–101 million compared with no mass treatment of schistosomiasis over a ten-year period. For a variation in efficacy between 30–70% of mass praziquantel administration for reducing the acquisition of FGS, annual administration of praziquantel to school-age children could result in net savings of US$36−92 million over a ten-year period.

Conclusions

In addition to reducing schistosomiasis burden, mass praziquantel administration may be a highly cost-effective way of reducing HIV infections in sub-Saharan Africa. Program costs per case of HIV averted are similar to, and under some conditions much better than, other interventions that are currently implemented in Africa to reduce HIV transmission. As a cost-saving strategy, mass praziquantel administration should be prioritized over other less cost-effective public health interventions.

Evidence from epidemiological and clinical studies supports the hypothesis that genital infection with Schistosoma haematobium increases the risk of becoming infected with HIV among women in sub-Saharan Africa. Praziquantel is an oral, nontoxic, inexpensive medication recommended for treatment of schistosomiasis, which might be able to prevent the development of genital schistosomiasis. We constructed a mathematical model of female genital schistosomiasis and HIV infections, which we calibrated using epidemiological data from Zimbabwe. We used this model to investigate the potential cost-effectiveness of mass drug administration with praziquantel as an intervention strategy for reducing HIV transmission in sub-Saharan Africa. We showed that mass drug administration with praziquantel may be a timely, innovative, and cost-saving intervention strategy for HIV prevention in sub-Saharan Africa. As a cost-saving strategy, mass drug administration with praziquantel should be prioritized over other less cost-effective public health interventions. Our findings indicate the possible benefit of scaling up schistosomiasis control efforts in sub-Saharan Africa, and especially in areas were Schistosoma haematobium and HIV are highly prevalent.

Schistosoma mansoni-related morbidity in a low-prevalence area of Brazil: a comparison between egg excretors and seropositive non-excretors

In areas where there is a low prevalence of schistosomiasis mansoni, faecal examination is a relatively insensitive method of detection and infected people may also be missed because most show only mild morbidity. In such settings, serology may be a more useful diagnostic tool than microscopy. In the present study, the clinical and biochemical characteristics of individuals who were stool-positive for Schistosoma mansoni eggs were compared with those of individuals, from the same low-prevalence area of Brazil, who were stool-negative but seropositive for the parasite. Overall, 269 subjects were checked both for schistosome eggs in their faeces (using Kato-Katz smears and Lutz sedimentation) and for anti-S. mansoni IgG in their sera (using an ELISA). Although 128 (48%) of these subjects were found seropositive, only 26 (10%) were found to be egg excretors and two of the egg excretors were seronegative. Compared with the seropositive egg-negatives, the egg excretors had significantly higher frequencies of fatigue, melaena, jaundice and swelling of the abdomen. The egg excretors also had higher frequencies of hepatomegaly (20% v. 16%) and splenomegaly (4% v. 1%). In both groups of subjects, mean concentrations of serum proteins and haemoglobin and mean leucocyte counts were in the normal range whereas most blood concentrations of alanine aminotransferase and many of those of aspartate aminotransferase were slightly elevated. Although the egg excretors tended to have low-intensity infections, it seems possible that the seropositive nonexcretors had even milder infections that could not be detected by faecal examination. The high frequency of cure observed when the egg excretors were given praziquantel at 40 mg/kg (94%) is probably another indication that most had light infections when they were treated.

In vitro and in vivo effects of hesperidin treatment on adult worms of Schistosoma mansoni

Hesperidin has been reported to exert a wide range of pharmacological effects, including antifungal, antiviral, antioxidant, anti-inflammatory and anticarcinogenic activities. Herein, the schistosomicidal activity of this compound was evaluated in vitro and in vivo. Using an in vitro assay, a concentration of 200 μg/ml of hesperidin resulted in the mortality of 100% adult worms of Schistosoma (S.) mansoni within 72 h and a partial tegumental alteration in 10% of worms. However, after 144 h incubation, 50 and 100 μg/ml concentrations showed 0% and 10% mortality in adult worms, respectively, without any changes to the tegument. Sublethal doses did not influence egg output nor the development of eggs deposited by pairs of adult worms. In an in vivo study, mice infected with S. mansoni and treated with 600 mg hesperidin/kg body weight showed a respective reduction of 50, 45.2, 50 and 47.5% of males, females, worm pairs and total worm burden. In addition, a respective reduction, based on the number of eggs/g tissue, of 41.5, 63.7 and 58.6% was observed in the liver, intestine and liver/intestinal tissue combined. Furthermore, S. mansoni-specific IgG level significantly increased with hesperidin treatment, whereas IgA and IgE levels were not significantly changed. IgM levels decreased in response to cercarial antigen preparation but were not altered in response to soluble worm or soluble egg antigen. As in hesperidin-treated mice, praziquantel-treated mice showed a similar pattern of specific antibody response to S. mansoni antigens. The present study represents the first report on the effects of the schistosomicidal activity of hesperidin.

Uptake of preventive treatment for intestinal schistosomiasis among school children in Jinja district, Uganda: a cross sectional study

Background

In Uganda, the current national health sector strategic and investment plan underscores schistosomiasis as one of the diseases targeted for elimination by the year 2015. However, uptake of treatment among school children is unknown but suspected to be low. We estimated the uptake and predictors of preventive treatment with praziquantel.

Methods

In a cross sectional study carried out in Jinja district of Uganda, a random sample of 1,010 children in 12 primary schools was questioned about their uptake of praziquantel, knowledge and perceptions about schistosomiasis, support for taking preventive treatment and the dangers of taking praziquantel. The prevalence and mean intensity of infection with Schistosoma mansoni were determined.

Results

Self reported uptake of praziquantel at last mass treatment was 28.2% (95% confidence interval (CI): 22.9%–33.6%). Overall prevalence and mean intensity of S. mansoni infection was 35% (95% CI: 25.4%–37.9%) and 116.1 eggs per gram (epg) of stool (95% CI: 98.3–137.1) respectively. Uptake of praziquantel was more likely if a child was from a school with high prevalence of infection, had knowledge about schistosomiasis transmission and prevention, and reported teachers’ support to take praziquantel. Of the 285 children who took praziquantel, 142 (49.8%) developed side effects. Of the 725 children who did not take the drug, 522 (72.0%) reported fear of side effects as a major reason for non-uptake.

Conclusions

Uptake of praziquantel in this population is very low. Fear of side effects of praziquantel, lack of knowledge about schistosomiasis transmission and prevention and lack of teacher support are some of the major factors associated with low uptake.

Comparative efficacy of one versus two doses of praziquantel on cure rate of Schistosoma mansoni infection and re-infection in Mayuge District, Uganda

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%) (χ(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.

Cost-effectiveness of a community-based intervention for reducing the transmission of Schistosoma haematobium and HIV in Africa

Epidemiological studies from sub-Saharan Africa show that genital infection with Schistosoma haematobium [corrected] may increase the risk for HIV infection in young women. Therefore, preventing schistosomiasis has the potential to reduce HIV transmission in sub-Saharan Africa. We developed a transmission model of female genital schistosomiasis and HIV infections that we fit to epidemiological data of HIV and female genital schistosomiasis prevalence and coinfection in rural Zimbabwe. We used the model to evaluate the cost-effectiveness of a multifaceted community-based intervention for preventing schistosomiasis and, consequently, HIV infections in rural Zimbabwe, from the perspective of a health payer. The community-based intervention combined provision of clean water, sanitation, and health education (WSH) with administration of praziquantel to school-aged children. Considering variation in efficacy between 10% and 70% of WSH for reducing S. haematobium [corrected] transmission, our model predicted that community-based intervention is likely to be cost-effective in Zimbabwe at an aggregated WSH cost corresponding to US $725-$1,000 per individual over a 20-y intervention period. These costs compare favorably with empirical measures of WSH provision in developing countries, indicating that integrated community-based intervention for reducing the transmission of S. haematobium [corrected] is an economically attractive strategy for reducing schistosomiasis and HIV transmission in sub-Saharan Africa that would have a powerful impact on averting infections and saving lives.

Drugs for treating Schistosoma mansoni infection

BACKGROUND

Schistosoma mansoni is a parasitic infection common in the tropics and sub-tropics. Chronic and advanced disease includes abdominal pain, diarrhoea, blood in the stool, liver cirrhosis, portal hypertension, and premature death.

OBJECTIVES

To evaluate the effects of antischistosomal drugs, used alone or in combination, for treating S. mansoni infection.

SEARCH METHODS

We searched MEDLINE, EMBASE and LILACS from inception to October 2012, with no language restrictions. We also searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2012) and mRCT. The reference lists of articles were reviewed and experts were contacted for unpublished studies.

SELECTION CRITERIA

Randomized controlled trials of antischistosomal drugs, used alone or in combination, versus placebo, different antischistosomal drugs, or different doses of the same antischistosomal drug for treating S. mansoni infection.

DATA COLLECTION AND ANALYSIS

One author extracted data and assessed eligibility and risk of bias in the included studies, which were independently checked by a second author. We combined dichotomous outcomes using risk ratio (RR) and continuous data weighted mean difference (WMD); we presented both with 95% confidence intervals (CI). We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

Fifty-two trials enrolling 10,269 participants were included. The evidence was of moderate or low quality due to the trial methods and small numbers of included participants.Praziquantel: Compared to placebo, praziquantel 40 mg/kg probably reduces parasitological treatment failure at one month post-treatment (RR 3.13, 95% CI 1.03 to 9.53, two trials, 414 participants, moderate quality evidence). Compared to this standard dose, lower doses may be inferior (30 mg/kg: RR 1.52, 95% CI 1.15 to 2.01, three trials, 521 participants, low quality evidence; 20 mg/kg: RR 2.23, 95% CI 1.64 to 3.02, two trials, 341 participants, low quality evidence); and higher doses, up to 60 mg/kg, do not appear to show any advantage (four trials, 783 participants, moderate quality evidence).The absolute parasitological cure rate at one month with praziquantel 40 mg/kg varied substantially across studies, ranging from 52% in Senegal in 1993 to 92% in Brazil in 2006/2007. Oxamniquine: Compared to placebo, oxamniquine 40 mg/kg probably reduces parasitological treatment failure at three months (RR 8.74, 95% CI 3.74 to 20.43, two trials, 82 participants, moderate quality evidence). Lower doses than 40 mg/kg may be inferior at one month (30 mg/kg: RR 1.78, 95% CI 1.15 to 2.75, four trials, 268 participants, low quality evidence; 20 mg/kg: RR 3.78, 95% CI 2.05 to 6.99, two trials, 190 participants, low quality evidence), and higher doses, such as 60 mg/kg, do not show a consistent benefit (four trials, 317 participants, low quality evidence).These trials are now over 20 years old and only limited information was provided on the study designs and methods. Praziquantel versus oxamniquine: Only one small study directly compared praziquantel 40 mg/kg with oxamniquine 40 mg/kg and we are uncertain which treatment is more effective in reducing parasitological failure (one trial, 33 participants, very low quality evidence). A further 10 trials compared oxamniquine at 20, 30 and 60 mg/kg with praziquantel 40 mg/kg and did not show any marked differences in failure rate or percent egg reduction.Combination treatments: We are uncertain whether combining praziquantel with artesunate reduces failures compared to praziquantel alone at one month (one trial, 75 participants, very low quality evidence).Two trials also compared combinations of praziquantel and oxamniquine in different doses, but did not find statistically significant differences in failure (two trials, 87 participants). Other outcomes and analyses: In trials reporting clinical improvement evaluating lower doses (20 mg/kg and 30 mg/kg) against the standard 40 mg/kg for both praziquantel or oxamniquine, no dose effect was demonstrable in resolving abdominal pain, diarrhoea, blood in stool, hepatomegaly, and splenomegaly (follow up at one, three, six, 12, and 24 months; three trials, 655 participants).Adverse events were not well-reported but were mostly described as minor and transient.In an additional analysis of treatment failure in the treatment arm of individual studies stratified by age, failure rates with 40 mg/kg of both praziquantel and oxamniquine were higher in children.

AUTHORS' CONCLUSIONS

Praziquantel 40 mg/kg as the standard treatment for S. mansoni infection is consistent with the evidence. Oxamniquine, a largely discarded alternative, also appears effective.Further research will help find the optimal dosing regimen of both these drugs in children.Combination therapy, ideally with drugs with unrelated mechanisms of action and targeting the different developmental stages of the schistosomes in the human host should be pursued as an area for future research.

Epidemiology and interactions of Human Immunodeficiency Virus - 1 and Schistosoma mansoni in sub-Saharan Africa

Human Immunodeficiency Virus-1/AIDS and Schistosoma mansoni are widespread in sub-Saharan Africa and co-infection occurs commonly. Since the early 1990s, it has been suggested that the two infections may interact and potentiate the effects of each other within co-infected human hosts. Indeed, S. mansoni infection has been suggested to be a risk factor for HIV transmission and progression in Africa. If so, it would follow that mass deworming could have beneficial effects on HIV-1 transmission dynamics. The epidemiology of HIV in African countries is changing, shifting from urban to rural areas where the prevalence of Schistosoma mansoni is high and public health services are deficient. On the other side, the consequent pathogenesis of HIV-1/S. mansoni co-infection remains unknown. Here we give an account of the epidemiology of HIV-1 and S. mansoni, discuss co-infection and possible biological causal relationships between the two infections, and the potential impact of praziquantel treatment on HIV-1 viral loads, CD4+ counts and CD4+/CD8+ ratio. Our review of the available literature indicates that there is evidence to support the hypothesis that S. mansoni infections can influence the replication of the HIV-1, cell-to-cell transmission, as well as increase HIV progression as measured by reduced CD4+ T lymphocytes counts. If so, then deworming of HIV positive individuals living in endemic areas may impact on HIV-1 viral loads and CD4+ T lymphocyte counts.

Efficacy of praziquantel syrup versus crushed praziquantel tablets in the treatment of intestinal schistosomiasis in Ugandan preschool children, with observation on compliance and safety

Preschool children (aged ≤5 years) have so far been overlooked by mass treatment campaigns targeting schistosomiasis, even though praziquantel (PZQ) has been shown to be well tolerated and effective within this age group. The WHO provided the Ugandan Ministry of Health with a syrup formulation of PZQ with the aim of assessing its safety and efficacy in comparison with crushed PZQ tablets for the treatment of intestinal schistosomiasis in preschool children. This study included 1144 preschool children randomly assigned to two treatment arms (PZQ syrup or crushed PZQ tablet) regardless of infection status for direct comparison. Diagnosis of intestinal schistosomiasis was assessed using single stool sample, double Kato-Katz smear examinations. Parasitological cure was assessed 3 weeks after treatment. The observed cure rate was 80.9% for the PZQ syrup arm and 81.7% for the crushed PZQ tablet arm, with egg reduction rates of 86.1% and 89.0%, respectively. Pre-treatment infection intensity was observed to influence cure rates significantly, with cure rates of 88.6% for light infections, 74.5% for moderate infections and 67.4% for heavy infections. No significant difference was found in non-compliance between the PZQ syrup (11.1%) and crushed PZQ tablet (14.7%) arms. PZQ syrup and crushed PZQ tablets have very similar efficacies in the treatment of intestinal schistosomiasis in preschool children.

Hepatosplenic morbidity due to Schistosoma mansoni in schoolchildren on Ukerewe Island, Tanzania

The study was conducted to assess infection intensity and morbidity due to Schistosoma mansoni in schoolchildren on Ukerewe Island in Lake Victoria, Tanzania, East Africa. Three hundred and sixty pupils who have never been treated previously were enrolled (180 males/180 females, age 6-17 years [median 10 years]) in three different schools of the island. Double stool samples were collected from each pupil and egg excretion was classified according to WHO recommendations. Ultrasound investigations were performed in accordance with the WHO Niamey-Belo-Horizonte protocol. Male (112/180, 62.2%) and female (104/180; 57.7%) pupils were infected (difference, not significant [n.s.]). In the positive 216 cases, egg excretion varied from 1 to 2,440 eggs per gramme stool (epg) [median 165 epg]. There were 69/216 (31.9%) who had a low grade, 105/216 (53.2%) had a moderate and 42/216 (14.8%) had a heavy infection. There was no significant difference between male and female sex nor with regard to age groups. There were 354/360 children who underwent sonography: 321 (90.7%) had splenomegaly, 316 (89.3%) showed a left lobe and 109 (30.9%) had a right lobe hepatomegaly. Overt signs of portal fibrosis (PF) were present in 19 children (5.4%) out of whom 11 presented with echogenic thickening of peripheral portal and 8 with thickening of central portal branches. Non-specific portal wall changes were seen in 6 children (1.7%). Association of PF to quantitative egg excretion was not seen (median in PF, 172 epg vs. median in non PF, 168 epg; difference, n.s.). Portal vein dilatation was seen in 101/354 (28.5%) cases. In Ukerewe, the prevalence of S. mansoni infection and infection intensity in children is high, yet overt hepatic morbidity is low as compared to other endemic foci. Non-specific ultrasonographic abnormalities including hepatosplenomegaly and portal vein dilatation were seen frequently but the fraction attributable to schistosomiasis is difficult to assess.

Utility of repeated praziquantel dosing in the treatment of schistosomiasis in high-risk communities in Africa: a systematic review

Background

Controversy persists about the optimal approach to drug-based control of schistosomiasis in high-risk communities. In a systematic review of published studies, we examined evidence for incremental benefits from repeated praziquantel dosing, given 2 to 8 weeks after an initial dose, in Schistosoma-endemic areas of Africa.

Methodology/Principal Findings

We performed systematic searches of electronic databases PubMed and EMBASE for relevant data using search terms ‘schistosomiasis’, ‘dosing’ and ‘praziquantel’ and hand searches of personal collections and bibliographies of recovered articles. In 10 reports meeting study criteria, improvements in parasitological treatment outcomes after two doses of praziquantel were greater for S. mansoni infection than for S. haematobium infection. Observed cure rates (positive to negative conversion in egg detection assays) were, for S. mansoni, 69–91% cure after two doses vs. 42–79% after one dose and, for S. haematobium, 46–99% cure after two doses vs. 37–93% after a single dose. Treatment benefits in terms of reduction in intensity (mean egg count) were also different for the two species—for S. mansoni, the 2-dose regimen yielded an weighted average 89% reduction in standardized egg counts compared to a 83% reduction after one dose; for S. haematobium, two doses gave a 93% reduction compared to a 94% reduction with a single dose. Cost-effectiveness analysis was performed based on Markov life path modeling.

Conclusions/Significance

Although schedules for repeated treatment with praziquantel require greater inputs in terms of direct costs and community participation, there are incremental benefits to this approach at an estimated cost of $153 (S. mansoni)–$211 (S. haematobium) per additional lifetime QALY gained by double treatment in school-based programs. More rapid reduction of infection-related disease may improve program adherence, and if, as an externality of the program, transmission can be reduced through more effective coverage, significant additional benefits are expected to accrue in the targeted communities.

Infection by Schistosoma worms causes serious disease among people who live in areas of Africa, South America, and Asia where these parasites are regularly transmitted. Although yearly treatment with the drug praziquantel is fairly effective in reducing or eliminating active infection, it does not cure everyone, and reinfection remains a continuing problem in high-risk communities. Studies have suggested that a repeat dose of praziquantel, given 2 to 8 weeks after the first dose, can improve cure rates and reduce remaining intensity of infections in population-based programs. Our systematic review of published research found that, on average, in Africa, such repeated dosing appears to offer particular advantages in the treatment of S. mansoni, the cause of intestinal schistosomiasis, but there was less consistent improvement after double-dosing for S. haematobium, the cause of urogenital schistosomiasis. Based on this evidence, we used a calibrated life-path model to predict the costs and benefits of a single-dose vs. a double-dose strategy in a typical high-risk community. Our projections suggest cost-effective incremental benefits from double dosing in terms of i) limiting a person's total years spent infected and ii) limiting the number of years they spend with heavy infection, with consequent improvements in quality of life.

A randomised controlled clinical trial on the safety of co-administration of albendazole, ivermectin and praziquantel in infected schoolchildren in Uganda

Integrated chemotherapy of neglected tropical diseases (NTD) through mass drug administration given as a single dose would increase treatment coverage and cost-effectiveness. This study reports on the safety of a combination of albendazole, ivermectin and praziquantel in the treatment of lymphatic filariasis (LF), schistosomiasis and soil-transmitted helminthiasis (STH) in infected children. In this randomised, controlled, single-blinded clinical trial conducted in 235 primary school children aged 5-18 years in Yumbe District in Northern Uganda, the triple combination therapy was compared with the current NTD programme regimen. Liver function testing was performed for all children who received combined therapy. The study included 48 children with LF alone, 60 children with schistosomiasis (Schistosoma mansoni), 41 children with STH, 49 children with schistosomiasis + LF and 37 children with all three types of infection. Children were closely monitored by a paediatrician for any adverse reactions for 7 days. No serious adverse events were experienced. However, 4 of 18 children in the test group and 2 of 3 children in the control group who did not report any ill conditions before treatment developed adverse drug reactions. The combined and conventional therapies were found to be equally safe. The efficacies of both therapies were comparable and satisfactory. [ClinicalTrials.gov identifier: NCT01050517].

The acceptability and safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and soil-transmitted helminthiasis in children aged 1-4 years in Uganda

OBJECTIVE

There is limited information on the acceptability and safety of praziquantel for treatment of schistosomiasis in children below the age of four years. In addition, although mebendazole has been extensively used together with praziquantel against infections with schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged children, no specific acceptability or safety studies have been published on this drug combination in younger children.

METHODS

A randomized clinical trial was conducted to determine the safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and STH in children aged 1 to 4 years.

RESULTS

A total of 596 children from Bwondha fishing community in Mayuge district and Wang-Kado fishing community in Nebbi district were investigated using duplicate Kato-Katz thick smears of two stool samples and 130 (21·8%) were found infected with S. mansoni. Of these, 19·2% (25) had heavy intensity of infections. Of the infected children, 82 were included and randomised into praziquantel (40 mg/kg) + mebendazole (500 mg) or praziquantel (40 mg/kg) alone.

CONCLUSION

Many symptoms were reported before treatment while very few were reported after treatment and all on treatment day. No serious adverse events were reported or observed after treatment. Praziquantel with or without mebendazole was well tolerated in small children in the study area.

Comparative randomised trial of high and conventional doses of praziquantel in the treatment of schistosomiasis mansoni

The efficacy of oral praziquantel in the treatment of schistosomiasis has been considered low by most public health institutions. In this paper, we compared the efficacy of two dosages of praziquantel (80 mg/kg vs. 50 mg/kg) in patients with chronic schistosomiasis mansoni. Two hundred eighty-eight patients with schistosomiasis from a community in Brazil were randomly divided into two groups: 145 patients (Group 1) received 80 mg/kg body weight of oral praziquantel divided in two equal doses with 1 h interval and 143 patients (Group 2) received 50 mg/kg body weight of oral praziquantel. To keep the study masked, patients in Group 2 received placebo 1 h after the first dose. All patients were subjected to clinical and ultrasonographic examination. Cure assessment was performed by repeating two stool examinations, by a quantitative method, at 30, 90 and 180 days after treatment. The morbidity of schistosomiasis was low, with a few cases of light periportal thickening and 16 cases of mild splenomegaly. The cure rates were 89.7% for Group 1 and 83.9% for Group 2. There was no difference in the efficacy of both therapeutic dosages of praziquantel assayed. The adverse reactions were more frequent with higher dosage.

Schistosoma mansoni Infections in young children: when are schistosome antigens in urine, eggs in stool and antibodies to eggs first detectable?

Background

In Uganda, control of intestinal schistosomiasis with preventive chemotherapy is typically focused towards treatment of school-aged children; the needs of younger children are presently being investigated as in lakeshore communities very young children can be infected. In the context of future epidemiological monitoring, we sought to compare the detection thresholds of available diagnostic tools for Schistosoma mansoni and estimate a likely age of first infection for these children.

Methods and Findings

A total of 242 infants and preschool children (134 boys and 108 girls, mean age 2.9 years, minimum 5 months and maximum 5 years) were examined from Bugoigo, a well-known disease endemic village on Lake Albert. Schistosome antigens in urine, eggs in stool and host antibodies to eggs were inspected to reveal a general prevalence of 47.5% (CI₉₅ 41.1–54.0%), as ascertained by a positive criterion from at least one diagnostic method. Although children as young as 6 months old could be found infected, the average age of infected children was between 3¼–3¾ years, when diagnostic techniques became broadly congruent.

Conclusion

Whilst different assays have particular (dis)advantages, direct detection of eggs in stool was least sensitive having a temporal lag behind antigen and antibody methods. Setting precisely a general age of first infection is problematic but if present Ugandan policies continue, a large proportion of infected children could wait up to 3–4 years before receiving first medication. To better tailor treatment needs for this younger ageclass, we suggest that the circulating cathodic antigen urine dipstick method to be used as an epidemiological indicator.

In sub-Saharan Africa, intestinal schistosomiasis is a debilitating disease caused by a worm infection. To arrest disease progression, de-worming medications are given out, often en masse, to school-aged children. In Uganda, however, much younger children can be infected, and in lakeshore communities both infants and pre-school children can already show signs and symptoms of intestinal schistosomiasis. To change de-worming practices, further information on the occurrence of infections in these younger is needed for evidence-based decision making. Our study applied current methods of disease diagnosis to better define the ‘age of first infection’ and estimate general infection prevalence within a disease-endemic village. Up to 50% of young children were clearly shown to have schistosomiasis and could likely wait up to 3–4 years before obtaining first treatment if present de-worming policies are not changed. In the context of identifying future treatment needs, we propose that antigen detection methods are most suitable.

Efficacy of artesunate with sulfalene plus pyrimethamine versus praziquantel for treatment of Schistosoma mansoni in Kenyan children: an open-label randomised controlled trial

BACKGROUND

Schistosomiasis is an important parasitic disease in Kenya. Decreasing susceptibility of schistosomes to praziquantel, the major drug used to reduce disease morbidity, has made assessment of new antischistosomal drugs a priority. We aimed to assess the safety and efficacy of an artesunate-based combination drug in the treatment of schistosomiasis.

METHODS

In this open-label randomised trial in Rarieda district of western Kenya, we enrolled school children (aged 6-15 years) who had Schistosoma mansoni infection according to duplicate Kato-Katz thick smears from a stool sample. Computer-generated block randomisation was used to assign children (1:1) to receive artesunate (100 mg) with sulfalene (also known as sulfamethoxypyrazine; 250 mg) plus pyrimethamine (12.5 mg) as one dose every 24 h for 3 days or one dose of praziquantel (40 mg/kg per day). The primary efficacy endpoint was the number of participants cured 28 days after treatment. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01054651.

RESULTS

Between October and December, 2009, 212 children were enrolled and assigned to receive artesunate with sulfalene plus pyrimethamine (n=106) or praziquantel (n=106). 69 patients (65%) were cured in the praziquantel treatment group compared with 15 (14%) in the artesunate with sulfalene plus pyrimethamine treatment group (p<0.0001). Adverse events were less common in patients taking artesunate with sulfalene plus pyrimethamine than in those taking praziquantel (22% [n=23] vs 49% [n=52], p<0.0001), and no drug-related serious adverse events occurred.

INTERPRETATION

The standard treatment with praziquantel is more effective than artesunate with sulfalene plus pyrimethamine in the treatment of children with S mansoni infection in western Kenya. Whether artemisinin-based combination therapy has a role in the treatment of schistosomiasis is unclear.

High rate of failure in treatment of imported schistosomiasis

BACKGROUND

There is an increasing number of imported cases of schistosomiasis in Europe, but there are only few studies on the efficacy of praziquantel for the treatment of schistosomiasis in non-endemic settings.

METHODS

Patients treated for schistosomiasis in 2003 to 2008 were offered reexamination with serology, eosinophil count, IgE, microscopy of 24 h urine samples and/or rectal biopsies >3 months after treatment. All patients had been treated with at least one dose of praziquantel 40 to 60 mg/kg >12 weeks after exposure and had not been reexposed to schistosomiasis after treatment.

RESULTS

Twenty-eight traveler (15 tourists and 13 expatriates) and two immigrants were reexamined after treatment. Viable ova were detected in six traveler (20%). Ova were found in 5/23 (22%) rectal biopsies and in 2/12 (17%) urine samples. Treatment failure was suspected in a symptomatic patient who 2 years after treatment had eightfold rise in antibody titer and elevated IgE but no detectable ova in urine or rectal biopsies. Additional 13 patients had one or more parameters, which could indicate persistent infection. There were no significant differences in eosinophil count, IgE or, change in antibody titer between patients with versus without detectable ova after treatment.

CONCLUSIONS

In traveler with a low parasite burden, assessment of treatment results can be difficult because of the low sensitivity of microscopy and persistence of antibodies for several years after treatment. We found a high rate of treatment failure among traveler, indicating that nonimmune patients may need more than the recommended single day of treatment for eradication of parasites. Until more sensitive and specific methods for detection of persistent, active infection are available, repeated treatment should be considered in patients with continuous symptoms or other indications of treatment failure even when viable ova cannot be detected by microscopy.