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Schistosomiasis is a neglected tropical disease that disproportionately affects the poorest people in tropical and subtropical countries. It is a major parasitic disease causing considerable morbidity in Ethiopia. Despite significant control efforts, schistosomiasis transmission is still widespread in many rural areas of the country. The aim of this study was to determine the prevalence and intensity of intestinal schistosomiasis among schoolchildren, as well as to identify schistosomiasis transmission sites in Gomma District, southwestern Ethiopia. Between October 2018 and September 2019, cross-sectional parasitological and malacological surveys were conducted in the study area. The study comprised 492 school-children aged 6 to 15 years old from four primary schools in Gomma District. To identify and quantify eggs of Schistosoma mansoni from the children, stool specimens were collected and processed using double Kato-Katz thick smears. Water bodies adjacent to human settlements in the study area were surveyed for snail intermediate hosts of S. mansoni. Morphological identification of collected snails was conducted, followed by examining their infection status using a dissecting microscope. The overall prevalence of S. mansoni infection was 73.8% (95%CI: 69.9-77.7%) and 41.6% of them had moderate-to-heavy infections. The prevalence of S. mansoni infection differed considerably by age group, with the older age groups (12-15) having a higher prevalence than the younger age groups (6-11) (p < 0.001). The prevalence of infection also varied significantly among schools; Dedo Ureche had the highest prevalence (86.9%) (p = 0.034), while Goga Kilole had relatively the lowest prevalence of S. mansoni infection (59.6%) (p = 0.003). A total of 1463 Biomphalaria pfeifferi snails were collected from 11 survey sites throughout the study area, with 357 (24.4%) of the snails shedding schistosomes cercariae. Despite intensified efforts to scale up mass drug administration in Ethiopia, this study reported high levels of S. mansoni infection among schoolchildren and snail intermediate hosts in rural communities in Gomma. Such a high infection rate warrants pressing needs for targeted and integrated interventions to control the disease in the area., (© 2022. The Author(s).)

Background: Distribution of schistosomiasis is more focal due to spatial heterogeneities in intermediate host snail dynamics and water contact behavior of humans. This makes the search for new transmission foci of schistosomiasis and its connection with malacologically receptive water bodies essential for effective control of its transmission. This study was intended to assess the prevalence of intestinal helminth infections among schoolchildren and Schistosoma mansoni transmission in Koga irrigation scheme surroundings, northwest Ethiopia., Materials and Methods: Cross-sectional parasitological and malacological surveys were conducted in three schools and nearby water bodies, respectively around Koga irrigation scheme. Stool specimens were collected from 421 randomly selected schoolchildren and microscopically examined using Kato-Katz and formol-ether concentration methods. Malacological surveys were carried out and the identified Biomphalaria pfeifferi snails were screened for schistosome infection. Swiss albino mice were exposed to schistosome cercariae shed by Biomphalaria pfeifferi for definite identification of Schistosoma species., Results: Among the examined schoolchildren, 22.6% (95% CI: 18.7%-26.9%) were positive for at least one intestinal helminths species. Ascaris lumbricoides was the most frequent intestinal helminth detected among forty (9.5%) children. Schistosoma mansoni was detected among 4.8% (95% CI: 2.9%-7.2%) of children and its prevalence was significantly higher among male children (p = 0.038) and those attending in Mengesha Jemberie Primary School (p = 0.044). Biomphalaria pfeifferi snails were identified in water bodies in close proximity to Mengesha Jemberie and Wotete Abay Primay schools. Schistosoma mansoni adult worms were harvested after exposure of mice to cercariae shed from Biomphalaria pfeifferi snails collected from water bodies nearby Mengesha Jemberie Primary School., Conclusions: Schistosoma mansoni infection of schoolchildren, findings of schistosome infected snails and establishment of mice infection confirm that transmission is taking place in the study areas. Hence, snail control and other measures such as provision of sanitary facilities and health education are recommended., Competing Interests: The authors have declared that no competing interests exist.

The World Health Organization (WHO) recommends periodic assessment of the therapeutic efficacy of praziquantel (PZQ) to detect reduced efficacy that may arise from drug resistance in schistosomes. In this multi-country study (2014), we assessed the therapeutic efficacy of a single oral dose of PZQ (40 mg/kg) against Schistosoma mansoni (Brazil, Cameroon, Ethiopia, Mali, Madagascar and Tanzania), S. haematobium (Cameroon, Ethiopia, Mali, Tanzania and Zanzibar) and S. japonicum (the Philippines) infections in school-aged children, across a total of 12 different trials. Each trial was performed according to the standardized methodology for evaluating PZQ efficacy as described by the WHO. Overall, therapeutic efficacy, measured as the reduction in arithmetic mean of schistosome egg counts following drug administration (egg reduction rate; ERR), was high for all three schistosome species (S. mansoni: 93.4% (95%CI: 88.8-96.8); S. haematobium: 97.7% (95%CI: 96.5-98.7) and S. japonicum: 90.0% (95%CI: 68.4-99.3). At the trial level, therapeutic efficacy was satisfactory (point estimate ERR ≥90%) for all three Schistosoma species with the exception of S. mansoni in Cameroon where the ERR was 88.5% (95%CI: 79.0-95.1). Furthermore, we observed that in some trials individual drug response could vary significantly (wide 95%CI) and that few non-responsive individuals could significantly impact ERR point estimates. In conclusion, these results do not suggest any established reduced efficacy of the standard PZQ treatment to any of the three schistosome species within these countries. Nevertheless, the substantial degree of variation in individual responses to treatment in some countries underpins the need for future monitoring. The reported ERR values serve as reference values to compare with outcomes of future PZQ efficacy studies to ensure early detection of reduced efficacies that could occur as drug pressure continues increase. Finally, this study highlights that 95%CI should be considered in WHO guidelines to classify the therapeutic efficacy of PZQ., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Schistosoma mansoni (S. mansoni) infection is a significant public health problem in Ethiopia, and has wide distribution in the country. The impact of the disease is particularly high on school-age children. Nationwide 385 endemic districts were identified, whereby control and elimination interventions are underway using school-based annual mass drug administration (MDA) with praziquantel. The national elimination program targets endemic districts as a whole. The aim of this study was to identify the transmission foci of Schistosoma mansoni and determine prevalence of soil-transmitted helminths (STHs) in Abeshge district., Methods: The study was conducted from April to May, 2019 among school-age children randomly selected from public elementary schools in Abeshge district, South-central Ethiopia. Demographic information and data on risk factors of S. mansoni infection were gathered using pre-tested questionnaire. Moreover, a stool sample was collected from each child and examined using Kato-Katz thick smear technique. The data were analyzed using STATA&#95;MP version 12., Results: A total of 389 school-age children from five public elementary schools were included in the study. The overall prevalence of S. mansoni and STHs was 19.3% (75/389) and 35% (136/389), respectively. The prevalence of S. mansoni was 60.6% in Kulit Elementary school, while it was zero in Geraba. The prevalence of S. mansoni was significantly higher among males (AOR = 2.6, 95% CI 1.3-5.1), those with habit of swimming and/or bathing in rivers (AOR = 2.9, 95%CI 1.3-5.1) and involved in irrigation activities (AOR = 2.9, 95% CI 1.0-8.3). Overall, the prevalence of S. mansoni was significantly higher among school children attending Kulit Elementary School compared to those attending the remaining schools (AOR = 12.5, 95%CI 6.2-25.1)., Conclusion: A wide variation of S. mansoni prevalence was observed among the school children in the different schools. Control interventions better identify and target foci of S. mansoni transmission, instead of targeting the district homogenously.

Background: Ov16 serology is considered a reference method for Onchocerca volvulus epidemiological mapping. Given the suboptimal sensitivity of this test and the fact that seroconversion takes more than a year after infection, additional serological tests might be needed to guide onchocerciasis elimination programmes. Recently, two linear epitopes encoded in OvMP-1 and OvMP-23 peptides were introduced as serological markers, but the observed antibody cross-reactivity in samples originating from Onchocerca volvulus non-endemic areas required further investigation., Methods: We evaluated both peptide markers in an O. volvulus hypo-endemic setting in Jimma Town, Ethiopia using peptide ELISA. For all individuals (n = 303), the infection status with soil-transmitted helminths and Schistosoma mansoni was known., Results: We found that 11 (3.6%) individuals were positive for anti-Ov16 IgG4 antibodies, while 34 (11.2%) and 15 (5.0%) individuals were positive for OvMP-1 and OvMP-23, respectively. Out of the 34 OvMP-1 positive samples, 33 were negative on the Ov16 IgG4 ELISA. Similarly, out of the 15 OvMP-23 positive samples, 14 scored negative on this reference method. No difference in seroprevalence for all three markers could be observed between uninfected individuals and individuals infected with different soil-transmitted helminths or S. mansoni. Moreover, the intensity of the response to OvMP-1, OvMP-23 or Ov16 was not significantly stronger in individuals carrying patent STH or S. mansoni infections, nor was there any correlation between the intensities of the responses to the three different antigens., Conclusions: This study demonstrates that a patent infection with either soil-transmitted helminths or S. mansoni does not lead to increased antibody recognition of both OvMP-1 and OvMP23.

Introduction: School children are among the high risk groups for soil-transmitted helminths (STHs) and Schistosoma mansoni (S. mansoni) infections in developing countries. The aim of this study was to determine the prevalence and associated factors of STHs and S. mansoni among primary school children., Methodology: A cross-sectional study was conducted from February 15 to March 30, 2016, involving a total of 340 primary school children (age range 6 to 19 years). Socio-demographic and related data were collected using interviewer-administered questionnaire. Stool samples were collected from each study participant and examined using direct wet mount and modified Kato-Katz thick smear technique. Intensity of the STHs and S. mansoni were determined by estimating the eggs per gram (EPG) of stool. Factors associated with STH and S. mansoni infections were analyzed using multivariable logistic regression model., Results: Prevalence of the STHs and S. mansoni were 38.2% and 12.94%, respectively. The main predictors of STH infections among the children studied were being in the age group of 16-19 years, untrimmed finger nail and household latrine unavailability. Moreover, male children, children with habit of swimming and bathing in the river had significantly higher odds of S. mansoni infection. Most of the children infected with the parasites had light infection., Conclusions: The burden of STHs and S. mansoni was high among the school children. Deworming intervention should be strengthened, along with awareness creation on proper disposal of human excreta and personal hygiene. Regular monitoring of the burden of the parasites and mass drug administration is required., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2018 Temam Ibrahim, Endalew Zemene, Yaregal Asres Ayenew, Dinberu Seyoum, Abebaw Tiruneh, Lealem Gedefaw, Zeleke Mekonnen.)

Background: Intestinal schistosomiasis is one of the neglected tropical parasitic diseases caused by Schistosoma mansoni. Currently, the control measures for the disease are mainly based on mass drug administration (MDA) with praziquantel (PZQ) targeting the school-age children. In Ethiopia, the potential foci for schistosomiasis and therapeutic efficacy of PZQ among school-age children remain poorly explored. Therefore, we determined both the prevalence and intensity of S. mansoni infection and the therapeutic efficacy of PZQ among school children in the Manna District (new foci for S. mansoni), Jimma Zone, southwest Ethiopia., Methods: A cross-sectional study was conducted among the school children aged between 6 and 18 years in three primary schools in Manna district from March to April 2014. For diagnosis of S. mansoni, a single stool sample was obtained from each child and processed using single Kato Katz and examined under light microscopy. A questionnaire was used to collect demographic information of the school children participated in the study. School children excreting eggs of S. mansoni were administered with 40 mg/kg of PZQ and re-examined after three weeks post-treatment. The therapeutic efficacy of PZQ against S. mansoni was evaluated by means of cure rate and egg reduction rate., Results: The overall prevalence of S. mansoni among the school children in the three primary schools in Manna District was 24.0 %. Higher prevalence was recorded for males 25.6 % (61/238) than for females 22.5 % (59/262). Majority (27.5 %) of infection intensity was light with mean faecal egg count (FEC) of 202 eggs per gram (EPG). The therapeutic efficacy of PZQ at a dose of 40 mg/kg was highly efficient (cure rate of 99.1 % and egg reduction rate of 99.9 %) among the school children in the three primary schools in Manna District., Conclusions: The school children in the three primary schools of Manna District, Jimma Zone were at moderate risk of the morbidity caused by S. mansoni (prevalence > 10 % and < 50 % according to WHO threshold), and hence a biannual MDA with PZQ is required. PZQ available on the local market was found efficient and can be recommended for individual treatment in absence of MDA. The therapeutic efficacy of PZQ at 40 mg/kg against S. mansoni was high in the study area.

Background: Our group has recently provided a proof-of-principle for the examination of pooled stool samples using McMaster technique as a strategy for the rapid assessment of intensity of soil-transmitted helminth infections (STH, Ascaris lumbricoides, Trichuris trichiura and hookworm). In the present study we evaluated this pooling strategy for the assessment of intensity of both STH and Schistosoma mansoni infections using the Kato-Katz technique., Methods: A cross-sectional survey was conducted in 360 children aged 5-18 years from six schools in Jimma Zone (southwest Ethiopia). We performed faecal egg counts (FECs) in both individual and pooled samples (pools sizes of 5, 10 and 20) to estimate the number of eggs per gram of stool (EPG) using the Kato-Katz technique. We also assessed the time to screen both individual and pooled samples., Results: Except for hookworms, there was a significant correlation (correlation coefficient = 0.53-0.95) between the mean of individual FECs and the FECs of pooled samples for A. lumbricoides, T. trichiura and S. mansoni, regardless of the pool size. Mean FEC were 2,596 EPG, 125 EPG, 47 EPG, and 41 EPG for A. lumbricoides, T. trichiura, S. mansoni and hookworm, respectively. There was no significant difference in FECs between the examination of individual and pooled stool samples, except for hookworms. For this STH, pools of 10 resulted in a significant underestimation of infection intensity. The total time to obtain individual FECs was 65 h 5 min. For pooled FECs, this was 19 h 12 min for pools of 5, 14 h 39 min for pools of 10 and 12 h 42 min for pools of 20., Conclusions: The results indicate that pooling of stool sample holds also promise as a rapid assessment of infections intensity for STH and S. mansoni using the Kato-Katz technique. In this setting, the time in the laboratory was reduced by 70 % when pools of 5 instead of individual stool samples were screened.

Background: The endemicity of human schistosomiasis has long been established in Ethiopia, and new foci have also been continuously reported.The objective of this study was to determine the transmission and magnitude of schistosomiasis in Hayk area, northeastern Ethiopia., Methods: A cross sectional parasitological survey involving 384 school children was conducted for intestinal schistosomiasis between January and March 2010 in two primary schools in Hayk area, northeastern Ethiopia. The stool samples were processed for microscopic examination using Kato-Katz technique. Malacological survey and observation on human water contact activities were also carried out. Snails were checked for schistosome infection by shedding and lab-bred mice were exposed to the cercariae shed from Biomphalaria pfeifferi en masse. Adult Schistosoma mansoni worms were harvested from the mice after 45 days of exposure to the schistosome cercariae., Results: The overall prevalence and intensity of intestinal schistosomiasis among school children in Hayk Number 1 and Hayk Number 2 Primary Schools was found to be 45% and 161 epg, respectively. The prevalence of infection had relationship with age and sex. Males were more infected than females. Children in the age group 15-19 years had the highest infection rate, followed by 10-14 and 5-9 years age group. Schistosome infection in Biomphalaria pfeifferi was 3.2%. Schistosome infection was also established in laboratory-bred mice and adult Schistosoma mansoni worms were harvested., Conclusion: The observed intestinal schistosomiasis with prevalence of 45% among young children, collection of schistosome infected Biomphalaria pfeifferi, and the establishment of lab infection in mice showed that transmission of intestinal schistosomiasis is taking place in the area. Preventive chemotherapy with praziquantel should be immediately put in place to reduce morbidity and interrupt transmission of schistosomiasis in the area.

Background: Parasitic infection like schistosomiasis is known to exert a negative effect on nutritional status of school-aged children. However, studies associating parasitic infections with undernutrition are scarce. Thus, this study was primarily to document the association between Schistosoma mansoni infection and undernutrition among school-aged children in a rural setting of Fincha'a Sugar Estate, Ethiopia., Methods: A cross-sectional study was conducted on a total of 453 school-aged children (5-18 years). Stool specimen was collected and examined using the standard Kato-katz technique. Children's height-for-Age Z-score (HAZ) and Body mass index-for-Age Z- score (BAZ) was determined. Z-Scores for each nutritional index were compared with the WHO child growth standards reference values. Children were considered stunted or wasted as HAZ or BAZ falls below -2 standard deviations, respectively., Result: The overall prevalence of Schistosoma mansoni infection was 53.2%. Out of the total school children examined, 11.5% and 13.2% were stunted and wasted, respectively. Multivariate logistic regression analysis was done to determine the relationship between Schistosoma mansoni infection and nutritional status controlling for other factors. Accordingly, stunting was not significantly associated while wasting was negatively associated with Schistosoma mansoni infection. Paternal occupation was the best predictor of stunting and wasting such that, unemployed fathers have 4.28 (95% CI; 2.13, 8.63) (p < 0.001) and 3.83, 95% CI; 1.89, 7.79) (p < 0.001) chance of having stunted and wasted children, respectively., Conclusion: Schistosoma mansoni infection is highly prevalent in the study area. The high prevalence of wasting, and moderate level of stunting among study subjects in this study area indicate that they are affected by both infection and undernutrition. Therefore, regular preventive chemotherapy against S. mansoni and other control measures are recommended. Moreover, possibilities of synchronized nutritional rehabilitation and creation of employment opportunities to the families should be looked for.

Background: Intestinal schistosomiasis due to Schistosoma mansoni is prevalent and widely distributed in Ethiopia. The disease continues to spread to previously non-endemic areas mainly in connection with water resource development and population movement., Objectives: To assess the transmission and magnitude of Schistosoma mansoni infection among school children in Addisalem and Lachi Primary Schools in Mekele City, northern Ethiopia., Methods: A cross-sectional study was carried out in two primary schools in Mekele City in March 2011. Stool specimens were collected and processed for quantitative microscopic examination using Kato-Katz technique and ova were quantified Search for intermediate snail hosts was carried out in Elala stream and collected snails were examined for trematode infection by shedding after they were individually exposed to electric light for about one to two hours., Result: The overall prevalence of S. mansoni infection was 26.3% and for those infected with S. mansoni the mean intensity of infection was 50 egg per gram of stool (epg). About 1.9%, 20.8% and 77.4% of the positive children for S. mansoni had heavy, moderate and light infection, respectively. All collected snails were identified to be Biomphalaria pfeifferi, intermediate host for S. mansoni, and 2 of them shed cercariae, accounting for 2.5% (2/80) infection rate of the snails., Conclusion: The present study showed that transmission of intestinal schistosomiasis is taking place in Ellala stream. The finding of infected children with S. mansoni, the presence of infected snails in the stream as well as the prevalence of S. mansoni being above 5% all confirm the endemicity of the area for S. mansoni infection. Preventive and control measures should be instituted to reduce on-going transmission and morbidity of the disease in the area.