Prevalence, Intensity, and Associated Factors of Schistosoma mansoni among School Children in Northwest Ethiopia

Intestinal schistosomiasis in remote areas of Southwest Ethiopia, a target region for large-scale mass drug administration

As 2030 approaches, the World Health Organization's due date for ending intestinal schistosomiasis as a public health problem in all endemic areas, understanding the current trends in the burden of schistosomiasis among schoolchildren in endemic areas is critical for monitoring the progress, identifying areas for improvement, and developing strategies to plan for instant response to mitigate the burden of schistosomiasis. From February to April of 2023, 328 students from three primary schools in Southwest Ethiopia participated in an institution-based cross-sectional study in the detection of Schistosoma mansoni. Intestinal schistosomiasis was identified among 242 school children, with a rate of infection of 73.8% (95% CI: (64.8-83.4%)). The rate of infection was higher among study participants aged between 10 and 13 years [AOR = 1.93, 95% CI: (1.1, 3.44). About 75% of the male participants were infected with Schistosoma mansoni [AOR = 0.83, 95% CI (0.49, 1.41). Nearly half (48.1%) of the S. mansoni infections among study participants were identified as heavy infections. More than half of the male study participants (50.3%) infected with Schistosoma mansoni had heavy infection intensity. Of the total female schoolchildren infected with Schistosoma mansoni, about 44.4% had a heavy infection. The prevalence and intensity of infection of Schistosoma mansoni in the study area are significantly noticeable, raising doubts on the effectiveness of the interventional programs or pin-points possible re-infection. Strategies to end the disease as a public health threat, mainly in remote and endemic areas, should consider novel integrated strategies targeting the life cycle of schistosomes besides the large-scale mass drug administration.

Schistosoma Infection Burden and Risk Factors among School-Aged Children in a Rural Area of the Democratic Republic of the Congo

Despite continuous efforts to control schistosomiasis (SCH) in the Democratic Republic of the Congo (DRC), it still poses a significant challenge. In order to enhance control measures, additional research is necessary. This study documents the burden of SCH infection and its predictors in a rural area of the DRC. We conducted a household cross-sectional study from June to August 2021 among 480 school-aged children (SAC) aged 5-15 years living in a rural area of Kisangi, in the southwest DRC. We collected and examined stool, urine, and blood samples of each child. Additionally, we obtained data on anthropometry, socio-demographics, household information, and individual water contact behaviors. The overall prevalence of SCH infection was 55.8% (95% CI: 51.4-60.3), with prevalences of 41% (95% CI: 36.6-45.5), 36.3% (95% CI: 31.9-40.6), and 38.4% (95% CI: 32.6-44.3) for S. haematobium and S. mansoni infections and both infections, respectively. Among those with SCH infection, most had a light (67.5%) or heavy (51.7%) infection intensity. The geometric mean egg count was 16.6 EP 10 mL (95% CI: 12.9-21.3) for S. haematobium and 390.2 EPG (95% CI: 300.2-507.3) for S. mansoni. However, age (10 years and above (aOR: 2.1; 95% CI: 1.5-3.1; p < 0.001)) was an independent risk factor for SCH infection. The overall prevalence of malaria infection was 16.9% (95% CI: 13.5-20.2), that of stunting was 28.7% (95% CI: 24.7-32.8), that of underweight was 17.1% (95% CI: 12.8-21.4), and that of thinness was 7.1% (95% CI: 4.8-9.4). Anemia was prevalent at 49.4% (95% CI: 44.9-5), and the median Hb level of all participants was 11.6 g/dL (IQR: 10.5-12.6 g/dL). Anemia was strongly associated with SCH infection (aOR: 3.4; 95% CI: 2.3-5.1; p < 0.001) yet there was no association with the risk for malaria infection (aOR: 1.0; 95% CI: 0.6-1.8; p = 0.563). In addition, the risk of anemia increased with heavy infection intensities (p < 0.026 and p < 0.013 for S. haematobium and S. mansoni, respectively). However, stunting had a protective factor for anemia (aOR: 0.3; 95% CI: 0.2-0.4; p < 0.001). To conclude, SCH infection was widespread among the SAC and strongly linked to anemia. These results provide evidence of the hyperendemicity of infection in the study area, which requires preventative measures such as chemotherapy to reduce the schistosomiasis-associated morbidity, and micronutrient supplements to avoid anemia.

Distribution and seasonal abundance of Biomphalaria snails and their infection status with Schistosoma mansoni in and around Lake Tana, northwest Ethiopia

Biomphalaria snails, namely B. pfeifferi and B. sudanica, are the principal intermediate hosts for Schistosoma mansoni infection in Ethiopia. Epidemiological studies of Biomphalaria snails and their infection status with S. mansoni is vital for public health planning. This study aimed to assess the spatial and seasonal abundance of Biomphalaria snails as well as their infection status with S. mansoni around Lake Tana, northwest Ethiopia. Malacological survey was conducted from January 2021 to December 2021 in ten different collection sites in and around Lake Tana. Snail collection was performed for 20 min from each collection site seasonally (four times in a year) using a standard scoop and handpicking from aquatic vegetation. All collected snails were carefully examined based on their morphological features and all live Biomphalaria snails were subjected to cercariae shedding experiment. Descriptive statistics were used to determine the prevalence of S. mansoni infection and its relationship with snail collection sites and seasons. A total of 3886 freshwater snails were collected from ten collection sites around Lake Tana. Out of the total snails collected, 1606 (41.3%; 95% CI 39.77-42.89%) were Biomphalaria spp. The highest (374) and the lowest numbers (98) of Biomphalaria snails were collected from Shinne River and Qunzela Lakeshore, respectively. Out of the 1375 live Biomphalaria snails, 14.4% (95% CI 12.59-16.37%) snails shed cercariae, but only 4.87% (95% CI 3.79-6.15%) were cercariae of S. mansoni. The infection prevalence of S. mansoni ranged from 10.59% at the Cherechera site to 1.49% at Gumara River. Biomphalaria snail infections with S. mansoni cercariae were observed throughout the season, the highest and the lowest infection rates being in the spring and summer seasons. Significant differences in the prevalence of S. mansoni infection in Biomphalaria snails were observed across study sites and seasons (p < 0.05). Biomphalaria snails were the most abundant freshwater snails found in nearly all of snail collection sites throughout the year. It was revealed that nearly five percent of Biomphalaria snails were infected with S. mansoni cercariae. This study highlights the importance of appropriate snail control strategies to support the ongoing prevention and control of schistosomiasis around Lake Tana.

Prevalence of S. mansoni Infection and Associated Risk Factors among School Children in Guangua District, Northwest Ethiopia

Methods

A cross-sectional study design was employed. Four hundred twenty-two participants were selected. Data was collected through observation and interview with structured questionnaire. Stool specimens were collected and examined using two-slide Kato-Katz method. The data were analyzed using SPSS version 23. Logistic regression was fitted for analysis. Variables with p value <0.25 in the univariate logistic regression analysis were entered into the multivariable logistic regression model. Those with <0.05 were identified as significantly associated risk factors. To assure the quality of the data, training was given for data collectors and supervisors, and the tools were pretested on 5% of the sample size.

Results

404 (95.7%) school children were enrolled in the study. The overall prevalence of S. mansoni was 12.6%. School children in the age group 5-9 years old (AOR (95% CI): 22.27 (3.70-134.01), p = 0.001), age group 10-14 years old (AOR (95% CI): 4.58 (1.14-18.42), p = 0.032), grade levels 5-8 (AOR (95% CL): 14.95 (4.297-52.03), p = 0.001),who swim frequently (AOR (95% CI): 11.35 (2.33-55.33), p = 0.003), and those who cultivate near the irrigation area (AOR (95% CI): 7.10 (2.31-21.80), p = 0.001) were significantly associated with high risk of S. mansoni infection. Conclusion and Recommendation. From the finding of the current study, it can be concluded that the prevalence of Schistosoma mansoni in the study area is relatively high. Age of fourteen and younger years old, swimming in the river, and irrigation practice were the main risk factors of S. mansoni infection. Thus, therapeutic interventions as well as health education are desirable.

Prevalence of Schistosoma mansoni infection among children in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Schistosomiasis is a neglected tropical disease caused by mainly Schistosoma mansoni and Schistosoma hematobium. The disease is very common in Africa including Ethiopia. Schistosoma mansoni is a major public health problem in Ethiopia especially among children. This review is aimed to indicate the prevalence of Schistosoma mansoni among children at the national and regional levels.

METHODS AND MATERIAL

The PRISMA guidelines were followed. An electronic search of PubMed, Google Scholar, Web of Science, Scopus, MEDLINE, and Google search were carried out using key terms. Articles published from the proceeding of professional associations such as the Ethiopian medical laboratory association, the Ethiopian public health association, and annual national research conferences were also searched to find additional eligible studies. Data were extracted independently by two investigators, and cross-checked by a third reviewer. The quality of included studies was assessed using JBI quality assessment criteria. Data were extracted using Microsoft excel and finally analyzed using STATA version 12. The pooled prevalence was done using a random-effects model.

RESULT

Overall 49 studies involving 20,493 children (10,572 male and 9, 921 females) were included in this meta-analysis. The pooled prevalence of Schistosoma mansoni infection was 37.13% (95%CI:30.02-44.24). High heterogeneity was observed with I2 of 99.4%, P < 0.000. According to subgroup analysis, the pooled prevalence was high in the SNNPR (41.49%: 95%CI: 19.52-63.46) followed by the Amhara region (41.11%: 95%CI: 30.41-51.8), the Tigray region (31.40%: 95%CI:11.72-51.09), and the Oromia region (28.98%: 95%CI: 18.85-39.1). Year from 2011 to 2015 contributed to the highest prevalence of Schistosoma mansoni infection among children (46.31%: 95%:34.21-59.05).

CONCLUSION

This study revealed a 37.13% prevalence of Schistosoma mansoni infection among children. This is an alert to improve and implement appropriate control strategies such as mass drug administration in Ethiopia.

Prevalence, intensity and associated risk factors of Schistosoma mansoni infections among schoolchildren around Lake Tana, northwestern Ethiopia

BACKGROUND

Schistosomiasis is one of the widely distributed neglected tropical diseases. It is a serious public health problem in sub-Saharan Africa. The disease is highly prevalent and widely distributed in Ethiopia due to suitable environmental factors and human activities. The prevalence and infection intensity varied from locality to locality in the country. This study aimed to assess the prevalence and intensity of S. mansoni infection and associated risk factors among schoolchildren around Lake Tana.

METHODS

A school-based cross-sectional study was conducted among 710 schoolchildren from February to April 2021 in eight selected primary schools around Lake Tana. A questionnaire was used to collect data on socio-demographic information and potential risk factors of S. mansoni infection. After collecting socio-demographic information, students were requested to bring about 2grams of stool specimens for parasitological examination. The collected stool samples were processed using a single Kato-Katz and Ritchie's concentration techniques. The data were analyzed using SPSS software version 23 and factors with a p-value < 0.05 were considered as statistically significant.

RESULTS

The overall prevalence of S. mansoni was 34.9% (95% CI: 31.4-38.7) among schoolchildren in the study area. The eggs per gram (EPG) of stool ranged from 24 to 1659 with arithmetic and geometric mean values of 138.1 EPG and 85.1 EPG, respectively. The majority of S. mansoni infections (61.4%) were classified as low infection intensity. Among the different determinant factors being male (AOR = 1.74; 95%CI = 1.233-2.457; P-value = 0.002), bathing habits (AOR = 1.494; 95%CI = 1.013-2.199; P-value = 0.043) and students attending at Qunzela primary school (AOR = 10.545; 95%CI = 3.264-34.067; P-value = 0.001), Alabo primary school (AOR = 3.386; 95%CI = 1.084-10.572; P-value = 0.036) were significantly associated with S. mansoni infection.

CONCLUSION

This study revealed that more than one-third of schoolchildren were infected by S. mansoni in the study area. The majority of the infections were classified as low infection intensity. Being male, bathing habits and schools in which students attended were independent explanatory factors for S. mansoni infection. Therefore, integrated control strategies are needed to improve the health conditions of schoolchildren in the study area.