Assessment of seasonality in soil-transmitted helminth infections across 14 schools in Jimma Town, Ethiopia

Effect of Soil Temperature on Canine Soil-Transmitted Nematodes in Kandy District with the First Record of Hookworm, Ancylostoma tubaeforme from Sri Lanka

PURPOSE

Soil-transmitted nematodes (STNs) are widespread in tropical and subtropical regions, particularly where the communities are socio-economically challenged. We investigated the effect of soil temperature on the prevalence and intensity of STN infection in free-roaming dogs.

METHODS

Fresh faecal samples collected from free-roaming dogs in Digana and Pussellawa town areas in the Kandy District, Sri Lanka, were microscopically analysed for canine STNs. Soil temperature was measured at each sampling site. Highly prevalent canine hookworm Ancylostoma, was further studied using PCR and sequencing, followed by phylogenetic analysis.

RESULTS

The soil temperature ranged between 28 and 31 °C (mean = 29.79 °C) and 18-21 °C (mean = 19.52 °C) in Digana and Pussellawa, respectively, showing a significant difference in the two sites (Students t-test t = 1.68, p < 0.0001). Of the total 44 dogs sampled, 41 (93.2%) were positive for STNs. During microscopic analysis, five nematodes: Ancylostoma spp., Capillaria sp., Strongyloides sp., Toxocara canis, and Trichuris sp., were identified. Ancylostoma species (93.2%) were the most prevalent, followed by Strongyloides sp. (22.7%) and Toxocara canis (15.9%). Infection prevalence of Strongyloides sp. was higher in Digana (40.9%) compared to that in Pussellawa (4.5%; Chi-square test, χ2 = 8.28, p = 0.004) and also the infection intensity from Digana (EPG = 8.02 ± 20.2) compared to that from Pussellawa (0.45 ± 2.1; Mann Whitney U test, p = 0.006). Amplicons (ITS1-5.8S-ITS2) of the expected size for A. caninum, and A. tubaeforme were produced. An A. caninum sequence reported here (OQ101719) illustrated the highest similarity of 99.2% to one of the local sequences (MZ707153) upon pairwise comparison.

CONCLUSION

Digana, with a higher soil temperature than Pussellawa, had a significantly higher prevalence and infection intensity, particularly Strongyloides sp. This study also signifies the first molecular identification of hookworm species A. tubaeforme in Sri Lanka.

Prevalence and Determinants of Geohelminthiasis among School-Age Children in Jimma City, Ethiopia

School-age children (SAC) are at a higher risk of geohelminth or soil-transmitted helminth (STH) infections due to their practice of walking and playing barefoot, lack of adequate sanitary facilities, and poor personal hygiene. In Ethiopia, periodic deworming has been implemented since 2013 with the aim of interrupting the transmission of STH in children by 2025. To evaluate the likely success of such a control program, it is crucial to monitor the transmission of STH, especially in peri-urban settings where environmental sanitation is modest. The aim of this study was to determine the prevalence and determinants of STH infections among SAC in peri-urban areas of Jimma City, Southwestern Ethiopia. A community-based cross-sectional study was conducted in five peri-urban Kebeles of Jimma City from July to September, 2021. Systematic random sampling was used to select 522 households with at least one child, and 478 children (5-15 years old) were recruited randomly from the households. Data on sociodemographic and potential risk factors were collected using a structured questionnaire. Stool samples from each study participant were collected and examined microscopically using the Kato-Katz technique. Multivariate logistic regression model was used to identify risk factors associated with STH infections. The prevalence of any STH among SAC was 23.4%, with Ascaris lumbricoides being the predominant STH species (15.7%), followed by Trichuris trichiura (9%) and hookworm (2.1%). Most (86.6%) of the STH-positive SAC had a single infection and a light infection intensity (88.2%), with a mean intensity of 367.4 eggs per gram. Location of Kebele (AOR = 2.73; 95% CI: 1.21-6.16, p=0.016), lack of hand washing after defecation (AOR = 6.39; 95% CI: 3.16-12.95, p < 0.001), untrimmed fingernails (AOR = 2.65; 95% CI: 1.56-4.51, p < 0.001), and lack of previous deworming (AOR = 2.90; 95% CI: 1.47-5.74, p=0.002) were significant predictors for STH infections among SAC. In conclusion, the study revealed that STH infections are significant health problem in the peri-urban areas of Jimma City. Strengthening periodic deworming and improving children's hygiene through health education are required to reduce the transmission.

Prevalence of soil-transmitted helminths infections among preschool and school-age children in Ethiopia: a systematic review and meta-analysis

BACKGROUND

There is a lack of comprehensive national data on prevalence, geographical distribution of different species, and temporal trends in soil-helminthiasis (STHs). Therefore, this study aimed to provide a summary and location of the available data on STHs infection among preschool and school-age children in Ethiopia.

METHODS

The search was carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar on data published between 1997 to February 2020 for studies describing the rate of STHs infection among preschool and school-age in Ethiopian. We followed the Patient, Intervention, Comparison, and Outcome (PICO) approach to identify the studies. Meta-regression was performed to understand the trends and to summarize the prevalence using the "metaprop" command using STATA software version 14.0 RESULTS: A total of 29,311 of the 61,690 children examined during the period under review were infected with one or more species of intestinal parasites yielding an overall prevalence of 48% (95% CI: 43-53%). The overall pooled estimate of STHs was 33% (95% CI: 28-38%). The prevalence was 44% (95% CI: 31-58%) in SNNPR, 34% (95% CI: 28-41%) in Amhara region, 31% (95% CI: 19-43%) in Oromia region and 10% (95% CI: 7-12%) in Tigray region. Soil-transmitted helminths infection rate has been decreasing from 44% (95% CI: 30-57%) pre-Mass Drug Administration (MDA) era (1997-2012) to 30% (95% CI: 25-34%) post-MDA (2013-2020), although statistically not significant (p = 0.45). A lumbricoides was the predominant species with a prevalence of 17%.

CONCLUSION

Southern Nations Nationalities and Peoples Region, Amhara, and Oromia regions carry the highest-burden and are categorized to Moderate Risk Zones (MRZ) and therefore, requiring MDA once annually with Albendazole or Mebendazole. The prevalence of STHs decreased after MDA compared to before MDA, but the decline was not statistically significant. A. lumbricoides was the predominant species of STHs among preschool and school-age children in Ethiopia. The high prevalence of STHs observed in this review, underscores the need for better control and prevention strategies in Ethiopia.

Prevalence, intensity and endemicity of intestinal schistosomiasis and soil-transmitted helminthiasis and its associated factors among school-aged children in Southern Ethiopia

Preventive chemotherapy (PC), the main strategy recommended by the World Health Organization to eliminate soil-transmitted helminthiasis (STH) and schistosomiasis (SCH), should be strengthened through identification of the remaining SCH transmission foci and evaluating its impact to get a lesson. This study was aimed to assess the prevalence of STH/SCH infections, the intensity of infections, and factors associated with STH infection among school-aged children (SAC) in Uba Debretsehay and Dara Mallo districts (previously not known to be endemic for SCH) in southern Ethiopia, October to December 2019. Structured interview questionnaire was used to collect household data, anthropometric measurements were taken and stool samples collected from 2079 children were diagnosed using the Kato-Katz technique. Generalize mixed-effects logistic regression models were used to assess the association of STH infections with potential predictors. A P-value less than 0.05 was considered statistically significant. The prevalence of Schistosoma mansoni in the Dara Mallo district was 34.3% (95%CI 30.9–37.9%). Light, moderate, and heavy S. mansoni infections were 15.2%, 10.9%, and 8.2% respectively. The overall prevalence of any STH infection was 33.2% with a 95% confidence interval (CI) of 31.1–35.3%. The intensity of infections was light (20.9%, 11.3% & 5.3%), moderate (1.1%, 0.1% & 0.4%) and heavy (0.3%, 0% & 0%) for hookworm, whipworm and roundworms respectively. The overall moderate-to-heavy intensity of infection among the total diagnosed children was 2% (41/2079). STH infection was higher among male SAC with Adjusted Odds Ratio (AOR) of 1.7 (95%CI 1.4–2.1); occupation of the household head other than farmer or housewife (AOR = 0.5; 95%CI 0.3–0.8), middle [AOR = 1.1; 95%CI 1.0–1.3] or high [AOR = 0.7; 95%CI 0.5–0.9] socioeconomic status. Dara Mallo district was moderate endemic for S. mansoni; and it needs sub-district level mapping and initiating a deworming campaign. Both districts remained moderate endemic for STH. Evidence-based strategies supplementing existing interventions with the main focus of the identified factors is important to realize the set targets.

Soil transmitted helminth infection in primary school children varies with ecozone in the Ngorongoro Conservation Area, Tanzania

BACKGROUND

Soil-transmitted helminthiasis is a neglected tropical disease, thriving in environments of poverty and disadvantage. Our objective was to determine the prevalence and intensity of four soil transmitted helminths (STH) among primary school children in the Ngorongoro Conservation Area (NCA), Tanzania.

METHODS

A cross-sectional study was performed between May 15^th and June 2^nd, 2014. Six of 20 primary schools were chosen, based on elevation, designated low elevation ecozone (LEE) or high elevation ecozone (HEE). A total of 340 children from standards one to four were recruited. Height and weight of each child was determined and body mass index (BMI) was calculated. Stool samples were analyzed using the Kato-Katz, Wisconsin, and Baermann techniques to detect STH eggs and larvae. An interviewer-administered questionnaire on socio-demographic variables was used to capture information from the school's headmaster and a checklist was used to assess sanitation facilities.

RESULTS

STHs identified included Ascaris (presumably lumbricoides), Trichuris (presumably trichiura), hookworms (presumably Ancylostoma duodenale and/or Necator americanus), and Strongyloides (presumably stercoralis). The overall prevalence of STH infection was 29.0% in LEE and 34.0% in HEE. Prevalence was 34.3% and 28.2% in males versus females, respectively. Ascaris sp. were only identified in HEE, prevalence of Trichuris sp. and hookworms were significantly higher in HEE compared to LEE, and Strongyloides spp. prevalence was lower in HEE. Intensity of Trichuris sp. was significantly higher in HEE and lower for hookworms. We did not detect a significant relationship between BMI and helminth intensity; however, BMI was lower in lower elevations and in males vs. females. Sanitation practices are taught at the schools, but challenges were identified when implementing. Latrine facilities were available and latrine-cleaning routines were practiced; however, hand washing practices were challenging due to restricted water availability.

CONCLUSIONS

Significant differences in prevalence in HEE and LEE exist, and STH infections are still very common among school children suggesting that anthelminthic intervention and education may be necessary in this region. Based on this outcome, the study area in the NCA would be classified as a medium risk area, where periodic treatment recommendations should be based on prevalence estimations in the different ecozones.

TRIAL REGISTRATION

Ethics approval was obtained from the Catholic University of Health and Allied Sciences (CUHAS; Lake Zone Institutional Review Board MR/53/100/307)); the Conjoint Health Research Ethics Board (CHREB) at the University of Calgary in Canada (Study ID REB14-0127); the National Institute of Medical Research (NIMR) of Tanzania; and the Tanzania Commission for Science and Technology (COSTEC).

Prevalence of Soil-Transmitted Helminth Infection Among School-Aged Children of Ethiopia: A Systematic Review and Meta-Analysis

Background:

Soil-transmitted helminths (STH) are still major health problems in resource-poor countries. Despite several epidemiological studies were available in Ethiopia, summarized data on the prevalence of STH among school-aged children (SAC) is lacking in the country.

Objective:

This study was aimed to summarize the existing published studies of STH among SAC children in Ethiopia.

Methods:

The search was carried out in open access databases such as Science Direct, Scopus, and PubMed Central which reported STH in Ethiopia. Open access articles published between 2000 and 2019 were included in this meta-analysis. The pooled prevalence was determined using a random-effect model while heterogeneities between studies were evaluated by I² test.

Results:

A total of 46 338 children (Male = 23 374 and Female = 22 964) were included in the 70 eligible studies for this meta-analysis. The pooled prevalence of STH among SAC was 33.4%; 95% CI, 29.3% to 37.7% in Ethiopia. Ascaris lumbricoides (19.9%; 95% CI, 17.2%-22.6%) was the most prevalent STH followed by Trichuris trichiura (12.4%; 95% CI, 10.6%-14.1%), and hookworm (7.9%; 95% CI, 6.9%-8.9%) infection in the country. High prevalence of STH was observed in Oromia (42.5%; 95% CI, 31.6%-53.4%) followed by SNNPR (38.3%; 95% CI, 27.7%-48.8%) and Amhara (32.9%; 95% CI, 27.0%-38.8%) regional states. High heterogeneity on the prevalence of STH was observed across studies within and among regions (I² > 96% and P < .001).

Conclusion:

This review showed that more than one-third of the Ethiopian SAC were infected with STH. The high prevalence of STH observed in this review highlight the needs of improved control and prevention strategies in Ethiopia.

Prevalence and Associated Factors of Soil-Transmitted Helminth Infections among Children Living with and without Open Defecation Practices in Northwest Ethiopia: A Comparative Cross-Sectional Study

Soil-transmitted helminth (STH) infections cause devastating effect in human health. School-age children (SAC) account for the highest prevalence of STH infections in sub-Sahara. Open defecation practicing might be the major contributing factor, and creating an open defecation-free (ODF) declared community is also a big challenge. This study aimed to assess the prevalence of STH infections and associated factors among SAC in ODF declared and open defecation-practicing kebeles. A comparative cross-sectional study was conducted among 806 SAC from January 2019 to April 2019. Questionnaire-based data were collected using a structured questionnaire. Stool samples were collected and processed via the Kato-Katz technique. Prevalence and associated factors were computed with descriptive statistics and regression, respectively. Variables with a P-value < 0.05 were considered as significantly associated. This study revealed that the prevalence of STH infections in open defecation-practicing and ODF declared kebeles were 39.0% and 30.0%, respectively. Wearing open shoes, wearing shoes sometimes, and playing with soil were significantly associated (P < 0.01) with STH infections in ODF declared kebeles. Similarly, wearing shoes sometimes, not using latrine, and playing with soil were also significantly associated (P < 0.01) with STH infections in open defection-practicing kebeles. In conclusion, lower prevalence of STH infections was recorded in ODF declared than in open defection-practicing kebeles. Wearing shoes sometimes, playing with soil, and not using latrine were associated with STH infections. Therefore, creating an ODF environment and community awareness should be strengthened.