Abstract
Background & objectives
Soil-transmitted helminth (STH) infections are a significant public health concern, affecting over 1.5 billion people worldwide. STH infection among children leads to stunted growth, impaired cognitive development, and reduced productivity. In India, while multi-prong efforts are being made to control STH infections including mass drug administration (MDA) programme, the problem is still prevalent. This study aimed to investigate the prevalence, type of STH and determinants associated with STH infection among children (1-15 yr) in a tribal dominated district of Odisha, India.
Methods
A cross-sectional survey was carried out among 2320 children aged 1-15 yr in the Nabarangapur district of Odisha, sampling 30 clusters from five blocks using the Probability Proportional to Size (PPS) method. Participants were randomly selected from each cluster for screening, which included anthropometric measurements to assess nutritional status and cognitive evaluation using the Vineland Maturity Test scale (VSMS). Morning stool samples from 1927 children were collected, processed and examined microscopically to detect STH infections and Kato Katz thick smear technique was used for STH-positive cases to count the eggs.
Results
Of the 1927 children, 255 (13.2%) were found infected with one or more STH species. Among the STH positives, hook worm was the most common with a prevalence of 71.3 per cent, followed by Ascaris lumbricoides (round worm) at 28.2 per cent. The mean age (±standard deviation) of STH positive children was 6.5 (± 3.29) yr. Practicing open defecation, was significantly associated with higher STH infection rate. Based on the egg count of STH-positive cases, majority (90.5%) had mild infection, 4.7 per cent moderate and 4.3 per cent severe infection.
Interpretation & conclusions
The present study indicated that school-going children in the study setting, especially from tribal areas, carried considerable risk of STH infection. Identifying the prevalent risk factors, developing multi-prong integrated strategies could be effective in preventing and controlling STH infection in these areas. The interventions need to focus on improving awareness on STH, ensuring hygiene and sanitation practices and compliance to biannual administration of albendazole under health programmes.
Keywords: Albendazole, ascariasis, hookworm, kato-katz, microscopy, prevalence, soil transmitted helminths, trichuriasis
Globally, soil-transmitted helminth (STH) infections affect a staggering 1.5 billion people, equivalent to 24 per cent of the world’s population and about 10 per cent are co-infected with two or more species1. Specifically, Ascariasis (Ascaris lumbricoides) affects around 1.2 billion people, Trichuriasis (Trichuris trichiura) 795 million, and hookworm (Ancylostoma duodenale and Necator americanus) affects around 740 million people worldwide1. The majority of the vulnerable population, such as preschool-age children, school-age children, adolescent girls, and pregnant and lactating women, reside in areas with high transmission rates, necessitating urgent treatment and preventive measures2. India bears the highest burden of STH infection, with an estimated 375 million cases, according to the 2013 Global Burden of Disease report. The most prevalent STH infections are caused by A. lumbricoides, hookworms, and T. trichiura. A meta-analysis of 39 studies across 19 Indian States (2000–2015) found STH infection rates varying from 7 to 70 per cent, with a 16.6 per cent prevalence in Puri district, Odisha3,4. STH infections can cause significant morbidity, affecting nutrition and cognitive function5. These infections are linked to stunted growth and impaired cognitive development, particularly in school-aged children6. Although mortality from STH is rare, long-term effects include reduced cognitive abilities, intellectual capacity, and productivity5. Prevalence is closely tied to environmental and socioeconomic factors6. In 2002, the World Health Assembly launched a global initiative for STH control through mass administration of Albendazole (ALB) or Mebendazole (MEB)7, with World Health Organization (WHO) recommending periodic treatment using one of the four anti-parasitic drugs, though MEB and ALB are most commonly used8.
Effective control requires chemotherapy combined with improvements in clean water, sanitation, and hygiene practices9. Since 2015, India’s Ministry of Health and Family Welfare (MoHFW) has run the world’s largest school-based deworming programme, targeting 240 million children biannually on National Deworming Days (NDD)2. Assessing the prevalence and intensity of STH infection is crucial for launching effective parasite control measures. There are many regions in India showing higher rates of STH infection, where the mass drug administration (MDA) programmes have been implemented for an extended period. However, there is a dearth of information pertaining to the prevalence, intensity, and types of STH infections, especially among children in tribal areas. Our study aimed to address these knowledge gaps and explore the associated determinants of STH infections to understand the dynamics of STH infections in this region.
Materials & Methods
This cross-sectional study was conducted by the department of Epidemiology, Indian Council of Medical Research-Regional Regional Medical Research Centre (ICMR-RMRC), Bhubaneswar, Odisha, India. The study was started after obtaining the ethical clearance by the Institutional Ethics Committee of ICMR-RMRC.
Study design and setting
This study was carried out in Nabarangapur district of Odisha, an aspirational district having 55.8 per cent of the population as tribal10 (more than 10 different tribes)11. The timeline of this study was 3 yr and 10 months from March 2021 to December 2024. The study district has 10 blocks (sub-district level administrative units) with a total of 1597 villages. Five blocks were randomly selected for the study and six clusters/villages from each block (a total of 30 clusters) were selected using the probability proportional to size (PPS) method. For the identification and mobilisation of eligible children, the local medical officer and frontline health workers were approached and requested for support.
Sample size
Assuming the prevalence of STH infection as 13.3 per cent12 and considering absolute precision of 2.5 per cent, design effect of 2 and a non-response rate of 20 per cent, the desired sample size was estimated to be 1772 rounded off to 1800. A total of 30 clusters were selected, with a desired sample size of 60 participants (children aged 1-15 yr) from each cluster. Under the study, a total of 2,320 children (averaging 77 participants/cluster) were finally recruited after obtaining informed assent and written consent from parents through a household survey. Among these participants, morning stool samples could be collected from 1927 study participants by visiting door to door, with a 16.9 per cent dropout. The study objectives were explained to parents, community leaders, school teachers and frontline workers. Only willing children, along with their parents, were enrolled after obtaining informed written consent from the parents and assent from the children. Several participants withdrew from the study due to scheduling conflicts and personal time constraints. Additionally, a small number of participants cited a lack of interest in continuing their participation.
Data collection
The research team visited selected clusters and villages to inform parents and teachers about the study objectives. Respondents were interviewed to collect socio-demographic data, including house type, drinking water source, toilet facilities, handwashing practices, and deworming history. Nutritional status was assessed using standardised anthropometric measures, including height, weight, body mass index (BMI), and mid-upper arm circumference (MUAC)13. One of the primary psychological evaluation instruments for assessing social and adaptive functions for many years, both internationally and in India, is the Vineland Social Maturity Scale (VSMS). Additionally, VSMS is utilized as a stand-in test to evaluate social skills. When a child is not cooperative or has poor verbal skills, for example, other key intelligence tests cannot be utilised to assess Intelligence Quotient (IQ). Cognitive assessment was conducted using the VSMS by the study personnel trained by a psychologist, to measure the Social Quotient (SQ) of participants14.
For stool sample collection, the team explained the procedure to the children and parents, providing a collection kit. Children were given a labelled vial, a wooden spatula, and a cardboard sheet. They were instructed to collect about 10 g of stool the next morning and securely seal it in the container. Samples were placed in zip-lock bags and transported in cool boxes to the field lab within 4-5 h.
In the field lab, samples were stored at 2-8°C. A trained technician performed microscopic examinations to identify STH-positive samples. These were further processed using the Kato Katz method to quantify helminth eggs (eggs per gram of stool) and assess infection intensity15.
To minimise potential biases, random selection of study clusters was employed, and standardised protocols were used for data collection, sample handling, and laboratory analyses to reduce measurement and observer bias.
Anthropometric measurement
Anthropometric variables such as height, weight, and MUAC of all study participants were measured by trained researchers using standardised measuring tools (digital weighing machine, stadiometer and MUAC tape)16. Based on the measurements, their nutritional status (stunting, wasting and underweight/overweight) was assessed individually using the “z-score” package of R 4.4.1 version for all the malnutrition indicators, as per the WHO standardised scale13,16.
Data analysis
To determine the prevalence and degree of STH infection, the data were analysed using the child anthropometry “z-score” package in the statistical software R 4.4.1Version data analysis module which is based on the WHO child growth standard. To take into consideration uneven selection probabilities, all the estimations were measured taking 95 per cent confidence interval. The promotions were compared using the Chi-square test. Additionally, Geographic Information System (GIS) data were used to map the STH-positive cases using QGIS software. By using VSMS: Indian adaptation, the IQ of the study participants was calculated using the formula: IQ score = Mental age/Chronological age x 100, and analysed for any association with STH status. The process of participant enrolment, sample collection and STH status is presented in the table I.
Table I.
Showing the participant enrolment status
| Name of clusters/village | No. of children approached | No. of participants whose consent was obtained | No. of stool samples collected |
|---|---|---|---|
| Phatakote | 102 | 84 | 80 |
| Bhatigam | 144 | 122 | 123 |
| Betal | 102 | 95 | 85 |
| Dangriguda | 100 | 90 | 79 |
| Pokhnaguda | 114 | 102 | 97 |
| Churahandi | 66 | 62 | 54 |
| Amlabhata | 90 | 77 | 76 |
| Goud-Deopalli | 77 | 73 | 68 |
| Lakdipala | 64 | 60 | 53 |
| Merai Janiguda | 106 | 94 | 88 |
| Khatiguda | 60 | 55 | 54 |
| Pujariguda | 107 | 96 | 84 |
| landuguda | 67 | 60 | 47 |
| K. Semela | 71 | 68 | 61 |
| Junapani | 68 | 65 | 58 |
| Phampuni | 49 | 43 | 35 |
| Keragam | 52 | 50 | 43 |
| Duragam | 50 | 44 | 42 |
| Khatiguda | 55 | 49 | 45 |
| Karlipadar | 67 | 61 | 55 |
| Pendrabandha | 83 | 78 | 69 |
| Birisadi | 64 | 61 | 57 |
| Tohara | 100 | 95 | 79 |
| Tentuliguda | 101 | 94 | 84 |
| Jorabandha | 69 | 63 | 60 |
| Banamahuli | 52 | 50 | 44 |
| Gambhariguda | 70 | 66 | 62 |
| Kondioda | 81 | 77 | 71 |
| Bhojapur | 22 | 19 | 17 |
| Phatika | 67 | 59 | 57 |
| Total | 2320 | 2112 | 1927 |
The relationship between STH infection and different socio-demographic, hygiene and behavioural factors were assessed using logistic regression models. First, individual logistic regressions were performed to calculate unadjusted (crude)odds ratio (OR) for each factor, followed by an adjusted model to account for other potential confounders. The analysis was conducted using STATA version 14.0 (StataCorp in College Station, TX.), and a P<0.05 was considered statistically significant. The assumptions of logistic regression, including the absence of multicollinearity and the linearity of log odds for continuous variables, were assessed. Hygiene factors (open-defecation and handwashing) were analysed for children greater than five years of age, and results reported with 95 per cent confidence intervals (CIs).
Results
The mean age (± standard deviation) of the 1927 children recruited with stool examination in this study was 6.46 (±3.25) yr. Males comprised slightly more than half of the population (50.4%). In terms of socio-demographic categories, participants from Scheduled Castes (SC) made up the largest group, 47.8 per cent, Scheduled Tribes (ST) at 31.3 per cent, followed by Other Backward Classes (OBC) at 15.9 per cent. The majority of the participants were from nuclear families (81.2%), and 56.8 per cent were attending school. About 82 per cent of participants aged more than five years practised open defecation, while 82.3 per cent adhered to regular handwashing. Thirteen per cent of the recruited children (255/1927; 13.2%) were found to be STH positive, with a mean age of 6.5 (±3.29) years, and 44.8% were girls. School-going children (6–15 yr) showed a higher prevalence (15.53%) compared to younger (1-5 yr) ones (9.7%), which was statistically significant.
The detailed information about socio-demographic characteristics, Water, Sanitation, and Hygiene (WASH) practices, open defecation status and ALB consumption in the last six months are presented in table IIA. Upon assessing the cognitive status of study participants using VSMS test and evaluating the (IQ) score, the majority (91%) scored as average, followed by low average (8.15%) and no statistically significant association was found between STH positivity and cognitive status (Table IIB). The detailed information about socio-demographic characteristics, WASH practices, open defecation status and ALB consumption in the last six months are presented in table IIA. The geographical distribution of the study participants (blocks and clusters) is depicted in figure 1. The distribution of study participants and their STH positivity are presented in figure 2 (supplementary file).
Table IIA.
Distribution of study participants according to their socio-demographic characteristics, WASH practices and STH status (n = 1927)
| Characteristics | STH –ve n=1672 (%) | 95% CI | STH +ve n=255 (%) | 95% CI | Total n=1927 (%) | χ2 (P value) |
|---|---|---|---|---|---|---|
| Age (yr) | ||||||
| 1-5 | 745 (90.3) | (88.3–92.1) | 80 (9.7) | (7.9–11.7) | 825 (42.8) | 15.2* (<0.01) |
| 6-15 | 927 (84.1) | (81.8–86.3) | 175 (15.9) | (13.7–18.2) | 1102 (57.2) | |
| Gender | ||||||
| Female | 843 (88.2) | (86.1–90.2) | 113 (11.8) | (9.8–13.9) | 956 (49.6) | 3.1 (0.08) |
| Male | 829 (85.4) | (83.1–87.6) | 142 (14.6) | (12.4–16.9) | 971 (50.3) | |
| Category | ||||||
| General | 83 (88.3) | (81.1–93.5) | 11 (11.7) | (6.5–18.9) | 94 (4.8) | 13.3* (<0.01) |
| OBC | 264 (86) | (81.7–89.6) | 43 (14) | (10.4–18.3) | 307 (15.9) | |
| SC | 823 (89.4) | (87.2–91.3) | 98 (10.6) | (8.7–12.8) | 921 (47.8) | |
| ST | 502 (83) | (79.8–85.9) | 103 (17) | (14.1–20.2) | 605 (31.3) | |
| Family type | ||||||
| Nuclear | 1366 (87.3) | (85.7–88.8) | 199 (12.7) | (11.2–14.3) | 1565 (81.2) | 1.7 (0.19) |
| Joint | 306 (84.5) | (80.3–88.1) | 56 (15.5) | (11.9–19.7) | 362 (18.8) | |
| Schooling status | ||||||
| Schooling | 925 (84.5) | (82.0–86.7) | 170 (15.5) | (13.3–18) | 1095 (56.8) | 12.7 (<0.01) |
| AWC | 687 (90.2) | (88.0–92.2) | 75 (9.8) | (7.8–12) | 762 (39.5) | |
| No schooling | 60 (85.7) | (74.4–93.1) | 10 (14.3) | (6.9–25.6) | 70 (36.3) | |
| Open defecation practice (age >5 yr) | ||||||
| Yes | 737 (81.7) | (79.0–84.3) | 165 (18.3) | (15.7–21) | 902 (81.8) | 20.7 (<0.01) |
| No | 190 (95) | (90.9–97.6) | 10 (5) | (2.4–9.1) | 200 (18.1) | |
| WASH practice (age >5 yr) | ||||||
| Yes | 760 (83.7) | (81.1–86.1) | 148 (16.3) | (13.9–18.9) | 908 (82.3) | 0.5 (0.47) |
| No | 167 (86.1) | (80.1–90.7) | 27 (13.9) | (9.3–19.9) | 194 (17.6) | |
| Taken Albendazole drug in last 6 months | ||||||
| Yes | 1589 (87.1) | (85.5–88.6) | 235 (12.9) | (11.4–14.5) | 1824 (94.7) | 3.1 (0.07) |
| No | 83 (80.6) | (71.6–87.5) | 20 (19.4) | (12.5–28.4) | 103 (5.3) | |
The total percentage was calculated column-wise, while STH positive and STH negative values were determined row-wise. The percentages for characteristics like ‘Open Defecation practice’, ‘WASH Practice’ are based on participants of age > 5 years. AWC, anganwadi centre; STH, soil transmitted helminths; ST, Schedule tribe; SC, Schedule caste; OBC, Other backward category. *significant
Table IIB.
Distribution of study participants according to their Cognitive (IQ Score) and STH status
| IQ Score | Low average (80-89), n (%) | Average(90-109), n (%) | Very superior (130 above), n (%) | Total | χ2 (P value) |
|---|---|---|---|---|---|
| STH Negative | 143 (8.6) | 1528 (91.4) | 1 (0.05) | 1672 | 2.9 (0.2) |
| STH Positive | 14 (5.5) | 241 (94.5) | 0 (0) | 255 | |
| Total | 157 | 1769 | 1 | 1927 |
STH, soil transmitted helminths
Fig. 1.
The map shows. Nabarangpur district and its block boundaries. The administrative map, obtained from the Survey of India office, was georeferenced to ensure spatial accuracy. All map production and digitization were carried out in-house as part of our project development efforts. Source: QGIS Software 3.4 (Open Source Software).
Fig. 2.
Heat map showing block wise STH positive cases in Nabarangapur district of Odisha. Source: QGIS Software 3.4 (Open Source Software).
Supplementary File
The overall prevalence of STH infection among the study children was found to be 13.2 per cent. The prevalence of STH infection among boys and girls was 14.6 per cent and 11.8 per cent respectively and no statistically significant difference was found. The presence of STH infection among children practising open defecation was found to be high (18.29%) compared to children using toilet facilities (5%), and this difference was found to be statistically significant (P<0.01).
Among the study children, 34.4 per cent were stunted, 19.6 per cent had wasting, and 23.1 per cent were underweight. While a significant association was found between STH infection and wasting (P =0.05), no strong association was observed between STH positivity and stunting, underweight, or acute malnutrition. The detailed anthropometric indices, nutritional status and STH infection are depicted in (Table III)2.
Table III.
Distribution and association between STH infection and nutritional status
| Nutritional Status | STH -ve | 95% CI | STH +ve | 95% CI | Total | χ2 |
|---|---|---|---|---|---|---|
| Prevalence % | (P value) | |||||
| Stunting (height/age <- 2SD) | 568 (85.7) | (83.0–88.3) | 95 (14.3) | 11.7-17 | 663 | 0.9 (0.3) |
| (34.4) | ||||||
| Wasting (weight/height <-2SD) | 247 (92.9) | (89.8–96) | 19 (7.1) | 4.0-10.2 | 266 | 3.8 (0.1) |
| (19.6) | ||||||
| Underweight (weight/age < -2SD) | 350 (90.2) | (87.2–93.2) | 38 (9.8) | 6.8-12.8 | 388 | |
| (23.2) | 1.3 (0.3) | |||||
| Overweight (weight/age > 2SD) | 12 (92.3) | (77.8–106.8) | 1 | 6.8-22.2 | 13 | |
| -7.7 | (0.8) | |||||
| Malnutrition status based on MUAC | ||||||
| Severe Acute malnutrition | 39 (97.5) | (92.7–102.3) | 1 | 2.3-7.3 | 40 | |
| (MUAC <11.5 cm) | -2.5 | (2.1) | ||||
| Mild to Moderate (>=11.5 to | 86 (85.2) | (78.2–92.1) | 15 (14.9) | 7.9-21.8 | 101 | 4.3 (0.1) |
| 12.5 cm) | (5.2) | |||||
| Normal (MUAC >12.5 cm) | 1547 (86.6) | (85.0–88.2) | 239 (13.4) | 11.8-15 | 1786 | |
| (92.7) | ||||||
MUAC, Mid upper arm circumference; SD Standard Deviation
Among the 255 STH positive samples, hookworm was found to be the most common infection, with a prevalence of 71.3 per cent, followed by A. lumbricoides, having a prevalence 28.2 per cent. None was found to be infected with T. trichiura. Only one child (0.4%) was found to be infected with both hookworm and A. lumbricoides. The infection intensity was determined based on the helminthic egg count. For A. lumbricoides, egg count ranges 1-4999, 5000– 49999, and ≥50000 were considered as mild, moderate and severe intensity, respectively. Similarly, for hookworm, egg counts ranging from 1-1999, 2000-3999,and ≥4000 were considered as mild, moderate and severe intensity, respectively17. Among the STH-positive children, the majority (90.5%) had mild infection followed by 4.7 per cent with moderate and 4.3 per cent with severe infection. The detailed status of different helminth infections including their intensity of infection is depicted in table IV.
Table IV.
Presence of various Helminths and their infection intensity among STH positives (n= 255)
| Sl.no. | Helminth type | Total (N=255) | Mild (range) | Moderate (range) | Severe (range) |
|---|---|---|---|---|---|
| 1 | lumbricoides (Roundworm) | 72 | (1-4999), 71 | (5000-49,999), 1 | (≥50,000), 0 |
| 2 | (HW) | 182 | (1-1999) 160 | (2000-3999), 11 | (≥4000),11 |
| 3 | Both HW and RW | 1 | 1 | 0 | 0 |
| Total | 255 | 232 | 12 | 11 |
RW, roundworm; HW, hookworm
Table V presents the results of unadjusted and adjusted logistic regression analyses on factors associated with STH infection. In the unadjusted analysis, children aged 1-5 yr had significantly lower odds of STH infection than those aged 6-15 yr (OR = 0.57, 95 per cent CI: 0.43-0.75, P<0.001). However, age was excluded from the adjusted model since only children above five years were analysed to consider hygiene factors like open defecation and handwashing. Handwashing after defecation was a strong protective factor, reducing the odds of infection by 85 per cent (OR = 0.15, 95% CI: 0.05-0.47, P = 0.001). However, it was not included in the adjusted model due to collinearity.
Table V.
Logistic regression analysis of factors associated with STH infection (n=1927)
| Variable | Crude OR (95% CI) | Pvalue | Adjusted OR (95% CI) | P value |
|---|---|---|---|---|
| Age group (yr) | ||||
| 6-15 | 1 | — | — | — |
| 1-5 | 0.6 (0.43 - 0.75) | 0 | (Adjusted Model for Age > 5) | — |
| Gender | ||||
| Male | 1 | — | 1 | — |
| Female | 0.8 (0.6 - 1.02) | 0.1 | 0.8 (0.58 - 1.11) | 0.2 |
| Family type | ||||
| Nuclear | 1 | — | 1 | — |
| Joint family | 1.3 (0.91 - 1.73) | 0.2 | 1.1 (0.73 - 1.6) | 0.7 |
| Schooling | ||||
| No schooling | 1 | — | 1 | — |
| AWC | 0.7 (0.32 - 1.33) | 0.2 | 1.6 (0.13 - 19.71) | 0.7 |
| Class 1-10 | 1.1 (0.55 - 2.2) | 0.8 | 0.8 (0.09 - 7.23) | 0.8 |
| ALB taken (last 6 months) | ||||
| No | 1 | — | 1 | — |
| Yes | 0.6 (0.37 - 1.02) | 0.1 | 0.6 (0.32 - 0.98) | 0.04 |
| Hand washing | ||||
| No | 1 | — | Omitted (Collinearity) | — |
| Yes | 0.2 (0.05 - 0.47) | 0.001 | — | — |
| Open defecation | ||||
| No | 1 | — | 1 | — |
| Yes | 0.9 (0.6 - 1.24) | 0.4 | 1.1 (0.72 - 1.69) | 0.7 |
AWC, anganwadi centre; ALB, Albendazole
Taking ALB in the past six months significantly lowered the risk of STH infection in both unadjusted (OR = 0.61, 95% CI: 0.37-1.02, P = 0.059) and adjusted analyses (OR = 0.56, 95% CI: 0.32-0.98, P = 0.041), highlighting its effectiveness as a deworming treatment.
Discussion
This study, conducted in Eastern India among children aged 1-15 in a tribal district, revealed a widespread prevalence of STH. Worldwide, the majority of STH cases are caused by two primary parasites: A. lumbricoides and T. trichiura, followed by hookworm infections18. In this study, the most common STH infections were hookworm (HW) and roundworm (RW; A. lumbricoides), with no case of whipworm (T. trichiura) found among the study participants. The overall prevalence of STH was 13.2 per cent, closely aligning with the findings of Kattula et al19, who reported a range of 5.9-12.1 per cent in rural areas. Furthermore, the prevalence of hookworm infections was higher (9.5%) than that of Ascaris infections (3.8%), consistent with other studies showing a higher prevalence of hookworm compared to Ascaris infections20. The predominance of hookworm infections over other STH in our study could be due to geo-environmental factors and occupational practices. The absence of T. trichiura suggests its limited presence in this setting, supporting findings from similar research21. Moreover, other studies have also shown that Ascaris and Trichuris are more common in urban areas, whereas hookworm predominantly affects rural children22.
This study found that STH infections were more prevalent among males (14.6%), likely due to their increased exposure to infected soil when accompanying their fathers to fields or engaging in outdoor activities23. School-aged children (6-15 yr) had a higher prevalence (15.53%) than preschool-aged children (9.7%), which is consistent with the findings of Avhad24 and Greenland et al25, who attributed this to greater exposure to contaminated environments and poorer hygiene practices among older children. However, Awasthi et al26 reported a significantly higher prevalence (65.9%) in preschool children in rural Uttar Pradesh, a region where open defecation contributed to the spread of STH infections. The strong link between open defecation and STH was evident in this study, with a prevalence of 18.3 per cent among children practicing open defecation, compared to 5 per cent among those using toilets. The Swachh Bharat Mission might have contributed to improved sanitation, as 92.4 per cent of families in the study reported using household toilets, a stark contrast with the findings from earlier surveys27. Nonetheless, persistent open defecation remains a challenge, underscoring the need for ongoing sanitation initiatives28. Hand washing practices also play a crucial role in STH transmission, with children who did not use soap after defecation being at significantly higher risk of infection. This finding echoed the results from other studies which showed that poor hand hygiene was associated with STH risk29. The use of sanitation facilities and regular shoe-wearing reduced infection risk, though Kaliappan et al30 did not find a strong link between inconsistent shoe-wearing and increased STH risk.
Anthelminthic treatments, such as a single dose of albendazole, have proven effective in treating A. lumbricoides and hookworm, with cure rates of 88per cent and 78 per cent, respectively31. Regular MDA programs have demonstrated success, with a study in southern India reporting a 77 per cent reduction in STH burden following regular deworming32. However, challenges persist, as evidenced by a study in Odisha, where nearly 50 per cent of children in urban slums remained infected after deworming12. While deworming improves growth outcomes in infected children, its impact on broader health markers, such as cognitive development or school attendance, is limited according to a Cochrane review of 41 trials33.
The link between STH infections and malnutrition is well-documented, with wasting found significantly associated with infection in this study (P=0.05), mirroring the findings from Geleto et al34 and Dhaka et al28. Although no significant association was found between STH infection and stunting or underweight, the higher burden of infection among malnourished children was concerning, as malnutrition can both result from and exacerbate parasitic infections35. Malnutrition and nutritional deficiencies can result from reduced appetite, poor nutrient intake, impaired absorption, increased nutrient loss, and altered metabolism36. Combining deworming with vitamin A supplementation has been shown to reduce Ascaris reinfection rates35, though the DEVTA study found no significant improvements in weight, haemoglobin, or mortality rates37. Long-term STH control will require a comprehensive approach addressing sanitation, hygiene, and malnutrition.
While this study provided important insights, there are some limitations that should be considered when interpreting the results. This study is one of the few to focus on STH prevalence in a tribal-dominated region, offering valuable insights into an underrepresented population. Its strengths include a large sample size, random cluster selection, and standardized methods for data collection and laboratory analysis, enhancing the reliability of the findings. While the study is limited to a single district in Odisha, which may slightly restrict the generalizability of the results, it still provides crucial data for similar regions. The 16.9 per cent dropout rate was unlikely to significantly impact the overall findings, as the sample remained robust and representative.
Considering the above findings and their implications, the study concludes that there is a noteworthy prevalence of helminth infection, at 13.2 per cent among the children (1-15 yr) in a tribal area. The STH prevalence data from this cross-sectional investigation, conducted in several blocks of the Odisha district of Nabarangapur, served as the basis for this research. Age-related increase in prevalence suggested that recurrent infections had a cumulative effect. These findings highlight the necessity of focused and integrated public health initiatives to control and prevent helminth infection, especially among children of rural and tribal areas. Comprehensive control measures, such as mass medicine administration, access to clean and safe drinking water and sanitation, and health education campaigns around good hygiene habits, are essential to counteract the detrimental consequences of helminth infections. Ensuring the implementation of ongoing public health programs, including school health programs and their better coverage, would help to prevent the helminth infections and ensure the well-being of the children.
Acknowledgment
Authors acknowledge Dr. Sobharani Mishra, former CDM and PHO Nabarangapur for her support in linking the research team with the medical officers and front-line workers to conduct the study. All the frontline workers for their constant support and help during the field activity, Dr. Banamber Sahoo (Library and Information Officer) ICMR-RMRC Bhubaneswar, Mr. Somya Ranjan Nayak, Mr. Afeeq K., Prachi Prabha Panda who supported technically in GIS mapping and analysis.
Financial support & sponsorship
This research was supported and funded by Indian Council of Medical Research (ICMR) (Grant no.: P-25/ECD/TSP/4/2020-21).
Conflicts of Interest
None.
Use of Artificial Intelligence (AI)-Assisted Technology for manuscript preparation
The authors confirm that there was no use of AI-assisted technology for assisting in the writing of the manuscript and no images were manipulated using AI.
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