2.1 Study area
Kogi East is located in Kogi State, North Central Nigeria. It is a geographical region comprising of nine (9) Local Government Areas (LGAs); Ankpa, Bassa, Dekina, Ibaji, Idah, Igalamela/Odolu, Ofu, Olamaboro and Omala (Figure 1). The District is located between latitude 6º32′33.8′′N to 8º02′44.8′′N and longitude 6º42′08.5′′E to 7º51′50.3′′E [14]. The District occupies an area of 26,197 square kilometres sharing boundaries with six (6) states of Nigeria. To the North; it shares boundaries with Nassarawa, to the West with Edo and Delta States, while to the East by Benue, Anambra and Enugu States [15].
2.2. Ethical approval
Ethical clearance was obtained from Research Ethics Committee, Kogi State Ministry of Health (KSMoH), Lokoja with reference number MOH/KGS/1376/1/82 and permission was obtained from the State Universal Basic Education Board (SUBEB), Lokoja with reference number KG/SUBEB/GEN/04/’T’ which was conveyed to the Education Secretaries of the 9 LGAs and the Headmasters (mistress) of the schools.
2.3. Inclusion and exclusion criteria
Children attending schools in rural communities of Kogi East with ages from 5 to 14 years were included in this study. Preschool-aged children (<5 years) and children older than 14 years attending rural schools in Kogi East were excluded from this study.
2.4. School mobilization and sensitization
Advocacy visits were paid to the Honourable Commissioner for Health and this was preceded by letters from the KSMoH and also the SUBEB to the Education Secretaries of the Local Government Education Authorities (LGEAs).
2.5. Study design
The study was carried out between January 2018 and December, 2019. District-wide mapping for STH infections was conducted in all the nine (9) LGAs of Kogi East (Ankpa, Bassa, Dekina, Ibaji, Idah, Igalamela/Odolu, Ofu, Olamaboro and Omala LGAs) in a coordinated manner using WHO National protocol framework [16] and was in line with the Federal Ministry of Health (FMoH) protocol on integrated epidemiological mapping and baseline survey for STHs [2]. Randomised selection of schools was done followed by a randomised systematic selection of children in the schools to be surveyed. Enrolled school age children were targeted from the surveyed schools (Figure 2).
2.6. Sample size
During the baseline survey, a total of 100 pupils were sampled in each LGA according to the WHO national protocol framework [16]. This study sampled 36 pupils per school, that is, 36 pupils in five schools (180 samples) per LGA, which gave a sample size of 1620. However, with the minimum sample size of 100 pupils per LGA, the minimum sample size of 900 was reached.
2.7. Statement of consent of participants
Written consents were obtained from the guardians/parents of study participants, informing them of their rights and granting permission for their children to participate in the study.
2.8. Selection of participating schools and children
In all the LGAs, five (5) schools were randomly selected from different communities in the rural areas of the LGAs, that is, a total of 45 schools were sampled. A sampling frame developed was used for selection of pupils in each selected school. A total of 36 pupils of both sexes, males and females were selected on pro-rata basis from 5 – 16 years old (class one to class six) from each school sampled.
2.9. Sample collection and parasitological examination
Stool samples were collected from selected schoolchildren using sterile specimen bottles. Each child in the study was given a sterile specimen bottle to take home after which instruction on how sample collection was explained to them. A single faecal sample was collected from each child and preserved using 10% formalin. Stool samples were taken to the Department of Animal and Environmental Biology, Kogi State University, Anyigba for parasitological examination using formal ether sedimentation technique [17].
In a suitable container, 1 g of stool sample was mixed thoroughly with 10ml of saline solution to form an emulsion which was then filtered through fine mesh gauze into a conical centrifuge tube. Suspension was centrifuged at Relative Centrifuge Force (RCF) of 600 g (about 2000 rpm) for about 10 minutes yielding about 0.5 ml of sediment. After supernatant was discarded, the sediment was washed with 10 ml of saline solution, and then recentrifuged. This was done repeatedly until supernatant became clear. After the last wash, supernatant was discarded and 10 ml of 10% formalin was added, mixed, and then the mixture was allowed to stand for 5 minutes to effect fixation. About 2 ml of ethyl acetate was added; tube was stoppered and vigorously mixed. The mixture was centrifuged at 450 g RCF (about 1500 rpm) for 10 minutes which gave four results; a top layer of ethyl acetate, plug of debris, layer of formalin, and sediment. Plug of debris from the side of the tube were removed using the applicator stick, and the top three layers were carefully discarded. With a pipette, the remaining sediment was mixed with the small amount of fluid and a drop each was transferred to a drop of saline and iodine on a glass side, covered with coverslip and examined microscopically for the presence of parasitic forms.
2.10. Selection of endemic schools for intervention studies
The results obtained from the survey served as the baseline assessment. A total of 10 schools were selected from the baseline study, the criteria for selection was based on highest infection rate. Five schools each were paired with another five schools with the closest proximity. The five (5) schools with the highest infection rate served as the intervention group while the other five (5) schools served as the control group. An open-label pair-matched cluster-randomized controlled trial study design was used (Figure 3).
2.11. Randomization and masking
The unit of randomization was the school. To ensure a balanced proportion of children in each group and comparison between intervention and control schools with regard to expected baseline STH prevalence, schools were matched according to geographical zone. Within each pair, one school was randomly allocated to deworming and health education (intervention school) and the other to deworming alone (control school) (Figure 3).
2.12. Deworming of endemic schools for follow-up studies
Following baseline assessment, all children in the 10 selected schools were given a 400 mg chewable albendazole tablet (Manufactured and Donated by GlaxoSmithKline to World Health Organization). The tablets used for this study were obtained from NTDs Unit, Kogi State Ministry of Health, Lokoja, Nigeria and each child was monitored to ensure that the tablet is chewed and swallowed. Efficacy of the albendazole treatment was assessed in a random sampling of 60 pupils each from 3 schools dewormed to check for the presence of at least one of the STH species [18].
2.13. Health education intervention
The health education intervention was administered during every visit at each intervention school and it consist of two components.
First, pupils were taught on STH acquisition, transmission and prevention. Urban School Health Kit by WHO [19] was adopted during this component. During this intervention, pupils were taught on ways to improve their personal hygiene and understand the importance of preventing STH infection.
Secondly, a half-day workshop was organized for teachers with the goal of promoting an integrated health curriculum. These workshops was held following deworming.
Posters highlighting key health messages were distributed and displayed in strategic locations around the school. The key messages for prevention used in this study are; washing hands before eating, washing hands with soap after playing with soil, washing hands with soap after using the toilet, wearing slippers or shoes when going outside, avoiding open (indiscriminate) defecation, washing vegetables and fruits before consumption, drinking clean (boiled) water, covering food from flies and cutting nails periodically.
2.14. Follow-up studies
The follow-up assessments commenced one month after deworming and was carried out monthly until re-infection of STHs was observed (Figure 4). The stool specimens collected on every visit were transported to the laboratory where they were examined within 48 hours. Similar procedure used in parasitological examination of samples as stated above was used.
2.15. Statistical Analyses
Data were entered using Microsoft Excel version 2013. Descriptive statistics were used to compute prevalence and incidence. The student t-test was used to determine the level of significant between the intervention group and the control group. All analyses were performed using Statistical Package for Social Sciences (SPSS) software (Version 22.0 for Windows; SPSS Inc., Chicago, IL, USA).