Parasitic Infections in Finger-sucking School Age Children : The Pediatric Infectious Disease Journal

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Parasitic Infections in Finger-sucking School Age Children

Idowu, Olufunmilayo Ajoke PhD*; Babatunde, Omolayo BSc*; Soniran, Temidayo MSc*; Adediran, Adekunle MB BS

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The Pediatric Infectious Disease Journal 30(9):p 791-792, September 2011. | DOI: 10.1097/INF.0b013e31821e8449
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Finger sucking (FS) is a common habit among many children. It is common with children <2 years of age and may signal hunger, fatigue, sleep, teething, and shyness.1 School age children are often the group that has the highest parasitic infection rate as well as the highest worm burden, which contribute greatly to the contamination of the environment.2 The sucking habit of children may be one of the key means of completing the fecal-oral life cycle of some intestinal parasites. Availability of safe water for drinking and washing hand is important for promoting health in schools.2 Effective hand washing includes the use of warm water, soap, and a clean dry towel. Ukoli3 reported that the use of drugs for the treatment of fecal-orally transmitted parasites is limited if the conditions promoting transmission are not removed. Parasitic infections in children can promote malnutrition and retard the growth of the children. It can affect the weight and height of these children through impaired digestion, malabsorption, and poor growth rate.4,5 The effect of parasitic infection on cognitive function in children has been reported.6 This study investigates whether FS is a risk factor for parasitic infection among school children.


Study Area.

The study was conducted in 6 randomly selected primary schools in Abeokuta, Ogun State Capital in the southwest of Nigeria. Abeokuta is an urban settlement that is densely populated consisting of civil servants and traders. The town has social amenities such as electricity and pipe-borne water. The majority of residents belong to the Yoruba ethnic group.

Ethical Clearance and Informed Consent.

The written approval was obtained from the ethical committee of the Local Government Area, whereas the school authorities, parents, and pupils gave verbal and written informed consent to participate.

Sampling Method.

Semi-structured questionnaires were given to selected pupils from randomly selected schools (using a balloting method). All FS pupils from each school were enrolled and, for each FS child enrolled in the study, a nonfinger-sucking (NFS) child living under similar conditions was also enrolled. Information was also obtained from parents and teachers on the age and FS habit of pupils, toilet facilities at home and school, academic performance of pupils, previous treatment for fecal-oral parasitic infections, access to good water, and eating habits of the pupils. Height and weight of each pupil were obtained using meter rule and weighing scale, respectively.

Specimen Collection.

Enrolled pupils were directed to defecate into the clean papers, and small portions of the fresh stool samples were collected in well labeled universal tubes in paper bags and taken to the laboratory for investigation.

Examination of Stool Samples.

Physical observation of stool samples was carried out immediately after receipt in the laboratory. Presence of blood stains, mucus, and stool consistency were observed.

Direct wet examination of stool sample in saline solution was done using a compound microscope to observe the mobility of the parasites. Formal ether concentration technique was also used for the concentration of the parasites in each stool sample.

Data Analysis.

Data obtained were analyzed using Epi6-info version 6.047 (CDC, Atlanta GA).


We enrolled 100 randomly selected pupils, including 50 FS pupils and 50 NFS pupils. Five different fecal-orally transmitted parasites were observed in the study of which Entamoeba histolytica (33%) was the most prevalent parasite; others were Ascaris lumbricoides (23%), Enterobius vermicularis (17%), Trichuris trichiura (14%), and Giardiaduodenalis (12.8%) (Table 1).

Parasite Distribution by Species and Pupil Gender Among Finger-sucking and Nonfinger-sucking Children

The frequency of fecal-orally transmissible infection among FS pupils was 94% (47 pupils) as compared with 66% (33 pupils) of NFS pupils (P < 0.05). Infection was significantly higher among female (82%) than male (46%) pupils in the NFS group; however, there was no significant difference between sex and infection among children who sucked their fingers.

Treatment of infection as a measure of controlling fecal-orally transmitted parasites had no beneficial effect on finger suckers. The prevalence of infection among finger suckers who had previously treated for helminth infection and pupils who had not been treated for helminth infection was similar. The NFS group exhibited some level of reduced prevalence among previously treated pupils as compared with the untreated pupils.

The type of toilet facilities was also observed to influence distribution of infections. FS significantly increased the frequency of infection among those using a pit latrine (97%) as compared with NFS children using a pit latrine (70%) (P = 0.019); however, there was no significant difference between FS (90%) and NFS (59%) children using the water closet (P = 0.22).


In this study on the risk factors associated with FS in the transmission of intestinal parasites, the highest prevalence of infection was found for Entamoeba histolytica (33%), whereas G.duodenalis (13%) had the lowest prevalence. A similar study among school children in the eastern part of Nigeria reported 4.9% prevalence of infection with A. lumbricoides, 2.5% with hookworm, and 0.7% with T. trichiura.8 Although G.duodenalis is prevalent in children, the present study is also in agreement with that of Houmsou et al9 who reported the lowest prevalence of infection with G.duodenalis in the middle belt region of Nigeria. In various previous studies carried out in Abeokuta, a high prevalence of intestinal helminths, especially A. lumbricoides was reported among school children.10,11T. trichiura infections is known to have similar conditions influencing its endemicity and that of A. lumbricoides.12

A higher frequency of infection was observed among FS pupils (94%) than NFS pupils (66%). FS creates a route of transmission for these parasites and has contributed to the observed high prevalence of infection. There have been reported cases of indiscriminate defecation leading to fecal contamination of the environment in the study community.13,14 School age children have also been known to be more exposed to the risks of being infected with these fecal oral parasites because of their poor level of personal hygiene, coupled with the fact that they involve themselves in activities that facilitate contact with the soil where the ova and cysts of these parasites are found. The toilet facilities available to most of these school children have also been reported to be poorly used and lack regular water supply.11

There was no significant difference in sex regarding parasite infection among FS pupils, but a higher percentage of females (82%) were infected than males (46%) among NFS pupils. This is similar to the result of Ekpenyong and Eyo study,8 in which prevalence of infection was significantly more common in females than males.

History of previous treatment of intestinal parasites had no effect on the prevalence of infection among FS pupils as observed in this present study. All finger suckers who had been previously treated for these parasites and those who had not been treated were positive for infection. This shows that the FS habit exposed these pupils to reinfection, despite previous treatment of the parasites. An earlier study in Abeokuta and other towns in the state using a Monrate tool predicted a 3-month reinfection period for helminth in school children,10,15 FS would probably increase the reinfection period because of the continuous hand-to-mouth activities of FS children.

These results strengthen the need for education of parents and their children on the risks associated with FS, especially in areas where there is a high level of fecal contamination. The need to improve sanitary conditions is also to be emphasized.


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parasites; infections; finger-sucking; children

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