Parents will be explained the purpose of the study and will be asked for written consent for participation of their children in the study. If the parents give the consent then a stool pot will be given to them to collect stool samples for microscopic examination for intestinal parasites. The inclusion criteria are; 1) age of the child is 2-5 years old, 2) he/she has not been suffering from serious chronic illness, 3) the child stool test must be positive for STH, 4) he/she had not been taken any antehelminthic drug in the previous six months, 5) parents/guardian are agree for their child participation in the study. The exclusion criteria are; 1) age of the child less than 2 years old and more than 5 years old, 2) his/her stool test negative for any intestinal helminth, 3) he/she has been suffering from serious chronic illness, 4) parents/guardian are not willing to give consent for their child's participation in the study, 5) if he/she receives any antehelminthic drug after survey but before the study interventions. The survey will be done in the first months of the study, and then children will be enrolled according to above mentioned inclusion/exclusion criteria. During screening if any child is found severely malnourished it will be considered as'danger sign' according to WHO and IMCI guideline he/she will be referred to an appropriate facility even if she/he is not enrolled in the study. Simple randomization technique will be applied to divide the children into two groups: A) Conventional treatment group who will receive anti-helminthic treatment 400 mg of Albendazole in a single dose at six month interval and B) Intervention group, who will receive anti-helminthic 400 mg of Albendazole in a single dose treatment at three months interval. Stool samples will be collected from both groups prior to anti-helminthic therapy and will be examined quantitatively. However stool examination will not be carried out for intestinal parasite after giving 400 mg of Albendazole at 12 months.