Biannual Mass Deworming

Health status of children in the Philippines
The prevalence of soil transmitted helminth (STH) infections in elementary school children in the Philippines is 67% (Belizario et al. 2005),1 while the results of a recently concluded sentinel surveillance of STH infections using school children showed an infection rate of 54% (Belizario et al. 2009).2 STH infections impair healthy nutrition (Stephenson et al. 2000)3 through reduced food intake due to poor appetite and malabsorption (Crompton et al. 2002).4 As a result, untreated STH-infected children have higher levels of stunting (Stoltzfus et al. 1997),5 lower body-mass index, anemia, and undernourishment (Dantzer 2001, Stoltzfus 2004, de Leon and Lumampao 2005).6,7,8 Impaired metabolic functions trigger sleeplessness and negatively impact children’s motor development and cognitive performance (Ezeamama et al. 2005).9 STH infections early in life may therefore affect cognitive indicators, which are measured later in life (Kwalsvig 2002).10

International recommendations and health policies
A school-based intervention is the best way to reach the high risk STH-infected child population in the most cost-effective and systematic manner, using the mass drug-administration approach recommended by the World Health Organization, which does not require prior screening of children (WHO 2005).11 This approach is recommended by the Integrated Helminth Control Program that specifies a twice yearly deworming in January and July each year in the school setting (DOH 2006).12

Anthelminthic drugs can be included in large-scale public health interventions due to their safety and simple administration (Urbani et al. 2003).13 Ample evidence clearly demonstrates that regular treatment of STH infections produces immediate as well as long-term benefits that significantly contribute to positive health outcomes, particularly in schoolchildren (WHO 2005).14

Scientific evidence
The objective of regular deworming in endemic STH areas is to get rid of existing infections or to lower worm burden. Children may be reinfected after a short time. The intention of biannual deworming is to control the level of infection and keep the worm burden of infected individuals below the threshold that causes significant morbidity (Savioli et al. 1992).15 The prevalence of heavy STH infections declines by 30% after biannual drug treatment. In Uganda, children’s weight was 10% greater after treatment with albendazole every six months, as compared to the weight of children who did not receive this treatment (Alderman et al. 2006).16 In the slums of urban India, a series of studies have been conducted on the effect of biannual deworming using albendazole. Results show that stunting of infants and preschool children was reduced by 9.4% and weight improved by 35% within two years (Awasthi et al. 2001).17
References
  1. Belizario, V. Y. Jr., de Leon, W. U., Wambangco, M. L. et al. 2005. Baseline assessment of intestinal parasitism in selected public elementary schools in Luzon, Visayas and Mindanao. Acta Medica Philippina 2005; 39:11–21.
  2. Belizario, V. Y. Jr., de Leon, W. U., Lumampao, Y. F., Anastacio, M. B. M., and Tai, C. M. C. 2009. Sentinel Surveillance of Soil-Transmitted Helminthiasis in Selected Local Government Units in the Philippines. Asia-Pacific Journal of Public Health 2009; 21(1):26–42.
  3. Stephenson, L. S., Latham, M. C., Ottesen, E. A. 2000. Malnutrition and parasitic helminth infection. Parasitology 2000; 121(Suppl):S23–S38.
  4. Crompton, D. W. T., Nesheim, M. C. 2002. Nutritional impact of intestinal helminthiasis during the human life cycle. Annual Rev Nutr 2002; 22:35–59.
  5. Stoltzfus, R., Albonico, M., Tielsch, J. et al. 1997. Linear Growth Retardation in Zanzibari School Children. J Nutr 1997; 127(6):1099–1105.
  6. Dantzer, R. 2001. Cytokine-induced sickness behaviour: where do we stand? Brain Behav Immun 2001; 15(1): 7–24.
  7. Stoltzfus, R. J., Chwaya, H. M., Montresor, A. et al. 2004. Low dose daily iron supplementation improves iron status and appetite but not anemia, whereas quarterly anti helminthic treatment improves growth, appetite and anemia in Zanzibari pre-school children. J Nutr 2004; 134(2):348–356.
  8. de Leon, W., Lumampao, Y. 2005. Nationwide survey of intestinal parasitosis in pre-school children. Final report submitted to UNICEF; 2005; Manila, Philippines.
  9. Ezeamama, A. E., Friedman, J. F., Acosta, L. P. et al. 2005. Helminth infection and cognitive impairment among Filipino children. Am J Trop Med Hyg 2005; 72(5):540–548.
  10. Kwalsvig, J. 2002. Intestinal Nematodes and Cognitive Development. In: Holland, C. V., Kennedy, M. W. editors. World Class Parasites. Vol 2. The Geohelminths: Ascaris, Trichuris and Hookworm. London: Kluwer Academic Publishers. p. 63–73.
  11. World Health Organization. 2005. Deworming for Health and Development. Report of the third global meeting of the partners for parasite control; November 29–30, 2004; Geneva, Switzerland; p. 51.
  12. Department of Health. 2006. Integrated Helminth Control Program.
  13. Urbani, C., Albonico, M. 2003. Anthelminthic drug safety and drug administration in the control of soil-transmitted helminthiasis in community campaigns. Acta Trop 2003; 86(2–3):215–222.
  14. World Health Organization. 2005. Deworming for Health and Development.
  15. Savioli, L., Bundy, D., Tomkins, A. 1992. Intestinal parasitic infections: a soluble public health problem. Trans R Soc Trop Med Hyg 1992; 86(4):353–354.
  16. Alderman, H., Konde-Lule, J., Sebuliba, I. et al. Effect on weight gain of routinely giving albendazole to preschool children during child health days in Uganda: cluster randomised controlled trial. Br Med J 2006; 333(7559):122–127.
  17. Awasthi, S., Pande, V. K. 2001. Six-monthly de-worming in infants to study effects on growth. Indian J Pediatr 2001; 68(9):823–827.