Soil-transmitted helminth infections and taeniasis on Samosir Island, Indonesia

Soil-transmitted helminth (STH) infections are important causes of morbidity in poorer areas of developing countries, with high endemicity in Southeast Asia. Humans are most often exposed to the infective forms of STHs in areas with sub-standard sanitation. The number of STH infections globally was estimated at 1.5 billion in 2018. In Indonesia, the prevalence of STH infections ranges from 2.5% to 62.0%. STH and taeniasis infections were evaluated on Samosir Island, North Sumatra, Indonesia. Field surveys were conducted in January 2003, February 2005, and February 2006 in Simanindo Subdistrict, with a subsequent survey conducted in the subdistricts of Simanindo and Ronggurnihuta in September 2015. A total of 371 individuals were screened between 2003 and 2006 and 368 were screened in 2015 (314 from Simanindo and 54 from Ronggurnihuta). Fecal samples were collected and examined microscopically by the Kato-Katz technique. The prevalence of STH infections in Simanindo for the years 2003, 2005, 2006, and 2015 was 41.4%, 52.2%, 55.7%, and 46.8%, respectively. The 2015 prevalence of STH infections in Ronggurnihuta was 66.7%. Taenia asiatica taeniasis prevalence was 3.4% and 2.2% for the years 2003 and 2005, respectively, with no cases detected in 2006 or 2015. The prevalence of STH infections in Simanindo and Ronggurnihuta was similar to other STH prevalence values reported for Indonesia. Country-level values have not changed substantially from those reported in the 1980s and 1990s, where prevalence ranged from 40% to 70%. Improvement of personal hygiene and environmental sanitation for control of STH infections on Samosir Island will require collaboration among multiple sectors.