Tags

Type your tag names separated by a space and hit enter

What does soil-transmitted helminth elimination look like? Results from a targeted molecular detection survey in Japan.
Parasit Vectors. 2020 Jan 08; 13(1):6.PV

Abstract

BACKGROUND

Japan is one of the few countries believed to have eliminated soil-transmitted helminths (STHs). In 1949, the national prevalence of Ascaris lumbricoides was 62.9%, which decreased to 0.6% in 1973 due to improvements in infrastructure, socioeconomic status, and the implementation of national STH control measures. The Parasitosis Prevention Law ended in 1994 and population-level screening ceased in Japan; therefore, current transmission status of STH in Japan is not well characterized. Sporadic cases of STH infections continue to be reported, raising the possibility of a larger-scale recrudescence of STH infections. Given that traditional microscopic detection methods are not sensitive to low-intensity STH infections, we conducted targeted prevalence surveys using sensitive PCR-based assays to evaluate the current STH-transmission status and to describe epidemiological characteristics of areas of Japan believed to have achieved historical elimination of STHs.

METHODS

Stool samples were collected from 682 preschool- and school-aged children from six localities of Japan with previously high prevalence of STH. Caregivers of participants completed a questionnaire to ascertain access to water, sanitation and hygiene (WASH), and potential exposures to environmental contamination. For fecal testing, multi-parallel real-time PCR assays were used to detect infections of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale and Trichuris trichiura.

RESULTS

Among the 682 children, no positive samples were identified, and participants reported high standards of WASH.

CONCLUSIONS

To our knowledge, this is the first STH-surveillance study in Japan to use sensitive molecular techniques for STH detection. The results suggest that recrudescence of STH infections has not occurred, and that declines in prevalence have been sustained in the sampled areas. These findings suggest that reductions in prevalence below the elimination thresholds, suggestive of transmission interruption, are possible. Additionally, this study provides circumstantial evidence that multi-parallel real-time PCR methods are applicable for evaluating elimination status in areas where STH prevalence is extremely low.

Authors+Show Affiliations

Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan. Doctoral Leadership Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA. Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, USA.Doctoral Leadership Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan. Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.Department of Global Health, University of Washington, Seattle, Washington, USA. Department of Life Sciences, Natural History Museum, London, UK.Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA. Department of Life Sciences, Natural History Museum, London, UK.Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA.Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA.Department of Bacteriology, BML, Inc, Saitama, Japan.The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan. Department of Vector Ecology and Environment, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.Department of Epidemiology, University of Washington School of Public Health, Seattle, Washington, USA.Department of Global Health, University of Washington, Seattle, Washington, USA. Department of Life Sciences, Natural History Museum, London, UK. Departments of Medicine (Infectious Disease), Pediatrics and Epidemiology, University of Washington, Seattle, Washington, USA.Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA. Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, USA.Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan. shinjiro@nagasaki-u.ac.jp. Doctoral Leadership Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. shinjiro@nagasaki-u.ac.jp. The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan. shinjiro@nagasaki-u.ac.jp.No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

31915050

Citation

Hasegawa, Mitsuko, et al. "What Does Soil-transmitted Helminth Elimination Look Like? Results From a Targeted Molecular Detection Survey in Japan." Parasites & Vectors, vol. 13, no. 1, 2020, p. 6.
Hasegawa M, Pilotte N, Kikuchi M, et al. What does soil-transmitted helminth elimination look like? Results from a targeted molecular detection survey in Japan. Parasit Vectors. 2020;13(1):6.
Hasegawa, M., Pilotte, N., Kikuchi, M., Means, A. R., Papaiakovou, M., Gonzalez, A. M., Maasch, J. R. M. A., Ikuno, H., Sunahara, T., Ásbjörnsdóttir, K. H., Walson, J. L., Williams, S. A., & Hamano, S. (2020). What does soil-transmitted helminth elimination look like? Results from a targeted molecular detection survey in Japan. Parasites & Vectors, 13(1), 6. https://doi.org/10.1186/s13071-019-3875-z
Hasegawa M, et al. What Does Soil-transmitted Helminth Elimination Look Like? Results From a Targeted Molecular Detection Survey in Japan. Parasit Vectors. 2020 Jan 8;13(1):6. PubMed PMID: 31915050.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - What does soil-transmitted helminth elimination look like? Results from a targeted molecular detection survey in Japan. AU - Hasegawa,Mitsuko, AU - Pilotte,Nils, AU - Kikuchi,Mihoko, AU - Means,Arianna R, AU - Papaiakovou,Marina, AU - Gonzalez,Andrew M, AU - Maasch,Jacqueline R M A, AU - Ikuno,Hiroshi, AU - Sunahara,Toshihiko, AU - Ásbjörnsdóttir,Kristjana H, AU - Walson,Judd L, AU - Williams,Steven A, AU - Hamano,Shinjiro, AU - ,, Y1 - 2020/01/08/ PY - 2019/09/08/received PY - 2019/12/30/accepted PY - 2020/1/10/entrez PY - 2020/1/10/pubmed PY - 2020/5/30/medline KW - Ancylostoma duodenale KW - Ascaris lumbricoides KW - Multi-parallel real-time PCR KW - Necator americanus KW - STH KW - Soil-transmitted helminth KW - Targeted prevalence survey KW - Trichuris trichiura KW - WASH SP - 6 EP - 6 JF - Parasites & vectors JO - Parasit Vectors VL - 13 IS - 1 N2 - BACKGROUND: Japan is one of the few countries believed to have eliminated soil-transmitted helminths (STHs). In 1949, the national prevalence of Ascaris lumbricoides was 62.9%, which decreased to 0.6% in 1973 due to improvements in infrastructure, socioeconomic status, and the implementation of national STH control measures. The Parasitosis Prevention Law ended in 1994 and population-level screening ceased in Japan; therefore, current transmission status of STH in Japan is not well characterized. Sporadic cases of STH infections continue to be reported, raising the possibility of a larger-scale recrudescence of STH infections. Given that traditional microscopic detection methods are not sensitive to low-intensity STH infections, we conducted targeted prevalence surveys using sensitive PCR-based assays to evaluate the current STH-transmission status and to describe epidemiological characteristics of areas of Japan believed to have achieved historical elimination of STHs. METHODS: Stool samples were collected from 682 preschool- and school-aged children from six localities of Japan with previously high prevalence of STH. Caregivers of participants completed a questionnaire to ascertain access to water, sanitation and hygiene (WASH), and potential exposures to environmental contamination. For fecal testing, multi-parallel real-time PCR assays were used to detect infections of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale and Trichuris trichiura. RESULTS: Among the 682 children, no positive samples were identified, and participants reported high standards of WASH. CONCLUSIONS: To our knowledge, this is the first STH-surveillance study in Japan to use sensitive molecular techniques for STH detection. The results suggest that recrudescence of STH infections has not occurred, and that declines in prevalence have been sustained in the sampled areas. These findings suggest that reductions in prevalence below the elimination thresholds, suggestive of transmission interruption, are possible. Additionally, this study provides circumstantial evidence that multi-parallel real-time PCR methods are applicable for evaluating elimination status in areas where STH prevalence is extremely low. SN - 1756-3305 UR - https://www.unboundmedicine.com/medline/citation/31915050/What_does_soil_transmitted_helminth_elimination_look_like_Results_from_a_targeted_molecular_detection_survey_in_Japan_ L2 - https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-019-3875-z DB - PRIME DP - Unbound Medicine ER -