Giardiasis in Japan, the United States of America, and Europe from 2007 to 2023, highlighting a decline during the COVID-19 pandemic
2
Issued Date
2026-06-01
Resource Type
eISSN
19352735
Scopus ID
2-s2.0-105043422358
Pubmed ID
42296167
Journal Title
Plos Neglected Tropical Diseases
Volume
20
Issue
6
Rights Holder(s)
SCOPUS
Bibliographic Citation
Plos Neglected Tropical Diseases Vol.20 No.6 (2026) , e0014428
Suggested Citation
Mori H., Makuuchi R., Krokva D., Remez D., Prasertbun R., Hadano Y., Popruk S., Mahittikorn A., Maude R.R., Wannigama D.L., Tamaki R., Deshpande G.A., Frutos R., Smith C., Naito T. Giardiasis in Japan, the United States of America, and Europe from 2007 to 2023, highlighting a decline during the COVID-19 pandemic. Plos Neglected Tropical Diseases Vol.20 No.6 (2026) , e0014428. doi:10.1371/journal.pntd.0014428 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/117846
Title
Giardiasis in Japan, the United States of America, and Europe from 2007 to 2023, highlighting a decline during the COVID-19 pandemic
Author's Affiliation
Xiamen University
London School of Hygiene & Tropical Medicine
Nagasaki University
Universitas Airlangga
Juntendo University School of Medicine
John A. Burns School of Medicine
Faculty of Tropical Medicine, Mahidol University
Ramathibodi Hospital
Faculty of Medicine Ramathibodi Hospital, Mahidol University
Mahidol Oxford Tropical Medicine Research Unit
Juntendo Hospital
Shimane University Hospital
Yamagata Prefectural Central Hospital
Interactions Hôtes-Vecteurs-Parasites-Environnement Dans les Maladies Tropicales Négligées dues aux Trypanosomatides (INTERTRYP)
Yamagata University Hospital
London School of Hygiene & Tropical Medicine
Nagasaki University
Universitas Airlangga
Juntendo University School of Medicine
John A. Burns School of Medicine
Faculty of Tropical Medicine, Mahidol University
Ramathibodi Hospital
Faculty of Medicine Ramathibodi Hospital, Mahidol University
Mahidol Oxford Tropical Medicine Research Unit
Juntendo Hospital
Shimane University Hospital
Yamagata Prefectural Central Hospital
Interactions Hôtes-Vecteurs-Parasites-Environnement Dans les Maladies Tropicales Négligées dues aux Trypanosomatides (INTERTRYP)
Yamagata University Hospital
Corresponding Author(s)
Other Contributor(s)
Abstract
BACKGROUND: Giardiasis is one of the most common enteric protozoal infections worldwide. It is frequently reported as an enteric parasitic infection in the United States of America (USA) and Europe, whereas reported incidence in Japan is substantially lower. This study characterized age-specific, geographic, and temporal patterns of reported giardiasis incidence in Japan, the USA, and Europe using publicly available surveillance data. METHODOLOGY/PRINCIPAL FINDINGS: This retrospective study analyzed surveillance data from the National Institute of Infectious Diseases (NIID) in Japan, the Centers for Disease Control and Prevention (CDC), and the European Centre for Disease Prevention and Control (ECDC) to describe epidemiological patterns, possible explanatory factors, and temporal trends before and during the COVID-19 pandemic. Annual trends were examined using all available surveillance years: 2007-2023 for Japan and Europe and 2007-2022 for the USA. Age-specific patterns were compared between the pre-pandemic (2017-2019) and pandemic (2020-2022) periods, and geographic patterns were examined using available regional data. Incidence rates in the USA and Europe were approximately 5 per 100,000 population, whereas reported incidence in Japan remained below 0.1 per 100,000. Age-specific patterns differed: incidence peaked in children aged 0-14 years in Europe, and in children aged 0-4 years and adults aged 25-39 years in the USA, whereas in Japan, incidence was highest among adults aged 25-44 years and relatively high among those aged ≥65 years. Geographic patterns also differed, with higher incidence in Tokyo, Nordic and Baltic countries and selected European countries, and New England and Midwestern states. Annual incidence was significantly lower in the COVID-19-onset period than in the pre-COVID-19 period across all regions. CONCLUSIONS/SIGNIFICANCE: These findings suggest that exposure patterns and possible explanatory factors differ by region and age group, highlighting the importance of region- and age-specific prevention strategies.