A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
COVID-19 pandemic containment measures in 2020 selectively altered established Cryptosporidium hominis anthroponotic transmission in Spain. Rapid emergence and expansion of hypertransmissible human-adapted gp60 subtypes such as IfA12G1R5 and, less markedly, IbA13G3 followed. Conversely, transmission of the largely zoonotic C. parvum remained comparatively stable, yielding a dual epidemiologic scenario in this country.
Cryptosporidiosis is a public health concern in Europe; outbreaks have been linked to contaminated drinking water, recreational water, and fresh produce ( 1 , 2 ). In 2020, the European Union reported 1.7 confirmed cases/100,000 population ( https://www.ecdc.europa.eu/en/publications-data/cryptosporidiosis-annual-epidemiological-report-2020 ), although the true burden is likely underestimated because of underdiagnosis and underreporting.
The COVID-19 pandemic and associated nonpharmaceutical interventions altered the epidemiology of gastrointestinal pathogens ( 3 ). The effects of those measures on Cryptosporidium species varied, as shown in time-series analyses comparing prepandemic and postpandemic incidence of cryptosporidiosis and molecular data from countries in Europe (England, Scotland, and Wales) and New Zealand ( 4 – 6 ). Furthermore, a postpandemic study in Spain of young children with diarrhea demonstrated an interruption in the transmission of C. hominis , but not C. parvum ( 7 ). We collated prepandemic and postpandemic molecular data from published literature and from multicenter, nonoutbreak studies to investigate the molecular epidemiology of Cryptosporidium infection in Spain after the interruption in transmission of C. hominis and the relaxation of COVID-19 containment measures in 2020.
We searched PubMed, Web of Science, and Scopus databases for molecular studies on human cryptosporidiosis conducted in Spain published during January 2010–December 2020 ( Appendix ). Search terms included Cryptosporidium , human, hominis , parvum , gp60 , subtype, and Spain. We identified 7 studies reporting molecular data on Cryptosporidium from laboratory-confirmed clinical samples collected in Spain during 2000‒2016; a total of 806 isolates were characterized ( Appendix Table). Among C. hominis (76.1%), subtype family Ib predominated (90.7%); subtype IbA10G2 accounted for 99.6% of isolates. Among C. parvum (24.0%), subtype family IIa predominated (87.1%), followed by IIn (7.3%) and IId (5.2%).
During December 2013–December 2019, we collected Cryptosporidium -positive clinical fecal samples routinely submitted for genotyping to the National Reference Laboratory at the Spanish National Centre for Microbiology from 7 regions ( Table 1 ). We obtained additional prepandemic samples through a dedicated multicenter nonoutbreak study across 4 tertiary hospitals in 2 regions ( Table 1 ). During March–December 2023, we collected postpandemic Cryptosporidium -positive clinical samples through a dedicated multicenter nonoutbreak study across 8 tertiary hospitals in 2 regions ( Table 2 ). Upon receipt, all samples were subjected to confirmatory testing and genotyping at the gp60 marker in accordance…