Spatiotemporal epidemiology of cryptosporidiosis in the Republic of Ireland, 2008–2017: development of a space–time “cluster recurrence” index

Abstract

Background Ireland frequently reports the highest annual Crude Incidence Rates (CIRs) of cryptosporidiosis in the EU, with national CIRs up to ten times the EU average. Accordingly, the current study sought to examine the spatiotemporal trends associated with this potentially severe protozoan infection. Methods Overall, 4509 cases of infection from January 2008 to December 2017 were geo-referenced to a Census Small Area (SA), with an ensemble of geo-statistical approaches including seasonal decomposition, Local Moran’s I, and space–time scanning used to elucidate spatiotemporal patterns of infection. Results One or more confirmed cases were notified in 3413 of 18,641 Census SAs (18.3%), with highest case numbers occurring in the 0–5-year range (n = 2672, 59.3%). Sporadic cases were more likely male (OR 1.4) and rural (OR 2.4), with outbreak-related cases more likely female (OR 1.4) and urban (OR 1.5). Altogether, 55 space–time clusters (≥ 10 confirmed cases) of sporadic infection were detected, with three “high recurrence” regions identified; no large urban conurbations were present within recurrent clusters. Conclusions Spatiotemporal analysis represents an important indicator of infection patterns, enabling targeted epidemiological intervention and surveillance. Presented results may also be used to further understand the sources, pathways, receptors, and thus mechanisms of cryptosporidiosis in Ireland.

A summary of cryptosporidiosis outbreaks reported in France and overseas departments, 2017–2020

“…Cryptosporidium spp. are notifiable as causative agents of human infection in UK, even if, there is no legal obligation to report outbreaks apart from those that are considered food-borne ( Boudou et al, 2021 ; Chalmers et al, 2019 ). Considering cryptosporidiosis in France as a notifiable disease together with a stronger implication from public health agencies could greatly improve reporting.…”

Sporadic Shiga Toxin–Producing Escherichia coli–Associated Pediatric Hemolytic Uremic Syndrome, France, 2012–2021

“…We performed space–time scans over the 10-year study period and annually. On the basis of the results of annual space–time scans, we calculated the cluster recurrence index developed by Boudou et al to identify geographic areas where significant clusters occurred at least once during the study period ( 10 ). We conducted all statistical analyses by using R version 4.2 and SaTScan version 9.7 ( 17 ).…”

Spatio-temporal evolution of COVID-19 in the Republic of Ireland and the Greater Dublin Area (March to November 2020): A space-time cluster frequency approach

“… Flaxman et al, 2020 , Ghosh et al, 2021 , Adams-Prassl et al, 2022 , Ghosh and Cartone, 2020 , Güemes et al, 2021 , Haase and Pratschke, 2005 , Hesse and Rafferty, 2020 , Kulldorff, 2018 , Kulldorff et al, 2005 , Alfano and Ercolano, 2020 , Mingolla and Lu, 2022 , Talic et al, 2021 , Boudou et al, 2021 …”