Campylobacteriosis in Finland: Passive Surveillance in 2004-2021 and a Pilot Case-Control Study with Whole-Genome Sequencing in Summer 2022.

Campylobacteriosis causes a significant disease burden in humans worldwide and is the most common type of zoonotic gastroenteritis in Finland. To identify infection sources for domestic Campylobacter infections, we analyzed Campylobacter case data from the Finnish Infectious Disease Register (FIDR) in 2004-2021 and outbreak data from the National Food- and Waterborne Outbreak Register (FWO Register) in 2010-2021, and conducted a pilot case-control study (256 cases and 756 controls) with source attribution and patient sample analysis using whole-genome sequencing (WGS) in July-August 2022. In the FIDR, 41% of the cases lacked information on travel history. Based on the case-control study, we estimated that of all cases, 39% were of domestic origin. Using WGS, 22 clusters of two or more cases were observed among 185 domestic cases, none of which were reported to the FWO register. Based on this case-control study and source attribution, poultry is an important source of campylobacteriosis in Finland. More extensive sampling and comparison of patient, food, animal, and environmental isolates is needed to estimate the significance of other sources. In Finland, campylobacteriosis is more often of domestic origin than FIDR notifications indicate. To identify the domestic cases, travel information should be included in the FIDR notification, and to improve outbreak detection, all domestic patient isolates should be sequenced.

Invasive listeriosis in Finland: surveillance and cluster investigations, 2011-2021.

Foodborne pathogen Listeria monocytogenes may cause serious, life-threatening disease in susceptible persons. We combined data from Finnish national listeriosis surveillance, patient interview responses, and laboratory data of patient samples and compared them to listeria findings from food and food production plants collected as part of outbreak investigations during 2011-2021. The incidence of invasive listeriosis in Finland (1.3/100000 in 2021) is higher than the EU average (0.5/100000 in 2021), and most cases are observed in the elderly with a predisposing condition. Many cases reported consuming high-risk foods as well as improper food storage. Since ongoing patient interviews and whole genome sequencing were introduced, several listeriosis outbreaks were detected and food sources identified. Recommendations about high-risk foods for listeriosis and proper food storage should be better communicated to susceptible people. In Finland, patient interviews and typing and comparing listeria isolates in foods and patient samples are crucial in solving outbreaks and determining measures to control invasive listeriosis.

Cryptosporidium parvum: an emerging occupational zoonosis in Finland.

BACKGROUND: Cryptosporidiosis has increased in recent years in Finland. We aimed to identify risk factors for human cryptosporidiosis and to determine the significance of Cryptosporidium parvum as a causative agent. Based on notifications to the Finnish Infectious Disease Register (FIDR), we conducted a case-control study and genotyped Cryptosporidium species from patient samples from July to December 2019. We also retrieved the occupational cryptosporidiosis cases from 2011 to 2019 from the Finnish Register of Occupational Diseases (FROD). RESULTS: Of 272 patient samples analyzed, 76% were C. parvum and 3% C. hominis. In the multivariable logistic regression analysis of 82 C. parvum cases and 218 controls, cryptosporidiosis was associated with cattle contact (OR 81, 95% confidence interval (CI) 26-251), having a family member with gastroenteritis (OR 34, 95% CI 6.2-186), and spending time at one's own vacation home (OR 15, 95% CI 4.2-54). Of the cases, 65% had regular cattle contact. The most common gp60 subtypes identified were IIaA15G2R1 and IIaA13G2R1. In FROD, 68 recognized occupational cryptosporidiosis cases were registered in 2011-2019. CONCLUSIONS: C. parvum is the most common Cryptosporidium species found in humans in Finland and poses a moderate to high risk of occupational infection for people working with cattle. The number of occupational notifications of cryptosporidiosis increased between 2011 and 2019. Cryptosporidiosis should be recognized as an important occupational disease among persons working with livestock in Finland, criteria to identify occupational cryptosporidiosis need to be created, and occupational safety in cattle-related work should be improved.

Cryptosporidiosis in Finland is predominantly of domestic origin: investigation of increased reporting, 1995-2020.

BACKGROUND: Cryptosporidiosis is gastroenteritis caused by Cryptosporidium. Since 2017, reporting of cryptosporidiosis has increased in Finland. METHODS: We describe demographics of cryptosporidiosis cases notified to Finnish Infectious Disease Register (FIDR) during a 21-year surveillance period, 1995-2020, and a retrospective investigation of increased cryptosporidiosis in Ostrobothnian hospital districts in summer 2018. RESULTS: Incidence of cryptosporidiosis during the period 2017-2020 represented 20-fold increase from the period 1995-2016, with the highest incidence detected in Ostrobothnia. In 2018, cryptosporidiosis in Ostrobothnia was associated with living on or visiting a farm where the production animals had diarrhoea, noticing more flies than usual, gardening or handling manure and having a family member with gastroenteritis. Four gp60 subtypes were identified in patient samples: IIaA18G1R1, IIaA15G2R1, IIaA13G2R1 and IIaA15G1R1. CONCLUSIONS: In Finland, Cryptosporidium has been included in gastrointestinal PCR diagnostic panels in most clinical laboratories since 2016. Since then, the number of reported cases has subsequently increased, indicating improved diagnostics and awareness of the illness. In 2018, several C. parvum subtypes were identified in patients suggesting that the increase was not caused by a single source. Cryptosporidiosis increased in Finland in 2020 despite hand washing recommendations and travel restrictions imposed during the COVID-19 pandemic, indicating that domestic cases are more frequent than previously considered. To monitor cause and origin of cryptosporidiosis and the effect of control measures, Cryptosporidium should be identified at subspecies level, and travel history should be included in FIDR notification. Those working with cattle and calves require precise instructions on how to prevent C. parvum infection.

Characterisation of and risk factors for extended-spectrum ß-lactamase producing Enterobacterales (ESBL-E) in an equine hospital with a special reference to an outbreak caused by Klebsiella pneumoniae ST307:CTX-M-1.

BACKGROUND: Extended-spectrum ß-lactamase producing Enterobacterales (ESBL-E) are important causative agents for infections in humans and animals. At the Equine Veterinary Teaching Hospital of the University of Helsinki, the first infections caused by ESBL-E were observed at the end of 2011 leading to enhanced infection surveillance. Contact patients were screened for ESBL-E by culturing infection sites and rectal screening. This study was focused on describing the epidemiology and microbiological characteristics of ESBL-E from equine patients of the EVTH during 2011-2014, and analysing putative risk factors for being positive for ESBL-E during an outbreak of Klebsiella pneumoniae ST307. RESULTS: The number of ESBL-E isolations increased through 2012-2013 culminating in an outbreak of multi-drug resistant K. pneumoniae ST307:blaCTX-M-1:blaTEM:blaSHV during 04-08/2013. During 10/2011-05/2014, altogether 139 ESBL-E isolates were found from 96 horses. Of these, 26 were from infection-site specimens and 113 from rectal-screening swabs. A total of 118 ESBL-E isolates from horses were available for further study, the most numerous being K. pneumoniae (n = 44), Escherichia coli (n = 31) and Enterobacter cloacae (n = 31). Hospital environmental specimens (N = 47) yielded six isolates of ESBL-E. Two identical E. cloacae isolates originating from an operating theatre and a recovery room had identical or highly similar PFGE fingerprint profiles as five horse isolates. In the multivariable analysis, mare-foal pairs (OR 4.71, 95% CI 1.57-14.19, P = 0.006), length of hospitalisation (OR 1.62, 95% CI 1.28-2.06, P < 0.001) and passing of a nasogastric tube (OR 2.86, 95% CI 1.03-7.95, P = 0.044) were associated with being positive for ESBL-E during the K. pneumoniae outbreak. CONCLUSIONS: The occurrence of an outbreak caused by a pathogenic ESBL-producing K. pneumoniae ST307 strain highlights the importance of epidemiological surveillance of ESBL-E in veterinary hospitals. Limiting the length of hospitalisation for equine patients may reduce the risk of spread of ESBL-E. It is also important to acknowledge the importance of nasogastric tubing as a potential source of acquiring ESBL-E. As ESBL-E were also found in stomach drench pumps used with nasogastric tubes, veterinary practices should pay close attention to appropriate equipment cleaning procedures and disinfection practices.