Substantial impact of the COVID-19 pandemic on the reported number of diagnosed chronic hepatitis C virus infections in the Netherlands, 2019-2021.

BACKGROUND: The COVID-19 pandemic has widespread consequences for health facilities, social contacts, and health-seeking behaviour, affecting the incidence, diagnosis and reporting of other infectious diseases. We examined trends in reported chronic hepatitis C virus (HCV) infections and associated transmission routes in the Netherlands to identify the potential impact of COVID-19 on access to healthcare (testing) services. METHODS: We analysed notification data of patients with chronic HCV reported to the National Notifiable Disease Surveillance System from January 2019 until December 2021 in the Netherlands. Rates of newly reported chronic cases per 100,000 population with 95% confidence intervals (CI) were calculated, and we compared proportional changes in transmission routes for chronic HCV between 2019, 2020 and 2021. RESULTS: During the study period, a total of 1,521 chronic HCV infections were reported, 72% males, median age 52 years, and an overall rate of 8.8 (95%CI 8.4-9.2) per 100,000 population. We observed an overall decline (-41.9%) in the number of reported chronic HCV in 2020 compared to 2019, with the sharpest decline in men who have sex with men (MSM)-related transmission (-57.9% in 2020, p = 0.005). CONCLUSIONS: Reported cases of chronic HCV strongly declined during the COVID-19 pandemic when healthcare services were scaled down. Between February and June 2021, reported chronic HCV cases increased again, indicating a recovery of healthcare services. MSM showed the largest decline compared to other groups. Further research is needed to fully understand the impact of access to healthcare, health seeking behaviour, and (sexual) transmission risks of HCV during the COVID-19 pandemic.

Risk factors for developing acute gastrointestinal, skin or respiratory infections following obstacle and mud run participation, the Netherlands, 2017.

BackgroundIn the Netherlands, obstacle, mud and survival runs are increasingly popular. Although outbreaks of gastroenteritis have been reported following these events, associated health risks have not been systematically assessed.AimTo investigate the incidence of acute gastrointestinal infections (AGI), skin infections (SI) and respiratory infections (RI) among obstacle run participants, as well as risk factors.MethodsBetween April and October 2017, we conducted a retrospective cohort study among 2,900 participants of 17 obstacle runs in the Netherlands. Demographic, symptomatic and behavioural data were collected from participants via an online questionnaire 1 week after participation in an obstacle run. Stool specimens were obtained from respondents for microbiological tests. Adjusted relative risks (aRR) and 95% confidence intervals (CI) using multilevel binomial regression analysis were calculated.ResultsOf 2,646 respondents (median age: 33 years; 53% male), 76 had AGI after the obstacle run; ingesting mud was associated with AGI (aRR: 1.7; 95% CI: 1.2-4.9) and 38 respondents had AGI during or in the week before the obstacle run. Overall, 103 respondents reported SI and 163 RI. Rinsing off in a hot tub was associated with SI (aRR: 2.2; 95% CI: 1.7-2.8). Of 111 stool specimens, 13 tested positive for six different pathogens. No clusters were found.ConclusionThe reported incidence of AGI, SI and RI was low. Risk of these infections could be decreased by informing participants on preventive measures, e.g. showering vs rinsing in the hot tub, avoiding ingesting mud and not participating with symptoms of AGI.

[Gastroenteritis at sporting events with water and mud: an example to illustrate outbreak investigation methods]. / Gastro-enteritis bij sportevenementen met water en modder.

OBJECTIVE To determine the size and causative pathogen of the outbreak and to identify risk factors for developing gastroenteritis among participants of the Survivalrun in Udenhout in September 2016. Design Retrospective cohort study. METHODS We sent an invitation to go to an online questionnaire to participants and volunteers of the Survivalrun by email. The link to the questionnaire was also shared on the Facebook page and website of the Survivalrun. We calculated attack rates (AR) and relative risks (RR) for several exposures to identify risk factors for developing diarrhoea and/or vomiting within 3 days after the run. In addition, stool samples of six participants were tested for common gastrointestinal pathogens. RESULTS A total of 444 people completed the questionnaire. Symptoms of gastroenteritis were reported by 163 study participants (37%). Five participants reported symptoms of gastroenteritis in the week before and three participants during the Survivalrun. Multivariate analysis identified the following risk factors for developing gastroenteritis: participation on the second day of the run(RR 2.4: 95% CI 1.1-5.3), ingesting water (RR 1.7: 95% CI 1.3-2.3) and ingesting mud (RR 1.3: 95% CI 1.1-1.6). Four out of six stool samples tested positive for norovirus (various types). CONCLUSION This outbreak investigation shows that pathogens, such as norovirus, can easily spread during sporting events where participants have to move through water and mud. Specific methods and knowledge of the circumstances are essential for a thorough outbreak investigation.