Effect of vaccination on severity and infectiousness of measles during an outbreak in the Netherlands, 2013-2014.

An outbreak of measles in the Netherlands in 2013-2014 provided an opportunity to assess the effect of MMR vaccination on severity and infectiousness of measles.Measles is notifiable in the Netherlands. We used information on vaccination, hospitalisation, complications, and most likely source(s) of infection from cases notified during the outbreak. When a case was indicated as a likely source for at least one other notified case, we defined it as infectious. We estimated the age-adjusted effect of vaccination on severity and infectiousness with logistic regression.Of 2676 notified cases, 2539 (94.9%) were unvaccinated, 121 (4.5%) were once-vaccinated and 16 (0.6%) were at least twice-vaccinated; 328 (12.3%) cases were reported to have complications and 172 (6.4%) cases were hospitalised. Measles in twice-vaccinated cases led less often to complications and/or hospitalisation than measles in unvaccinated cases (0% and 14.5%, respectively, aOR 0.1 (95% CI 0-0.89), P = 0.03). Of unvaccinated, once-vaccinated and twice-vaccinated cases, respectively, 194 (7.6%), seven (5.1%) and 0 (0%) were infectious. These differences were not statistically significant (P > 0.05).Our findings suggest a protective effect of vaccination on the occurrence of complications and/or hospitalisation as a result of measles and support the WHO recommendation of a two-dose MMR vaccination schedule.

[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.

A cross-sectional study to assess the long-term health status of patients with lower respiratory tract infections, including Q fever.

Patients with a lower respiratory tract infection (LRTI) might be at risk for long-term impaired health status. We assessed whether LRTI patients without Q fever are equally at risk for developing long-term symptoms compared to LRTI patients with Q fever. The study was a cross-sectional cohort design. Long-term health status information of 50 Q fever-positive and 32 Q fever-negative LRTI patients was obtained. Health status was measured by the Nijmegen Clinical Screening Instrument. The most severely affected subdomains of the Q fever-positive group were 'general quality of life' (40%) and 'fatigue' (40%). The most severely affected subdomains of the Q fever-negative group were 'fatigue' (64%) and 'subjective pulmonary symptoms' (35%). Health status did not differ significantly between Q fever-positive LRTI patients and Q fever-negative LRTI patients for all subdomains, except for 'subjective pulmonary symptoms' (P = 0·048).