Bus Riding as Amplification Mechanism for SARS-CoV-2 Transmission, Germany, 20211.

To examine the risk associated with bus riding and identify transmission chains, we investigated a COVID-19 outbreak in Germany in 2021 that involved index case-patients among bus-riding students. We used routine surveillance data, performed laboratory analyses, interviewed case-patients, and conducted a cohort study. We identified 191 case-patients, 65 (34%) of whom were elementary schoolchildren. A phylogenetically unique strain and epidemiologic analyses provided a link between air travelers and cases among bus company staff, schoolchildren, other bus passengers, and their respective household members. The attack rate among bus-riding children at 1 school was ≈4 times higher than among children not taking a bus to that school. The outbreak exemplifies how an airborne agent may be transmitted effectively through (multiple) short (<20 minutes) public transport journeys and may rapidly affect many persons.

Incidence of notified Lyme borreliosis in Germany, 2013-2017.

Lyme borreliosis (LB) is the most commonly reported tick-borne disease in Germany. In 9/16 states, notification of erythema migrans (EM), acute neuroborreliosis (NB) and Lyme arthritis (LA) is mandatory. We describe incidence measures, time trends, geographical distribution and frequencies of manifestations to better understand LB epidemiology and target prevention measures. We used cases notified in the 9 states and confirmed by local health offices, 2013-2017, to calculate incidences by time, place and person. Altogether, we observed 56,446 cases. Disease onset peaked yearly in July. Incidence ranged from 26/100,000 (2015) to 41/100,000 (2013) with mean annual incidences 2013-2017 on district level between 0.5/100,000 and 138/100,000. Median age was 54 years with peaks in boys (5-9 years, mean incidence 36/100,000) and women (50-69 years, mean incidence 57/100,000). 95% experienced EM only, 2.7% NB and 2.1% LA. 54% were female, but more men had NB (56%) and LA (53%, p < 0.001). Hospitalisation was recorded for 10% of LA and 71% of NB cases. LB remains an important public health concern in Germany with marked regional variation. To facilitate early diagnosis and treatment, health authorities should raise awareness among physicians and promote prevention strategies among the general population: tick-bite-protection, prompt tick removal and medical consultation.

Two consecutive large outbreaks of Salmonella Muenchen linked to pig farming in Germany, 2013 to 2014: Is something missing in our regulatory framework?

In 2013, raw pork was the suspected vehicle of a large outbreak (n = 203 cases) of Salmonella Muenchen in the German federal state of Saxony. In 2014, we investigated an outbreak (n = 247 cases) caused by the same serovar affecting Saxony and three further federal states in the eastern part of Germany. Evidence from epidemiological, microbiological and trace-back investigations strongly implicated different raw pork products as outbreak vehicles. Trace-back analysis of S. Muenchen-contaminated raw pork sausages narrowed the possible source down to 54 pig farms, and S. Muenchen was detected in three of them, which traded animals with each other. One of these farms had already been the suspected source of the 2013 outbreak. S. Muenchen isolates from stool of patients in 2013 and 2014 as well as from food and environmental surface swabs of the three pig farms shared indistinguishable pulsed-field gel electrophoresis patterns. Our results indicate a common source of both outbreaks in the primary production of pigs. Current European regulations do not make provisions for Salmonella control measures on pig farms that have been involved in human disease outbreaks. In order to prevent future outbreaks, legislators should consider tightening regulations for Salmonella control in causative primary production settings.

Effectiveness of routine and booster pertussis vaccination in children and adolescents, federal state of Brandenburg, Germany, 2002-2012.

BACKGROUND: In Germany, whole-cell pertussis vaccines were rapidly replaced by high-concentration acellular pertussis-containing vaccines (3+1 doses from 2 months of age) starting in 1995. Boosters were recommended for 9- to 17-year-olds (2000) and for 5- to 6-year-olds (2006). Pertussis incidence remains high despite rising vaccination coverage (VC). Therefore, we analyzed VC and vaccine effectiveness (VE) in the federal state of Brandenburg. METHODS: In a stratified case-cohort analysis, we compared VC of reported pertussis cases with VC assessed in schools and kindergartens in the following strata: Children aged 2-3 years born 2005-2009 (toddlers), 5-7 years born 1995-2006 (pre-schoolers) and 15-16 years born 1995-1996 (adolescents). We calculated VE for primary and booster vaccination using Poisson regression. RESULTS: Four-dose VE decreased from 96.9% in toddlers [95% confidence interval (CI): 72.2-99.3] to 87.8% in pre-schoolers (95% CI: 79.7-92.7) to 81.7% in adolescents (95% CI: 40.6-92.8). Four-dose VE was lower in pre-schoolers born after 1996 (75.4%) than in those born 1995-1996, ~1% and ~21% of whom had received ≥1 dose of whole-cell pertussis vaccines, respectively. VE was higher in pre-schoolers and adolescents who received a booster (92.8%and 96.5%, respectively). However, overall booster VC was only 19% and 76% in these age groups, respectively. CONCLUSIONS: We observed high VE of routine pertussis vaccination, with evidence of waning over time and improved VE after booster vaccination. Increased uptake and monitoring of recommended pertussis boosters is urgently recommended to decrease high pertussis morbidity particularly in older children and adolescents.

Home range size of willow tits: a response to winter habitat loss.

We examined the behavioral response to habitat loss and fragmentation of willow tits (Parus montanus) in winter in a mosaic forest landscape in northern Finland. We studied habitat preference, flock size and home range size of 16 flocks, half of which had their territories in forests fragmented by forestry and half in continuous forest. We predicted that birds would respond to habitat loss by enlarging their home range and/or diminishing group size. In addition, to compensate for fragmentation effects, willow tits might be expected to include more optimal habitat into their territories. Flocks included on average 3.9 birds and occupied territories of 12.6 ha. Willow tits avoided open areas (clear cuts and young sapling stands) and preferred mature forests and older sapling stands or pine bogs equally. Birds responded to habitat loss by enlarging their home ranges but not by reducing the group size. Large territories included a smaller proportion of mature forests, but the proportion of sapling and pine bog habitat did not change. Birds on territories that included a large proportion of open habitat localized their activity on several distinct habitat patches that were distributed over a wide area. We conclude that willow tits adjust territory use to compensate for the inclusion of unsuitable habitat within home ranges, and older sapling areas and pine bogs serve as surrogates for mature forests. However, birds did not enlarge the proportion of forest habitat in their territories with increasing habitat loss. Thus, our data do not suggest a strong effect of fragmentation, but imply that forestry practices reduce suitable wintering habitat and carrying capacity in the area. Thus winter habitat loss may explain the observed population decline of willow tits in Finland during recent decades.