Epidemiology of campylobacteriosis and acute gastroenteritis from a human and health system's perspective in Switzerland

In humans, the zoonotic disease campylobacteriosis is caused by an infection with Campylobacter spp. The infection often leads to acute gastroenteritis (AG), a syndrome which is characterised by diarrhoea, nausea and other gastrointestinal symptoms. Infectious intestinal diseases (IID) other than campylobacteriosis such as salmonellosis or norovirus infections can also result in AG. The disease and health system burden of campylobacteriosis and AG in general is considerable and around 230,000 cases of campylobacteriosis alone are recorded annually in Europe. In Switzerland, the surveillance of IID is based on a mandatory notification system for laboratory-confirmed cases of certain IIDs while there is no distinct surveillance of AG. About 7000 cases of campylobacteriosis and 1200 cases of salmonellosis are recorded annually in the Swiss notification system. Cases suffering from a mild episode of IID often do not seek health care and consequently are never diagnosed and recorded. As a result the entire disease and health system burden of AG caused by IID is unknown. The present PhD thesis assesses causes for an infection with Campylobacter spp. in wintertime and the disease and health system burden of IID and AG at the primary care level in Switzerland. Determinants for the registration of IID cases along the burden-of-illness pyramid and the case management of AG patients in primary care are also explored

Time trends of positivity rates from foodborne pathogen testing in Switzerland, 2003 to 2012

Campylobacteriosis and salmonellosis are important foodborne diseases in Europe, including in Switzerland. In 2014, notification rates for Switzerland were 92.9 per 100 000 population for campylobacteriosis and 15.2 per 100 000 population for salmonellosis. These notification rates originate from laboratory-based surveillance whereby positive test results are reported to the National Notification System for Infectious Diseases. Consequently, notification rates do not directly correspond to the disease burden among the population as the number of positive tests depends on patients' healthcare-seeking behaviour, stool sampling rates and other factors.; We assessed laboratory positivity rates (proportion of positive tests among all tests performed) of diagnostic tests for Campylobacter and Salmonella from five private laboratories in Switzerland between 2003 and 2012. We analysed demographic characteristics, temporal and spatial distribution of test numbers and positivity rates. Predictors for a positive test and disease seasonality were assessed with logistic regression analyses.; A total of 135 122 (13 095 positive) Campylobacter tests and 136 997 (2832 positive) Salmonella tests were obtained with positive tests corresponding to 20.4% and 17.2% of notified campylobacteriosis and salmonellosis cases, respectively. The number of tests conducted annually increased for both pathogens by 51% from 2003 to 2012. Annual positivity rates of Campylobacter increased from 7.6 to 11.1% and rates of Salmonella decreased from 2.7 to 1.5%. The largest increases in annual Campylobacter positivity rates were observed for patients older than 85 years (+193.7%), followed by children aged 5-9 years (+131.9%). Positivity rates and test numbers for both diseases by month or calendar week showed a distinct seasonality, with peak rates for Salmonella occurring in autumn and for Campylobacter in summer and at the turn of the year. These findings were independent of patients' age and sex.; Both positivity rates and notification rates showed increasing trends for Campylobacter and decreasing trends for Salmonella, suggesting that these trends reflect changes in disease epidemiology at population level. The continuous assessment of positivity rates remains important to appropriately interpret changes observed in the notification system especially considering the increasing use of multiplex polymerase chain reaction test panels where multiple pathogens are tested simultaneously

A tradition and an epidemic : determinants of the campylobacteriosis winter peak in Switzerland

Campylobacteriosis is the most frequently reported food borne infection in Switzerland. We investigated determinants of infections and illness experience in wintertime. A case-control study was conducted in Switzerland between December 2012 and February 2013. Cases were recruited among laboratory-confirmed campylobacteriosis patients. Population-based controls were matched according to age group, sex and canton of residence. We determined risk factors associated with campylobacteriosis, and help seeking behaviour and illness perception. The multivariable analysis identified two factors associated with an increased risk for campylobacteriosis: consumption of meat fondue (matched odds ratio [mOR] 4.0, 95 % confidence interval [CI] 2.3-7.1) and travelling abroad (mOR 2.7, 95 % CI 1.1-6.4). Univariable analysis among meat fondue consumers revealed chicken as the type of meat with the highest risk of disease (mOR 3.8, 95 % CI 1.1-13.5). Most frequently reported signs and symptoms among patients were diarrhoea (98 %), abdominal pain (81 %), fever (66 %), nausea (44 %) and vomiting (34 %). The median perceived disease severity was 8 on a 1-to-10 rating scale. Patients reported a median duration of illness of 7 days and 14 % were hospitalised. Meat fondues, mostly "Fondue chinoise", traditionally consumed during the festive season in Switzerland, are the major driver of the epidemic campylobacteriosis peak in wintertime. At these meals, individual handling and consumption of chicken meat may play an important role in disease transmission. Laboratory-confirmed patients are severely ill and hospitalisation rate is considerable. Public health measures such as decontamination of chicken meat and improved food handling behaviour at the individual level are urgently needed

Acute gastroenteritis in primary care : a longitudinal study in the Swiss Sentinel Surveillance Network, Sentinella

Acute gastroenteritis (AG) leads to considerable burden of disease, health care costs and socio-economic impact worldwide. We assessed the frequency of medical consultations and work absenteeism due to AG at primary care level, and physicians' case management using the Swiss Sentinel Surveillance Network "Sentinella".; During the 1-year, longitudinal study in 2014, 172 physicians participating in "Sentinella" reported consultations due to AG including information on clinical presentation, stool diagnostics, treatment, and work absenteeism.; An incidence of 2146 first consultations due to AG at primary care level per 100,000 inhabitants in Switzerland was calculated for 2014 based on reported 3.9 thousand cases. Physicians classified patients' general condition at first consultation with a median score of 7 (1 = poor, 10 = good). The majority (92%) of patients received dietary recommendations and/or medical prescriptions; antibiotics were prescribed in 8.5%. Stool testing was initiated in 12.3% of cases; more frequently in patients reporting recent travel. Among employees (15-64 years), 86.3% were on sick leave. Median duration of sick leave was 4 days.; The burden of AG in primary care is high and comparable with that of influenza-like illness (ILI) in Switzerland. Work absenteeism is substantial, leading to considerable socio-economic impact. Mandatory infectious disease surveillance underestimates the burden of AG considering that stool testing is not conducted routinely. While a national strategy to reduce the burden of ILI exists, similar comprehensive prevention efforts should be considered for AG

Initial values for the BTB cattle-human transmission model (S3 Supporting information).

<p>Initial values for the BTB cattle-human transmission model (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005214#pntd.0005214.s003" target="_blank">S3 Supporting information</a>).</p

Parameters of the BTB cattle-human transmission model assuming a stable prevalence (endemic stability).

<p>Parameters of the BTB cattle-human transmission model assuming a stable prevalence (endemic stability).</p

Partial rank correlation coefficients (PRCC) sensitivity analysis of time to elimination (left) and total cost (right) on parameter values.

<p>Partial rank correlation coefficients (PRCC) sensitivity analysis of time to elimination (left) and total cost (right) on parameter values.</p

Total cost of the interventions that reach elimination for different proportions of tested animals and 2mm cut-off test (yellow) and 4mm cut off test (blue).

<p>Total cost of the interventions that reach elimination for different proportions of tested animals and 2mm cut-off test (yellow) and 4mm cut off test (blue).</p