[Pandemic 2009/10: reflections on the utility of the vaccination actions in Hesse]. / Pandemie 2009/10: Betrachtungen zum Nutzen der Impfaktion in Hessen.

In the state of Hesse (Germany) all vaccinations were administered either by the public health-care (ÖGD) or private health-care facilities and were registered by week and age group. In the following article, the benefit of the vaccination campaign will be looked at in terms of preventable consultations due to acute respiratory tract infections (AK-ARI). AK-ARI were registered with the nation-wide sentinel of the AGI. Scenarios regarding timing and age-specific coverage are modelled. The achieved timing and age distribution was compared to assumed ideal distributions, e. g., having achieved the final coverage 2 weeks before epidemic start or having applied the used vaccine exclusively for the most affected age group 5-14 years. The timing and coverage actually achieved (7% overall) prevented an estimated 1.4% or, respectively, 1.1% of the total consultation excess. With the same amount of vaccine but ideally applied at least 2 weeks -before the begin of the epidemic and exclusively to the age group of the 5- to 14-year olds, an estimated 13.9% or, respectively, 18.2% of the total excess could have been prevented. The simulated scenarios give estimations as to what benefit potentially could have been achieved during the A(H1N1)pdm09 pandemic. Both the delayed successive access to vaccine and the not ideal age distribution reduced the benefit to about 30% of the optimum. These exemplary estimates underline the importance of timeliness and valid prioritising of vaccination campaigns, although footing on just one outcome. It appears beneficial to reduce uncertainties for a solid prioritisation by, e. g., timely extended surveillance. Short-term decisions and adoptions are likely for future campaigns, e. g., due to unexpected changes in the epidemic, demanding flexibility in the application management.

[Campylobacteriosis outbreaks in the state of Hesse, Germany, 2005-2011: raw milk yet again]. / Campylobacteriose-Ausbrüche in Hessen, 2005-2011 - und immer wieder Rohmilch.

BACKGROUND: Campylobacter is the most frequently reported cause of acute infectious diarrhea in Germany. Campylobacter outbreaks are rare events. However, their investigation provides useful information on risks of infection and unused prevention potentials. METHODS: We analyzed the Hessian database for notifiable diseases for cases of campylobacteriosis reported from 2005 through 2011. For campylobacter outbreaks including five or more cases we prospectively obtained additional information from local public health authorities. RESULTS: From 2005 through 2011, 29,473 cases of campylobacteriosis were reported in Hesse, Germany (approx. 6 million inhabitants), yielding an annual incidence ranging from 53.4 to 81.4 cases per 100,000 inhabitants. Only 236 cases were part of 16 outbreaks with five or more cases. Among these, six outbreaks occurred among groups traveling outside Germany, four were associated with the consumption of raw milk. For eight outbreaks consumption of poultry was considered a probable or - based on the frequent consumption of poultry during group travel - possible vehicle of infection. Two of the raw-milk associated outbreaks were reported among two groups who visited the same farm within 18 days. Five of 14 members of several families and 77 of 117 students fell sick. The local public health authority was only informed when both groups had visited the farm. CONCLUSION: The reported outbreaks can be attributed to known risk factors for campylobacteriosis - consumption of raw milk and poultry and international travel. This underlines that prevention possibilities are insufficiently used. These include avoiding the consumption of unpasteurized milk and milk products, the hygienically correct handling of raw poultry and timely identification and notification of outbreaks to public health authorities.

[Timely registration of fatalities in the state of Hessen. Experiences during the influenza A/H1N1 pandemic]. / Zeitnahe Erfassung und Übermittlung von Todesfällen in Hessen. Eine erste Einschätzung zur Influenza-A/H1N1v-Pandemie.

Timely registration of fatalities is important for the assessment of course, extent, risk of age groups, and magnitude or severity of health threats. Nevertheless, timely data of casualties are not available on the state or national level. The current paper describes the implementation and structure of a surveillance system for the timely registration of casualties in the state of Hesse (Germany) and the experience obtained during the pandemic 2009/10. The delay of the case-based registration appears tolerable and after 2 weeks more than 80% of all deaths for a given week are registered. In 2008, the forwarding of the electronically registered data from the registry offices (95% of all cases) to the state statistical office (HSL) had been accelerated from a monthly to a weekly base. The HSL provides--on a weekly basis--this case-based data in accordance with data protection rules to the Hesse State Health Office (HLPUG, "Hessischer Landesprüfungs- und Untersuchungsamt im Gesundheitswesen"). During the pandemic, the data allowed assessment of the excess mortality with a delay of 2 weeks. No significant excess mortality was apparent; however, a slight increase was observed in the age groups 15-34, 35-49, and 50-59. Correlation of time with the severity of the A/H1N1v epidemic was not very strong. Hence, the data did not indicate an excess significantly exceeding the number of death cases registered with the mandatory reporting system of 21 cases for Hesse.

[The burden of acute gastrointestinal illness in Hesse--a telephone survey]. / Die Krankheitslast durch akute Gastroenteritiden in Hessen--ein Telefonsurvey.

INTRODUCTION: Mandatory notifications of laboratory diagnosed cases of acute gastroenteritis are essential for public health surveillance of food-borne diseases; however, reported cases represent a subset of infection in the community. We aimed to determine the magnitude and distribution of self-reported, acute gastrointestinal illness in Hesse, Germany, and to describe factors associated with seeking medical care. METHODS: We conducted a retrospective, cross-sectional telephone survey in 4 551 randomly selected households from September 2004 to August 2006. We used a standardised questionnaire to collect data on the interview partner and all children ≤ 15 years living in the household. The case definition was 3 or more loose stools or any vomiting in 24 h, during the 4 weeks preceding the interview, but excluding those with non-infectious causes. Frequency data were weighted to the Hessian population. RESULTS: Among the contacted households, 81% participated. 137 of the 2 100 children ≤ 15 years met the case definition, yielding an adjusted annual incidence rate of 0.86 (95% CI 0.72-1.03) episodes per person-year. 167 of the 4 551 study participants ≥ 16 years met the case definition, yielding an adjusted annual incidence rate of 0.46 (95% CI 0.37-0.51) episodes per person-year. This extrapolates to 807 000 (95% CI 672 000-962 000) cases of acute gastroenteritis in Hesse each year for children ≤ 15 years of age and 2 225 000 (95% CI 1 880 000-2 625 000) cases in individuals ≥ 16 years. On multivariate analysis, among individuals aged ≤ 15 years with an acute gastroenteritis, factors associated with seeking medical care included age, vomiting ≥ 3 times in 24 h, fever, and duration of illness. Among cases ≥ 16 years, duration of illness was associated with seeking medical care. Of those seeking medical care, 15% provided a stool sample. CONCLUSION: Acute gastrointestinal illness appears to pose a significant burden in the Hessian population. Cases of acute gastrointestinal illness ascertained through laboratory-based public health surveillance likely differ systematically from unreported cases. Further research into the pathogen-specific burden is needed to better target intervention strategies.

Urban-rural differences of age- and species-specific campylobacteriosis incidence, Hesse, Germany, July 2005 - June 2006.

Campylobacter infection is the most common cause of bacterial gastroenteritis worldwide. This study examines the association between campylobacteriosis incidence and degree of urbanicity in Hesse, Germany, by age and Campylobacter species. During a one-year period (July 2005­June 2006), Hessian local health authorities provided information on municipality of residence for 3,315 campylobacteriosis cases. We calculated age- and Campylobacter species-specific incidences for six levels of urbanicity, as defined by population density and accessibility of centres. For children under five years old, living in inner rural areas (incidence rate ratio (IRR): 2.9; 95% confidence interval (CI): 1.9 to 4.4) and for children aged 5­14 years living in inner rural (IRR: 2.1; 95% CI: 1.3 to 3.1) or intermediate areas (inner intermediate area IRR: 1.8; 95% CI: 1.2 to 2.7; outer intermediate area IRR: 2.1; 95% CI: 1.3 to 3.3) was associated with a statistically significantly higher campylobacteriosis risk (reference category: inner urban area). Calculations by Campylobacter species showed a higher risk of gastroenteritis due to C. coli for inhabitants (all ages) of non-urban areas. This study suggests that differences in risk factors by age, Campylobacter species and degree of urbanicity do exist. For children contact with animals or the environment may be responsible for a substantial proportion of sporadic Campylobacter infections.

[Epidemiology of severe Clostridium difficile infections in Hesse, Germany in 2008-2009]. / Schwer verlaufende Clostridium-difficile-Infektionen in Hessen 2008 - 2009.

BACKGROUND AND OBJECTIVE: Clostridium difficile is a major cause of health care associated infections in industrialized countries. During the past decade, the incidence and clinical severity of C. difficile infections (CDI) have increased markedly. This increase has been associated with the emergence of a possibly highly virulent strain, the C. difficile PCR ribotype 027. We investigated the emergence of severe CDI and the associated PCR ribotypes in Hesse, Germany. PATIENTS AND METHODS: We conducted a retrospective analysis of clinical information and ribotyping results of all cases of severe CDI that were reported to the Hesse State Health Office or sent to our microbiologic diagnostic laboratory for detection and molecular typing of C. difficile in severe cases of CDI from 01/2008 to 12/2009. The data of a of 88 patients and 50 isolates were analysed. RESULTS: 89% of patients were at least 65 years old; the mean age was 77 years. The clinical outcome was known in 85 patients. 27% had died within 30 days of the diagnosis of CDI. Ribotyping results were available in 39 and 11 patients from 2008 and 2009, respectively. The isolates were assigned to nine different ribotypes. RT 027 and RT 001 were the most frequent ribotypes with 31 and 10 isolates, respectively. All other ribotypes were isolated once or twice. CONCLUSION: Our data indicate that C. difficile RT 027 and RT 001 are prevalent in Hesse and are often associated with severe or notifiable CDI. The high prevalence of RT 027 among the reported CDI cases does not indicate a generally high prevalence of the latter strain in Hesse, because detection of RT 027 was a case definition criterion, a fact that may cause a bias in the reported data. Further investigation would help to improve our understanding of the molecular epidemiology of severe CDI and to improve the prevention strategies.

Clostridium difficile ribotypes 001, 017, and 027 are associated with lethal C. difficile infection in Hesse, Germany.

From January 2008 to April 2009, 72 cases of severe Clostridium difficile infection were reported from 18 different districts in the state of Hesse, Germany. A total of 41 C. difficile isolates from 41 patients were subjected to PCR ribotyping. PCR ribotype (RT) 027 was the most prevalent strain accounting for 24 of 41 (59%) of typed isolates, followed by RT 001 (eight isolates, 20%), RT 017 and 042 (two isolates each), and RT 003, 066, 078, 081, and RKI-034 (one isolate each). Eighteen patients had died within 30 days after admission. C. difficile was reported as underlying cause of or contributing to death in 14 patients, indicating a case fatality rate of 19%. The patients with lethal outcome attributable to C. difficile were 59-89 years-old (median 78 years). Ribotyping results were available for seven isolates associated with lethal outcome, which were identified as RT 027 in three and as RT 001 and 017 in two cases each. Our data suggest that C. difficile RT 027 is prevalent in some hospitals in Hesse and that, in addition to the possibly more virulent RT 027, other toxigenic C. difficile strains like RT 001 and 017 are associated with lethal C. difficile infections in this region.

Active immunisation during an outbreak of hepatitis A in a German day-care centre.

During an outbreak in a German day-care centre (DCC) caring for 100 children HAV vaccination was recommended for children, employees and household members of cases. A retrospective cohort study was done to evaluate vaccine uptake and identify possible risk factors for disease. Between 19 December 2004 and 30 January 2005 eight DCC children and seven household members fulfilled the case definition, i.e. had clinical hepatitis (14) or were diagnosed with asymptomatic HAV infection (1). Following the recommendation to vaccinate, given on 23 December 2004, 66.7% (46/69) of DCC children, 15.8% (29/184) of household members and 5/5 of employees were vaccinated, and three vaccinated children and two not vaccinated children fell ill. One of 11 children who received human normal immunoglobulin (HNIG) and four of 58 children who did not receive HNIG fell ill. In households in which the DCC child received HAV vaccine and/or HNIG, seven (5.6%) of 125 household members fulfilled the case definition. In households of non-immunised children none of the 59 household members fell ill. We conclude that, although most vaccinations were administered promptly, they may not have been timely enough to impact the course of the outbreak.

[Estimation of influenza vaccine effectiveness using routine surveillance data]. / Zur Schätzung der Schutzwirkung der Influenzaimpfung aus Surveillancedaten.

The continuous antigenic drift of influenza viruses requires annual adaptation of the vaccine. Protection depends largely on the match of the variants represented in the vaccine with the viruses actually known to be in circulation and may differ considerably from season to season. Therefore studies to assess the efficacy and effectiveness of the vaccine are conducted rather sporadically on an annual basis and it would be desirable to make use of routinely available data from surveillance programs. We compared two different approaches: (1) the "screening method" where cases are identified from laboratory data and controls are taken from data on vaccination rates and (2) a second method that uses the same cases, but controls were influenza-negative individuals with influenza-like illness (also identified from laboratory data). The sensitivity of the methods to confounders that were considered as relevant was tested with a simulation. Both methods were applied to the data of the German influenza surveillance data of the season 2004/2005. The estimated effectiveness over all age groups was rather low with both methods, but comparable with other estimations from the literature. We observed differences in certain age groups between the methods as well as large differences between particular age groups within one method. Possible explanations are random variations due to low numbers in age strata and other influences not yet considered. Therefore the estimations should be interpreted with care; however, relative comparisons among seasons may still be meaningful.

[Tasks, principles and methods of applied infectious disease epidemiology/field epidemiology]. / Aufgaben, Prinzipien und Methoden der angewandten/aufsuchenden Infektionsepidemiologie.

Applied infectious disease epidemiology/field epidemiology involves the application of epidemiologic methods to unexpected health problems when a rapid, on-site investigation is necessary for timely intervention. While field investigations of acute problems share the need of high methodological quality with prospectively planned studies, they may differ in several respects. In particular, because field investigations of ten start without a clear hypothesis, they may require the use of descriptive studies to generate a hypothesis before analytic studies are conducted. There also may be an immediate need to protect the population's health, pressure to intervene may conflict with the need to investigate and publicity may introduce bias. Outbreak investigations are paradigms of the use and methodology of applied infectious disease epidemiology/field epidemiology. The steps of an outbreak investigation include verification, confirming the diagnosis, developing a case definition and case finding, describing the data in terms of time, place and person, risk identification, formulating and testing of a hypothesis, planning for further studies, establishing control measures and communicating the findings.

An outbreak of viral meningitis associated with a public swimming pond.

From July to October 2001, 215 cases of aseptic meningitis occurred among the inhabitants of the German city of Kassel and neighbouring counties. A matched case-control study identified bathing in a public, nature-like pond during the beginning of the outbreak as a risk factor for disease [matched odds ratio (mOR) 44.8, 95% confidence interval (CI) 3.9-515.6]. Among bathers, patients with meningitis spent more time in the water (mOR 18.8, 95% CI 2.0-174.1) and swallowed water more frequently (mOR = 7.3, 95% CI 0.7-81.8). Of 30 cerebrospinal fluid samples tested, echovirus 30 was cultured from 16, and echovirus 13 from seven. An echovirus 30 sequence obtained from one pond water sample showed a 99% nucleotide and 100% amino-acid homology with patient isolates. This outbreak demonstrates the potential of nature-like swimming ponds to cause widespread community infection with substantial public health impact.

[Investigation of a listeriosis cluster: how complete are laboratory-based reports?]. / Untersuchung eines Listeriose-Clusters: Wie vollständig sind Labormeldungen?

BACKGROUND: In Germany, listeriosis surveillance is based on mandatory laboratory notification of Listeria monocytogenes. Local public health departments (LPHDs) forward the received reports anonymously to state public health departments (SPHDs) which send them to the national public health centre. For the 28th reporting week (RW) 2003, LPHDs reported four cases of listeriosis to the SPHD of Hesse, cumulating to 19 listeriosis cases in 2003 compared to four cases in RW 1 - 28, 2002. METHODS: To investigate this cluster, we asked LPHDs in Hesse and Lower Saxony, where a comparable increase in cases was observed, to collect food histories for the four weeks preceding illness for cases reported from 25. - 29. RW 2003. We performed laboratory-based active case detection by contacting laboratories accepting clinical specimens from Hesse, and evaluated reporting completeness at the state level for the period 1.1.2002 - 31.8.2003. RESULTS: Food histories of the eight cases interviewed did not permit to incriminate any particular food item. Of the 49 listeriosis cases identified through either LPHDs or active case detection, 29 (59 %) were reported, forwarded to the SPHD and identified through active case detection and four (8 %) were reported and forwarded, but not identified through active case detection. Four cases (8 %) were reported to three LPHDs, but not forwarded to the SPHD. These were identified through active case detection. Further twelve cases (24 %) were exclusively identified through active case detection. CONCLUSIONS: This assessment of reporting completeness suggests that the number of laboratory confirmed listeriosis cases exceeds the number registered at state level by at least 48 %. Completeness might be improved by electronic, automated reporting.

A foodborne outbreak of Salmonella enterica subsp. enterica serovar Madelia at a silver anniversary reception.

Reported here is an outbreak of Salmonella enterica subsp. enterica serovar Madelia infection that occurred among 44 persons attending a silver anniversary reception in Hesse, Germany. Isolates of Salmonella Madelia are extremely unusual, and no outbreaks associated with this serotype have been reported previously. Forty-two attendees were interviewed and information was obtained from each of them regarding demographic and clinical characteristics and food consumed at the reception. Twenty-four attendees submitted stool samples for microbiological testing, and 10 of these were culture-positive for S. Madelia. Twenty-three attendees met the case definition of infection, while 18 met the clinical case definition (i.e. vomiting or diarrhoea within 3 days of consuming food at the reception) and five had asymptomatic infection with S. Madelia. The most likely vehicles of infection were tortellini and a red pesto sauce.

Serogroup C meningococcal disease outbreak associated with discotheque attendance during carnival.

In the week following a carnival during 19-24 February 1998, an outbreak of meningococcal disease occurred in a rural German county. The available isolates belonged to phenotype C:2a:P1.2,5 and were clonally related by pulsed-field gel electrophoresis. A case-control study was done to identify risk factors for the outbreak and to define possible vaccination target groups. Five persons aged 13-16 years who fell ill during 24-27 February were included in the study. Four of 5 cases and 10 of 32 controls visited local discotheques (OR = 8.8; P = 0.06). Cases also visited discotheques more frequently than controls (chi2 for trend, P = 0.0002). Multiple discotheques during the carnival may have been predominant locations of transmission in this outbreak. Because this risk factor was limited in time, a mass community vaccination campaign was not initiated.