Epidemiology of campylobacteriosis in Germany – insights from 10 years of surveillance

Background: Campylobacteriosis caused by Campylobacter spp. is the most common notifiable bacterial gastrointestinal disease in Germany and a major problem in many other European countries as well. In contrast to other infectious diseases, e.g., salmonellosis, the annual number of notified campylobacteriosis cases has increased in Germany and other European countries from 2001–2010. Methods: National surveillance data from 2001 through 2010 were the basis of a detailed description of the epidemiological pattern of Campylobacter infections in Germany. Special focus was placed on geographical distribution and time trends of Campylobacter infections as well as the identification of risk groups. Results: In total, 588,308 cases of campylobacteriosis were recorded during the observed time period. The mean annual incidence increased from 67 cases/100,000 population in 2001 to 80/100,000 population in 2010. Almost 92% of the notified Campylobacter infections were acquired in Germany. A seasonal distribution was observed with a large peak in the summer months and a small peak in January. Incidence was highest in children ≤4 years and young adults 20–29 years of age. Especially young children living in rural regions in Germany seemed to be at high risk of Campylobacter infection. Conclusions: Campylobacter is the leading cause of bacterial gastroenteritis in Germany, and has been of rising public health concern. There is a need for enhanced prevention of Campylobacter infections and the data presented here may contribute to better target prevention measures with focus on identified risk groups such as children and young adults

Thermal stability of hepatitis E virus assessed by a molecular biological approach

Background: Hepatitis E virus (HEV) is a pathogen of emerging concern in industrialized countries. The consumption of wild boar meat has been identified as one risk factor for autochthonous HEV infections. Only limited information is available about thermal stability of HEV, mainly due to the lack of rapid and efficient cell culture systems for measurement of HEV infectivity. Methods: A molecular biological method was implemented in order to distinguish disassembled from intact viral particles using RNase treatment followed by quantitative real-time RT-PCR. The method was applied to a wild boar liver suspension containing HEV genotype 3. Results: Time-course analyses indicated that the decline of protected RNA could be described by a biphasic model with an initial decrease followed by a stationary phase. The stationary phase was reached after 1 hour at 4°C, 3 days at 22°C and 7 days at 37°C with log reductions of 0.34, 0.45 and 1.24, respectively. Protected RNA was detectable until the end of the experiments at day 50 or 70. Heat exposure for 1 minute resulted in a log reduction of 0.48 at 70°C and increased with higher temperatures to 3.67 at 95°C. Although HEV infectivity titration by inoculation of the liver suspension onto three cell lines did not succeed, the results of the RNase-based method are in accordance with published cell culture-based data. Conclusions: Measurement of intact viral particles using the RNase-based method may provide data on the stability of RNA viruses when cell culture-based infectivity titrations are not efficient or not available. The method enables processing of large sample numbers and may be suitable to estimate stability of HEV in different types of food

Marked Underreporting of Pertussis Requiring Hospitalization in Infants as Estimated by Capture-Recapture Methodology, Germany, 2013-2015

Background: In Germany, pertussis became notifiable in eastern federal states in 2002 and nationwide in March 2013. Infants are at greatest risk for severe disease, with a high proportion requiring hospitalization. We implemented enhanced hospital-based surveillance to estimate the incidence of pertussis requiring hospitalization among infants in Germany and to determine the proportion of infants hospitalized with pertussis too young to have been vaccinated. Methods: Enhanced surveillance was implemented within a nationwide hospital surveillance network (ESPED). We defined cases as children less than 1 year of age hospitalized due to laboratory-confirmed pertussis with disease onset from 01/07/2013-30/06/2015. We matched cases to those ascertained in the national statutory notification system, and estimated incidence using capture-recapture methodology. Results: The estimated annual incidence of pertussis requiring hospitalization in infants was 52/100,000 infants (95% confidence interval [CI] 48-57/100,000), with 39% under-reporting to the national notification system. During the two epidemiologic years under-reporting decreased from 46% to 32% and was lower in eastern than western federal states (21% vs. 40%). Within ESPED, 154 of 240 infants (64%) were younger than or still at the age recommended for the first vaccine dose;55 (23%) could have received one or more vaccine doses. Median length of hospitalization was 9 days (IQR 5-13 days) and 18% required intensive care treatment. Conclusions: Our study revealed a high burden of pertussis in infants with marked under-reporting, especially in western federal states where notification was only recently established. Strategies for the prevention of severe pertussis

Detection of hepatitis E virus in wild boars of rural and urban regions in Germany and whole genome characterization of an endemic strain

<p>Abstract</p> <p>Background</p> <p>Hepatitis E is an increasingly diagnosed human disease in Central Europe. Besides domestic pigs, in which hepatitis E virus (HEV) infection is highly prevalent, wild boars have been identified as a possible source of human infection. In order to assess the distribution of HEV in the wild boar population of Germany, we tested liver samples originating from different geographical regions for the presence of the HEV genome and compared the detected sequences to animal and human HEV strains.</p> <p>Results</p> <p>A total of 148 wild boar liver samples were tested using real-time RT-PCR resulting in an average HEV detection rate of 14.9% (95% CI 9.6–21.6). HEV was detected in all age classes and all geographical regions. However, the prevalence of HEV infection was significantly higher in rural as compared to urban regions (p < 0.001). Sequencing of the PCR products indicated a high degree of heterogenicity of the detected viruses within genotype 3 and a grouping according to their geographical origin. The whole genome sequence of an HEV isolate (wbGER27) detected in many wild boars in the federal state of Brandenburg was determined. It belongs to genotype 3i and shows 97.9% nucleotide sequence identity to a partial sequence derived from a human hepatitis E patient from Germany.</p> <p>Conclusion</p> <p>The results indicate that wild boars have to be considered as a reservoir for HEV in Germany and that a risk of HEV transmission to humans is present in rural as well as urban regions.</p

Hepatitis E virus antibody prevalence in hunters from a district in Central Germany, 2013: a cross-sectional study providing evidence for the benefit of protective gloves during disembowelling of wild boars

Background: In Germany, 17 % of the general human population have antibodies to hepatitis E virus (HEV) (recomLine HEV-IgG/IgM immunoassay [Mikrogen GmbH]). Wild boars represent an animal reservoir for HEV genotype 3, which is the common genotype in Germany. We estimated the seroprevalence among hunters with contact to wild boars to identify factors that may be associated with past or present HEV infection. Methods: In 2013, the local veterinarian authority in a district in Central Germany attended meetings of hunters who provided blood specimens and completed a questionnaire collecting information on age, sex, hunting-related activities and consumption of wild boar meat. Specimens of wild boars were taken during drive hunts in this district during the season 2012/2013. All specimens were tested for HEV RNA and anti-HEV IgM and IgG antibodies. Log-binomial regression was used to estimate prevalence ratios (PR) for the hunters. Results: Of 126 hunters (median age 55; 94 % male) 21 % tested positive for anti-HEV IgG antibodies (95 % confidence interval [CI] 13–28 %) (recomWell HEV IgG assay [Mikrogen GmbH]). Anti-HEV prevalence was highest in the age group of the 70–79-year-olds (67 %; 95 % CI 39–95 %). Wild boars showed an average anti-HEV prevalence of 41 %. HEV RNA was detected in 4/22 (18 %) liver specimens and in 1/22 (4.5 %) muscle specimens. Most wild boars were tested positive for HEV RNA (3/10; 30 %) and HEV-specific antibodies (7/15; 47 %) in the southwestern part of the district. Hunters preferring this hunting ground had a lower anti-HEV prevalence when gloves were frequently used during disembowelling of wild boars compared to hunters using gloves never or infrequently (age-adjusted PR 0.12; 95 % CI 0.02–0.86). Conclusions: Hunters may benefit from wearing gloves when in contact with blood or body fluids of HEV animal reservoirs. Anti-HEV prevalence among the hunters of this study did not significantly differ from that of the general population suggesting that other factors play a major role in the epidemiology of HEV in Germany

Novel Hepatitis E Virus Genotype in Norway Rats, Germany

Human hepatitis E virus infections may be caused by zoonotic transmission of virus genotypes 3 and 4. To determine whether rodents are a reservoir, we analyzed the complete nucleotide sequence of a hepatitis E–like virus from 2 Norway rats in Germany. The sequence suggests a separate genotype for this hepatotropic virus

Outbreak of cryptosporidium hominis following river flooding in the city of Halle (Saale), Germany, August 2013

Background: During weeks 32–33, 2013, 24 cases of cryptosporidiosis were notified in the city of Halle (annual mean 2008–2012: 9 cases). We investigated the outbreak to identify the source and recommend control measures, considering that between weeks 23–25 the river Saale which flows through the city centre overflowed the floodplain, parts of the city centre and damaged sewage systems. Methods: We defined a case as a resident of Halle with gastroenteritis, Cryptosporidium-positive stool and disease onset weeks 27 through 47. In a case–control study among kindergarten children, we compared cases and controls regarding environmental exposure, use of swimming pools, zoo visits and tap water consumption 14 days pre-onset or a corresponding 14-days-period (controls) and adjusted for residence. Stool specimens were tested by microscopy and PCR, and Cryptosporidium DNA was sequenced. Samples from public water system, swimming pools and river Saale were examined for Cryptosporidium oocysts (microscopy and PCR). Results: Overall, 167 cases were detected, 40/167 (24%) were classified as secondary cases. First disease onsets occurred during week 29, numbers peaked in week 34 and started to decrease in week 36. Median age was 8 years (range: 0–77). Compared to controls (n = 61), cases (n = 20) were more likely to report visits to previously flooded areas (OR: 4.9; 95%-CI: 1.4-18) and the zoo (OR: 2.6; 95%-CI: 0.9-7.6). In multivariable analysis visits to the floodplain remained the sole risk factor (OR: 5.5; 95%-CI: 1.4-22). Only C.hominis of a single genotype (IbA9G2) was detected in stools. Oocysts were detected in samples from the river, two local lakes and three public swimming pools by microscopy, but not in the public water supply. Conclusions: Evidence suggests that activities in the dried out floodplain led to infection among children. Secondary transmissions may be involved. Consequently, authorities recommended to avoid playing, swimming and having picnics in the flood-affected area. Health authorities should consider the potential health risks of long-term surviving parasites persisting on flooded grounds and in open waters even several weeks after the flooding and of bathing places close to sewage spill-overs. Preventive measures comprise water sampling (involving parasites), information of the public and prolonged closures of potentially contaminated sites

Untersuchung von Tierreservoiren des Hepatitis E-Virus in Deutschland

Hepatitis E is a notifiable disease in Germany, which is caused by the hepatitis E virus (HEV). In 2010, 220 hepatitis E cases have been recorded; 165 cases of these have been acquired in Germany. The reason for these cases has still to be elucidated but a zoonotic transmission seems to be likely. Wild boars and domestic pigs are worldwide regarded as the main animal reservoirs of HEV and several studies report food-borne hepatitis E cases after the consumption of undercooked or raw meat of wild boars or pigs. Other animal species, especially rats, have been discussed as HEV reservoir but so far only HEV-specific antibodies have been detected in these animals. By 2008, no data about the HEV prevalence in Germany in wild as well as domestic animals are available. Hence, the aim of the studies was to assess the HEV prevalence in different animal species in Germany, which are considered as HEV animal reservoirs, and to reveal possible zoonotic transmission routes. After the development and establishment of suitable detection methods, wild boars, domestic pigs and rats from different regions in Germany have been investigated for the presence of HEV or HEV-specific antibodies. In average, 14.9% (22/148) of the investigated wild boar liver samples have been tested positive for HEV RNA using real time RT-PCR. However, in the rural regions of Brandenburg and Thuringia a significantly higher prevalence rate (25.9% & 23.8%, respectively) have been found compared to the cities Berlin and Potsdam (4.1%). From the HEV positive wild boars the HEV genotypes 3a, 3c, 3h and 3i have been detected, which show a high sequence identity to human HEV strains from autochthonous hepatitis E cases. The genome of the strain wbGER27 has been sequenced completely and represents the first full-length sequence of HEV genotype 3i. In a second study, the HEV seroprevalence has been determined in domestic pigs using three different immunoassays, which results have been compared to each other. In general, the HEV seroprevalences determined ranged between 21.7% and 64.8% depending on the used immunoassay. By the development of a novel HEV broad-spectrum RT-PCR it was possible to detect for the first time an HEV-like virus in faecal samples of wild Norway rats from Germany showing about 50 to 60% sequence identity to other HEV genotypes. Using electron microscopy an HEV-like virus of 32-34 nm in diameter was demonstrated tentatively designated as rat HEV. Screening of organ samples of further wild Norway rats trapped at the same location resulted in the detection of two full-length genomic sequences of rat HEV. Phylogenetic analyses showed that rat HEV builds a separated branch between mammalian and avian HEV genotypes, probably representing a novel HEV genotype. Using a specific real time RT-PCR for rat HEV and immunohistochemical methods a hepatotropism of rat HEV could be revealed. In summary, in wild boars and domestic pigs HEV or HEV-specific antibodies have been detected; in rats an HEV-like virus has been discovered. Thus, a zoonotic HEV transmission from animal reservoirs to humans might be possible in Germany. Further studies are needed, investigating the presence of infectious HEV in meat of wild boars and domestic pigs and assessing the transmissibility of rat HEV from rats to humans. In addition, rat HEV might be used for the establishment of a rodent model for human hepatitis E. Using such a rodent model, the efficiency of different transmission routes may be assessed. Finally, other animal species should be screened for the presence of HEV-like viruses using the novel detection methods.Hepatitis E ist eine in Deutschland meldepflichtige Krankheit, die durch Hepatitis E-Viren (HEV) ausgelöst wird. Im Jahr 2010 wurden 220 Hepatitis E-Fälle an das Robert Koch-Institut (RKI) übermittelt, wovon 165 Fälle in Deutschland erworben wurden. Die Ansteckungsquelle dieser Fälle ist zurzeit unbekannt, es wird aber eine zoonotische Übertragung diskutiert. Wildschweine und Hausschweine gelten weltweit als die wichtigsten Tierreservoire für HEV; in mehreren Studien wurde von Hepatitis E-Fällen berichtet, die auf den Verzehr von HEV-kontaminiertem Wildschwein- oder Schweinefleisch zurückzuführen waren. Bei anderen Tieren, speziell bei Ratten, konnten bislang nur HEV-spezifische Antikörper nachgewiesen werden. Bis 2008 waren keine Daten zur HEV-Prävalenz in deutschen Haus- und Wildtieren verfügbar. Im Rahmen dieser Dissertation sollte eine erste Einschätzung der HEV-Prävalenz in Deutschland bei verschiedenen Tierarten, die als HEV-Reservoir dienen können, erfolgen, um mögliche Übertragungswege aufzudecken. In verschiedenen Studien wurden hierzu Nachweissysteme entwickelt und nachfolgend Wildschweine, Hausschweine sowie Ratten aus unterschiedlichen Regionen in Deutschland auf HEV oder HEV-spezifische Antikörper untersucht. Mittels Real-time RT-PCR konnte in 14,9 % (22/ 148) der untersuchten Wildschwein-Leberproben HEV RNA detektiert werden. Die Nachweisrate lag in den ländlichen Regionen in Brandenburg und Thüringen (25,9 % bzw. 23,8 %) dabei signifikant höher als in den Städten Berlin und Potsdam (4,1 %). Die detektierten Genotypen 3a, 3c, 3h und 3i zeigten starke Sequenzhomologien zu humanen HEV-Stämmen von autochthonen Hepatitis E-Fällen. Das Genom des HEV-Stammes wbGER27 wurde komplett sequenziert und stellt somit die erste vollständige Nukleotidsequenz des Genotyps 3i dar. In einer zweiten Studie wurde die HEV-Seroprävalenz in deutschen Hausschweinen untersucht. Die Ergebnisse von drei verschiedenen Immunoassays wurden dabei miteinander verglichen. Die Seroprävalenzen waren generell hoch, schwankten jedoch zwischen 21,7 % und 64,8 % abhängig vom verwendeten Assay. Durch die Entwicklung einer Breitspektrum-nested RT-PCR für HEV konnte zum ersten Mal ein Hepatitis E-ähnliches Virus in Kotproben von Wanderratten in Deutschland nachgewiesen werden. Elektronenmikroskopische Aufnahmen zeigen ein HEV-ähnliches Virus von 32-34 nm Größe. Dieses Virus wird vorläufig als rat HEV bezeichnet und zeigt etwa 50-60 % Sequenzhomologien zu den anderen HEV-Genotypen. Die Untersuchung von Organproben weiterer Wanderratten aus derselben Region führte zu der Detektion von zwei weiteren rat HEV-Stämmen, deren Genom komplett sequenziert werden konnte. Phylogenetische Analysen zeigten, dass rat HEV einen separaten Zweig zwischen anderen Säuger- und aviären HEV-Stämmen bildet. Durch eine spezifische Real- time RT-PCR für rat HEV und immunhistologische Untersuchungen konnte ein Hepatotropismus des Virus festgestellt werden. Zusammenfassend konnte sowohl in Wildschweinen als auch in Hausschweinen aus Deutschland HEV direkt oder indirekt nachgewiesen werden; in Ratten wurde darüber hinaus ein HEV-ähnliches Virus entdeckt. Eine zoonotische Übertragung von HEV von den Tierreservoiren auf den Menschen scheint also in Deutschland möglich zu sein. Weitere Studien sind nötig, um zu ermitteln, inwieweit infektiöse Viren im Fleisch der Wildschweine oder Hausschweine enthalten sind und ob rat HEV auf den Menschen übertragbar ist. Rat HEV könnte zur Etablierung eines Nagermodells für die humane Hepatitis E verwendet werden. Mit einem solchen Modell wäre es unter anderem auch möglich, die Effizienz der verschiedenen Übertragungswege des HEV zu ermitteln. Mit Hilfe der neu entwickelten Nachweissysteme sollten andere Tierarten ebenfalls auf HEV-ähnliche Viren untersucht werden