Epidemiologische Untersuchungen von Infektionskrankheiten, die durch Lebensmittel übertragen werden

Lebensmittelübertragende Infektionen durch kontaminierte Nahrungsmittel sind häufig und haben ein hohes Erregungspotential in der Öffentlichkeit. Ziel der Arbeiten in dieser Schrift ist die Bestimmung der Häufigkeit von lebensmittelübertragenen Infektionen und Erkrankungsfällen (Inzidenz oder Prävalenz) und die Erforschung der Krankheitsursachen, um die Präventionsmaßnahmen dieser Erkrankungen zu verbessern. Eine bundesweit durchgeführte Querschnittsstudie zur Häufigkeit und den assoziierten Faktoren von Gastroenteritiden konnte aufzeigen, dass in Deutschland jeder erwachsener Bürger pro Jahr im Durchschnitt ungefähr einen (0,95 Episoden) infektionsbedingten Durchfall durchmacht. In einer weiteren bundesweit repräsentativen Querschnittsstudie wurde anhand gewonnener Blutproben eine Prävalenz von 49,1% seropositiven Studienteilnehmern mit dem Parasiten Toxoplasma gondii bestimmt. Dieses Ergebnis war hoch im Vergleich zu ähnlichen internationalen Studien. Darüber hinaus konnte geschätzt werden, dass es jährlich 6.393 Toxoplasma gondii-Infektionen bei schwangeren Frauen gibt. Während eines großen Ausbruchs von Enterohämorrhagische Escherichia coli (EHEC) und des assoziierten Hämolytisch Urämischen Syndroms (HUS) in Deutschland im Jahr 2011 konnte eine ad Hoc durchgeführte Fall-Kontroll-Studie in Frankfurt (Main) den Einkauf an der Salatbar eines Unternehmens als assoziierten Faktor identifizieren. Dies konnte anhand der Daten aus dem bargeldlosen Bezahlsystem in zwei Kantinen ermittelt werden. Im gleichen Ausbruch konnte mittels einer ad Hoc durchgeführten retrospektiven Kohortenstudie bei den Restaurantbesuchern Sprossen auf den bestellten Gerichten als assoziierter Faktor identifiziert werden. Hierfür wurden die Daten der Menüpläne des Kochs genutzt. Durch diese Vorgehensweise konnten Schwierigkeiten mit dem Erinnerungsvermögen der Studienteilnehmer umgangen werden. In einer anderen mehrere Bundesländer betreffenden Krisensituation mit über 10.000 Gastroenteritis-Erkrankungen bei Kindern konnte durch die Implementierung einer Surveillance das Ausmaß des Ausbruchs aufgezeigt werden, sowie deren Verlauf beschrieben werden. Inspiriert von den Erfahrungen innerhalb des EHEC/HUS-Ausbruchs aus Frankfurt und Lübeck konnte in einer Studie zur Validität von Datenerhebungen von Lebensmittel-Expositionen in einer Kantine in Berlin der Anteil von Fehlklassifikationen beschrieben werden und somit die Notwendigkeit von schnellen Untersuchungen belegt werden. Die in dieser Schrift vorgestellten Arbeiten bildeten die Grundlage für konkrete Präventionsempfehlungen und waren die empirische Grundlage für Reaktionen auf bedeutende Public Health-Krisen. Das Erkrankungsrisiko durch lebensmittelübertragende Erreger in Deutschland ist signifikant. Daher müssen die Verantwortlichen im öffentlichen Gesundheitsdienst weiterhin auf große lebensmittelbedingte Ausbrüche vorbereitet sein. Entsprechend dieser Entwicklungen beschäftigt sich diese Arbeit mit epidemiologischen Aspekten dieser lebensmittelübertragener Erreger und zeigt neue Lösungsansätze für Vorgehensweisen in Ausbruchssituationen.Foodborne infections caused by contaminated foodstuffs are common and have a high potential for public attention. The aim of this work was to determine the frequency of foodborne infections and diseases cases (incidence or prevalence) and to investigate the determinants in order to improve disease prevention. A nationwide cross-sectional study on the incidence and associated factors of gastroenteritis indicates that in Germany every adult citizen experiences an average of almost one (0.95 episodes) episode of infectious diarrhea per year. In another nationwide representative cross-sectional study, a prevalence of 49.1% seropositive study participants with the parasite Toxoplasma gondii was determined on the basis of their study blood samples. This result was surprisingly high compared to similar studies in the international context. In addition, it was estimated that there are 6,393 Toxoplasma gondii-infections in pregnant women each year. During a large outbreak of Enterohaemorrhagic Escherichia coli (EHEC) and the associated Haemolytic Uraemic Syndrome (HUS) in Germany in 2011 an ad hoc case control study in Frankfurt (Main) was able to identify purchases at the salad bar of a company as an associated factor. This could be determined using the data from the cashless payment system in two company cafeterias. In the same outbreak, an ad hoc retrospective cohort study of restaurant visitors identified sprouts on the as part of the visitor’s dishes as an associated factor in Lübeck. The data from the chef's menu plans were used for this. With this method, difficulties with the memory ability of the study participants could be avoided. In another crisis situation affecting several federal states with more than 10,000 gastroenteritis diseases in children, the extent of the outbreak could be shown by the implementation of an ad hoc disease surveillance and the course of the outbreak described. Inspired by the experiences within the EHEC / HUS outbreak from Frankfurt and Lübeck, the proportion of misclassifications could be estimated in a study on the validity of recall of food exposures in a company cafeteria in Berlin and thus the need for quick examinations could be demonstrated. The work presented in this publication formed the basis for specific prevention recommendations and was the empirical basis for reactions to major public health crises. The risk of disease from foodborne pathogens in Germany is significant. Therefore, public health service must continue to be prepared for major foodborne outbreaks. In line with these developments, this work deals with epidemiological aspects of these foodborne pathogens and indicates new approaches for dealing with outbreak situations

Estimates of Toxoplasmosis Incidence Based on Healthcare Claims Data, Germany, 2011–2016

Toxoplasmosis is a zoonotic infection contracted through Toxoplasma gondii–contaminated food, soil, or water. Seroprevalence in Germany is high, but estimates of disease incidence are scarce. We investigated incidences for various toxoplasmosis manifestations using anonymized healthcare claims data from Germany for 2011–2016. Patients with a toxoplasmosis diagnosis during the annual observational period were considered incident. The estimated incidence was adjusted to the general population age/sex distribution. We estimated an annual average of 8,047 toxoplasmosis patients in Germany. The average incidence of non–pregnancy-associated toxoplasmosis patients was 9.6/100,000 population. The incidence was highest in 2011, at 10.6 (95% CI 9.4–12.6)/100,000 population, and lowest in 2016, at 8.0 (95% CI 7.0–9.4)/100,000 population. The average incidence of toxoplasmosis during pregnancy was 40.3/100,000 pregnancies. We demonstrate a substantial toxoplasmosis disease burden in Germany. Public health and food safety authorities should implement toxoplasmosis-specific prevention programs.Peer Reviewe

insights by genetic characterization

Background Giardia duodenalis is a common flagellated protozoan parasite that infects the small intestine of a wide range of vertebrate hosts. This study aimed to determine whether tracing of G. duodenalis isolates by current genetic typing tools is possible using an exemplary set of samples from infected cattle, buffalo and children from the Ismailia province, Egypt. Method A total of 804 fecal samples from ruminant animals was collected from 191 herds and 165 samples from diarrheal children below the age of 10 years. Parasites were detected in these samples using the copro-antigen RIDA®QUICK test and by real-time PCR. Samples were then genetically characterized based on the triosephosphate isomerase, glutamate dehydrogenase and β-giardin genes. Results The prevalence of G. duodenalis was 53% in ruminants and 21% in symptomatic children and infection was not positively correlated with diarrheal symptoms. Sequence typing analysis confirmed predominance of B-type sequences (>67%) in humans and E-type sequences (>81%) in ruminants over A-type sequences. For 39 samples the complete sequence information of the three marker gene fragments could be derived. Integration of the concatenated sequence information of the three marker gene fragments with the spatial data of the respective sample revealed that identical or near identical (only up to 1 out of 1358 bp different) concatenated sequencing types were spatially related in 4 out of 5 cases. Conclusion The risk of zoonotic infection emanating from ruminants even in high prevalence areas is negligible. Genetic characterization indicated a predominant anthropogenic cycle of infection within the pediatric population studied. Integration of sequence typing data with information on geographic origins of samples allows parasite sub- population tracing using current typing tools

Epidemiology of Giardia duodenalis infection in ruminant livestock and children in the Ismailia province of Egypt: insights by genetic characterization

Background: Giardia duodenalis is a common flagellated protozoan parasite that infects the small intestine of a wide range of vertebrate hosts. This study aimed to determine whether tracing of G. duodenalis isolates by current genetic typing tools is possible using an exemplary set of samples from infected cattle, buffalo and children from the Ismailia province, Egypt. Method: A total of 804 fecal samples from ruminant animals was collected from 191 herds and 165 samples from diarrheal children below the age of 10 years. Parasites were detected in these samples using the copro-antigen RIDA®QUICK test and by real-time PCR. Samples were then genetically characterized based on the triosephosphate isomerase, glutamate dehydrogenase and β-giardin genes. Results: The prevalence of G. duodenalis was 53% in ruminants and 21% in symptomatic children and infection was not positively correlated with diarrheal symptoms. Sequence typing analysis confirmed predominance of B-type sequences (>67%) in humans and E-type sequences (>81%) in ruminants over A-type sequences. For 39 samples the complete sequence information of the three marker gene fragments could be derived. Integration of the concatenated sequence information of the three marker gene fragments with the spatial data of the respective sample revealed that identical or near identical (only up to 1 out of 1358 bp different) concatenated sequencing types were spatially related in 4 out of 5 cases. Conclusion: The risk of zoonotic infection emanating from ruminants even in high prevalence areas is negligible. Genetic characterization indicated a predominant anthropogenic cycle of infection within the pediatric population studied. Integration of sequence typing data with information on geographic origins of samples allows parasite sub-population tracing using current typing tools

Lack of Evidence for Schmallenberg Virus Infection in Highly Exposed Persons, Germany, 2012

Schmallenberg virus, a novel orthobunyavirus, is spreading among ruminants, especially sheep, throughout Europe. To determine the risk for human infection, we conducted a survey among shepherds to assess possible exposure and symptoms. We also performed serologic and molecular assays. No evidence of transmission to humans was detected

Human Borna disease virus 1 (BoDV-1) encephalitis cases in the north and east of Germany

In 2021, three encephalitis cases due to the Borna disease virus 1 (BoDV-1) were diagnosed in the north and east of Germany. The patients were from the states of Thuringia, Saxony-Anhalt, and Lower Saxony. All were residents of known endemic areas for animal Borna disease but without prior diagnosed human cases. Except for one recently detected case in the state of Brandenburg, all >30 notified cases had occurred in, or were linked to, the southern state of Bavaria. Of the three detected cases described here, two infections were acute, while one infection was diagnosed retrospectively from archived brain autopsy tissue samples. One of the acute cases survived, but is permanently disabled. The cases were diagnosed by various techniques (serology, molecular assays, and immunohistology) following a validated testing scheme and adhering to a proposed case definition. Two cases were classified as confirmed BoDV-1 encephalitis, while one case was a probable infection with positive serology and typical brain magnetic resonance imaging, but without molecular confirmation. Of the three cases, one full virus genome sequence could be recovered. Our report highlights the need for awareness of a BoDV-1 etiology in cryptic encephalitis cases in all areas with known animal Borna disease endemicity in Europe, including virus-endemic regions in Austria, Liechtenstein, and Switzerland. BoDV-1 should be actively tested for in acute encephalitis cases with residence or rural exposure history in known Borna disease-endemic areas.Peer Reviewe

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

Listeriose-Ausbrüche in Deutschland – Hinweise auf geräucherte oder gebeizte Lachsprodukte als Ursache von Infektionen, Fortschreibung des Berichts aus 2021

Listeriose, verursacht durch das Bakterium Listeria (L.) monocytogenes, tritt in verschiedenen Formen auf und wird vor allem durch Konsum kontaminierter Lebensmittel übertragen. Die Krankheit ist mit teilweise schweren Verläufen und einer hohen Sterblichkeit assoziiert. Im Epidemiologischen Bulletin 3/2021 wurde ein Artikel zu 22 Listeriose-Ausbrüchen in Deutschland mit Hinweisen auf geräucherte oder gebeizte Lachsprodukte als Ursache von Infektionen publiziert. Im vorliegenden Bericht wird nun ein Update zur aktuellen Situation gegeben: Es konnten insgesamt 24 bundeslandübergreifende Listeriose-Ausbrüche mit Hinweisen auf geräucherte oder gebeizte Lachsprodukte als Ursache seit 2010 identifiziert werden. Dies sind zwei Ausbrüche mehr als im vorherigen Bericht. In den Jahren 2021 und 2022 gab es 66 Listeriose-Fälle in 15 Ausbrüchen. Die Daten bestätigen, dass geräucherte oder gebeizte Lachsprodukte in Deutschland weiterhin ein relevantes Risiko für Listeriose darstellen. Zudem ist insgesamt bei allen Listeriose-Ausbrüchen mit einer starken Untererfassung zu rechnen. Es ist deshalb davon auszugehen, dass die Erkrankungszahlen in der Bevölkerung in Deutschland deutlich höher sind.Peer Reviewe

Bakterielle Zoonosen mit Bedeutung für den öffentlichen Gesundheitsschutz in Deutschland – Vorkommen, Verbreitung und Übertragungswege

Bakterielle zoonotische Erreger sind häufig Auslöser von Erkrankungen mit teilweise schweren Verläufen. Sie sind wechselseitig zwischen Tieren (sowohl Wild- als auch Haustieren) und Menschen übertragbar. Die Transmissionswege sind sehr variabel, so kann die Übertragung u. a. durch orale Aufnahme über Lebensmittel, respiratorische Aufnahme über Tröpfchen und Aerosole sowie über Vektoren wie Zeckenstiche oder Nagerkontakte stattfinden. In diesem Zusammenhang sind auch das Auftreten und die Verbreitung von antibiotikaresistenten bakteriellen Erregern von zunehmender Bedeutung für den öffentlichen Gesundheitsschutz. Die Ausbreitung zoonotischer Erreger wird aktuell durch zahlreiche Faktoren verstärkt. Dazu gehören die Zunahme des internationalen Warenverkehrs, die Einengung der Lebensräume von Tieren und der dadurch zunehmend engere Kontakt zwischen Menschen und Wildtieren. Aber auch eine veränderte Tierhaltung in der Landwirtschaft und Klimaveränderungen können zur Ausbreitung beitragen. Der öffentliche Gesundheitsschutz und die Erforschung von Zoonosen sind deshalb von besonderer krankheitspräventiver, aber auch gesellschaftlicher, politischer und wirtschaftlicher Bedeutung. Ziel dieses Übersichtsartikels ist es, anhand von Beispielen die Spannbreite von Infektionskrankheiten darzustellen, die durch bakterielle zoonotische Erreger ausgelöst werden. Die unterschiedlichen Transmissionswege, epidemischen Potenziale und epidemiologischen Maßzahlen der beispielhaft gewählten Krankheiten sind Herausforderungen für den öffentlichen Gesundheitsdienst, den Tiergesundheitsdienst und die Lebensmittelüberwachung, deren Aufgabe es ist, die Bevölkerung vor diesen Infektionskrankheiten zu schützen.Bacterial zoonotic pathogens are often the cause of diseases, sometimes with severe outcomes. They are mutually transferable between animals (both wild and domestic) and humans. The transmission paths are very variable and include oral intake via food, respiratory infection via droplets and aerosols, or infections via vectors such as tick bites or rodent contact. Furthermore, the emergence and spread of antibiotic-resistant bacterial pathogens is of paramount public health concern. The likelihood of further spread is influenced by various factors. These include the increase in international trade, the endangerment of animal habitats, and the increasingly closer contact between humans and wild animals. Additionally, changes in livestock and climate change may also contribute. Therefore, research into zoonoses serves to protect human and animal health and is of particular social, political, and economic importance. The aim of this review article is to present the range of infectious diseases caused by bacterial zoonotic pathogens in order to provide a better understanding of the important work in public health services, animal health services, and food safety control. The different transmission routes, epidemic potentials, and epidemiological measures of the exemplary selected diseases show the challenges for the public health system to monitor and control the spread of these bacterial pathogens in order to protect the population from disease.Peer Reviewe