Andreas Gilsdorf

Communicable Diseases Prioritized for Surveillance and Epidemiological Research: Results of a Standardized Prioritization Procedure in Germany, 2011

Introduction To establish strategic priorities for the German national public health institute (RKI) and guide the institutes mid-term strategic decisions, we prioritized infectious pathogens in accordance with their importance for national surveillance and epidemiological research. Methods We used the Delphi process with internal (RKI) and external experts and a metric-consensus approach to score pathogens according to ten three-tiered criteria. Additional experts were invited to weight each criterion, leading to the calculation of a median weight by which each score was multiplied. We ranked the pathogens according to the total weighted score and divided them into four priority groups. Results 127 pathogens were scored. Eighty-six experts participated in the weighting; “Case fatality rate” was rated as the most important criterion. Twenty-six pathogens were ranked in the highest priority group; among those were pathogens with internationally recognised importance (e.g., Human Immunodeficiency Virus, Mycobacterium tuberculosis, Influenza virus, Hepatitis C virus, Neisseria meningitides), pathogens frequently causing large outbreaks (e.g., Campylobacter spp.), and nosocomial pathogens associated with antimicrobial resistance. Other pathogens in the highest priority group included Helicobacter pylori, Respiratory Syncytial Virus, Varicella zoster virus and Hantavirus. Discussion While several pathogens from the highest priority group already have a high profile in national and international health policy documents, high scores for other pathogens (e.g., Helicobacter pylori, Respiratory syncytial virus or Hantavirus) indicate a possible under-recognised importance within the current German public health framework. A process to strengthen respective surveillance systems and research has been started. The prioritization methodology has worked well; its modular structure makes it potentially useful for other settings.

Two clusters of human infection with influenza A/H5N1 virus in the Republic of Azerbaijan, February–March 2006

Following the appearance of influenza A/H5 virus infection in several wild and domestic bird species in the Republic of Azerbaijan in February 2006, two clusters of potential human avian influenza due to A/H5N1 (HAI) cases were detected and reported by the Ministry of Health (MoH) to the World Health Organization (WHO) Regional Office for Europe during the first two weeks of March 2006. On 15 March 2006, WHO led an international team, including infection control, clinical management, epidemiology, laboratory, and communications experts, to support the MoH in investigation and response activities. As a result of active surveillance, 22 individuals, including six deaths, were evaluated for HAI and associated risk infections in six districts. The investigations revealed eight cases with influenza A/H5N1 virus infection confirmed by a WHO Collaborating Centre for Influenza and one probable case for which samples were not available. The cases were in two unrelated clusters in Salyan (seven laboratory confirmed cases, including four deaths) and Tarter districts (one confirmed case and one probable case, both fatal). Close contact with and de-feathering of infected wild swans was considered to be the most plausible source of exposure to influenza A/H5N1 virus in the Salyan cluster, although difficulties in eliciting information were encountered during the investigation, because of the illegality of some of the activities that might have led to the exposures (hunting and trading in wild birds and their products). These cases constitute the first outbreak worldwide where wild birds were the most likely source of influenza A/H5N1 virus infection in humans. The rapid mobilisation of resources to contain the spread of influenza A/H5 in the two districts was achieved through collaboration between the MoH, WHO and its international partners. Control activities were supported by the establishment of a field laboratory with real-time polymerase chain reaction (RT-PCR) capacity to detect influenza A/H5 virus. Daily door-to-door surveillance undertaken in the two affected districts made it unlikely that human cases of influenza A/H5N1 virus infection remained undetected.

The first wave of pandemic influenza (H1N1) 2009 in Germany: From initiation to acceleration

BackgroundThe first imported case of pandemic influenza (H1N1) 2009 in Germany was confirmed in April 2009. However, the first wave with measurable burden of disease started only in October 2009. The basic epidemiological and clinical characteristics of the pandemic were analysed in order to understand the course of the pandemic in Germany.MethodsThe analysis was based on data from the case-based, mandatory German surveillance system for infectious diseases. Cases notified between 27 April and 11 November 2009 and fulfilling the case definition were included in the study.ResultsTwo time periods with distinct epidemiologic characteristics could be determined: 23,789 cases (44.1%) occurred during the initiation period (IP, week 18 to 41), and 30,179 (55.9%) during the acceleration period (AP, week 42 to 45). During IP, coinciding with school summer holidays, 61.1% of cases were travel-related and one death occurred. Strict containment efforts were performed until week 32. During AP the majority of cases (94.3%) was autochthonous, 12 deaths were reported. The main affected age group shifted from 15 to 19 years in IP to 10 to 14 years in AP (median age 19 versus 15 years; p < 0.001). The proportion of cases with underlying medical conditions increased from 4.7% to 6.9% (p < 0.001). Irrespective of the period, these cases were more likely to be hospitalised (OR = 3.6 [95% CI: 3.1; 4.3]) and to develop pneumonia (OR = 8.1 [95% CI: 6.1; 10.7]). Furthermore, young children (0 to 2 years) (OR = 2.8 [95% CI: 1.5; 5.2]) and persons with influenza-like illness (ILI, OR = 1.4 [95% CI: 1.0; 2.1]) had a higher risk to develop pneumonia compared to other age groups and individuals without ILI.ConclusionThe epidemiological differences we could show between summer and autumn 2009 might have been influenced by the school summer holidays and containment efforts. The spread of disease did not result in change of risk groups or severity. Our results show that analyses of case-based information can advise future public health measures.

Guidance for contact tracing of cases of Lassa fever, Ebola or Marburg haemorrhagic fever on an airplane: results of a European expert consultation

BackgroundTravel from countries where viral haemorrhagic fevers (VHF) are endemic has increased significantly over the past decades. In several reported VHF events on airplanes, passenger trace back was initiated but the scale of the trace back differed considerably. The absence of guidance documents to help the decision on necessity and scale of the trace back contributed to this variation.This article outlines the recommendations of an expert panel on Lassa fever, Ebola and Marburg haemorrhagic fever to the wider scientific community in order to advise the relevant stakeholders in the decision and scale of a possible passenger trace back.MethodThe evidence was collected through review of published literature and through the views of an expert panel. The guidance was agreed by consensus.ResultsOnly a few events of VHF cases during air travel are reported in literature, with no documented infection in followed up contacts, so that no evidence of transmission of VHF during air travel exists to date. Based on this and the expert opinion, it was recommended that passenger trace back was undertaken only if: the index case had symptoms during the flight; the flight was within 21 days after detection of the event; and for Lassa fever if exposure of body fluid has been reported. The trace back should only be done after confirmation of the index case. Passengers and crew with direct contact, seat neighbours (+/− 1 seat), crew and cleaning personal of the section of the index case should be included in the trace back.ConclusionNo evidence has been found for the transmission of VHF in airplanes. This information should be taken into account, when a trace back decision has to be taken, because such a measure produces an enormous work load. The procedure suggested by the expert group can guide decisions made in future events, where a patient with suspected VHF infection travelled on a plane. However, the actual decision on start and scale of a trace back always lies in the hands of the responsible people taking all relevant information into account.

Erster Erfahrungsaustausch zur H1N1-Pandemie in Deutschland 2009/2010

In April 2009 the first pandemic of the 21st century developed within a few weeks starting from Mexico. Its first wave reached Germany in autumn 2009 and was responsible for 1.8-3.5 million additional medical consultations. For the public health sector, this pandemic was one of the largest challenges of the last few decades. As a contribution to broader evaluations on national and international level, the Robert Koch Institute invited representatives from different professions involved in the pandemic response to participate in a workshop on 22-23 March 2010. This workshop was structured in short presentations, group work, and plenary discussions. Main experiences were that (a) pandemic preparedness was helpful, (b) the early warning systems were reliable, (c) vaccines were available within a few months, however, in limited amounts. Need for improvement was discussed for (a) effectiveness of vaccination logistics, (b) mechanisms for the reimbursement of the cost of vaccination, (c) availability of surveillance and monitoring systems, (d) integration of physicians in decision-making processes and health education, and (e) proactive communication strategies. Investments in the above mentioned areas can help to improve public health protection in the future.

The disease burden of hepatitis B, influenza, measles and salmonellosis in Germany: first results of the Burden of Communicable Diseases in Europe Study†

Setting priorities in the field of infectious diseases requires evidence-based and robust baseline estimates of disease burden. Therefore, the European Centre for Disease Prevention and Control initiated the Burden of Communicable Diseases in Europe (BCoDE) project. The project uses an incidence- and pathogen-based approach to measure the impact of both acute illness and sequelae of infectious diseases expressed in disability-adjusted life years (DALYs). This study presents first estimates of disease burden for four pathogens in Germany. The number of reported incident cases adjusted for underestimation served as model input. For the study period 2005-2007, the average disease burden was estimated at 33 116 DALYs/year for influenza virus, 19 115 DALYs/year for Salmonella spp., 8708 DALYs/year for hepatitis B virus and 740 DALYs/year for measles virus. This methodology highlights the importance of sequelae, particularly for hepatitis B and salmonellosis, because if omitted, the burden would have been underestimated by 98% and 56%, respectively.

Results from the First 12 Months of the National Surveillance of Healthcare Associated Outbreaks in Germany, 2011/2012

Background In August 2011, the German Protection against Infection Act was amended, mandating the reporting of healthcare associated infection (HAI) outbreak notifications by all healthcare workers in Germany via local public health authorities and federal states to the Robert Koch Institute (RKI). Objective To describe the reported HAI-outbreaks and the surveillance system’s structure and capabilities. Methods Information on each outbreak was collected using standard paper forms and notified to RKI. Notifications were screened daily and regularly analysed. Results Between November 2011 and November 2012, 1,326 paper forms notified 578 HAI-outbreaks, between 7 and 116 outbreaks per month. The main causative agent was norovirus (n = 414/578; 72%). Among the 108 outbreaks caused by bacteria, the most frequent pathogens were Clostridium difficile (25%) Klebsiella spp. (19%) and Staphylococcus spp. (19%). Multidrug-resistant bacteria were responsible for 54/108 (50%) bacterial outbreaks. Hospitals were affected most frequently (485/578; 84%). Hospital outbreaks due to bacteria were mostly reported from intensive care units (ICUs) (45%), followed by internal medicine wards (16%). Conclusion The mandatory HAI-outbreak surveillance system describes common outbreaks. Pathogens with a particular high potential to cause large or severe outbreaks may be identified, enabling us to further focus research and preventive measures. Increasing the sensitivity and reliability of the data collection further will facilitate identification of outbreaks able to increase in size and severity, and guide specific control measures to interrupt their propagation.

Serological Evidence of Asymptomatic Infections during Escherichia coli O104:H4 Outbreak in Germany in 2011

Introduction The largest known outbreak caused by a rare hybrid strain of Shiga toxin-producing E.coli (STEC) and enteroaggregative E. coli (EAEC) (E.coli O104:H4) of serotype O104:H4 occurred in Germany in 2011. Fenugreek sprouts acted as a transmission vehicle and were widely consumed in the outbreak area at the time of the epidemic. In total 3,842 people developed a clinical illness caused by this strain; however the rates of asymptomatic infections remain unclear. We aimed to develop a serological assay for detection of E.coli O104 LPS specific antibodies and to establish the post-outbreak levels of seropositivity among people with documented exposure to contaminated sprouts. Results and Discussion Developed serological assays (ELISA with 84% sensitivity, 63% specificity and Western Blot with 100% sensitivity, 82.5% specificity) identified 33% (16/49) level of asymptomatic infection. Relatively small sample size and a significant time- lapse between the onset of symptoms and serum samples collection (appr. 8 weeks) might explain the assay variability. No association was found between clinical or demographic characteristics and assay positivity. Larger studies are needed to understand the complexity of human immune response and factors influencing development of clinical symptoms. Development of intra-outbreak research plans will substantially aid the conduct of more thorough scientific investigation during an outbreak period.

[First exchange of experiences concerning the H1N1 pandemic in Germany 2009/2010: report on a workshop held March 22-23, 2010, in Berlin].

In April 2009 the first pandemic of the 21st century developed within a few weeks starting from Mexico. Its first wave reached Germany in autumn 2009 and was responsible for 1.8-3.5 million additional medical consultations. For the public health sector, this pandemic was one of the largest challenges of the last few decades. As a contribution to broader evaluations on national and international level, the Robert Koch Institute invited representatives from different professions involved in the pandemic response to participate in a workshop on 22-23 March 2010. This workshop was structured in short presentations, group work, and plenary discussions. Main experiences were that (a) pandemic preparedness was helpful, (b) the early warning systems were reliable, (c) vaccines were available within a few months, however, in limited amounts. Need for improvement was discussed for (a) effectiveness of vaccination logistics, (b) mechanisms for the reimbursement of the cost of vaccination, (c) availability of surveillance and monitoring systems, (d) integration of physicians in decision-making processes and health education, and (e) proactive communication strategies. Investments in the above mentioned areas can help to improve public health protection in the future.

Needs and obstacles of uniform immunisation schedules in the European Union

Immunisation schedules are developed by national committees on immunisation and may differ considerably between the European Union (EU) member states (MS). The European Commission has launched an initiative for a council recommendation with the aim to establish a scientifically substantiated reference childhood immunisation schedule for the EU. In our view this initiative implies the establishment of one European childhood immunisation schedule, which could lead to the perception that this schedule is the only one scientifically justified. The expectations that one uniform immunisation schedule will facilitate mobility of EU residents, improve data collection and increase vaccination coverage are either quantitatively or qualitatively not relevant or even ethically problematic. Arguments that uniform schedules would lead to lower vaccine prices and reduce the need for clinical trials appear to be more relevant but could be addressed more effectively by other measures. On the other hand the following factors may differ substantially between MS and thus support different immunisation schedules, such as (a) values and goals, (b) epidemiological situation, (c) health care delivery system, (d) logistics of vaccine delivery and (e) economic situation. We argue that uniform schedules should not be perceived as a goal in itself but rather as a possibly desired by-product following increasing agreement on goals and values between MS and improved evidence base to be used by national committees on immunisation.ZusammenfassungImpfempfehlungen werden von nationalen Impfkommissionen erarbeitet und können sich zwischen den Mitgliedsstaaten (MS) der Europäischen Union (EU) erheblich unterscheiden. Die Europäische Kommission startete eine Initiative für eine Empfehlung des Rates mit dem Ziel, einen europäischen, wissenschaftlich fundierten Referenz-Impfkalender für Kinder zu entwickeln. Unserer Meinung nach impliziert diese Initiative die Etablierung eines einzigen europäischen Impfkalenders, der als der einzig wissenschaftlich zu rechtfertigende bewertet werden könnte. Die Erwartungen, dass ein einheitlicher Impfkalender die Freizügigkeit von EU-Bewohnern erleichtern, die Datenerfassung verbessern und die Impfquote erhöhen könnte, erscheint quantitativ und qualitativ nicht relevant oder sogar ethisch bedenklich. Impfstoffpreise und der Bedarf für klinische Studien könnten durch einheitliche Impfkalender gesenkt werden, aber dies könnte durch alternative Maßnahmen sogar effektiver gelingen. Auf der anderen Seite unterscheiden sich folgende Faktoren zwischen den MS erheblich und begründen unterschiedliche Impfkalender, wie a) Werte und Zielsetzungen, b) epidemiologische Lage, c) Gesundheitsversorgungssysteme, d) Impflogistik und e) wirtschaftliche Situation. Die Vereinheitlichung von Impfkalendern sollte nicht als primäres Ziel gesehen werden, sondern allenfalls als Nebeneffekt infolge zunehmender Einigung über Ziele und Werte sowie einer verbesserten Evidenzgrundlage, die von nationalen Impfkommissionen verwendet werden könnte.