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We investigated a large outbreak of SARS-CoV-2 infections among passengers and crew members (60 cases in 132 persons) on a cruise ship sailing for 7 days on rivers in the Netherlands. Whole-genome analyses suggested a single or limited number of viral introductions consistent with the epidemiologic course of infections. Although some precautionary measures were taken, no social distancing was exercised, and air circulation and ventilation were suboptimal. The most plausible explanation for introduction of the virus is by persons (crew members and 2 passengers) infected during a previous cruise, in which a case of COVID-19 had occurred. The crew was insufficiently prepared on how to handle the situation, and efforts to contact public health authorities was inadequate. We recommend installing clear handling protocols, direct contacts with public health organizations, training of crew members to recognize outbreaks, and awareness of air quality on river-cruise ships, as is customary for most seafaring cruises.

In early May 2022, a global outbreak of mpox started among persons without travel history to regions known to be enzootic for monkeypox virus (MPXV). On 8 August 2022, the Netherlands reported its 1,000th mpox case, representing a cumulative incidence of 55 per million population, one of the highest cumulative incidences worldwide. We describe characteristics of the first 1,000 mpox cases in the Netherlands, reported between 20 May and 8 August 2022, within the context of the public health response. These cases were predominantly men who have sex with men aged 31-45 years. The vast majority of infections were acquired through sexual contact with casual partners in private or recreational settings including LGBTQIA+ venues in the Netherlands. This indicates that, although some larger upsurges occurred from point-source and/or travel-related events, the outbreak was mainly characterised by sustained transmission within the Netherlands. In addition, we estimated the protective effect of first-generation smallpox vaccine against moderate/severe mpox and found a vaccine effectiveness of 58% (95% CI: 17-78%), suggesting moderate protection against moderate/severe mpox symptoms on top of any possible protection by this vaccine against MPXV infection and disease. Communication with and supporting the at-risk population in following mitigation measures remains essential.

Background: Timely administration of post-exposure prophylaxis (PEP) can prevent rabies. For non-vaccinated persons, PEP consists of multiple vaccinations and rabies immunoglobulin (RIG) on indication. Since RIG is scarce, the need for PEP could be restricted through preventing animal contact and pre-exposure vaccination. We aimed to identify determinants for possible rabies exposure among travellers to provide more targeted pre-travel advice., Method: A case-control study was performed. Cases were defined as persons with a possible rabies exposure (category II or III injury according to WHO classification guidelines) in a rabies endemic country. Controls did not report exposure during travel. Multivariable logistic regression was performed., Results: 229 cases and 1427 controls were included. Predictors (p < 0.05) of possible rabies exposure were young age, male sex, travelling to Western or Southeastern Asia, visiting a monkey park, pet ownership, previously visited the same country and considering oneself an experienced traveller. Negative predictors were travelling for business, visiting friends and relatives, and fear of animals., Conclusions: Pre-travel advice should take the identified predictors into account to provide better targeted information and pre-exposure prophylaxis., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We used national registry data on human cases of Francisella tularensis subspecies holarctica infection to assess transmission modes among all 26 autochthonous cases in the Netherlands since 2011. The results indicate predominance of terrestrial over aquatic animal transmission sources. We recommend targeting disease-risk communication toward hunters, recreationists, and outdoor professionals.

Background: Travellers to rabies endemic countries should be counselled on rabies risk and, in case of high-risk, pre-exposure vaccination is advised. However, it is not clear which travellers exactly are at high risk. In this study we determined the incidence of possible rabies exposure in travel clinic visitors and compliance with pre-travel advice., Methods: Travellers to rabies endemic countries who visited a Dutch travel clinic between September 2017 and May 2018, were invited to participate., Results: Of 980 travellers, one percent was injured by a potentially rabid animal. Compliance with advice was low as 59% reported proximity to a potentially rabid animal and only half of those exposed sought medical advice. The most important predictors of proximity to a potentially rabid animal were young age, long travel duration, visiting a monkey forest and hiking for more than one day. Travel for business was associated with lower risk., Conclusion: Despite pre-travel advice, rabies risk behaviour was high. Therefore, we would recommend to keep the threshold for pre-travel vaccination low. Pending more data on rabies exposure risk, the identified predictors of proximity to potentially rabid animals could be used to tailor indications for pre-travel rabies vaccination., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

BackgroundThe risk of contracting rabies is low for travellers. However, the number of Dutch travellers potentially exposed abroad following an animal-associated injury and needing post-exposure prophylaxis (PEP) has increased, resulting in increased costs.AimHere, we evaluated the costs and the cost-effectiveness of different pre- and post-exposure interventions in the Netherlands, taking into account the 2018 World Health Organization (WHO) recommendations for the prevention of rabies.MethodsA decision tree-based economic model was constructed. We calculated and compared the cost of different WHO pre-exposure prophylaxis (PrEP) recommendations, intramuscular vs intradermal vaccination and PEP subsequent to increased vaccination coverage in risk groups. We estimated cost-effectiveness, expressed as incremental costs per rabies immunoglobulin (RIG) administration averted, using a societal perspective. Statistical uncertainty regarding number of travellers and vaccination coverage was assessed.ResultsTotal costs at the national level were highest using previous WHO recommendations from 2012, estimated at EUR 15.4 million annually. Intradermal vaccinations in combination with the current recommendations led to the lowest costs, estimated at EUR 10.3 million. Higher vaccination uptake resulted in higher overall costs. The incremental costs per RIG administration averted varied from EUR 21,300-46,800.ConclusionsThe change in rabies PrEP and PEP recommendations in 2018 reduced total costs. Strategies with increased pre-travel vaccination uptake led to fewer RIG administrations and fewer vaccinations after exposure but also to higher total costs. Although larger scale intradermal administration of rabies vaccine can reduce total costs of PrEP and can positively influence vaccination uptake, it remains a costly intervention.

BackgroundTimely notification of infectious diseases is essential for effective disease control and needs regular evaluation.AimOur objective was to evaluate the effects that statutory adjustments in the Netherlands in 2008 and raising awareness during outbreaks had on notification timeliness.MethodsIn a retrospective analyses of routine surveillance data obtained between July 2003 and November 2017, delays between disease onset and laboratory confirmation (disease identification delay), between laboratory confirmation and notification to Municipal Health Services (notification delay) and between notification and reporting to the National Institute for Public Health and the Environment (reporting delay) were analysed for 28 notifiable diseases. Delays before (period 1) and after the law change (periods 2 and 3) were compared with legal timeframes. We studied the effect of outbreak awareness in 10 outbreaks and the effect of specific guidance messages on disease identification delay for two diseases.ResultsWe included 144,066 notifications. Average notification delay decreased from 1.4 to 0.4 days across the three periods (six diseases; p < 0.05), reporting delay decreased mainly in period 2 (from 0.5 to 0.1 days, six diseases; p < 0.05). In 2016-2017, legal timeframes were met overall. Awareness resulted in decreased disease identification delay for three diseases: measles and rubella (outbreaks) and psittacosis (specific guidance messages).ConclusionsLegal adjustments decreased notification and reporting delays, increased awareness reduced identification delays. As disease identification delay dominates the notification chain, insight in patient, doctor and laboratory delay is necessary to further improve timeliness and monitor the impact of control measures during outbreaks.

The recent epidemic of Ebola virus disease (EVD) resulted in countries worldwide to prepare for the possibility of having an EVD patient. In this study, we estimate the costs of Ebola preparedness and response borne by the Dutch health system. An activity-based costing method was used, in which the cost of staff time spent in preparedness and response activities was calculated based on a time-recording system and interviews with key professionals at the healthcare organizations involved. In addition, the organizations provided cost information on patient days of hospitalization, laboratory tests, personal protective equipment (PPE), as well as the additional cleaning and disinfection required. The estimated total costs averaged €12.6 million, ranging from €6.7 to €22.5 million. The main cost drivers were PPE expenditures and preparedness activities of personnel, especially those associated with ambulance services and hospitals. There were 13 possible cases clinically evaluated and one confirmed case admitted to hospital. The estimated total cost of EVD preparedness and response in the Netherlands was substantial. Future costs might be reduced and efficiency increased by designating one ambulance service for transportation and fewer hospitals for the assessment of possible patients with a highly infectious disease of high consequences.

A seasonal reassortant A(H1N2) influenza virus harbouring genome segments from seasonal influenza viruses A(H1N1)pdm09 (HA and NS) and A(H3N2) (PB2, PB1, PA, NP, NA and M) was identified in March 2018 in a 19-months-old patient with influenza-like illness (ILI) who presented to a general practitioner participating in the routine sentinel surveillance of ILI in the Netherlands. The patient recovered fully. Further epidemiological and virological investigation did not reveal additional cases.

Background: The Ebola outbreak in West-Africa triggered risk communication activities to promote adequate preventive behaviour in the Netherlands. Our study investigated the level of knowledge, perceptions, and media use regarding Ebola., Methods: In December 2014, an online questionnaire was administered to the Dutch population (n = 526) and Health Care Workers (HCW) (n = 760)., Results: The mean knowledge score (range 0-15) of HCW (m = 13.3;SD = 1.4) was significantly higher than the general public (m = 10.8;SD = 2.0). No significant difference was found in perceived severity and susceptibility. Perceived fear of the general public (m = 2.5; SD = 0.8) was significantly higher than among HCW (m = 2.4; SD = 0.7). Respondents primarily used television to obtain information., Conclusions: While Ebola was perceived severe, it did not lead to excessive fear or perceived susceptibility for developing the disease. Nonetheless, our research showed that knowledge with respect to human-to-human transmission is low, while this is crucial to complying with preventive measures. Our study reveals priorities for improving risk communication.

Context: During the Ebola outbreak in West Africa in 2014-2015, close cooperation between the curative sector and the public health sector in the Netherlands was necessary for timely identification, referral, and investigation of patients with suspected Ebola virus disease (EVD)., Objective: In this study, we evaluated experiences in preparedness among stakeholders of both curative and public health sectors to formulate recommendations for optimizing preparedness protocols. Timeliness of referred patients with suspected EVD was used as indicator for preparedness., Design: In focus group sessions and semistructured interviews, experiences of curative and public health stakeholders about the regional and national process of preparedness and response were listed. Timeliness recordings of all referred patients with suspected EVD (13) were collected from first date of illness until arrival in the referral academic hospital., Results: Ebola preparedness was considered extensive compared with the risk of an actual patient, however necessary. Regional coordination varied between regions. More standardization of regional preparation and operational guidelines was requested, as well as nationally standardized contingency criteria, and the National Centre for Infectious Disease Control was expected to coordinate the development of these guidelines. For the timeliness of referred patients with suspected EVD, the median delay between first date of illness until triage was 2.0 days (range: 0-10 days), and between triage and arrival in the referral hospital, it was 5.0 hours (range: 2-7.5 hours). In none of these patients Ebola infection was confirmed., Conclusions: Coordination between the public health sector and the curative sector needs improvement to reduce delay in patient management in emerging infectious diseases. Standardization of preparedness and response practices, through guidelines for institutional preparedness and blueprints for regional and national coordination, is necessary, as preparedness for emerging infectious diseases needs a multidisciplinary approach overarching both the public health sector and the curative sector. In the Netherlands a national platform for preparedness is established, in which both the curative sector and public health sector participate, in order to implement the outcomes of this study.

In October 2016, a severe infection with swine influenza A(H1N1) virus of the Eurasian avian lineage occurred in a child with a previous history of eczema in the Netherlands, following contact to pigs. The patient's condition deteriorated rapidly and required life support through extracorporeal membrane oxygenation. After start of oseltamivir treatment and removal of mucus plugs, the patient fully recovered. Monitoring of more than 80 close unprotected contacts revealed no secondary cases., (This article is copyright of The Authors, 2016.)

Introduction: Despite sustained high vaccination coverage and a national guideline by the Health Council (HC-guideline) on tetanus postexposure prophylaxis (T-PEP), tetanus sporadically occurs in the Netherlands. This study aims to assess the added value of a bedside test for tetanus immunity (Tetanos Quick Stick (TQS); Ingen BioSciences Group, France), in the context of routine T-PEP in two adult cohorts: those born before introduction of tetanus toxoid vaccination in the National Immunization Programme (NIP) in 1957 (pre-NIP-cohort; n=196) and those born after (NIP-cohort; n=405)., Methods: Adults included at the time of visiting one of three participating EDs received T-PEP as per routine recommendations. Subsequently, a nurse performed the TQS and filled in a questionnaire. We compared the indication for T-PEP based on TQS results with those based on the HC-guideline and with actually administration of T-PEP, stratified by cohort., Results: Among the pre-NIP and NIP-cohort, 16% and 9%, respectively, received T-PEP, while this was not indicated based on the HC-guideline. Furthermore, 8% and 7%, respectively, did not get T-PEP, although it was indicated by the guideline. Comparing the indication derived from the HC-guideline with TQS result found that 22% (pre-NIP-cohort) and 8% (NIP-cohort) were not eligible for T-PEP according to the HC-guideline but had a negative TQS. Conversely, 36% (pre-NIP-cohort) and 73% (NIP-cohort) were eligible for T-PEP according to the HC-guideline but had positive TQS, indicating sufficient tetanus protection., Conclusion: Use of the TQS would allow better targeting of T-PEP. Furthermore, stricter adherence to the HC-guideline can prevent overimmunisation and decrease the risk of tetanus., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Despite high vaccination coverage, a mumps outbreak that affected mainly vaccinated university students and their contacts took place in the Netherlands in the period 2009-2012. We presented university students with a hypothetical case in which we offered them a measles, mumps, and rubella (MMR) booster vaccination to control the mumps outbreak. The aim of this study was to get insight into the determinants of university students' willingness to accept this vaccination., Methods: A questionnaire containing 38 items was developed for the purpose of assessing students' willingness and the psychosocial and social demographic determinants influencing their willingness to accept an MMR booster vaccination. In addition, we explored how organisational characteristics influenced the willingness to be vaccinated. Data were collected at six Dutch universities; a total of 790 students from various faculties were invited to participate. This was a convenience sampling procedure., Results: 687 university students participated (response rate 87.0%) and 60.4% of the participants said they would be willing accept the hypothetical MMR booster vaccination. The perceived seriousness of mumps (OR 6.1) was the most important predictor of willingness to accept vaccination. Students who expected the MMR vaccination to be effective and to prevent individual illness and who believed their own vaccination would help stop the epidemic were more likely to be willing than others. The students were more willing to accept vaccination when they perceived that the social norms of significant others and the government favoured vaccination. Organisational characteristics, such as offering vaccination cost free and offering it at the university site, increased students' willingness., Conclusion: During a mumps outbreak, university students were generally willing to accept a hypothetical MMR booster vaccination. Risk perception, outcome expectations, perceived social norms, and organisational characteristics should be taken into account in the planning of any vaccination campaign for university students during an outbreak of an infectious disease.

Background: Air travel has opened up opportunities for world transportation, but has also increased infectious disease transmission and public health risks. To control disease spread, airlines and governments are able to implement control measures in air travel. This study inventories experiences and applicability of infectious disease control measures., Methods: A literature search was performed in PubMed, including studies between 1990 and 2013. Search terms included air travel terms and intervention terms. Interventions were scored according outcome, required resources, preparation, passenger inconvenience and passenger compliance., Results: Provision of information to travelers, isolation, health monitoring, hygiene measures and vector control reportedly prevent disease spread and are well applicable. Contact tracing can be supportive in controlling disease spread but depend on disease characteristics. Exit and entry screening, quarantine and travel restrictions are unlikely to be very effective in preventing disease spread, while implementation requires extensive resources or travel implications., Conclusions: Control measures should focus on providing information towards travelers, isolation, health monitoring and hygiene measures. Appropriateness of measures depends on disease characteristics, and the required resources. As most studies analyze one type of measure in a particular situation, further research comparing the effectiveness of measures is recommended., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10.2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations.

Two Dutch travellers were infected with oseltamivir-resistant influenza A(H1N1)pdm09 viruses with an H275Y neuraminidase substitution in early August 2012. Both cases were probably infected during separate holidays at the Catalonian coast (Spain). No epidemiological connection between the two cases was found, and neither of them was treated with oseltamivir before specimen collection. Genetic analysis of the neuraminidase gene revealed the presence of previously described permissive mutations that may increase the likelihood of such strains emerging and spreading widely.

In February 2012 a rabid puppy dog was imported into Amsterdam, the Netherlands from Morocco via Spain. In a joint action between the Netherlands’ Food and Consumer Product Safety Authority, the Public Health Service of Amsterdam and the Centre for Infectious Disease Control all exposed human and animal contacts were traced and, when necessary, provided with post-exposure prophylaxis. During the importation, the international legislations with respect to vaccination requirements were not fully obeyed by veterinarians and custom services.

Between April and May 2010, several medical microbiological laboratories in the Netherlands notified a total of 90 cases of Salmonella enterica serovar Typhimurium with the same antibiogram type (resistant for ampicillin, tetracycline, and co-trimoxazol) and the same multiple locus variable number tandem repeats analysis pattern (03-16-09-NA-311) or single locus variants. Date of illness onset ranged from end of March to mid-May with a peak in the second week of April. Almost half of the cases were hospitalized. Cases completed a questionnaire about food items and other risk factors in the 7 days before illness onset. A matched case-control study was performed. Consumption of "ossenworst" (matched odds ratio 48.2 [95% confidence interval (CI): 3.9-595.9]) and filet américain (8.5 [95% CI: 1.0-73.6]) were found to be significant risk factors for illness. Eighty percent of the cases had eaten at least one or both raw meat products. The producer of the ground beef that was used to produce the "ossenworst" was identified, but no microbiological evidence was found. Consumers should be made more aware of the presence of raw meat in ready-to-eat products and of the potential risk in eating these products. Vulnerable persons such as young children, elderly, and persons with poor health should be discouraged from eating these products. Detection of this outbreak was mainly based on the antibiogram pattern that had identified possible cases 10 days before detailed typing results from the reference laboratory became available, thus facilitating early case findings.

After vaccination of Dutch children against mumps started in 1987 through the National Immunisation Programme the incidence of mumps decreased greatly. However, outbreaks of mumps have been occurring since the end of 2009, especially among students. We describe a vaccinated 20-year-old woman with uncomplicated mumps, a vaccinated 20-year-old student with mumps orchitis, and an unvaccinated 14-year-old boy who developed one-sided permanent deafness as a complication of mumps. Mumps outbreaks are likely caused by factors including incomplete protection following vaccination, waning of immunity, and intensive crowding. Mumps currently affects mainly people who were vaccinated more than 10 years ago. Outbreak response concentrates on surveillance, outbreak investigations, disease awareness, and provision of catch up vaccination to unvaccinated or incompletely vaccinated students. Adequate surveillance, important for building evidence for possible changes in mumps vaccination recommendations, depends on recognizing mumps and its complications.

Background: During the initial containment phase of influenza A/H1N1 2009, close contacts of cases were traced to provide antiviral prophylaxis within 48 h after exposure and to alert them on signs of disease for early diagnosis and treatment. Passengers seated on the same row, two rows in front or behind a patient infectious for influenza, during a flight of ≥ 4 h were considered close contacts. This study evaluates the timeliness of flight-contact tracing (CT) as performed following national and international CT requests addressed to the Center of Infectious Disease Control (CIb/RIVM), and implemented by the Municipal Health Services of Schiphol Airport., Methods: Elapsed days between date of flight arrival and the date passenger lists became available (contact details identified - CI) was used as proxy for timeliness of CT. In a retrospective study, dates of flight arrival, onset of illness, laboratory diagnosis, CT request and identification of contacts details through passenger lists, following CT requests to the RIVM for flights landed at Schiphol Airport were collected and analyzed., Results: 24 requests for CT were identified. Three of these were declined as over 4 days had elapsed since flight arrival. In 17 out of 21 requests, contact details were obtained within 7 days after arrival (81%). The average delay between arrival and CI was 3,9 days (range 2-7), mainly caused by delay in diagnosis of the index patient after arrival (2,6 days). In four flights (19%), contacts were not identified or only after > 7 days. CI involving Dutch airlines was faster than non-Dutch airlines (P < 0,05). Passenger locator cards did not improve timeliness of CI. In only three flights contact details were identified within 2 days after arrival., Conclusion: CT for influenza A/H1N1 2009 among flight passengers was not successful for timely provision of prophylaxis. CT had little additional value for alerting passengers for disease symptoms, as this information already was provided during and after the flight. Public health authorities should take into account patient delays in seeking medical advise and laboratory confirmation in relation to maximum time to provide postexposure prophylaxis when deciding to install contact tracing measures. International standardization of CT guidelines is recommended.

The 25 European overseas countries and territories (OCTs) are closely associated with the European Union (EU) through the four related UE Member States: Denmark, France, the Netherlands and the United Kingdom. In 2008 and 2009, these four EU Member States, in association with the European Centre for Disease Prevention and Control (ECDC), reviewed the OCTs’ needs, with the objectives of documenting their capacity to prevent and respond to infectious diseases outbreaks, and identifying deficiencies. This Euroroundup is based on the review’s main findings, and presents an overview of the OCTs’ geography and epidemiology, briefly introduces the legal basis on which they are linked to the EU and describes the surveillance and infectious disease response systems. As a result of their diversity the OCTs have heterogeneous epidemiological profiles. A common factor, however, is that the main burden of disease is non-communicable. Nevertheless, OCTs remain vulnerable to infectious diseases outbreaks. Their capacity for surveillance, early detection and response to such outbreaks is generally limited, with laboratory capacity issues and lack of human resources. Avenues for capacity strengthening should be explored by the OCTs and the related EU Member States, in collaboration with ECDC and regional public health networks where these exist.

Background: Timely reporting of infectious disease cases to public health authorities is essential to effective public health response. To evaluate the timeliness of reporting to the Dutch Municipal Health Services (MHS), we used as quantitative measures the intervals between onset of symptoms and MHS notification, and between laboratory diagnosis and notification with regard to six notifiable diseases., Methods: We retrieved reporting data from June 2003 to December 2008 from the Dutch national notification system for shigellosis, EHEC/STEC infection, typhoid fever, measles, meningococcal disease, and hepatitis A virus (HAV) infection. For each disease, median intervals between date of onset and MHS notification were calculated and compared with the median incubation period. The median interval between date of laboratory diagnosis and MHS notification was similarly analysed. For the year 2008, we also investigated whether timeliness is improved by MHS agreements with physicians and laboratories that allow direct laboratory reporting. Finally, we investigated whether reports made by post, fax, or e-mail were more timely., Results: The percentage of infectious diseases reported within one incubation period varied widely, between 0.4% for shigellosis and 90.3% for HAV infection. Not reported within two incubation periods were 97.1% of shigellosis cases, 76.2% of cases of EHEC/STEC infection, 13.3% of meningococcosis cases, 15.7% of measles cases, and 29.7% of typhoid fever cases. A substantial percentage of infectious disease cases was reported more than three days after laboratory diagnosis, varying between 12% for meningococcosis and 42% for shigellosis. MHS which had agreements with physicians and laboratories showed a significantly shorter notification time compared to MHS without such agreements., Conclusions: Over the study period, many cases of the six notifiable diseases were not reported within two incubation periods, and many were reported more than three days after laboratory diagnosis. An increase in direct laboratory reporting of diagnoses to MHS would improve timeliness, as would the use of fax rather than post or e-mail. Automated reporting systems have to be explored in the Netherlands. Development of standardised and improved measures for timeliness is needed.

In June 2008, three Dutch tourists participating in a mini-cruise in Turkey needed urgent repatriation for antitoxin treatment because of symptoms of botulism. Because there was a shortage of antitoxin in the Netherlands, an emergency delivery was requested from the manufacturer in Germany. An outbreak investigation was initiated into all nine cruise members, eight of whom developed symptoms. C. botulinum type B was isolated in stool culture from four of them. No other patients were notified locally. Food histories revealed locally purchased unprocessed black olives, consumed on board of the ship, as most likely source, but no left-overs were available for investigation. C. botulinum type D was detected in locally purchased canned peas, and whilst type D is not known to be a cause of human intoxication, its presence in a canned food product indicates an inadequate preserving process. With increasing tourism to areas where food-borne botulism is reported regularly special requests for botulism antitoxin may become necessary. Preparing an inventory of available reserve stock in Europe would appear to be a necessary and valuable undertaking.

Background: Public health measures at sea ports have posed a challenge for public health competent authorities, especially in the context of the influenza pandemic of 2009. This paper discusses the response of authorities to notifications of infectious diseases on passenger ships and the importance of assessing the risks related to cases of influenza. It further provides options for health measures and considerations for decision making during a pandemic such as the influenza pandemic of 2009., Discussion: Prevention and control of influenza have included action taken by both competent port authorities and ships' crews. Assessing the public health risk of each event reported from ships to competent authorities at ports is important before advice is given on implementation of control measures. Public health risk assessment involves appraisal of threats to passengers and crew on board the ship as well as to the population in the community., Summary: Any public health measures taken should be necessary and proportional to the threat. Measures at ports cannot alone be effective in the prevention of the spread of a disease to the community since other means of transport play a major role. Measures taken on board ships can be effective in containing the disease. Consistent policy based on common protocols and carried out by competent authorities at local, national, European, or international levels are essential.

Background: Nursing home influenza outbreaks occur in spite of established vaccination programs, and require rapid and sensitive laboratory confirmation for timely intervention., Objectives: To evaluate diagnostic approaches for rapid confirmation of nursing home influenza outbreaks., Study Design: Influenza virus real-time PCR and Directigen Flu A+B enzyme immunoassay were performed on nasopharyngeal swabs, nasopharyngeal washes and throat swabs collected from residents with clinical suspicion of influenza during seven probable nursing home outbreaks in 2004-2005 and 2005-2006. The efficacy of specimen sampling and transport management by Public Health Service outbreak team was evaluated., Results: PCR detected influenza RNA in 80% (68/85) of specimens from 81% (38/47) residents, confirming six suspected outbreaks. Immunoassay sensitivity was highest on nasopharyngeal swabs (38%; 11/29) with a positive predictive value of 100% compared to PCR. Nasopharyngeal swabs were equally sensitive to nasopharyngeal washes by PCR. Nasopharyngeal wash sampling appeared unpractical due to common underlying disability of residents. Outbreak team support was associated with a shorter time to PCR diagnosis compared to outbreaks with no logistical support (mean, 28.2h vs. 84h; P=0.05)., Conclusions: Influenza real-time PCR on nasopharyngeal swabs, obtained by Public Health Service outbreak teams, enabled rapid and sensitive confirmation of nursing home influenza outbreaks.

The influenza vaccine is considered safe, but information on vaccine-related adverse events is limited and a nationwide overview of adverse events is lacking. In 2006, after deaths occurred in Israel and the Netherlands following influenza vaccination, the Dutch Ministry of Health, Welfare and Sport (VWS) asked the National Institute for Public Health and the Environment (RIVM) twice for a recommendation regarding the continuation of the national vaccination campaign. After 4 deaths were reported in Israel in October 2006 following administration of Vaxigrip, the Dutch vaccination campaign was suspended for one week. One month later, 4 additional deaths were reported after influenza vaccination in the Netherlands. The newly appointed outbreak management team concluded that a causal relationship between vaccination and the deaths was highly unlikely, based on data regarding the individual cases, background mortality rates and prior reports of adverse events. Further suspension of the vaccination campaign was deemed unnecessary this time. A centralised nationwide registry of adverse events has since been established to provide further insight into the incidence of adverse events following influenza vaccination. Physicians are advised to report potential adverse events following influenza vaccination to the Netherlands Pharmacovigilance Centre Lareb (www.lareb.nl).

A 58-year-old woman was admitted due to a pseudomembranous pharyngitis. The patient had not been vaccinated against diphtheria. Corynebacterium ulcerans was cultured from a throat swab. The production of diphtheria toxin by these bacteria was demonstrated with PCR and an immunoprecipitation test. The patient was cared for in respiratory isolation and was treated with benzylpenicillin. She quickly recovered and was discharged four days after admission. A contact investigation did not reveal any dissemination of the toxin-producing C. ulcerans and a source was not found. In spite of the large-scale vaccination against diphtheria which has taken place in the Netherlands since 1953, a physician has to consider diphtheria in the differential diagnosis of patients who present with a clinical syndrome compatible with this disease. Either Corynebacterium diphtheriae or C. ulcerans could be the pathogen responsible.

Lassa, Ebola, Marburg and Crimean-Congo haemorrhagic fever viruses are the most important causes of viral haemorrhagic fever which is transmitted from person to person through contact with blood or excreta. A non-specific fever may be the initial symptom of viral haemorrhagic fever. By means of carefully noting where the patient has travelled, possible exposure to ill persons, vectors or an animal reservoir, and the incubation period (< or = 21 days versus longer), it is possible to estimate the risk of infection with one of these viruses. Using this approach it is possible to diagnose high-risk patients in good time and to take appropriate measures.

Two cases of Lassa fever have been reported in the Netherlands since viral haemorrhagic fevers became notifiable diseases in 1978. In 1980, an expatriate from Burkina Faso who was not seriously ill was confirmed by laboratory tests after his discharge from hospital. The second case occurred in 2000: the patient died on the 11th day of admission to hospital. The problems we faced in the management of this case and the contact investigation--more than one hundred contacts - highlighted the need for national recommendations in the Netherlands.