Mpox outbreak in the Netherlands, 2022: public health response, characteristics of the first 1,000 cases and protection of the first-generation smallpox vaccine.

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.

Extensive Spread of SARS-CoV-2 Delta Variant among Vaccinated Persons during 7-Day River Cruise, the Netherlands.

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.

Evaluating intra-action reviews at points of entry: ongoing learning opportunities during the COVID-19 pandemic.

BACKGROUND: Long-lasting crises, such as the COVID-19 pandemic, require proper interim evaluation in order to optimize response. The World Health Organization and the European Center for Disease Control have recently promoted the in(tra)-action review (IAR) method for this purpose. We systematically evaluated the added value of two IARs performed in the Dutch point of entry (PoE) setting. METHODS: Two online, 4-hour IAR meetings were organized in March 2021, for ports and airports respectively, to reflect on the ongoing COVID-19 response. Topics discussed were selected through a survey among participants. Participants were mainly self-selected by the (air)port public health service. Evaluation of the IAR method consisted of participant evaluation through a questionnaire, and hot and cold debriefs of the organizing team. Evaluation of the impact of the IAR was done through analysis of the meeting results, and a 3-month follow-up of the actions proposed during the meetings. RESULTS: Thirty-nine professionals joined the IAR meetings. In the participant evaluation (n = 18), 89% agreed or totally agreed the IAR made it possible to identify challenges and problems in the COVID-19 response at PoE. Participants especially appreciated the resulting insight in regional and national partners. Regarding the online setting of the meeting, participants suggested to choose accessible and familiar online tools. After 3 months, all national actions and actions for ports had been executed; some regional actions for airports required further attention. A major result was a new meeting structure for all ports and the participating national authorities in which remaining and newly occurring issues were discussed. CONCLUSIONS: Based on the evaluations, we conclude that the IAR method can be of value during long-term crises, such as the COVID-19 pandemic response. Although it is challenging to dedicate time and effort to the organization and attendance of IAR meetings during crisis, the IAR method is feasible in an online setting if appropriate organizing and technical capacity is available. A participatory set-up supports the IAR method as a starting point for continuous exchange and learning during ongoing crises.

Signalling and responding to zoonotic threats using a One Health approach: a decade of the Zoonoses Structure in the Netherlands, 2011 to 2021.

In the Netherlands, the avian influenza outbreak in poultry in 2003 and the Q fever outbreak in dairy goats between 2007 and 2010 had severe consequences for public health. These outbreaks led to the establishment of an integrated human-veterinary risk analysis system for zoonoses, the Zoonoses Structure. The aim of the Zoonoses Structure is to signal, assess and control emerging zoonoses that may pose a risk to animal and/or human health in an integrated One Health approach. The Signalling Forum Zoonoses (SO-Z), the first step of the Zoonoses Structure, is a multidisciplinary committee composed of experts from the medical, veterinary, entomology and wildlife domains. The SO-Z shares relevant signals with professionals and has monthly meetings. Over the past 10 years (June 2011 to December 2021), 390 different signals of various zoonotic pathogens in animal reservoirs and humans have been assessed. Here, we describe the Zoonoses Structure with examples from signals and responses for four zoonotic events in the Netherlands (tularaemia, Brucella canis, West Nile virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)). This may serve as an example for other countries on how to collaborate in a One Health approach to signal and control emerging zoonoses.

Estimated incubation period for monkeypox cases confirmed in the Netherlands, May 2022.

In May 2022, monkeypox outbreaks have been reported in countries not endemic for monkeypox. We estimated the monkeypox incubation period, using reported exposure and symptom-onset times for 18 cases detected and confirmed in the Netherlands up to 31 May 2022. Mean incubation period was 9.0 [corrected] days (5th-95th percentiles: 4.2-17.3), underpinning the current recommendation to monitor or isolate/quarantine case contacts for 21 days. However, as the incubation period may differ between different transmission routes, further epidemiological investigations are needed.

Tularemia Transmission to Humans, the Netherlands, 2011-2021.

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.

Rabies risk behaviour in a cohort of Dutch travel clinic visitors: A retrospective analysis.

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.

Towards defining core principles of public health emergency preparedness: scoping review and Delphi consultation among European Union country experts.

BACKGROUND: European Member States, the European Commission and its agencies work together to enhance preparedness and response for serious cross-border threats to health such as Ebola. Yet, common understanding of public health emergency preparedness across EU/EEA countries is challenging, because preparedness is a relatively new field of activity and is inherently fraught with uncertainty. A set of practical, widely accepted and easy to use recommendations for generic preparedness that bundles the activities described in separate guidance documents supports countries in preparing for any possible health threat. The aim of this consensus procedure was to identify and seek consensus from national-level preparedness experts from EU/EEA countries on key recommendations of public health emergency preparedness. METHODS: To identify key recommendations and to prioritize the recommendations we started with a literature consensus procedure, followed by a modified Delphi method for consultation of public health emergency preparedness leaders of EU/EEA countries. This consisted of six consecutive steps: a questionnaire to achieve consensus on a core set of recommendations, a face-to-face consultation, preselection of prioritized recommendations, a questionnaire to achieve consensus on the prioritized set and a face-to-face consensus meeting to further prioritize recommendations. RESULTS: As a result, EU/EEA experts selected 149 recommendations as core preparedness principles and prioritized 42. The recommendations were grouped in the seven domains: governance (57), capacity building and maintenance (11), surveillance (19), risk-assessment (16), risk- and crisis management (35), post-event evaluation (6) and implementation of lessons learned (5). CONCLUSIONS: This prioritised set of consensus principles can provide a foundation for countries aiming to evaluate and improve their preparedness for public health emergencies. The recommendations are practical, support generic preparedness planning, and can be used by all countries irrespective of their current level of preparedness.

Rabies vaccination strategies in the Netherlands in 2018: a cost evaluation.

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.

Public health response to two imported, epidemiologically related cases of Lassa fever in the Netherlands (ex Sierra Leone), November 2019.

On 20 November 2019, Lassa fever was diagnosed in a physician repatriated from Sierra Leone to the Netherlands. A second physician with suspected Lassa fever, repatriated a few days later from the same healthcare facility, was confirmed infected with Lassa virus on 21 November. Comprehensive contact monitoring involving high- and low-risk contacts proved to be feasible and follow-up of the contacts did not reveal any case of secondary transmission in the Netherlands.

Clinical Management of Argentine Hemorrhagic Fever using Ribavirin and Favipiravir, Belgium, 2020.

We report a case of Argentine hemorrhagic fever diagnosed in a woman in Belgium who traveled from a disease-endemic area. Patient management included supportive care and combination therapy with ribavirin and favipiravir. Of 137 potential contacts, including friends, relatives, and healthcare and laboratory workers, none showed development of clinical symptoms of this disease.

Qualitative Research: Institutional Preparedness During Threats of Infectious Disease Outbreaks.

BACKGROUND: As demonstrated during the global Ebola crisis of 2014-2016, healthcare institutions in high resource settings need support concerning preparedness during threats of infectious disease outbreaks. This study aimed to exploratively develop a standardized preparedness system to use during unfolding threats of severe infectious diseases. METHODS: A qualitative three-step study among infectious disease prevention and control experts was performed. First, interviews (n = 5) were conducted to identify which factors trigger preparedness activities during an unfolding threat. Second, these triggers informed the design of a phased preparedness system which was tested in a focus group discussion (n = 5) were conducted to identify which factors trigger preparedness activities during an unfolding threat. Second, these triggers informed the design of a phased preparedness system which was tested in a focus group discussion (n = 5) were conducted to identify which factors trigger preparedness activities during an unfolding threat. Second, these triggers informed the design of a phased preparedness system which was tested in a focus group discussion (. RESULTS: Four preparedness phases were identified: preparedness phase green is a situation without the presence of the infectious disease threat that requires centralized care, anywhere in the world. Phase yellow is an outbreak in the world with some likelihood of imported cases. Phase orange is a realistic chance of an unexpected case within the country, or unrest developing among population or staff; phase red is cases admitted to hospitals in the country, potentially causing a shortage of resources. Specific preparedness activities included infection prevention, diagnostics, patient care, staff, and communication. Consensus was reached on the need for the development of a preparedness system and national coordination during threats. CONCLUSIONS: In this study, we developed a standardized system to support institutional preparedness during an increasing threat. Use of this system by both curative healthcare institutions and the (municipal) public health service, could help to effectively communicate and align preparedness activities during future threats of severe infectious diseases.

Timeliness of infectious disease reporting, the Netherlands, 2003 to 2017: law change reduced reporting delay, disease identification delay is next.

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.

Exit and Entry Screening Practices for Infectious Diseases among Travelers at Points of Entry: Looking for Evidence on Public Health Impact.

A scoping search and a systematic literature review were conducted to give an insight on entry and exit screening referring to travelers at points of entry, by analyzing published evidence on practices, guidelines, and experiences in the past 15 years worldwide. Grey literature, PubMed. and Scopus were searched using specific terms. Most of the available data identified through the systematic literature review concerned entry screening measures at airports. Little evidence is available about entry and exit screening measure implementation and effectiveness at ports and ground crossings. Exit screening was part of the World Health Organisation's (WHO) temporary recommendations for implementation in certain points of entry, for specific time periods. Exit screening measures for Ebola Virus Disease (EVD) in the three most affected West African countries did not identify any cases and showed zero sensitivity and very low specificity. The percentages of confirmed cases identified out of the total numbers of travelers that passed through entry screening measures in various countries worldwide for Influenza Pandemic (H1N1) and EVD in West Africa were zero or extremely low. Entry screening measures for Severe Acute Respiratory Syndrome (SARS) did not detect any confirmed SARS cases in Australia, Canada, and Singapore. Despite the ineffectiveness of entry and exit screening measures, authors reported several important concomitant positive effects that their impact is difficult to assess, including discouraging travel of ill persons, raising awareness, and educating the traveling public and maintaining operation of flights from/to the affected areas. Exit screening measures in affected areas are important and should be applied jointly with other measures including information strategies, epidemiological investigation, contact tracing, vaccination, and quarantine to achieve a comprehensive outbreak management response. Based on review results, an algorithm about decision-making for entry/exit screening was developed.

Tick-Borne Encephalitis Virus Antibodies in Roe Deer, the Netherlands.

To increase knowledge of tick-borne encephalitis virus (TBEV) circulation in the Netherlands, we conducted serosurveillance in roe deer (Capreolus capreolus) during 2017 and compared results with those obtained during 2010. Results corroborate a more widespread occurrence of the virus in 2017. Additional precautionary public health measures have been taken.

Timeliness of notification systems for infectious diseases: A systematic literature review.

INTRODUCTION: Timely notification of infectious diseases is crucial for prompt response by public health services. Adequate notification systems facilitate timely notification. A systematic literature review was performed to assess outcomes of studies on notification timeliness and to determine which aspects of notification systems are associated with timely notification. METHODOLOGY: Articles reviewing timeliness of notifications published between 2000 and 2017 were searched in Pubmed and Scopus. Using a standardized notification chain, timeliness of reporting system for each article was defined as either sufficient (≥ 80% notifications in time), partly sufficient (≥ 50-80%), or insufficient (< 50%) according to the article's predefined timeframe, a standardized timeframe for all articles, and a disease specific timeframe. Electronic notification systems were compared with conventional methods (postal mail, fax, telephone, email) and mobile phone reporting. RESULTS: 48 articles were identified. In almost one third of the studies with a predefined timeframe (39), timeliness of notification systems was either sufficient or insufficient (11/39, 28% and 12/39, 31% resp.). Applying the standardized timeframe (45 studies) revealed similar outcomes (13/45, 29%, sufficient notification timeframe, vs 15/45, 33%, insufficient). The disease specific timeframe was not met by any study. Systems involving reporting by laboratories most often complied sufficiently with predefined or standardized timeframes. Outcomes were not related to electronic, conventional notification systems or mobile phone reporting. Electronic systems were faster in comparative studies (10/13); this hardly resulted in sufficient timeliness, neither according to predefined nor to standardized timeframes. CONCLUSION: A minority of notification systems meets either predefined, standardized or disease specific timeframes. Systems including laboratory reporting are associated with timely notification. Electronic systems reduce reporting delay, but implementation needs considerable effort to comply with notification timeframes. During outbreak threats, patient, doctors and laboratory testing delays need to be reduced to achieve timely detection and notification. Public health authorities should incorporate procedures for this in their preparedness plans.

Case of seasonal reassortant A(H1N2) influenza virus infection, the Netherlands, March 2018.

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.

Knowledge, perceptions and media use of the Dutch general public and healthcare workers regarding Ebola, 2014.

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.

Real-time Estimation of Epidemiologic Parameters from Contact Tracing Data During an Emerging Infectious Disease Outbreak.

BACKGROUND: Contact tracing can provide accurate information on relevant parameters of an ongoing emerging infectious disease outbreak. This is crucial to investigators seeking to control such an outbreak. However, crude contact tracing data are difficult to interpret and methods for analyzing these data are scarce. We present a method to estimate and visualize key outbreak parameters from contact tracing information in real time by taking into account data censoring. METHODS/RESULTS: Exposure type-specific attack rates and the reproduction number R(t) are estimated from contact tracing data by using maximum likelihood estimation to account for censored data. The attack rates reflect, in the context of contact tracing, the specificity of the contact definition; a higher value indicates relatively efficient contact tracing. The evolution of R(t) over time provides information regarding the effectiveness of interventions. To allow a real-time overview of the outbreak, the attack rates and the evolution of R(t) over time are visualized together with the case-contact network and epicurve. We applied the method to a well-documented smallpox outbreak in The Netherlands to demonstrate the added value. CONCLUSION: Our method facilitates the analysis of contact tracing information by quickly turning it into accessible information, helping outbreak investigators to make real-time decisions to more effectively and efficiently control infectious disease outbreaks.

Ebola in the Netherlands, 2014-2015: costs of preparedness and response.

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.