Influenza versus other respiratory viruses - assessing severity among hospitalised children, Belgium, 2011 to 2020.

BackgroundKnowledge on the burden attributed to influenza viruses vs other respiratory viruses in children hospitalised with severe acute respiratory infections (SARI) in Belgium is limited.AimThis observational study aimed at describing the epidemiology and assessing risk factors for severe disease.MethodsWe retrospectively analysed data from routine national sentinel SARI surveillance in Belgium. Respiratory specimens collected during winter seasons 2011 to 2020 were tested by multiplex real-time quantitative PCR (RT-qPCR) for influenza and other respiratory viruses. Demographic data and risk factors were collected through questionnaires. Patients were followed-up for complications or death during hospital stay. Analysis focused on children younger than 15 years. Binomial logistic regression was used to identify risk factors for severe disease in relation to infection status.ResultsDuring the winter seasons 2011 to 2020, 2,944 specimens met the study case definition. Complications were more common in children with underlying risk factors, especially asthma (adjusted risk ratio (aRR): 1.87; 95% confidence interval (CI): 1.46-2.30) and chronic respiratory disease (aRR: 1.88; 95% CI: 1.44-2.32), regardless of infection status and age. Children infected with non-influenza respiratory viruses had a 32% higher risk of complications (aRR: 1.32; 95% CI: 1.06-1.66) compared with children with influenza only.ConclusionMulti-virus testing in children with SARI allows a more accurate assessment of the risk of complications and attribution of burden to respiratory viruses beyond influenza. Children with asthma and respiratory disease should be prioritised for clinical care, regardless of their virological test result and age, and targeted for prevention campaigns.

Diagnostic approach to monkeypox outbreak, a case-control study.

BACKGROUND: An international outbreak of the monkeypox (MPX) virus is ongoing with a different clinical presentation than previously reported. OBJECTIVE: A monocentric retrospective study was designed to investigate clinical predictors of confirmed MPX cases among a group of patients referred for MPX screening. Furthermore, the additional value of performing a real-time polymerase chain reaction (RT-PCR) on multiple anatomical sites was analyzed. METHODS: Between 28/05/2022 and 22/07/2022, the medical records of patients referred for MPX screening were investigated. Patients with positive RT-PCR were defined as cases, while the ones with negative RT-PCR as controls. Multivariable regression analysis was performed to estimate predictors of MPX diagnosis. RESULTS: Among the 141 included patients, 85 (60%) had at least one positive RT-PCR for MPX. Carrying out RT-PCR only on the swab obtained by skin lesion sampling, 7 patients (7/85: 8%) would have been misdiagnosed. Multivariable regression analysis showed significant differences in the independent variables: "being men who have sex with men (MSM)", "living with HIV", "having multiple sexual partners in the last 3 weeks", and "having skin lesions in the anogenital area" for prediction of MPX diagnosis. These four discriminants were used to create a score to improve diagnosis in patients screened for MPX. CONCLUSION: MPX diagnosis was associated with being MSM, living with HIV, having multiple sexual partners, and presenting with anogenital skin lesions. In this study, the derived score had good sensitivity and specificity to predict MPX diagnosis. Finally, performing multi-site swabs for MPX RT-PCR might lower false negative rates.

Outbreak of invasive meningococcal disease caused by a meningococcus serogroup B in a nursery school, Wallonia, Belgium, 2018.

Although most invasive meningococcal disease (IMD) cases are sporadic without identified transmission links, outbreaks can occur. We report three cases caused by meningococcus B (MenB) at a Belgian nursery school over 9 months. The first two cases of IMD occurred in spring and summer 2018 in healthy children (aged 3-5 years) attending the same classroom. Chemoprophylaxis was given to close contacts of both cases following regional guidelines. The third case, a healthy child of similar age in the same class as a sibling of one case, developed disease in late 2018. Microbiological analyses revealed MenB with identical finetype clonal complex 269 for Case 1 and 3 (unavailable for Case 2). Antimicrobial susceptibility testing revealed no antibiotic resistance. Following Case 3, after multidisciplinary discussion, chemoprophylaxis and 4CMenB (Bexsero) vaccination were offered to close contacts. In the 12-month follow-up of Case 3, no additional cases were reported by the school. IMD outbreaks are difficult to manage and generate public anxiety, particularly in the case of an ongoing cluster, despite contact tracing and management. This outbreak resulted in the addition of MenB vaccination to close contacts in Wallonian regional guidelines, highlighting the potential need and added value of vaccination in outbreak management.

One year of laboratory-based COVID-19 surveillance system in Belgium: main indicators and performance of the laboratories (March 2020-21).

BACKGROUND: With the spread of coronavirus disease 2019 (COVID-19), an existing national laboratory-based surveillance system was adapted to daily monitor the epidemiological situation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the Belgium by following the number of confirmed SARS-CoV-2 infections, the number of performed tests and the positivity ratio. We present these main indicators of the surveillance over a one-year period as well as the impact of the performance of the laboratories, regarding speed of processing the samples and reporting results, for surveillance. METHODS: We describe the evolution of test capacity, testing strategy and the data collection methods during the first year of the epidemic in Belgium. RESULTS: Between the 1st of March 2020 and the 28th of February 2021, 9,487,470 tests and 773,078 COVID-19 laboratory confirmed cases were reported. Two epidemic waves occurred, with a peak in April and October 2020. The capacity and performance of the laboratories improved continuously during 2020 resulting in a high level performance. Since the end of November 2020 90 to 95% of the test results are reported at the latest the day after sampling was performed. CONCLUSIONS: Thanks to the effort of all laboratories a performant exhaustive national laboratory-based surveillance system to monitor the epidemiological situation of SARS-CoV-2 was set up in Belgium in 2020. On top of expanding the number of laboratories performing diagnostics and significantly increasing the test capacity in Belgium, turnaround times between sampling and testing as well as reporting were optimized over the first year of this pandemic.

Spotlight influenza: Extending influenza surveillance to detect non-influenza respiratory viruses of public health relevance: analysis of surveillance data, Belgium, 2015 to 2019.

BackgroundSeasonal influenza-like illness (ILI) affects millions of people yearly. Severe acute respiratory infections (SARI), mainly influenza, are a leading cause of hospitalisation and mortality. Increasing evidence indicates that non-influenza respiratory viruses (NIRV) also contribute to the burden of SARI. In Belgium, SARI surveillance by a network of sentinel hospitals has been ongoing since 2011.AimWe report the results of using in-house multiplex qPCR for the detection of a flexible panel of viruses in respiratory ILI and SARI samples and the estimated incidence rates of SARI associated with each virus.MethodsWe defined ILI as an illness with onset of fever and cough or dyspnoea. SARI was defined as an illness requiring hospitalisation with onset of fever and cough or dyspnoea within the previous 10 days. Samples were collected in four winter seasons and tested by multiplex qPCR for influenza virus and NIRV. Using catchment population estimates, we calculated incidence rates of SARI associated with each virus.ResultsOne third of the SARI cases were positive for NIRV, reaching 49.4% among children younger than 15 years. In children younger than 5 years, incidence rates of NIRV-associated SARI were twice that of influenza (103.5 vs 57.6/100,000 person-months); co-infections with several NIRV, respiratory syncytial viruses, human metapneumoviruses and picornaviruses contributed most (33.1, 13.6, 15.8 and 18.2/100,000 person-months, respectively).ConclusionEarly testing for NIRV could be beneficial to clinical management of SARI patients, especially in children younger than 5 years, for whom the burden of NIRV-associated disease exceeds that of influenza.

Evaluation of the added value of viral genomic information for predicting severity of influenza infection.

BACKGROUND: The severity of an influenza infection is influenced by both host and viral characteristics. This study aims to assess the relevance of viral genomic data for the prediction of severe influenza A(H3N2) infections among patients hospitalized for severe acute respiratory infection (SARI), in view of risk assessment and patient management. METHODS: 160 A(H3N2) influenza positive samples from the 2016-2017 season originating from the Belgian SARI surveillance were selected for whole genome sequencing. Predictor variables for severity were selected using a penalized elastic net logistic regression model from a combined host and genomic dataset, including patient information and nucleotide mutations identified in the viral genome. The goodness-of-fit of the model combining host and genomic data was compared using a likelihood-ratio test with the model including host data only. Internal validation of model discrimination was conducted by calculating the optimism-adjusted area under the Receiver Operating Characteristic curve (AUC) for both models. RESULTS: The model including viral mutations in addition to the host characteristics had an improved fit ([Formula: see text]=12.03, df = 3, p = 0.007). The optimism-adjusted AUC increased from 0.671 to 0.732. CONCLUSIONS: Adding genomic data (selected season-specific mutations in the viral genome) to the model containing host characteristics improved the prediction of severe influenza infection among hospitalized SARI patients, thereby offering the potential for translation into a prospective strategy to perform early season risk assessment or to guide individual patient management.

Vaccine effectiveness against infection and onwards transmission of COVID-19: Analysis of Belgian contact tracing data, January-June 2021.

In Belgium, high-risk contacts of an infected person were offered PCR-testing irrespective of their vaccination status. We estimated vaccine effectiveness (VE) against infection and onwards transmission, controlling for previous infections, household-exposure and temporal trends. We included 301,741 tests from 25 January to 24 June 2021. Full-schedule vaccination was associated with significant protection against infection. In addition, mRNA-vaccines reduced onward transmission: VE-estimates increased to >90% when index and contact were fully vaccinated. The small number of viral-vector vaccines included limited interpretability.

Monitoring of human coronaviruses in Belgian primary care and hospitals, 2015-20: a surveillance study.

BACKGROUND: Seasonal human coronaviruses (hCoVs) broadly circulate in humans. Their epidemiology and effect on the spread of emerging coronaviruses has been neglected thus far. We aimed to elucidate the epidemiology and burden of disease of seasonal hCoVs OC43, NL63, and 229E in patients in primary care and hospitals in Belgium between 2015 and 2020. METHODS: We retrospectively analysed data from the national influenza surveillance networks in Belgium during the winter seasons of 2015-20. Respiratory specimens were collected through the severe acute respiratory infection (SARI) and the influenza-like illness networks from patients with acute respiratory illness with onset within the previous 10 days, with measured or reported fever of 38°C or greater, cough, or dyspnoea; and for patients admitted to hospital for at least one night. Potential risk factors were recorded and patients who were admitted to hospital were followed up for the occurrence of complications or death for the length of their hospital stay. All samples were analysed by multiplex quantitative RT-PCRs for respiratory viruses, including seasonal hCoVs OC43, NL63, and 229E. We estimated the prevalence and incidence of seasonal hCoV infection, with or without co-infection with other respiratory viruses. We evaluated the association between co-infections and potential risk factors with complications or death in patients admitted to hospital with seasonal hCoV infections by age group. Samples received from week 8, 2020, were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). FINDINGS: 2573 primary care and 6494 hospital samples were included in the study. 161 (6·3%) of 2573 patients in primary care and 371 (5·7%) of 6494 patients admitted to hospital were infected with a seasonal hCoV. OC43 was the seasonal hCoV with the highest prevalence across age groups and highest incidence in children admitted to hospital who were younger than 5 years (incidence 9·0 [95% CI 7·2-11·2] per 100 000 person-months) and adults older than 65 years (2·6 [2·1-3·2] per 100 000 person-months). Among 262 patients admitted to hospital with seasonal hCoV infection and with complete information on potential risk factors, 66 (73·3%) of 90 patients who had complications or died also had at least one potential risk factor (p=0·0064). Complications in children younger than 5 years were associated with co-infection (24 [36·4%] of 66; p=0·017), and in teenagers and adults (≥15 years), more complications arose in patients with a single hCoV infection (49 [45·0%] of 109; p=0·0097). In early 2020, the Belgian SARI surveillance detected the first SARS-CoV-2-positive sample concomitantly with the first confirmed COVID-19 case with no travel history to China. INTERPRETATION: The main burden of severe seasonal hCoV infection lies with children younger than 5 years with co-infections and adults aged 65 years and older with pre-existing comorbidities. These age and patient groups should be targeted for enhanced observation when in medical care and in possible future vaccination strategies, and co-infections in children younger than 5 years should be considered during diagnosis and treatment. Our findings support the use of national influenza surveillance systems for seasonal hCoV monitoring and early detection, and monitoring of emerging coronaviruses such as SARS-CoV-2. FUNDING: Belgian Federal Public Service Health, Food Chain Safety, and Environment; Belgian National Insurance Health Care (Institut national d'assurance maladie-invalidité/Rijksinstituut voor ziekte-en invaliditeitsverzekering); and Regional Health Authorities (Flanders Agentschap zorg en gezondheid, Brussels Commission communautaire commune, Wallonia Agence pour une vie de qualité).

Prioritisation for future surveillance, prevention and control of 98 communicable diseases in Belgium: a 2018 multi-criteria decision analysis study.

BACKGROUND: National public health agencies are required to prioritise infectious diseases for prevention and control. We applied the prioritisation method recommended by the European Centre for Disease Prevention and Control to rank infectious diseases, according to their relative importance for surveillance and public health, to inform future public health action in Belgium. METHODS: We applied the multi-criteria-decision-analysis approach. A working group of epidemiologists and statisticians from Belgium (n = 6) designed a balanced set of prioritisation criteria. A panel of Belgian experts (n = 80) allocated in an online survey each criteria a weight, according to perceived relative importance. Next, experts (n = 37) scored each disease against each criteria in an online survey, guided by disease-specific factsheets referring the period 2010-2016 in Belgium. The weighted sum of the criteria's scores composed the final weighted score per disease, on which the ranking was based. Sensitivity analyses quantified the impact of eight alternative analysis scenarios on the top-20 ranked diseases. We identified criteria and diseases associated with data-gaps as those with the highest number of blank answers in the scoring survey. Principle components of the final weighted score were identified. RESULTS: Working groups selected 98 diseases and 18 criteria, structured in five criteria groups. The diseases ranked highest were (in order) pertussis, human immunodeficiency virus infection, hepatitis C and hepatitis B. Among the five criteria groups, overall the highest weights were assigned to 'impact on the patient', followed by 'impact on public health', while different perceptions were identified between clinicians, microbiologists and epidemiologists. Among the 18 individual criteria, 'spreading potential' and 'events requiring public health action' were assigned the highest weights. Principle components clustered with thematic disease groups. Notable data gaps were found among hospital-related diseases. CONCLUSIONS: We ranked infectious diseases using a standardised reproducible approach. The diseases ranked highest are included in current public health programs, but additional reflection for example about needs among risk groups is recommended. Cross-reference of the obtained ranking with current programs is needed to verify whether resources and activities map priority areas. We recommend to implement this method in a recurrent evaluation cycle of national public health priorities.

Rapid establishment of a national surveillance of COVID-19 hospitalizations in Belgium.

BACKGROUND: In response to the COVID-19 epidemic, caused by a novel coronavirus, it was of great importance to rapidly collect as much accurate information as possible in order to characterize the public health threat and support the health authorities in its management. Hospital-based surveillance is paramount to monitor the severity of a disease in the population. METHODS: Two separate surveillance systems, a Surge Capacity survey and a Clinical survey, were set up to collect complementary data on COVID-19 from Belgium's hospitals. The Surge Capacity survey collects aggregated data to monitor the hospital capacity through occupancy rates of beds and medical devices, and to follow a set of key epidemiological indicators over time. Participation is mandatory and the daily data collection includes prevalence and incidence figures on the number of COVID-19 patients in the hospital. The Clinical survey is strongly recommended by health authorities, focusses on specific patient characteristics and relies on individual patient data provided by the hospitals at admission and discharge. CONCLUSIONS: This national double-level hospital surveillance was implemented very rapidly after the first COVID-19 patients were hospitalized and revealed to be crucial to monitor hospital capacity over time and to better understand the disease in terms of risk groups and outcomes. The two approaches are complementary and serve different needs.

Capturing respiratory syncytial virus season in Belgium using the influenza severe acute respiratory infection surveillance network, season 2018/19.

BackgroundRespiratory syncytial virus (RSV) is a common cause of severe respiratory illness in young children (< 5 years old) and older adults (≥ 65 years old) leading the World Health Organization (WHO) to recommend the implementation of a dedicated surveillance in countries.AimWe tested the capacity of the severe acute respiratory infection (SARI) hospital network to contribute to RSV surveillance in Belgium.MethodsDuring the 2018/19 influenza season, we started the SARI surveillance for influenza in Belgium in week 40, earlier than in the past, to follow RSV activity, which usually precedes influenza virus circulation. While the WHO SARI case definition for influenza normally used by the SARI hospital network was employed, flexibility over the fever criterion was allowed, so patients without fever but meeting the other case definition criteria could be included in the surveillance.ResultsBetween weeks 40 2018 and 2 2019, we received 508 samples from SARI patients. We found an overall RSV detection rate of 62.4% (317/508), with rates varying depending on the age group: 77.6% in children aged < 5 years (253/326) and 34.4% in adults aged ≥ 65 years (44/128). Over 90% of the RSV-positive samples also positive for another tested respiratory virus (80/85) were from children aged < 5 years. Differences were also noted between age groups for symptoms, comorbidities and complications.ConclusionWith only marginal modifications in the case definition and the period of surveillance, the Belgian SARI network would be able to substantially contribute to RSV surveillance and burden evaluation in children and older adults, the two groups of particular interest for WHO.

Incidence estimation from sentinel surveillance data; a simulation study and application to data from the Belgian laboratory sentinel surveillance.

BACKGROUND: Inverse probability weighting (IPW) methods can be used to estimate the total number of cases from the sample collected through sentinel surveillance. Central to these methods are the inverse weights which can be derived in several ways and, in this case, represent the probability that laboratory (lab) sentinel surveillance detects a lab-confirmed case. METHODS: We compare different weights in a simulation study. Weights are obtained from the proportion of participating labs over all labs. We adjust these weights for attractiveness and density of labs over population. The market share of sentinel labs, as estimated by the econometric Huff-model, is also considered. Additionally, we investigate the effect of not recognizing sentinel labs as sentinel labs when they report no cases. We estimate the bias associated with the different weights as the difference between the simulated number of cases and the estimate of this total from the sentinel sample. As motivating data examples, we apply an extended Huff-model to four pathogens under laboratory sentinel surveillance in Belgium between 2010 and 2015 and discuss the model fit. We estimate the total number of lab-confirmed cases associated with Rotavirus, influenza virus, Y. enterocolitica and Campylobacter spp.. The extended Huff-model takes the lab-concept, the number of reimbursements and the number of departments, lab-density, regional borders, distance and competition between labs in account. RESULTS: Estimates obtained with the Huff-model were most accurate in the more complex simulation scenarios as compared to other weights. In the data examples, several significant coefficients are identified, but the fit of the Huff-model to the Belgian sentinel surveillance data leaves much variability in market shares unexplained. CONCLUSION: The Huff-model allows for estimation of the spatial and population coverage of sentinel surveillance and through IPW-methods also for the estimation of the total number of cases. The Huff-model's gravity function allows us to differentiate inside an area while estimating from the full dataset. Our data examples show that additional data on the participation to surveillance and practices of labs is necessary for a more accurate estimation.

The value of seroprevalence data as surveillance tool for Lyme borreliosis in the general population: the experience of Belgium.

BACKGROUND: Serological surveillance, based on the measurement of the presence of specific antibodies in a given population, can be used in addition to traditional and routine disease surveillance methods. The added value of this has been largely documented for vaccine-preventable diseases, but to a lesser extent for vector-borne diseases. This study aimed to evaluate the utility of seroprevalence data as additional source of information on the epidemiology of Lyme borreliosis in Belgium. METHODS: In total, 3215 residual blood samples collected in 2013-2015 were analysed with Liaison® Borrelia IgG kit (DiaSorin S.p.A, Saluggia, Italy). Positive and equivocal results were further examined with immunoblotting (recomLine Borrelia IgG kit, Mikrogen, Neuried, Germany). Crude prevalence estimates of equivocal and seropositive results were calculated and further adjusted accounting for clustered sampling and standardized for age, sex and population per province, according to the Belgian population structure in 2014. The effect of age, sex and region on seropositivity was assessed using log-binomial regression. RESULTS: The overall weighted national seroprevalence for Borrelia burgdorferi sensu lato, adjusted for clustered sampling, age, sex and province was 1.06% (95%CI 0.67-1.67). Although not statistically significant, the highest prevalences were observed in men and in those younger than 15 years or older than 59 years of age. At provincial level, the seroprevalence estimates do not follow the geographical distribution of tick bites and diagnoses of Lyme borreliosis as detected through other surveillance systems. CONCLUSIONS: Although the use of residual samples for seroprevalence estimates has several advantages, it seems to be a limited tool for serological surveillance of Lyme borreliosis in Belgium, other than follow-up of trends if repeated over time. A population-based sampling strategy might provide a more representative nationwide sample, but would be very time intensive and expensive. Seroprevalence studies within risk groups or risk areas in Belgium could provide a useful alternative approach to complement routine surveillance data of Lyme borreliosis.

Low hepatitis C prevalence in Belgium: implications for treatment reimbursement and scale up.

BACKGROUND: Prevalence data of chronic hepatitis C virus (HCV) infection are needed to estimate the budgetary impact of reimbursement of direct-acting antivirals (DAAs). In Belgium, the restricted reimbursement criteria are mainly guided by regional seroprevalence estimates of 0.87% from 1993 to 1994. In this first Belgian nationwide HCV prevalence study, we set out to update the seroprevalence and prevalence of chronic HCV infection estimates in the Belgian general population in order to guide decisions on DAA reimbursement. METHODS: Residual sera were collected through clinical laboratories. We collected data on age, sex and district. HCV antibody status was determined with ELISA and confirmed with a line-immunoassay (LIA). In specimens with undetermined or positive LIA result, HCV viral load was measured. Specimens were classified seronegative, seropositive with resolved infection, indicative of chronic infection and with undetermined HCV status according to the test outcomes. Results were standardized for age, sex and population per district, and adjusted for clustered sampling. RESULTS: In total 3209 specimens, collected by 28 laboratories, were tested. HCV seropositivity in the Belgian general population was estimated to be 0.22% (95% CI: 0.09-0.54%), and prevalence of chronic HCV infection 0.12% (95% CI: 0.03-0.41). In individuals of 20 years and older, these estimates were 0.26% (95% CI: 0.10-0.64%) and 0.13% (95% CI: 0.04-0.43), respectively. Of the total estimated number of HCV seropositive individuals in Belgium, 66% were between 50 and 69 years old. CONCLUSIONS: Prevalence of HCV seropositivity and chronic infection in the Belgian general population were low and comparable to many surrounding countries. These adjusted prevalences can help estimate the cost of reimbursement of DAAs and invite Belgian policy makers to accelerate the scaling up of reimbursement, giving all chronically infected HCV patients a more timely access to treatment.

Distribution of HCV genotypes in Belgium from 2008 to 2015.

BACKGROUND: The knowledge of circulating HCV genotypes and subtypes in a country is crucial to guide antiviral therapy and to understand local epidemiology. Studies investigating circulating HCV genotypes and their trends have been conducted in Belgium. However they are outdated, lack nationwide representativeness or were not conducted in the general population. METHODS: In order to determine the distribution of different circulating HCV genotypes in Belgium, we conducted a multicentre study with all the 19 Belgian laboratories performing reimbursed HCV genotyping assays. Available genotype and subtype data were collected for the period from 2008 till 2015. Furthermore, a limited number of other variables were collected: some demographic characteristics from the patients and the laboratory technique used for the determination of the HCV genotype. RESULTS: For the study period, 11,033 unique records collected by the participating laboratories were used for further investigation. HCV genotype 1 was the most prevalent (53.6%) genotype in Belgium, with G1a and G1b representing 19.7% and 31.6%, respectively. Genotype 3 was the next most prevalent (22.0%). Further, genotype 4, 2, and 5 were responsible for respectively 16.1%, 6.2%, and 1.9% of HCV infections. Genotype 6 and 7 comprise the remaining <1%. Throughout the years, a stable distribution was observed for most genotypes. Only for genotype 5, a decrease as a function of the year of analysis was observed, with respectively 3.6% for 2008, 2.3% for 2009 and 1.6% for the remaining years. The overall M:F ratio was 1.59 and was mainly driven by the high M:F ratio of 3.03 for patients infected with genotype 3. Patients infected with genotype 3 are also younger (mean age 41.7 years) than patients infected with other genotypes (mean age above 50 years for all genotypes). The patients for whom a genotyping assay was performed in 2008 were younger than those from 2015. Geographical distribution demonstrates that an important number of genotyped HCV patients live outside the Belgian metropolitan cities. CONCLUSION: This national monitoring study allowed a clear and objective view of the circulating HCV genotypes in Belgium and will help health authorities in the establishment of cost effectiveness determinations before implementation of new treatment strategies. This baseline characterization of the circulating genotypes is indispensable for a continuous surveillance, especially for the investigation of the possible impact of migration from endemic regions and prior to the increasing use of highly potent direct-acting antiviral (DAA) agents.

Burden of salmonellosis, campylobacteriosis and listeriosis: a time series analysis, Belgium, 2012 to 2020.

Salmonellosis, campylobacteriosis and listeriosis are food-borne diseases. We estimated and forecasted the number of cases of these three diseases in Belgium from 2012 to 2020, and calculated the corresponding number of disability-adjusted life years (DALYs). The salmonellosis time series was fitted with a Bai and Perron two-breakpoint model, while a dynamic linear model was used for campylobacteriosis and a Poisson autoregressive model for listeriosis. The average monthly number of cases of salmonellosis was 264 (standard deviation (SD): 86) in 2012 and predicted to be 212 (SD: 87) in 2020; campylobacteriosis case numbers were 633 (SD: 81) and 1,081 (SD: 311); listeriosis case numbers were 5 (SD: 2) in 2012 and 6 (SD: 3) in 2014. After applying correction factors, the estimated DALYs for salmonellosis were 102 (95% uncertainty interval (UI): 8-376) in 2012 and predicted to be 82 (95% UI: 6-310) in 2020; campylobacteriosis DALYs were 1,019 (95% UI: 137-3,181) and 1,736 (95% UI: 178-5,874); listeriosis DALYs were 208 (95% UI: 192-226) in 2012 and 252 (95% UI: 200-307) in 2014. New actions are needed to reduce the risk of food-borne infection with Campylobacter spp. because campylobacteriosis incidence may almost double through 2020.

Health crises due to infectious and communicable diseases : European preparedness and response tools in an international context.

The combination of changes in eating habits, ways of living, globalisation, extensive travelling and the migration of millions of people around the world may be contributing to increased health risks. Certainly, health crises today are proving highly complex. More and more people are travelling and may carry with them unexpected virus vectors such as mosquitoes. Preparedness is challenging and there is a need for action plans to safeguard the growing at-risk population. Health crises can potentially affect a large proportion of the population and may lead to a significant increase in mortality or to an abnormally high death rate. This should be integrated into the general concept of national and international surveillance in order to provide a prepared response in the event of crisis. This paper provides an inventory of the relevant laws, guidelines and tools in Europe (and to a lesser degree, beyond), and proposes answers to the health crisis problems associated with infectious and communicable diseases. In crisis management, communication is an important factor to consider. This paper can serve as a tool for people involved in crisis preparedness.

Risk ranking of foodborne parasites: State of the art.

In a time of increasing threats and decreasing financial resources, monitoring and controlling all possible foodborne hazards at the same time and to the same extent has become more challenging than ever. Therefore, attention is increasingly being paid to the so-called "risk ranking" methods that enable decision makers to focus on the most important foodborne hazards - even when time is limited and knowledge incomplete. In this review paper, we provide an overview of the most common quantitative methods and metrics used for ranking the risks associated with foodborne parasites and present the state of the art on risk ranking exercises for foodborne parasites. A number of risk ranking metrics and methods are available, ranging from simple approaches that can be used to assess the health or economic impact of a foodborne parasitic disease, to more complicated but more comprehensive multi-criteria assessments. For health impact assessment, measures of population health such as disease occurrence and number of deaths; Disability-Adjusted Life Years (DALYs) measuring the healthy life years lost; and Quality-Adjusted Life Years (QALYs) measuring the number of life years lived in optimal health, are described. For economic impact assessment, applied approaches that measure the cost-of-illness from a societal perspective and stated preference methods are outlined. Finally, Multi-Criteria Decision Analysis (MCDA), which can be used to integrate multiple metrics and criteria into a single ranking, is described. These risk ranking methods for foodborne parasites are increasingly performed to aid priority setting at global, regional, and national levels. As different stakeholders have their own prioritization objectives and beliefs, the outcome of such exercises is necessarily context-dependent. Therefore, when designing a risk ranking exercise for foodborne parasites, it is important to choose the metrics and methods, as well as what to rank, in the light of the predefined context of the question being addressed and the target audience.

Assessing the sensitivity and representativeness of the Belgian Sentinel Network of Laboratories using test reimbursement data.

BACKGROUND: The Belgian Sentinel Network of Laboratories (SNL) was created in 1983 in order to monitor trends in infectious diseases. Given the evolution of the surveillance system, such as the waivers, fusions and adhesions of laboratories over time, it is important to evaluate whether the SNL is still fit for purpose. This study aims to evaluate aspects of the sensitivity and representativeness of the SNL by means of a test coverage analysis. METHODS: We estimated test coverage of the SNL using the ratio of reimbursed tests performed by participating laboratories to the total number of tests performed between 2007 and 2012, for 12 (groups of) pathogens. We further evaluated the geographical difference coverage of the SNL at regional and provincial levels. RESULTS: We found that test coverage of the SNL was stable over time and close to, or greater than, 50 % for the 12 (groups of) pathogens studied. These results hold for the three regions of Belgium but not for all provinces. We showed that some provinces had a low test coverage for some pathogens and that test coverage was more variable over time at provincial level. CONCLUSIONS: This sensitivity and representativeness study based on test coverage suggests that the SNL is capable to describe trend and to monitor changes in the 12 (groups of) pathogens studied both at national and regional levels. Therefore, the SNL is useful to contribute to estimate the burden of disease and to inform preventive measures. It should however be reinforced to allow to be used as an alert system at provincial level.