Critically Ill Patients with Visceral Nocardia Infection, France and Belgium, 2004-2023.

We studied 50 patients with invasive nocardiosis treated during 2004-2023 in intensive care centers in France and Belgium. Most (65%) died in the intensive care unit or in the year after admission. Nocardia infections should be included in the differential diagnoses for patients in the intensive care setting.

Respiratory Viruses in Wastewater Compared with Clinical Samples, Leuven, Belgium.

In a 2-year study in Leuven, Belgium, we investigated the use of wastewater sampling to assess community spread of respiratory viruses. Comparison with the number of positive clinical samples demonstrated that wastewater data reflected circulation levels of typical seasonal respiratory viruses, such as influenza, respiratory syncytial virus, and enterovirus D68.

The impact of diabetes on mortality rates after lower extremity amputation.

OBJECTIVE: To assess the impact of diabetes, amputation level, sex and age on mortality rates after lower extremity amputation (LEA) in Belgium, and to assess temporal trends in one-year survival rates from 2009 to 2018. METHODS: Nationwide data on individuals who underwent minor and major LEA from 2009 to 2018 were collected. Kaplan-Meier survival curves were constructed. A Cox regression model with time-varying coefficients was used to estimate the likelihood of mortality after LEA in individuals with or without diabetes. Matched amputation-free individuals with or without diabetes were used for comparison. Time trends were analysed. RESULTS: Amputations 41,304 were performed: 13,247 major and 28,057 minor. Five-year mortality rates in individuals with diabetes were 52% and 69% after minor and major LEA, respectively (individuals without diabetes: 45% and 63%, respectively). In the first six postoperative months, no differences in mortality rates were found between individuals with or without diabetes. Later, hazard ratios (HRs) for mortality in individuals with diabetes (compared with no diabetes) after minor LEA ranged from 1.38 to 1.52, and after major LEA from 1.35 to 1.46 (all p ≤ 0.005). Among individuals without LEA, HRs for mortality in diabetes (versus no diabetes) were systematically higher compared to the HRs for mortality in diabetes (versus no diabetes) after minor and major LEA. One-year survival rates did not change for individuals with diabetes. CONCLUSIONS: In the first six postoperative months, mortality rates after LEA were not different between individuals with or without diabetes; later, diabetes was significantly associated with increased mortality. However, as HRs for mortality were higher in amputation-free individuals, diabetes impacts mortality less in the minor and major amputation groups relative to the comparison group of individuals without LEA.

Nationwide quality assurance of high-throughput diagnostic molecular testing during the SARS-CoV-2 pandemic: role of the Belgian National Reference Centre.

Since the onset of the coronavirus disease (COVID-19) pandemic in Belgium, UZ/KU Leuven has played a crucial role as the National Reference Centre (NRC) for respiratory pathogens, to be the first Belgian laboratory to develop and implement laboratory developed diagnostic assays for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and later to assess the quality of commercial kits. To meet the growing demand for decentralised testing, both clinical laboratories and government-supported high-throughput platforms were gradually deployed across Belgium. Consequently, the role of the NRC transitioned from a specialised testing laboratory to strengthening capacity and coordinating quality assurance. Here, we outline the measures taken by the NRC, the national public health institute Sciensano and the executing clinical laboratories to ensure effective quality management of molecular testing throughout the initial two years of the pandemic (March 2020 to March 2022).

Cross-border differences in the prevalence and risk factors for carriage of antimicrobial resistance in children attending daycare centers: a point prevalence study in the Netherlands and Belgium.

BACKGROUND: Day care centres (DCCs) are ideal settings for drug-resistant bacteria to emerge. Prevalence numbers of faecal carriage of antimicrobial resistant bacteria in these settings are rare. We aimed to determine the prevalence of faecal antimicrobial resistant bacteria carriage in children attending DCCs and to assess and identify infection risk factors within DCCs in The Netherlands and Belgium. METHODS: A point-prevalence study was conducted in 28 Dutch (499 children) and 18 Belgian (448 children) DCCs. Stool samples were taken from the children's diapers and a questionnaire was filled in by their parents. Hygiene related to stool and toilet use, hygiene related to food, environmental contamination, hand hygiene and hygiene guidelines were assessed conform a standardized questionnaire by the infection prevention and control expert visiting the DCC. Multilevel logistical regression analyses were used to define which characteristics predicted the presence of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenemase-producing Enterobacterales (CPE), vancomycin-resistant enterococci (VRE), and ciprofloxacin-resistant Enterobacterales (CipR-E). RESULTS: The ESBL-E prevalence was 16% (n = 71) in Belgium and 6% (n = 30) in the Netherlands. The CipR-E prevalence was 17% (n = 78) in Belgium and 8% (n = 38) in the Netherlands. Antimicrobial use (RR: 0.30; 95% CI: 0.33-0.48) and hospital admissions (RR: 0.37; 95% CI: 0.25-0.54) were lower in the Netherlands. Children travelling to Asia were at higher risk of being an ESBL-E carrier. Children using antimicrobials were at higher risk of being a CipR-E carrier. Cleaning the changing mat after each use was found as a protective factor for CipR-E carriage. CONCLUSIONS: We established a significant difference in ESBL-E and CipR-E carriage and antimicrobial use and hospital admissions between the Netherlands and Belgium among children attending DCCs. The differences between both countries should be further studied to improve the policy on anti-microbial use and hospital admissions in children.

Non-adherence and non-persistence with antiretroviral treatment in Belgium: A real-world evaluation using a pharmacy database, 2018-2021.

PURPOSE: To evaluate the real-world rates of non-adherence and non-persistence to antiretroviral therapy (ART) among treatment-naïve adult patients with HIV after a 12-month follow-up period in Belgium. METHODS: A retrospective analysis of longitudinal pharmacy claims was conducted using the Pharmanet database from January 1, 2018, to December 31, 2021. Non-adherence was assessed over 12 months and reported as the proportion of days covered below the 80% threshold. Non-persistence was defined as the first 90-day gap in treatment between the two types of ART dispensed. Poisson regression with robust standard error and Cox proportional hazard models were used to assess the factors associated with non-adherence and non-persistence, respectively. RESULTS: Overall, 2999 patients were initiated on ART between 2018 and 2021. After a 12-month follow-up, the proportions of non-adherence and non-persistence were 35.6% and 15.9%, respectively in 2018, and decreased to 18.7% and 6.8%, respectively in 2021. Non-adherence was higher among women, Brussels residents, and those receiving multiple-tablet regimens (MTRs). Similarly, the prevalence of non-persistence was higher among women and MTR recipients. CONCLUSION: Among treatment-naïve adults with HIV in Belgium, non-adherence, and non-persistence to ART showed improvement over the study period but remained at high levels. Disparities were observed by sex and between geographical regions. Prioritizing strategies targeting women in Brussels and facilitating the transition from MTRs to single-tablet regimens should be emphasized optimize adherence to ART in Belgium.

Clinical audit of quality of care among patients with viral hepatitis in primary care in a low endemic region.

BACKGROUND: The current hepatitis B (HBV) and hepatitis C virus (HCV) screening practices may fail to detect many infected patients who could benefit from new therapeutic agents to limit progression to cirrhosis and hepatocellular carcinoma. OBJECTIVES: This study assessed the test positivity rate and cascade of care of viral hepatitis patients in primary care in a low endemic region as well as the testing policy of abnormal alanine aminotransferase (ALT) level. METHODS: This is a retrospective clinical audit among primary health care practices in Flanders, Belgium, assessing patients with an active medical file between 2019 and 2021. RESULTS: A total of 84/89 (94.4%) primary health care practices participated representing 621,573 patients of which 1069 patients (0.17%) were registered as having viral hepatitis, not further specified. Detailed information was available from 38 practices representing 243,723/621,573 (39.2%) patients of which 169 (0.07%) were HBsAg positive and 99 (0.04%) anti-HCV positive. A total of 96/134(71.6%) chronic HBV-infected and 31/77(40.3%) chronic HCV-infected patients were referred to a hepatologist. A total of 30,573/621,573(4.9%) patients had an abnormal ALT level, and by at random selection, more detailed information was obtained on 211 patients. Information on high-risk groups was missing in up to 60%. In patients with abnormal ALT level, HBsAg and anti-HCV testing were conducted in 37/211(17.5%) and 25/211(11.8%), respectively. CONCLUSION: In a low endemic region, the testing rate and cascade of care of HBV and HCV-infected patients can be improved in primary care, especially in high-risk groups and patients with abnormal ALT levels.

Infections with the hepatitis B virus (HBV) and hepatitis C virus (HCV) are a leading cause of death worldwide. Over the last decade, several new therapeutic agents have been developed and can now prevent hepatitis-related deaths. Awareness and increasing testing rates for viral hepatitis in primary care could therefore contribute to control these diseases. The findings of our clinical audit among primary health care practices in Flanders, Belgium demonstrate that screening for HBV and HCV infection can be improved in primary health care in a low endemic region, especially in high-risk groups (e.g. migrants who originate from an endemic country) and patients with abnormal ALT level. The observed suboptimal testing rate in primary health care may be due to a lack of information on risk groups. Future research should focus on interventions to enhance testing, linkage to care, and treatment initiation for HBV and HCV infection among well-defined risk groups in primary health care.

Precarious employment and mental health in the Belgian service voucher system: the role of working conditions and perceived financial strain.

INTRODUCTION: Jobs in domestic cleaning are often conceived as 'precarious employment' (PE)-i.e. a multidimensional concept referring to accumulated adverse characteristics of employment due to workers' weak bargaining position. Against this background, the Belgian service voucher system (SVS) was implemented aimed at creating formal and stable, subsidized domestic services jobs. PURPOSE: The current study assesses the relationship between PE and mental health (WHO5) in the Belgian SVS, accounting for the potential mediating role of working conditions and perceived financial strain at the household level. METHODS: We analysed a cross-sectional sample of 1,115 Belgian SVS domestic cleaners, collected in 2019 through an online survey. A mediation model was estimated. RESULTS: The crude effect of PE on adverse mental health was strong (ß 0.545-S.E. 0.063). However, 50% of the association between PE and mental well-being was mediated by work task characteristics (quantitative demands, physical demands, task variation and autonomy) and 25% by household-level perceived financial strain. The remaining direct effect of PE on adverse mental well-being is ß 0.066 (S.E. 0.032-25% of the total effect). CONCLUSION: These findings are the first based on the Belgian Employment Precariousness Scale (EPRES-BE) and are consistent with earlier-made-but seldom simultaneously tested-assumptions on the mechanisms relating PE to adverse mental health-i.e. involving direct associations and indirect associations via adverse working conditions and material deprivation. Based on the results, we recommend more democratic and higher-quality management practices in the SVS, in addition to higher wages and working time reduction.

Trends in socioeconomic inequalities in cause-specific premature mortality in Belgium, 1998-2019.

BACKGROUND: Higher levels of socioeconomic deprivation have been consistently associated with increased risk of premature mortality, but a detailed analysis by causes of death is lacking in Belgium. We aim to investigate the association between area deprivation and all-cause and cause-specific premature mortality in Belgium over the period 1998-2019. METHODS: We used the 2001 and 2011 Belgian Indices of Multiple Deprivation to assign statistical sectors, the smallest geographical units in the country, into deprivation deciles. All-cause and cause-specific premature mortality rates, population attributable fraction, and potential years of life lost due to inequality were estimated by period, sex, and deprivation deciles. RESULTS: Men and women living in the most deprived areas were 1.96 and 1.78 times more likely to die prematurely compared to those living in the least deprived areas over the period under study (1998-2019). About 28% of all premature deaths could be attributed to socioeconomic inequality and about 30% of potential years of life lost would be averted if the whole population of Belgium faced the premature mortality rates of the least deprived areas. CONCLUSION: Premature mortality rates have declined over time, but inequality has increased due to a faster pace of decrease in the least deprived areas compared to the most deprived areas. As the causes of death related to poor lifestyle choices contribute the most to the inequality gap, more effective, country-level interventions should be put in place to target segments of the population living in the most deprived areas as they are facing disproportionately high risks of dying.

Reevaluating the timing of Neanderthal disappearance in Northwest Europe.

Elucidating when Neanderthal populations disappeared from Eurasia is a key question in paleoanthropology, and Belgium is one of the key regions for studying the Middle to Upper Paleolithic transition. Previous radiocarbon dating placed the Spy Neanderthals among the latest surviving Neanderthals in Northwest Europe with reported dates as young as 23,880 ± 240 B.P. (OxA-8912). Questions were raised, however, regarding the reliability of these dates. Soil contamination and carbon-based conservation products are known to cause problems during the radiocarbon dating of bulk collagen samples. Employing a compound-specific approach that is today the most efficient in removing contamination and ancient genomic analysis, we demonstrate here that previous dates produced on Neanderthal specimens from Spy were inaccurately young by up to 10,000 y due to the presence of unremoved contamination. Our compound-specific radiocarbon dates on the Neanderthals from Spy and those from Engis and Fonds-de-Forêt demonstrate that they disappeared from Northwest Europe at 44,200 to 40,600 cal B.P. (at 95.4% probability), much earlier than previously suggested. Our data contribute significantly to refining models for Neanderthal disappearance in Europe and, more broadly, show that chronometric models regarding the appearance or disappearance of animal or hominin groups should be based only on radiocarbon dates obtained using robust pretreatment methods.

Multimorbidity healthcare expenditure in Belgium: a 4-year analysis (COMORB study).

BACKGROUND: The complex management of health needs in multimorbid patients, alongside limited cost data, presents challenges in developing cost-effective patient-care pathways. We estimated the costs of managing 171 dyads and 969 triads in Belgium, taking into account the influence of morbidity interactions on costs. METHODS: We followed a retrospective longitudinal study design, using the linked Belgian Health Interview Survey 2018 and the administrative claim database 2017-2020 hosted by the Intermutualistic Agency. We included people aged 15 and older, who had complete profiles (N = 9753). Applying a system costing perspective, the average annual direct cost per person per dyad/triad was presented in 2022 Euro and comprised mainly direct medical costs. We developed mixed models to analyse the impact of single chronic conditions, dyads and triads on healthcare costs, considering two-/three-way interactions within dyads/triads, key cost determinants and clustering at the household level. RESULTS: People with multimorbidity constituted nearly half of the study population and their total healthcare cost constituted around three quarters of the healthcare cost of the study population. The most common dyad, arthropathies + dorsopathies, with a 14% prevalence rate, accounted for 11% of the total national health expenditure. The most frequent triad, arthropathies + dorsopathies + hypertension, with a 5% prevalence rate, contributed 5%. The average annual direct costs per person with dyad and triad were €3515 (95% CI 3093-3937) and €4592 (95% CI 3920-5264), respectively. Dyads and triads associated with cancer, diabetes, chronic fatigue, and genitourinary problems incurred the highest costs. In most cases, the cost associated with multimorbidity was lower or not substantially different from the combined cost of the same conditions observed in separate patients. CONCLUSION: Prevalent morbidity combinations, rather than high-cost ones, made a greater contribution to total national health expenditure. Our study contributes to the sparse evidence on this topic globally and in Europe, with the aim of improving cost-effective care for patients with diverse needs.

The co-production process of an assessment programme: Between clarifying identity and developing the quality of French-speaking Belgian community health centres.

BACKGROUND: The assessment of primary care organizations is considered to be essential for improving care. However, the assessments' acceptability to professionals poses a challenge. Developing assessment programmes in collaboration with the end-users is a strategy that is widely encouraged to make interventions better targeted. By doing so, it can help to prevent resistance and encourage adherence to the assessment. This process, however, is rarely reported. This paper aims to fill this gap by describing the process of the co-production of an assessment programme for community health centres (CHCs) affiliated to the Federation of Community Health Centres (FCHC) in French-speaking Belgium. METHODS: We conducted a documentary study on the co-production of the assessment programme before carrying out semi-structured interviews with the stakeholders involved in its development. RESULTS: CHCs in French-speaking Belgium are increasing in number and are becoming more diverse. For the FCHC, this growth and diversification pose challenges for the meaning of CHC (an identity challenge) and what beneficiaries can expect in terms of the quality of organizations declaring themselves CHC (a quality challenge). Faced with this double challenge, the FCHC decided to develop an assessment programme, initially called Label, using participatory action research. During the co-production process, this initial programme version was abandoned in favour of a new name "DEQuaP". This new name embodies new objectives and new design regarding the assessment programme. When studying the co-production process, we attributed these changes to two controversies. The first concerns how much and which type of variety is desired among CHCs part of the FCHC. The second concerns the organization of the FCHC in its capacity as a federation. It shed light on tensions between two professional segments that, in this paper, we called "political professionalism" and "pragmatic professionalism". CONCLUSIONS: These controversies show the importance of underlying challenges behind the development of an assessment programme for CHCs. This provided information about the evolution of the identity of multidisciplinary organizations in primary care. Issues raised in the development of this assessment programme also show the importance of considering assessment methods that reflect and embody the current realities of these organizations and the way of developing these assessment methods.

Estimation of antimicrobial resistance of Mycoplasma genitalium, Belgium, 2022.

BackgroundAntimicrobial resistance (AMR) of Mycoplasma genitalium (MG) is a growing concern worldwide and surveillance is needed. In Belgium, samples are sent to the National Reference Centre of Sexually Transmitted Infections (NRC-STI) on a voluntary basis and representative or robust national AMR data are lacking.AimWe aimed to estimate the occurrence of resistant MG in Belgium.MethodsBetween July and November 2022, frozen remnants of MG-positive samples from 21 Belgian laboratories were analysed at the NRC-STI. Macrolide and fluoroquinolone resistance-associated mutations (RAMs) were assessed using Sanger sequencing of the 23SrRNA and parC gene. Differences in resistance patterns were correlated with surveillance methodology, socio-demographic and behavioural variables via Fisher's exact test and logistic regression analysis.ResultsOf the 244 MG-positive samples received, 232 could be sequenced for macrolide and fluoroquinolone RAMs. Over half of the sequenced samples (55.2%) were resistant to macrolides. All sequenced samples from men who have sex with men (MSM) (24/24) were macrolide-resistant. Fluoroquinolone RAMs were found in 25.9% of the samples and occurrence did not differ between socio-demographic and sexual behaviour characteristics.ConclusionAlthough limited in sample size, our data suggest no additional benefit of testing MG retrieved from MSM for macrolide resistance in Belgium, when making treatment decisions. The lower occurrence of macrolide resistance in other population groups, combined with emergence of fluoroquinolone RAMs support macrolide-resistance testing in these groups. Continued surveillance of resistance in MG in different population groups will be crucial to confirm our findings and to guide national testing and treatment strategies.

Emergence and spread of a mupirocin-resistant variant of the European epidemic fusidic acid-resistant impetigo clone of Staphylococcus aureus, Belgium, 2013 to 2023.

BackgroundAntimicrobial resistance to mupirocin and fusidic acid, which are used for treatment of skin infections caused by Staphylococcus aureus, is of concern.AimTo investigate resistance to fusidic acid and mupirocin in meticillin-susceptible S. aureus (MSSA) from community-acquired skin and soft tissue infections (SSTIs) in Belgium.MethodsWe collected 2013-2023 data on fusidic acid and mupirocin resistance in SSTI-associated MSSA from two large Belgian laboratories. Resistant MSSA isolates sent to the Belgian Staphylococci Reference Centre were spa-typed and analysed for the presence of the eta and etb virulence genes and the mupA resistance gene. In addition, we whole genome sequenced MSSA isolates collected between October 2021 and September 2023.ResultsMupirocin resistance increased between 2013 and 2023 from 0.5-1.5% to 1.7-5.6%. Between 2018 and 2023, 91.4% (64/70) of mupirocin-resistant isolates were co-resistant to fusidic acid. By September 2023, between 8.9% (15/168) and 10.1% (11/109) of children isolates from the two laboratories were co-resistant. Of the 33 sequenced isolates, 29 were sequence type 121, clonal and more distantly related to the European epidemic fusidic acid-resistant impetigo clone (EEFIC) observed in Belgium in 2020. These isolates carried the mupA and fusB genes conferring resistance to mupirocin and fusidic acid, respectively, and the eta and etb virulence genes.ConclusionWe highlight the spread of a mupirocin-resistant EEFIC in children, with a seasonal trend for the third quarter of the year. This is of concern because this variant is resistant to the two main topical antibiotics used to treat impetigo in Belgium.

50 Years of terrorism in Belgium: a review of 121 incidents in the global terrorism database.

OBJECTIVES: Belgium is not only prone to inland terrorism but also attracts terrorist factions aiming at various political, diplomatic, military, and/or religious targets. This study aimed to identify and characterize all documented terrorist attacks in Belgium reported to the Global Terrorism Database (GTD) over a period of 50 years. METHODS: The GTD was searched for all terrorist attacks in Belgium between 1970 and 2019. Analyses were performed on temporal factors, location, target type, attack and weapon type, attacker type, and number of casualties or hostages. RESULTS: In 50 years, 121 incidents accounted for 80 confirmed fatalities and 498 injured people. Bombings and explosions were the most frequently identified attack type (46.3%), followed by assassination (16.5%), infrastructure damage (15.7%) and armed or unarmed assaults (14.0%). Governmental and diplomatic institutions were the most frequent target (24.0%). For those perpetrators the GTD did have enough information we saw a timely change from far left and separatist dominating the early decades to Jihadi groups in the last decade, while anti-semitic factions were active in every decade. CONCLUSION: In contrast to other studies, this study did not show an increase over time. Left-wing perpetrators dominated the eighties. In 50 years of terrorist activity in Belgium, the health care system was spared. Devastating mass casualty attacks challenging the health care system are rare in Belgium.

[Protontherapy : principles, advantages, limitations, indications, perspectives...and some Belgian peculiarities]. / La protonthérapie : principes, avantages, limitations, indications, perspectives...et quelques histoires belges.

Most radiotherapy treatments are nowadays delivered with linear accelerators producing photons. This robust radiation technique improved outstandingly during the last three decades, allowing treatments for most tumoural indications with an exquisite accuracy, a formidable effectiveness, a low toxicity, and a very low cost for the society. Therefore, the reasons for using and developing the more expensive hadron therapy and more particularly proton therapy may seem futile. In the current article targeting the general practitioners readership, we look at the principles of this innovative technique, its inherent advantages and limitations, the current and future indications, the challenges and perspectives for the future. We conclude with an overview of the Belgian landscape in terms of installation, operation, access and reimbursement procedures.

L'essentiel des traitements de radiothérapie sont délivrés à l'aide d'accélérateurs linéaires produisant des photons. La technique est robuste et a connu une évolution fulgurante ces trois dernières décennies, apportant une efficacité redoutable et une extrême précision dans de nombreuses indications tumorales, avec les avantages d'un risque de toxicité réduit et d'un coût sociétal extrêmement faible. Dès lors, quel intérêt y aurait-il à utiliser et développer des traitements de radiothérapie par hadrons, et plus particulièrement par protons, sachant que les coûts d'installation et de production sont, au bas mot, décuplés par rapport aux photons ? Dans cet article destiné en première intention aux praticiens de santé généralistes, nous abordons les principes de fonctionnement, les avantages et limitations inhérents à la technique, les indications actuelles et celles qui se profilent, les défis et perspectives à venir. Nous terminons, enfin, par un tour d'horizon du paysage belge en termes d'installation, de fonctionnement, d'accès et de modalités de remboursement.

Combined Phylogeographic Analyses and Epidemiologic Contact Tracing to Characterize Atypically Pathogenic Avian Influenza (H3N1) Epidemic, Belgium, 2019.

The high economic impact and zoonotic potential of avian influenza call for detailed investigations of dispersal dynamics of epidemics. We integrated phylogeographic and epidemiologic analyses to investigate the dynamics of a low pathogenicity avian influenza (H3N1) epidemic that occurred in Belgium during 2019. Virus genomes from 104 clinical samples originating from 85% of affected farms were sequenced. A spatially explicit phylogeographic analysis confirmed a dominating northeast to southwest dispersal direction and a long-distance dispersal event linked to direct live animal transportation between farms. Spatiotemporal clustering, transport, and social contacts strongly correlated with the phylogeographic pattern of the epidemic. We detected only a limited association between wind direction and direction of viral lineage dispersal. Our results highlight the multifactorial nature of avian influenza epidemics and illustrate the use of genomic analyses of virus dispersal to complement epidemiologic and environmental data, improve knowledge of avian influenza epidemiologic dynamics, and enhance control strategies.

Genome Analysis of Triploid Hybrid Leishmania Parasite from the Neotropics.

We discovered a hybrid Leishmania parasite in Costa Rica that is genetically similar to hybrids from Panama. Genome analyses demonstrated the hybrid is triploid and identified L. braziliensis and L. guyanensis-related strains as parents. Our findings highlight the existence of poorly sampled Leishmania (Viannia) variants infectious to humans.

Human Immunity and Susceptibility to Influenza A(H3) Viruses of Avian, Equine, and Swine Origin.

Influenza A viruses (IAVs) of subtype H3 that infect humans are antigenically divergent from those of birds, horses, and swine. Human immunity against these viruses might be limited, implying potential pandemic risk. To determine human risk, we selected 4 avian, 1 equine, and 3 swine IAVs representing major H3 lineages. We tested serum collected during 2017-2018 from 286 persons in Belgium for hemagglutination inhibiting antibodies and virus neutralizing antibodies against those animal-origin IAVs and tested replication in human airway epithelia. Seroprevalence rates for circulating IAVs from swine in North America were >51%, swine in Europe 7%-37%, and birds and equids ≤12%. Replication was efficient for cluster IV-A IAVs from swine in North America and IAVs from swine in Europe, intermediate for IAVs from horses and poultry, and absent for IAVs from wild birds and a novel human-like swine IAV in North America. Public health risk may be highest for swine H3 IAVs.

Surveillance and Genomic Characterization of Influenza A and D Viruses in Swine, Belgium and the Netherlands, 2019-2021.

During 2019-2021, we isolated 62 swine influenza A viruses in Belgium and the Netherlands. We also detected influenza D in pigs in the Netherlands. The ever-changing diversity of influenza viruses and the identification of influenza D emphasize the need for more virus surveillance.