Risk factors for hepatitis E virus seropositivity in Dutch blood donors

Background: A marked increase of hepatitis E cases has recently been observed in the Netherlands. Causes of the (re-)emergence of hepatitis E virus (HEV) and exact sources and routes of transmission of HEV infection are currently unknown. We aimed to identify risk factors for HEV seropositivity. Methods: Using the Wantai EIA, 2100 plasma samples of blood donors from all over the Netherlands aged 18-70 years were tested for anti-HEV IgG antibodies. A questionnaire on socio-demographic characteristics, health, and potential risk factors for HEV exposure was sent to these participants. Results: The overall IgG-seroprevalence was 31% (648/2100) and increased with age. Several food products were independently associated with IgG-seropositivity in a multivariate analysis adjusting for age and gender among 1562 participants who completed the questionnaire: traditional Dutch dry raw sausages called "cervelaat", "fijnkost", "salami" and "salametti" which are generally made from raw pork and beef (aOR 1.5; 95%CI 1.2-1.9), frequent consumption of bovine steak (aOR 1.3; 95%CI 1.0-1.7), and frequent consumption of smoked beef (aOR 1.3 95%CI 1.0-1.7). Although not frequently reported, contact with contaminated water was also a risk factor for seropositivity (aOR 2.5; 95%CI 1.5-4.4). Lower seroprevalence was associated with eating raspberries, going out for dinner, and contact with wild animals and dogs. Conclusion: Several pork food products, mainly dry raw sausages, and contact with contaminated water were associated with past HEV infection in the Netherlands. Further investigation is needed into the prevalence and infectivity of HEV in these risk factor food products, as well as investigation of the production methods and possible origin of HEV-contamination within these sausages, e.g. very small amounts of pork liver, pig-derived blood products as food additive, or the pork muscle tissue

Epidemiology of Lyme borreliosis and other tick-borne diseases in the Netherlands

Lyme borreliosis is caused by Borrelia burgdorferi sensu lato bacteria, and transmitted through tick bites. The disease most commonly manifests as erythema migrans, a slowly expanding skin lesion at the site of the tick bite. Disseminated Lyme borreliosis can develop when the infection spreads to the nervous system, joints, skin or sometimes the heart. Most patients with Lyme borreliosis recover after antibiotic treatment, but some experience persisting symptoms such as musculoskeletal pain, neurocognitive symptoms and fatigue. The research presented in this thesis provides insight in the epidemiology, disease burden and risk factors for Lyme borreliosis, and the incidence of other tick-borne infections. This is useful information for public health decision making and developing prevention strategies against Lyme borreliosis and other tick-borne diseases

A case-control study into risk factors for acute hepatitis E in the Netherlands, 2015-2017.

A case-control study was performed (2015-2017) to identify risk factors for acute hepatitis E in the Netherlands. A questionnaire on potential sources of hepatitis E virus (HEV) exposure, health and socio-demographics was completed by 376 patients with acute hepatitis E, and 1534 controls matched for age, gender and region of residence. Traditional Dutch dry raw sausages of pork muscle meat, called "cervelaat", "snijworst", and "boerenmetworst" were reported by 72% of the patients, and 46% of controls (aOR 3.0; 95%CI 2.2-4.1), with a population attributable fraction (PAF) of 48%. Direct contact with pigs and working with a septic tank were strong risk factors (aOR 3.1; 95%CI 1.3-7.3 and aOR 6.9; 95%CI 1.2-40.8, respectively), with a low PAF (2% and 1%, respectively). Host risk factors were pre-existing liver disease (aOR 3.8; 95%CI 2.0-7.1), diabetes (aOR 2.1; 95%CI 1.4-3.2), immunosuppressive medication (aOR 2.5; 95%CI 1.5-4.1), and gastric acid inhibitors (aOR 2.3; 95%CI 1.7-3.1). Dry raw pork sausages were the major source of HEV infection among our study population. The prevalence and cause of HEV contamination in these pork muscle meat products require further investigation. Infrequently reported, yet strong risk factors were contact with pigs, or a septic tank

Physician reported incidence of early and late Lyme borreliosis

Abstract Background Lyme borreliosis is the most common vector-borne disease in Europe and North America. The objective of this study is to estimate the incidence of tick bites and Lyme borreliosis, representative of our entire country, including erythema migrans, disseminated Lyme borreliosis and persisting symptoms attributed to Lyme borreliosis. Methods A questionnaire on clinical diagnoses of Lyme borreliosis was sent to all GPs, company physicians, and medical specialists. To adjust for possible misclassification and telescoping bias, we sent additional questionnaires to categorize reported cases according to likelihood of the diagnosis and to exclude cases diagnosed outside the target period. Results Adjusted annual incidence rate for disseminated Lyme borreliosis was 7.7 GP reports per 100,000 inhabitants, and for persisting symptoms attributed to Lyme borreliosis was 5.5 GP reports per 100,000 inhabitants, i.e. approximately 1,300 and 900 cases respectively. GP consultations for tick bites and erythema migrans diagnoses were 495 and 132 per 100,000 inhabitants, respectively, i.e. 82,000 and 22,000 cases in 2010. Conclusions This is the first reported nationwide physician survey on the incidence of tick bites and the whole range of manifestations of Lyme borreliosis, including persisting symptoms attributed to Lyme borreliosis. This is crucial for complete assessment of the public health impact of Lyme borreliosis

Decrease in tick bite consultations and stabilization of early Lyme borreliosis in the Netherlands in 2014 after 15 years of continuous increase

BackgroundNationwide surveys have shown a threefold increase in general practitioner (GP) consultations for tick bites and early Lyme borreliosis from 1994 to 2009 in the Netherlands. We now report an update on 2014, with identical methods as for the preceding GP surveys.MethodsTo all GPs in the Netherlands, a postal questionnaire was sent inquiring about the number of consultations for tick bites and erythema migrans diagnoses (most common manifestation of early Lyme borreliosis) in 2014, and the size of their practice populations.ResultsContrasting to the previously rising incidence of consultations for tick bites between 1994 and 2009, the incidence decreased in 2014 to 488 consultations for tick bites per 100,000 inhabitants, i.e., 82,000 patients nationwide. This survey revealed a first sign of stabilization of the previously rising trend in GP diagnosed erythema migrans, with 140 diagnoses per 100,000 inhabitants of the Netherlands. This equals about 23,500 annual diagnoses of erythema migrans nationwide in 2014.ConclusionsIn contrast to the constantly rising incidence of GP consultations for tick bites and erythema migrans diagnoses in the Netherlands between 1994 and 2009, the current survey of 2014 showed a first sign of stabilization of erythema migrans diagnoses and a decreased incidence for tick bite consultations.<br/