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

Past and present of hepatitis E in the Netherlands

Recent studies show that endemic hepatitis E virus (HEV) infection occurs frequently in some developed countries. In the Netherlands in 2013, the routine screening of 35,220 plasma donations for HEV RNA showed 20 donors to be viremic (1:1761), which seems to contradict reports of declining HEV seroprevalence in the recent past. To asses HEV infection pressure changes over time, archived samples from Dutch blood donations collected in 1988 and 2000 were tested for anti-HEV immunoglobulin (Ig)G. The findings were compared to the HEV seroprevalence among donors in 2011. The age-adjusted prevalence of anti-HEV IgG for Dutch donors aged 18 to 64 declined from 46.6% in 1988 to 27.3% in 2000 and to 20.9% in 2011. The reduction of seroprevalence was apparent for all age groups between 1988 and 2000, and for donors older than 40 between 2000 and 2011, but the seroprevalence among donors aged 18 to 29 increased between 2000 and 2011. Recent changes in HEV infection pressure are more apparent in the youngest donors, who to a lesser extent reflect cumulative exposure to HEV in the past. Donors aged 18 to 21 showed decreasing HEV seroprevalence from 19.8% in 1988 to 7.0% in 1995 and to 4.3% in 2000, followed by an increase to 12.7% in 2011. HEV antibody patterns in young and old Dutch donors, in 1988 to 2011, suggest that decades ago, HEV was ubiquitous and most persons acquired infection. Subsequently HEV incidence was low during a prolonged period, to increase again in recent year

Screening of blood donors for chronic Coxiella burnetii infection after large Q fever outbreaks

The Netherlands experienced major Q fever outbreaks from 2007 through 2009. An increasing number of human chronic Q fever cases has been reported in the affected area. Blood donors unaware of chronic Coxiella burnetii infection might be infectious for transfusion recipients. Local blood donations were screened for serologic signs of chronic Coxiella infection. From August 2012 through January 2013, a total of 2490 serum samples were collected from all consenting blood donors in the most affected Q fever outbreak area and screened for Phase II anti-Coxiella immunoglobulin G antibodies using an enzyme-linked immunosorbent assay (ELISA). (Phase II antibodies are considered indicative for resolved or ongoing Coxiella infection.) Reactive samples were confirmed by quantitative immunofluorescent Phase I and II antibody testing. A Phase I antibody titer of at least 1024 was considered indicative for chronic Coxiella infection. For 179 donors archived samples from 2009 and 2010 were available to study the long-term course of Coxiella antibodies. A total of 110 of 2490 donors were confirmed positive for Phase II Coxiella antibodies (4.4%; 95% confidence interval, 3.7%-5.3%), of which 79 were reactive for Phase I antibodies, with a maximum titer of 256. In 15 of 24 donors (62.5%), testing positive for Phase II antibodies in 2009 and 2010, ELISA reactivity had declined to negativity in 2012 and 2013. After large Q fever outbreaks in the Netherlands, no sign of potentially infectious chronic Coxiella infection was found among blood donors in the most affected area. Using an ELISA for detection, Coxiella antibodies in previously exposed donors waned quickl

An Evaluation of Hepatitis E Virus Molecular Typing Methods

Background: Hepatitis E virus (HEV) is a major cause of acute viral hepatitis. Better understanding of HEV subtypes involved in hepatitis E infections is essential. Investigation of sources and routes of transmission and the identification of potential clusters/outbreaks rely upon molecular typing of viral strains. A study was carried out to evaluate the ability of laboratories to undertake molecular typing with genotype and subtype determination. Methods: A blinded panel of 11 different Orthohepevirus A strains was distributed to 28 laboratories performing HEV sequence analysis. Laboratories used their routine HEV sequencing and genotyping methods. Results: Results were returned by 25 laboratories. Overall, 93% samples were assigned to the correct genotype and 81% were assigned to the correct subtype. Fragments amplified for typing ranged in size and the sequencing assays targeted both the structural and non-structural protein-coding regions. There was good agreement between the reported sequences where methods targeted overlapping fragments. In some cases, incorrect genotypes/subtypes were reported, including those not contained in the panel, and in one case, a genotype was reported for a blinded control sample containing Zika virus; collectively these data indicate contamination problems. Conclusions: In general, identification of genotypes was good; however, in a small number of cases, there was a failure to generate sequences from some of the samples. There was generally broad agreement between the use of online typing tools such as the one provided by HEVnet and curated lists of published HEV reference sequences; however, going forward harmonization between these resources is essential

Risk Factors and Screening for Trypanosoma cruzi Infection of Dutch Blood Donors.

BACKGROUND:Blood donors unaware of Trypanosoma cruzi infection may donate infectious blood. Risk factors and the presence of T. cruzi antibodies in at-risk Dutch blood donors were studied to assess whether specific blood safety measures are warranted in the Netherlands. METHODOLOGY:Birth in a country endemic for Chagas disease (CEC), having a mother born in a CEC, or having resided for at least six continuous months in a CEC were considered risk factors for T. cruzi infection. From March through September 2013, risk factor questions were asked to all donors who volunteered to donate blood or blood components. Serum samples were collected from donors reporting one or more risk factors, and screened for IgG antibodies to T. cruzi by EIA. RESULTS:Risk factors for T. cruzi infection were reported by 1,426 of 227,278 donors (0.6%). Testing 1,333 at-risk donors, none (0.0%; 95%, CI 0.0-0.4%) was seroreactive for IgG antibodies to T. cruzi. A total of 472 donors were born in a CEC; 553 donors reported their mother being born in a CEC; and 1,121 donors reported a long-term stay in a CEC. The vast majority of reported risk factors were related to Suriname and Brazil. Overall, the participants resided for 7,694 years in CECs, which equals 2.8 million overnight stays. Of those, 1.9 million nights were spent in Suriname. CONCLUSIONS/SIGNIFICANCE:Asymptomatic T. cruzi infection appears to be extremely rare among Dutch blood donors. Blood safety interventions to mitigate the risk of T. cruzi transmission by transfusion would be highly cost-ineffective in the Netherlands, and are thus not required

Meat consumption is a major risk factor for hepatitis E virus infection

The incidence of autochthonous hepatitis E virus genotype 3 (HEV gt3) infections in Western Europe is high. Although pigs are a major reservoir of the virus, the exact sources and transmission route(s) of HEV gt3 to humans remain unclear. To determine the role of meat consumption at a population level, the seroprevalence of anti-HEV IgG antibodies was compared between Dutch blood donors with a vegetarian lifestyle and donors who consume meat on a daily basis. The age-weighted anti-HEV IgG seroprevalence among donors not eating meat was significantly lower than among meat-eating donors (12.4% vs 20.5%, p = 0.002). For both groups the prevalence strongly increased with age and the difference in prevalence was apparent for all age groups. Compared with meat-eating donors, the incidence of HEV infection is significantly lower among donors not eating meat, indicating that meat consumption is a major risk factor for HEV infectio

Usutu virus infection in Dutch blood donors

BACKGROUND: The screening of Dutch blood donations for West Nile virus (WNV) may be imminent, as WNV emerges in nearby countries and more donors travel to WNV-affected regions. Since 2016 the related, mosquito-borne Usutu virus (USUV) causes seasonal mortality in Dutch birds. To what extent will human USUV infections affect Dutch WNV donor screening?. STUDY DESIGN AND METHODS: From April through September 2018, plasma samples from blood donations in blackbird-rich regions were stored. When increased bird mortality was reported in August, samples from July, August, and September were tested for USUV-RNA in pools of eight, using a home-brew combined WNV/USUV-PCR assay. Reactive pools were deconstructed. Original plasma units and samples of previous and follow-up donations of reactive donors were tested for USUV- and WNV-RNA, and for antibody responses. RESULTS: The number of USUV RNA-positive, WNV RNA-negative donations was 0 of 2688 donations in July, 6 of 4416 in August (1:736), and 1 of 4936 in September. The seven infected donors tested negative for USUV-RNA in preceding and follow-up donations. For 6 donors, seroconversion for USUV-antibodies was demonstrated. All index donations tested positive in a commonly used PCR-assay for WNV donor screening. Three exposed recipients did not show signs of infection. Screening a random subset of 1092 donations from September for USUV-IgG antibodies showed that 22 donors tested reactive; for three donors retrospective testing identified an USUV PCR-positive pre-seroconversion donation. CONCLUSION: Seasonal USUV infection in Dutch blood donors is common. Cross-reactivity in molecular assays for WNV-screening occurs, but can be resolved using USUV- and WNV-specific PCR-primers and sequencing of viral RNA

Distribution of risk factors for <i>T</i>. <i>cruzi</i> infection over donor age groups in the Netherlands.

<p>Distribution of risk factors for <i>T</i>. <i>cruzi</i> infection over donor age groups in the Netherlands.</p

Comparison of Hepatitis E Virus Sequences from Humans and Swine, The Netherlands, 1998–2015

Pigs are suspected to be a major source of zoonotic hepatitis E virus (HEV) infection in industrialized countries, but the transmission route(s) from pigs to humans are ill-defined. Sequence comparison of HEV isolates from pigs with those from blood donors and patients in 372 samples collected in The Netherlands in 1998 and 1999 and between 2008 and 2015 showed that all sequences were genotype 3 except for six patients (with travel history). Subgenotype 3c (gt3c) was the most common subtype. While the proportion of gt3c increased significantly between 1998 and 2008, it remained constant between 2008 and 2015. Among the few circulating HEV subtypes, there was no difference observed between the human and the pig isolates. Hepatitis E viruses in humans are very likely to originate from pigs, but it is unclear why HEV gt3c has become the predominant subtype in The Netherlands

Distribution of EIA signals in serum samples screened for presence of IgG antibodies to <i>Trypanosoma cruzi</i>.

<p>The samples were collected from 1,333 Dutch blood donors reporting risk factors for <i>T</i>. <i>cruzi</i> infection. A sample-to-cutoff (S/CO) value < 1.0 is considered negative, indicating the absence of <i>T</i>. <i>cruzi</i> antibodies.</p