Hans L. Zaaijer

Silent hepatitis E virus infection in Dutch blood donors, 2011 to 2012

In Europe, the dynamics of endemic hepatitis E virus (HEV) infection remain enigmatic. We studied the presence of silent HEV infection among Dutch blood donors. Using donations collected throughout the Netherlands in 2011 and 2012, 40,176 donations were tested for HEV RNA in 459 pools of 48 or 480 donations. Deconstruction of the reactive pools identified 13 viraemic donors. In addition, 5,239 donors were tested for presence of anti-HEV IgG and IgM and for HEV RNA when IgM-positive. Of the 5,239 donations, 1,401 (27%) tested repeat-positive for HEV IgG, of which 49 (3.5%) also tested positive for anti-HEV IgM. Four of the HEV IgM-positive donors tested positive for HEV RNA. HEV IgG seroprevalence ranged from 13% among donors younger than 30 years to 43% in donors older than 60 years. The finding of 17 HEV RNA-positive donations among 45,415 donations corresponds to one HEV-positive blood donation per day in the Netherlands. For 16 of the 17 HEV RNA-positive donors, genotyping succeeded, revealing HEV genotype 3, which is circulating among Dutch pigs. Apparently, silent HEV infection is common in the Netherlands, which possibly applies to larger parts of Europe.

International collaborative study on the second EUROHEP HCV-RNA reference panel

Eighty-six laboratories participated in a collaborative study and tested the second EUROHEP HCV-RNA reference panel. The coded panel comprised 4 HCV-RNA positive plasma samples (one weak positive), 6 HCV-RNA negative plasma samples and two dilution series of HCV-RNA genotype 1 and 3 plasma standards. The 86 laboratories submitted 136 coded data forms for evaluation. Of these data sets 99 were tested using a PCR assay developed in-house, 28 using a commercially available HCV-PCR test (AMPLICOR, Roche Diagnostic Systems) and 9 using other amplification methods. Twenty-two data forms (16%) had faultless results, 39 (29%) missed the weak positive sample only and 75 data sets (55%) had false positive and/or false negative results. Participants using the commercial HCV-PCR test tended to reach a sufficient quality score more often than investigators using assays developed in-house (64% versus 45%, P = 0.11). The UNG system in the commercial HCV-PCR test did not prevent five laboratories generating false-positive results in the 6 HCV-RNA negative samples. Among the laboratories with satisfactory results, up to 10000-fold differences in sensitivity were observed in the dilution series. The 50% and 90% laboratories detection endpoints in the dilution series of the HCV genotype 1 plasma standard were approximately 600 genome equivalents per ml (geq/ml) and 7750 geq/ml according to a standard applied in a signal amplification assay (bDNA, Chiron). Our results suggest that the detection efficiency for genotype 3 by commercial HCV-RNA assays is lower than by the in-house assays. Internationally characterized HCV-RNA plasma standards should be made available for validation and standardization of HCV-RNA assays for HCV diagnosis and virological safety testing of blood products.

Fourth Human Parechovirus Serotype

We identified a novel human parechovirus (HPeV) type (K251176-02) from a neonate with fever. Analysis of the complete genome showed K251176-02 to be a new HPeV genotype. Since K251176-02 could not be neutralized with antibodies against known HPeV serotypes 1–3, it should be classified as a fourth HPeV serotype.

Cluster of Cases of Acute Hepatitis Associated with Hepatitis E Virus Infection Acquired in The Netherlands

Increasing evidence suggests that hepatitis E virus (HEV) infection may occur in developed countries and that swine may act as a reservoir. We report a cluster of 2 confirmed cases and 1 presumptive case of hepatitis associated with HEV. The typed strain from 1 case was related to HEV strains found in North America and Europe, and it was also related to a cluster of swine HEV strains found in The Netherlands. Our findings indicate that locally acquired HEV infections in industrialized countries may be overlooked. Routine testing for HEV infection in patients with acute hepatitis in The Netherlands should be considered before a diagnosis of autoimmune hepatitis is reached and steroid therapy is initiated.

Persistent humoral immune defect in highly active antiretroviral therapy-treated children with HIV-1 infection: loss of specific antibodies against attenuated vaccine strains and natural viral infection.

OBJECTIVE. In the pre–highly active antiretroviral therapy era, a loss of specific antibodies was seen. Our objective with this study was to describe the loss of specific antibodies during treatment with highly active antiretroviral therapy. METHODS. In a prospective, single-center, cohort study of 59 children with HIV-1 infection, we investigated the long-term effect of highly active antiretroviral therapy on the titers and course of specific antibodies against measles, mumps, and rubella vaccine strains compared with wild-type varicella zoster virus, cytomegalovirus, and Epstein-Barr virus. RESULTS. During highly active antiretroviral therapy, age-adjusted CD4+ T cells and B cells increased, whereas total immunoglobulin levels declined. Although these children were preimmunized before the start of highly active antiretroviral therapy, only 24 (43%) had antibodies against all 3 measles, mumps, and rubella. Antibodies against measles, mumps, and rubella were lost in 14 (40%), 11 (38%), and 5 (11%) children who were seropositive at baseline. We also observed loss of varicella zoster virus immunoglobulin G in 7 (21%) of 34, cytomegalovirus immunoglobulin G in 3 (7%) of 45, but none of 53 Epstein-Barr virus–seropositive children. During highly active antiretroviral therapy, primary vaccination in 3 patients and 15 revaccinations in those with negative serology demonstrated incomplete seroconversion. CONCLUSIONS. Humoral reactivity in children with HIV-1 infection remains abnormal during highly active antiretroviral therapy. Despite immune reconstitution, antibodies against live-attenuated vaccine and wild-type natural virus strains disappear over time in up to 40% of children with HIV-1 infection.

Long-Term Therapy With Tenofovir Is Effective for Patients Co-Infected With Human Immunodeficiency Virus and Hepatitis B Virus

BACKGROUND & AIMS We investigated the long-term efficacy and renal safety of tenofovir disoproxil fumarate (TDF), administered to patients co-infected with human immunodeficiency virus and hepatitis B virus (HBV) as part of an antiretroviral therapy. METHODS We performed a multicenter, prospective cohort study of 102 patients co-infected with human immunodeficiency virus and HBV who were treated with TDF. RESULTS At baseline, 80% of patients had a detectable viral load (HBV DNA >20 IU/mL). Among patients positive for hepatitis B e antigen (HBeAg) (n = 67), 92% had a virologic response (HBV DNA <20 IU/mL) after 5 years of treatment. There was no difference between patients with or without lamivudine resistance at baseline (P = .39). Loss rates of HBeAg and hepatitis B s antigen (HBsAg) were 46% and 12%, respectively. Among HBeAg-negative patients (n = 15), 100% had a virologic response after 4 years of treatment and 2 (13%) lost HBsAg. Twenty subjects (20%, all HBeAg-negative) had undetectable HBV DNA at baseline; during a median follow-up period of 52 months (interquartile range, 41-63 mo), 19 (95%) maintained a virologic response and 2 (10%) lost HBsAg. Overall, one patient acquired a combination of resistance mutations for anti-HBV drugs and experienced a virologic breakthrough. Three (3%) patients discontinued TDF because of increased serum creatinine levels. The estimated decrease in renal function after 5 years of TDF therapy was 9.8 mL/min/1.73 m(2), which was most pronounced shortly after TDF therapy was initiated. CONCLUSIONS TDF, administered as part of antiretroviral therapy, is a potent anti-HBV agent with a good resistance profile throughout 5 years of therapy. Only small nonprogressive decreases in renal function were observed.

Reliability of the third-generation recombinant immunoblot assay for hepatitis C virus

BACKGROUND: In a confirmatory laboratory, the second‐generation recombinant immunoblot assay (RIBA‐2) was replaced by the third‐ generation RIBA (RIBA‐3) in March 1993. The aim of this validation study was to compare the sensitivity and specificity of RIBA‐2 and RIBA‐ 3 in a routine setting, by using a validated hepatitis C virus (HCV) RNA polymerase chain reaction to establish plasma viremia.

Coxiella burnetii infection among blood donors during the 2009 Q-fever outbreak in The Netherlands.

BACKGROUND: In 2007, 2008, and 2009 outbreaks of Q‐fever occurred in the Netherlands with increasing magnitude. The 2009 outbreak with 2354 reported cases is the largest human Q‐fever outbreak ever recorded. To assess the extent of infection and the safety of donated blood, we tested local blood donations for presence of Coxiella burnetii antibodies and DNA.

Fatal human rabies due to duvenhage virus from a bat in Kenya: failure of treatment with coma-induction, ketamine, and antiviral drugs.

11Department of Infectious Diseases, Tropical Medicine and AIDS, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, 2Department ofNeurology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, 3Department of Intensive Care, Academic Medical Center, University ofAmsterdam, Amsterdam, The Netherlands, 4Department of Clinical Virology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands,5Department of Virology, Erasmus Medical Centre, Rotterdam, The Netherlands, 6Department of Radiology, Academic Medical Center, University of Amsterdam,Amsterdam, The Netherlands, 7Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, 8Centre of Expertise forRabies, Canadian Food Inspection Agency, Ottawa Laboratory (Fallowfield), Ottawa, Ontario, Canada

Follow-up of 686 patients with acute Q fever and detection of chronic infection

BACKGROUND Recent outbreaks in the Netherlands allowed for laboratory follow-up of a large series of patients with acute Q fever and for evaluation of test algorithms to detect chronic Q fever, a condition with considerable morbidity and mortality. METHODS For 686 patients with acute Q fever, IgG antibodies to Coxiella burnetii were determined using an immunofluorescence assay at 3, 6, and 12 months of follow-up. Polymerase chain reaction (PCR) was performed after 12 months and on earlier serum samples with an IgG phase I antibody titer ≥ 1:1024. RESULTS In 43% of patients, the IgG phase II antibody titers remained high (≥ 1:1024) at 3, 6, and 12 months of follow-up. Three months after acute Q fever, 14% of the patients had an IgG phase I titer ≥ 1:1024, which became negative later in 81%. IgG phase I antibody titers were rarely higher than phase II titers. Eleven cases of chronic Q fever were identified on the basis of serological profile, PCR results, and clinical presentation. Six of these patients were known to have clinical risk factors at the time of acute Q fever. In a comparison of various serological algorithms, IgG phase I titer ≥ 1:1024 at 6 months had the most favorable sensitivity and positive predictive value for the detection of chronic Q fever. CONCLUSIONS The wide variation of serological and PCR results during the follow-up of acute Q fever implies that the diagnosis of chronic Q fever, necessitating long-term antibiotic treatment, must be based primarily on clinical grounds. Different serological follow-up strategies are needed for patients with and without known risk factors for chronic Q fever.