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1.
Nature ; 544(7650): 309-315, 2017 04 20.
Article in English | MEDLINE | ID: mdl-28405027

ABSTRACT

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics.


Subject(s)
Ebolavirus/genetics , Ebolavirus/physiology , Genome, Viral/genetics , Hemorrhagic Fever, Ebola/transmission , Hemorrhagic Fever, Ebola/virology , Climate , Disease Outbreaks/statistics & numerical data , Ebolavirus/isolation & purification , Geography , Hemorrhagic Fever, Ebola/epidemiology , Humans , Internationality , Linear Models , Molecular Epidemiology , Phylogeny , Travel/legislation & jurisprudence , Travel/statistics & numerical data
2.
BMC Med ; 20(1): 406, 2022 10 24.
Article in English | MEDLINE | ID: mdl-36280827

ABSTRACT

BACKGROUND: The diagnostic accuracy of unsupervised self-testing with rapid antigen diagnostic tests (Ag-RDTs) is mostly unknown. We studied the diagnostic accuracy of a self-performed SARS-CoV-2 saliva and nasal Ag-RDT in the general population. METHODS: This large cross-sectional study consecutively included unselected individuals aged ≥ 16 years presenting for SARS-CoV-2 testing at three public health service test sites. Participants underwent molecular test sampling and received two self-tests (the Hangzhou AllTest Biotech saliva self-test and the SD Biosensor nasal self-test by Roche Diagnostics) to perform themselves at home. Diagnostic accuracy of both self-tests was assessed with molecular testing as reference. RESULTS: Out of 2819 participants, 6.5% had a positive molecular test. Overall sensitivities were 46.7% (39.3-54.2%) for the saliva Ag-RDT and 68.9% (61.6-75.6%) for the nasal Ag-RDT. With a viral load cut-off (≥ 5.2 log10 SARS-CoV-2 E-gene copies/mL) as a proxy of infectiousness, these sensitivities increased to 54.9% (46.4-63.3%) and 83.9% (76.9-89.5%), respectively. For the nasal Ag-RDT, sensitivities were 78.5% (71.1-84.8%) and 22.6% (9.6-41.1%) in those symptomatic and asymptomatic at the time of sampling, which increased to 90.4% (83.8-94.9%) and 38.9% (17.3-64.3%) after applying the viral load cut-off. In those with and without prior SARS-CoV-2 infection, sensitivities were 36.8% (16.3-61.6%) and 72.7% (65.1-79.4%). Specificities were > 99% and > 99%, positive predictive values > 70% and > 90%, and negative predictive values > 95% and > 95%, for the saliva and nasal Ag-RDT, respectively, in most analyses. Most participants considered the self-performing and result interpretation (very) easy for both self-tests. CONCLUSIONS: The Hangzhou AllTest Biotech saliva self Ag-RDT is not reliable for SARS-CoV-2 detection, overall, and in all studied subgroups. The SD Biosensor nasal self Ag-RDT had high sensitivity in individuals with symptoms and in those without prior SARS-CoV-2 infection but low sensitivity in asymptomatic individuals and those with a prior SARS-CoV-2 infection which warrants further investigation.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19/diagnosis , Cross-Sectional Studies , COVID-19 Testing , Saliva , Sensitivity and Specificity , Antigens, Viral
3.
BMC Med ; 20(1): 97, 2022 02 24.
Article in English | MEDLINE | ID: mdl-35197052

ABSTRACT

BACKGROUND: Rapid antigen diagnostic tests (Ag-RDTs) are the most widely used point-of-care tests for detecting SARS-CoV-2 infection. Since the accuracy may have altered by changes in SARS-CoV-2 epidemiology, indications for testing, sampling and testing procedures, and roll-out of COVID-19 vaccination, we evaluated the performance of three prevailing SARS-CoV-2 Ag-RDTs. METHODS: In this cross-sectional study, we consecutively enrolled individuals aged >16 years presenting for SARS-CoV-2 testing at three Dutch public health service COVID-19 test sites. In the first phase, participants underwent either BD-Veritor System (Becton Dickinson), PanBio (Abbott), or SD-Biosensor (Roche Diagnostics) testing with routine sampling procedures. In a subsequent phase, participants underwent SD-Biosensor testing with a less invasive sampling method (combined oropharyngeal-nasal [OP-N] swab). Diagnostic accuracies were assessed against molecular testing. RESULTS: Six thousand nine hundred fifty-five of 7005 participants (99%) with results from both an Ag-RDT and a molecular reference test were analysed. SARS-CoV-2 prevalence and overall sensitivities were 13% (188/1441) and 69% (129/188, 95% CI 62-75) for BD-Veritor, 8% (173/2056) and 69% (119/173, 61-76) for PanBio, and 12% (215/1769) and 74% (160/215, 68-80) for SD-Biosensor with routine sampling and 10% (164/1689) and 75% (123/164, 68-81) for SD-Biosensor with OP-N sampling. In those symptomatic or asymptomatic at sampling, sensitivities were 72-83% and 54-56%, respectively. Above a viral load cut-off (≥5.2 log10 SARS-CoV-2 E-gene copies/mL), sensitivities were 86% (125/146, 79-91) for BD-Veritor, 89% (108/121, 82-94) for PanBio, and 88% (160/182, 82-92) for SD-Biosensor with routine sampling and 84% (118/141, 77-89) with OP-N sampling. Specificities were >99% for all tests in most analyses. Sixty-one per cent of false-negative Ag-RDT participants returned for testing within 14 days (median: 3 days, interquartile range 3) of whom 90% tested positive. CONCLUSIONS: Overall sensitivities of three SARS-CoV-2 Ag-RDTs were 69-75%, increasing to ≥86% above a viral load cut-off. The decreased sensitivity among asymptomatic participants and high positivity rate during follow-up in false-negative Ag-RDT participants emphasise the need for education of the public about the importance of re-testing after an initial negative Ag-RDT should symptoms develop. For SD-Biosensor, the diagnostic accuracy with OP-N and deep nasopharyngeal sampling was similar; adopting the more convenient sampling method might reduce the threshold for professional testing.


Subject(s)
COVID-19 , Adolescent , Antigens, Viral/analysis , COVID-19 Testing , COVID-19 Vaccines , Cross-Sectional Studies , Humans , SARS-CoV-2 , Sensitivity and Specificity
4.
Emerg Infect Dis ; 25(7): 1394-1396, 2019 07.
Article in English | MEDLINE | ID: mdl-31008703

ABSTRACT

We evaluated the benefit of whole blood versus plasma to detect acute Zika virus infections. Comparison of Zika virus quantitative reverse transcription PCR results in single timepoint whole blood-plasma pairs from 227 patients with suspected Zika virus infection resulted in confirmation of 8 additional patients with Zika virus infection.


Subject(s)
Diagnostic Tests, Routine , Serologic Tests , Zika Virus Infection/diagnosis , Zika Virus Infection/virology , Zika Virus , Algorithms , Diagnostic Tests, Routine/methods , Humans , RNA, Viral/blood , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Serologic Tests/methods , Zika Virus/classification , Zika Virus/genetics
5.
J Infect Dis ; 218(5): 688-697, 2018 07 24.
Article in English | MEDLINE | ID: mdl-29617822

ABSTRACT

Background: A high genetic barrier to resistance to the integrase strand transfer inhibitor (INSTI) dolutegravir has been reported in vitro and in vivo. We describe the dynamics of INSTI resistance-associated mutations (INSTI-RAMs) and mutations in the 3'-polypurine tract (3'-PPT) in relation to virologic failure (VF) observed in the randomized Dolutegravir as Maintenance Monotherapy for HIV-1 study (DOMONO, NCT02401828). Methods: From 10 patients with VF, plasma samples were collected before the start of cART and during VF, and were used to generate Sanger sequences of integrase, the 5' terminal bases of the 3' long terminal repeat (LTR), and the 3'-PPT. Results: Median human immunodeficiency virus RNA load at VF was 3490 copies/mL (interquartile range 1440-4990 copies/mL). INSTI-RAMs (S230R, R263K, N155H, and E92Q+N155H) were detected in 4 patients, no INSTI-RAMs were detected in 4 patients, and sequencing of the integrase gene was unsuccessful in 2 patients. The time to VF ranged from 4 weeks to 72 weeks. In 1 patient, mutations developed in the highly conserved 3'-PPT. No changes in the terminal bases of the 3'-LTR were observed. Conclusions: The genetic barrier to resistance is too low to justify dolutegravir maintenance monotherapy because single INSTI-RAMs are sufficient to cause VF. The large variation in time to VF suggests that stochastic reactivation of a preexisting provirus containing a single INSTI-RAM is the mechanism for failure. Changes in the 3'-PPT point to a new dolutegravir resistance mechanism in vivo. Clinical Trials Registration: NCT02401828.


Subject(s)
Drug Resistance, Viral , HIV Infections/drug therapy , HIV Infections/virology , HIV Integrase Inhibitors/administration & dosage , HIV-1/drug effects , Heterocyclic Compounds, 3-Ring/administration & dosage , Mutation , Adult , Female , HIV-1/isolation & purification , Humans , Maintenance Chemotherapy/methods , Male , Middle Aged , Oxazines , Piperazines , Pyridones , Randomized Controlled Trials as Topic , Sequence Analysis, DNA , Treatment Failure , Viral Load
6.
Liver Int ; 38(5): 792-796, 2018 05.
Article in English | MEDLINE | ID: mdl-29285885

ABSTRACT

BACKGROUND AND AIMS: Infection with Hepatitis E virus (HEV) can cause chronic liver disease in immunocompromised hosts. In transplant recipients, the use of certain immunosuppressants and food habits has been proposed as risk factors for HEV. In individuals infected with the human immunodeficiency virus (HIV), risk factors for HEV infection are less clear. We aimed to study the association between a mutation in the progesterone receptor (PR) named PROGINS and HEV-infected in HIV-positive individuals. METHODS: We evaluated the presence of the SNP PROGINS via KASP in serum samples of 64 HIV-positive individuals and 187 healthy controls. We performed ELISA tests to address the serum levels of IL-10 and IL-12, as well as T-cell stimulation assays in peripheral blood to address immune response in individuals with PROGINS. RESULTS: We found a significant association between the presence of PROGINS mutation and HEV seroprevalence in individuals infected with HIV (30% in HIV+/HEV+ versus 2% in HIV+/HEV, respectively, P = .009). Moreover, we found that HIV+/HEV+ individuals expressing the PROGINS mutation had lower serum levels of IL-10 and higher levels of IL-12. The presence of the mutation led to a reduced response upon stimulation of CD4+ and CD8+ T cells compared to those without the mutation, suggesting an immune modulation associated with PROGINS. CONCLUSIONS: Our study identified a mutation in the PR that provides significant insights into mechanisms of HEV infection in immunosuppressed individuals.


Subject(s)
Genetic Predisposition to Disease , HIV Seropositivity/complications , Hepatitis E/genetics , Receptors, Progesterone/genetics , Adult , CD4 Lymphocyte Count , Case-Control Studies , Female , Hepatitis E virus , Humans , Immunocompromised Host , Interleukin-10/blood , Interleukin-12/blood , Male , Middle Aged , Mutation , Polymorphism, Single Nucleotide , Risk Factors , Seroepidemiologic Studies , Transplant Recipients
7.
BMC Infect Dis ; 18(1): 251, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29859062

ABSTRACT

BACKGROUND: HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe. METHODS: This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence. The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence. RESULTS: At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32-3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by analysing drug-naïve patients (29.5% vs 21.2%, P = 0.032). Strong correlation was observed between sP120T and rtM204I/V (P < 0.001), and their co-presence determined an increased HBV-DNA. At least one NA-induced immune-escape mutation occurred in 28.6% of patients, and their selection correlated with genotype-A (OR[95%CI]:2.03[1.32-3.10],P = 0.001). Finally, stop-codons are present in 8.4% of patients also at HBsAg-positions 172 and 182, described to enhance viral oncogenic-properties. CONCLUSIONS: Immune-escape mutations and stop-codons develop in a large fraction of NA-exposed patients from Europe. This may represent a potential threat for horizontal and vertical HBV transmission also to vaccinated persons, and fuel drug-resistance emergence.


Subject(s)
Antiviral Agents/therapeutic use , Codon, Terminator , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/immunology , Mutation , Adult , Amino Acid Substitution , Europe , Female , Genotype , Hepatitis B Surface Antigens/immunology , Hepatitis B virus/immunology , Hepatitis B, Chronic/drug therapy , Hepatitis B, Chronic/virology , Humans , Male , Middle Aged
8.
J Hepatol ; 66(5): 1082-1095, 2017 05.
Article in English | MEDLINE | ID: mdl-27913223

ABSTRACT

Hepatitis E virus (HEV) infections are not limited to the liver but may also affect other organs. Several diseases, including Guillain-Barré syndrome, neuralgic amyotrophy, glomerulonephritis, cryoglobulinemia, pancreatitis, lymphoma, thrombopenia, meningitis, thyroiditis and myocarditis have been observed in the context of hepatitis E. To date, the definite pathophysiological links between HEV and extrahepatic manifestations are not yet established. However, it is suggested that HEV infection might be causative based on serological studies, case series, in vitro data and animal models. In particular, neuronal and renal diseases as well as pancreatitis seem to be caused by HEV, while a causative relationship between HEV and other diseases is more doubtful. Either direct cytopathic tissue damage by extrahepatic replication, or immunological processes induced by an overwhelming host immune response, are possible origins of HEV-associated extrahepatic manifestations. Hepatologists should be aware of the possibility that acute or chronically HEV-infected patients could develop extrahepatic manifestations. Neurologists, nephrologists, rheumatologists and other groups of physicians should consider HEV infection as a potential differential diagnosis when observing one of the diseases described in this review. Ribavirin and steroids have been used in small groups of patients with extrahepatic manifestations of HEV, but the efficacy of these drugs still needs to be verified by large, multicenter studies. This article comprehensively reviews the published literature regarding HEV and extrahepatic manifestations. We discuss the probability of specific extrahepatic diseases being caused by previous or ongoing HEV infection, and summarize the published knowledge about antiviral treatment in extrahepatic disorders.


Subject(s)
Hepatitis E/complications , Animals , Brachial Plexus Neuritis/etiology , Guillain-Barre Syndrome/etiology , Hepatitis, Autoimmune/etiology , Humans , Kidney Diseases/etiology , Mental Disorders/etiology , Monoclonal Gammopathy of Undetermined Significance/etiology , Pancreatitis/etiology , Thrombocytopenia/etiology
9.
J Gen Virol ; 98(6): 1294-1298, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28597817

ABSTRACT

Patients in high-risk groups continue to transmit the hepatitis C virus (HCV) and frequently experience reinfections. Since little is known regarding the immune response to HCV during reinfection, we compared primary and consecutive acute HCV infections in patients with an HIV infection, and focused on the cytokine bridging innate to adaptive immunity. We observed that the serum levels of IL-12p40, MIP-1ß, MIG and IP-10 increased during primary acute HCV infection, but not during subsequent secondary acute reinfections. The weaker pro-inflammatory cytokine responses observed during HCV reinfections suggest more limited secondary acute immune responses, which may prevent damage to the infected liver.


Subject(s)
Coinfection/immunology , Cytokines/blood , HIV Infections/complications , Hepacivirus/immunology , Hepatitis C/complications , Hepatitis C/immunology , Adaptive Immunity , Coinfection/pathology , Hepatitis C/pathology , Humans , Immunity, Innate , Recurrence , Retrospective Studies
10.
J Virol ; 90(9): 4394-401, 2016 May.
Article in English | MEDLINE | ID: mdl-26889028

ABSTRACT

UNLABELLED: Genotype 3 (gt3) hepatitis E virus (HEV) infections are emerging in Western countries. Immunosuppressed patients are at risk of chronic HEV infection and progressive liver damage, but no adequate model system currently mimics this disease course. Here we explore the possibilities of in vivo HEV studies in a human liver chimeric mouse model (uPA(+/+)Nod-SCID-IL2Rγ(-/-)) next to the A549 cell culture system, using HEV RNA-positive EDTA-plasma, feces, or liver biopsy specimens from 8 immunocompromised patients with chronic gt3 HEV. HEV from feces- or liver-derived inocula showed clear virus propagation within 2 weeks after inoculation onto A549 cells, compared to slow or no HEV propagation of HEV RNA-positive, EDTA-plasma samples. These in vitro HEV infectivity differences were mirrored in human-liver chimeric mice after intravenous (i.v.) inoculation of selected samples. HEV RNA levels of up to 8 log IU HEV RNA/gram were consistently present in 100% of chimeric mouse livers from week 2 to week 14 after inoculation with human feces- or liver-derived HEV. Feces and bile of infected mice contained moderate to large amounts of HEV RNA, while HEV viremia was low and inconsistently detected. Mouse-passaged HEV could subsequently be propagated for up to 100 days in vitro In contrast, cell culture-derived or seronegative EDTA-plasma-derived HEV was not infectious in inoculated animals. In conclusion, the infectivity of feces-derived human HEV is higher than that of EDTA-plasma-derived HEV both in vitro and in vivo Persistent HEV gt3 infections in chimeric mice show preferential viral shedding toward mouse bile and feces, paralleling the course of infection in humans. IMPORTANCE: Hepatitis E virus (HEV) genotype 3 infections are emerging in Western countries and are of great concern for immunosuppressed patients at risk for developing chronic HEV infection. Lack of adequate model systems for chronic HEV infection hampers studies on HEV infectivity and transmission and antiviral drugs. We compared the in vivo infectivity of clinical samples from chronic HEV patients in human liver chimeric mice to an in vitro virus culture system. Efficient in vivo HEV infection is observed after inoculation with feces- and liver-derived HEV but not with HEV RNA-containing plasma or cell culture supernatant. HEV in chimeric mice is preferentially shed toward bile and feces, mimicking the HEV infection course in humans. The observed in vivo infectivity differences may be relevant for the epidemiology of HEV in humans. This novel small-animal model therefore offers new avenues to unravel HEV's pathobiology.


Subject(s)
Genotype , Hepatitis E virus/genetics , Hepatitis E/virology , Animals , Cell Line , Chronic Disease , Disease Models, Animal , Hepatitis E virus/metabolism , Hepatocytes/transplantation , Hepatocytes/virology , Host-Pathogen Interactions , Humans , Mice , Viral Load , Virus Replication
11.
Euro Surveill ; 22(11)2017 Mar 16.
Article in English | MEDLINE | ID: mdl-28333617

ABSTRACT

A Dutch traveller returning from Suriname in early March 2017, presented with fever and severe acute liver injury. Yellow fever was diagnosed by (q)RT-PCR and sequencing. During hospital stay, the patient's condition deteriorated and she developed hepatic encephalopathy requiring transfer to the intensive care. Although yellow fever has not been reported in the last four decades in Suriname, vaccination is recommended by the World Health Organization for visitors to this country.


Subject(s)
Insect Vectors/virology , Travel , Yellow Fever/diagnosis , Yellow fever virus/isolation & purification , Adult , Animals , Anti-Bacterial Agents/therapeutic use , Doxycycline/therapeutic use , Female , Humans , Insect Bites and Stings , Netherlands , Reverse Transcriptase Polymerase Chain Reaction , Suriname , Treatment Outcome , Yellow Fever/blood , Yellow Fever/drug therapy , Yellow fever virus/genetics
12.
Hepatology ; 62(1): 87-100, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25808668

ABSTRACT

UNLABELLED: To identify immunological mechanisms that govern distinct clinical phases of a chronic hepatitis B virus (HBV) infection-immune tolerant (IT), immune active (IA), inactive carrier (IC), and hepatitis B e antigen (HBeAg)-negative (ENEG) hepatitis phases-we performed a systems biology study. Serum samples from untreated chronic HBV patients (n = 71) were used for multiplex cytokine measurements, quantitative hepatitis B surface antigen (HBsAg), HBeAg levels, HBV genotype, and mutant analysis. Leukocytes were phenotyped using multicolor flow cytometry, and whole-blood transcriptome profiles were generated. The latter were compared with liver biopsy transcriptomes from IA (n = 16) and IT (n = 3) patients. HBV viral load as well as HBeAg and HBsAg levels (P < 0.001), but not leukocyte composition, differed significantly between distinct phases. Serum macrophage chemotactic protein 1, interleukin-12p40, interferon (IFN)-gamma-inducible protein 10, and macrophage inflammatory protein 1 beta levels were different between two or more clinical phases (P < 0.05). Comparison of blood transcriptomes identified 64 differentially expressed genes. The gene signature distinguishing IA from IT and IC patients was predominantly composed of highly up-regulated immunoglobulin-encoding genes. Modular repertoire analysis using gene sets clustered according to similar expression patterns corroborated the abundant expression of B-cell function-related genes in IA patients and pointed toward increased (ISG) transcript levels in IT patients, compared to subsequent phases. Natural killer cell activities were clustered in clinical phases with biochemical liver damage (IA and ENEG phases), whereas T-cell activities were higher in all phases, compared to IT patients. B-cell-related transcripts proved to be higher in biopsies from IA versus IT patients. CONCLUSION: HBV clinical phases are characterized by distinct blood gene signatures. Innate IFN and B-cell responses are highly active during the IT and IA phases, respectively. This suggests that the presumed immune tolerance in chronic HBV infections needs to be redefined.


Subject(s)
Gene Expression Profiling , Hepatitis B, Chronic/blood , Hepatitis B, Chronic/immunology , Transcriptome , Adult , Cytokines/blood , Female , Flow Cytometry , Hepatitis B/genetics , Humans , Immunity, Innate , Immunophenotyping , Male , Middle Aged , Systems Biology , Viral Core Proteins/genetics , Young Adult
13.
J Med Virol ; 88(6): 1035-43, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26629781

ABSTRACT

Although hepatitis B virus (HBV) infection is hyperendemic in Ethiopia and constitutes a major public health problem, little is known about its genetic diversity, genotypes, and circulation. The aim of this study was to determine the molecular epidemiology and genetic diversity of HBV in Ethiopia, using 391 serum samples collected from HBsAg-positive blood donors living in five different geographic regions. The HBV S/pol gene was amplified, sequenced, and HBV genotypes, subgenotypes, serotypes, and major hydrophilic region (MHR) variants were determined. Phylogenetic analysis of 371 samples (95%) revealed the distribution of genotypes A (78%) and D (22%) in Ethiopia. Further phylogenetic analysis identified one subgenotype (A1) within genotype A, and 4 subgenotypes within genotype D (D1; 1.3%, D2; 55%, D4; 2.5%, and D6; 8.8%). Importantly, 24 isolates (30%) of genotype D formed a novel phylogenetic cluster, distinct from any known D subgenotypes, and two A/D recombinants. Analysis of predicted amino-acid sequences within the HBsAg revealed four serotypes: adw2 (79%), ayw1 (3.1%), ayw2 (7.8%), and ayw3 (11.6%). Subsequent examination of sequences showed that 51 HBV isolates (14%) had mutations in the MHR and 8 isolates (2.2%) in the reverse transcriptase known to confer antiviral resistance. This study provides the first description of HBV genetic diversity in Ethiopia with a predominance of subgenotypes A1 and D2, and also identified HBV isolates that could represent a novel subgenotype. Furthermore, a significant prevalence of HBsAg variants in Ethiopian population is revealed.


Subject(s)
Genetic Variation , Hepatitis B virus/genetics , Hepatitis B, Chronic/epidemiology , Hepatitis B, Chronic/virology , Hepatitis B/epidemiology , Hepatitis B/virology , Adolescent , Adult , Amino Acid Sequence , Antibodies, Viral/blood , Base Sequence , DNA, Viral/blood , Ethiopia/epidemiology , Female , Genotype , Hepatitis B Surface Antigens/blood , Hepatitis B Surface Antigens/genetics , Humans , Male , Middle Aged , Mutation , Phylogeny , Prevalence , Sequence Analysis, DNA , Serogroup , Young Adult
14.
Bull World Health Organ ; 94(12): 880-892, 2016 Dec 01.
Article in English | MEDLINE | ID: mdl-27994281

ABSTRACT

OBJECTIVE: To examine the diagnostic performance of real-time reverse transcription (RT)-polymerase chain reaction (PCR) assays for Zika virus detection. METHODS: We compared seven published real-time RT-PCR assays and two new assays that we have developed. To determine the analytical sensitivity of each assay, we constructed a synthetic universal control ribonucleic acid (uncRNA) containing all of the assays' target regions on one RNA strand and spiked human blood or urine with known quantities of African or Asian Zika virus strains. Viral loads in 33 samples from Zika virus-infected patients were determined by using one of the new assays. FINDINGS: Oligonucleotides of the published real-time RT-PCR assays, showed up to 10 potential mismatches with the Asian lineage causing the current outbreak, compared with 0 to 4 mismatches for the new assays. The 95% lower detection limit of the seven most sensitive assays ranged from 2.1 to 12.1 uncRNA copies/reaction. Two assays had lower sensitivities of 17.0 and 1373.3 uncRNA copies/reaction and showed a similar sensitivity when using spiked samples. The mean viral loads in samples from Zika virus-infected patients were 5 × 104 RNA copies/mL of blood and 2 × 104 RNA copies/mL of urine. CONCLUSION: We provide reagents and updated protocols for Zika virus detection suitable for the current outbreak strains. Some published assays might be unsuitable for Zika virus detection, due to the limited sensitivity and potential incompatibility with some strains. Viral concentrations in the clinical samples were close to the technical detection limit, suggesting that the use of insensitive assays will cause false-negative results.


Subject(s)
Real-Time Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/standards , Zika Virus Infection/diagnosis , Humans , Sensitivity and Specificity
15.
Euro Surveill ; 21(39)2016 Sep 29.
Article in English | MEDLINE | ID: mdl-27719751

ABSTRACT

The Dutch virus-typing network VIRO-TypeNed reported an increase in ECHOvirus 6 (E-6) infections with neurological symptoms in the Netherlands between June and August 2016. Of the 31 cases detected from January through August 2016, 15 presented with neurological symptoms. Ten of 15 neurological cases were detected in the same province and the identified viruses were genetically related. This report is to alert medical and public health professionals of the circulation of E-6 associated with neurological symptoms.


Subject(s)
Disease Outbreaks , Echovirus 6, Human/isolation & purification , Echovirus Infections/epidemiology , Meningitis, Aseptic/epidemiology , Meningitis, Aseptic/virology , Population Surveillance/methods , Public Health , Adolescent , Adult , Cerebrospinal Fluid/virology , Child , Child, Preschool , Clinical Laboratory Information Systems , Echovirus 6, Human/genetics , Echovirus Infections/diagnosis , Echovirus Infections/virology , Humans , Middle Aged , Netherlands/epidemiology , Phylogeny , Young Adult
16.
Euro Surveill ; 21(39)2016 Sep 29.
Article in English | MEDLINE | ID: mdl-27719752

ABSTRACT

VIRO-TypeNed is a collaborative molecular surveillance platform facilitated through a web-based database. Genetic data in combination with epidemiological, clinical and patient data are shared between clinical and public health laboratories, as part of the surveillance underpinning poliovirus eradication. We analysed the combination of data submitted from 2010 to 2014 to understand circulation patterns of non-polio enteroviruses (NPEV) of public health relevance. Two epidemiological patterns were observed based on VIRO-TypeNed data and classical surveillance data dating back to 1996: (i) endemic cyclic, characterised by predictable upsurges/outbreaks every two to four years, and (ii) epidemic, where rare virus types caused upsurges/outbreaks. Genetic analysis suggests continuous temporal displacement of virus lineages due to the accumulation of (silent) genetic changes. Non-synonymous changes in the antigenic B/C loop suggest antigenic diversification, which may affect population susceptibility. Infections were frequently detected at an age under three months and at an older, parenting age (25-49 years) pointing to a distinct role of immunity in the circulation patterns. Upsurges were detected in the summer and winter which can promote increased transmissibility underlying new (cyclic) upsurges and requires close monitoring. The combination of data provide a better understanding of NPEV circulation required to control and curtail upsurges and outbreaks.


Subject(s)
Clinical Laboratory Information Systems , Databases, Nucleic Acid , Enterovirus Infections/epidemiology , Enterovirus/genetics , Laboratories , Population Surveillance/methods , Disease Outbreaks/prevention & control , Endemic Diseases , Enterovirus/isolation & purification , Enterovirus Infections/diagnosis , Enterovirus Infections/virology , Epidemics , Humans , Molecular Sequence Data , Netherlands/epidemiology , Public Health , Serotyping
17.
Euro Surveill ; 21(48)2016 Dec 01.
Article in English | MEDLINE | ID: mdl-27934581

ABSTRACT

In October 2016, a severe infection with swine influenza A(H1N1) virus of the Eurasian avian lineage occurred in a child with a previous history of eczema in the Netherlands, following contact to pigs. The patient's condition deteriorated rapidly and required life support through extracorporeal membrane oxygenation. After start of oseltamivir treatment and removal of mucus plugs, the patient fully recovered. Monitoring of more than 80 close unprotected contacts revealed no secondary cases.


Subject(s)
Extracorporeal Membrane Oxygenation , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/diagnosis , Respiratory Tract Infections/virology , Severe Acute Respiratory Syndrome/therapy , Animals , Antiviral Agents/therapeutic use , Humans , Influenza, Human/drug therapy , Influenza, Human/virology , Intensive Care Units, Pediatric , Netherlands , Orthomyxoviridae Infections/transmission , Orthomyxoviridae Infections/veterinary , Orthomyxoviridae Infections/virology , Oseltamivir/therapeutic use , Real-Time Polymerase Chain Reaction , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/drug therapy , Severe Acute Respiratory Syndrome/complications , Swine , Swine Diseases/transmission , Swine Diseases/virology , Treatment Outcome
18.
Emerg Infect Dis ; 21(9): 1667-9, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26291986

ABSTRACT

Notification of 2 imported cases of infection with Middle East respiratory syndrome coronavirus in the Netherlands triggered comprehensive monitoring of contacts. Observed low rates of virus transmission and the psychological effect of contact monitoring indicate that thoughtful assessment of close contacts is prudent and must be guided by clinical and epidemiologic risk factors.


Subject(s)
Contact Tracing , Coronavirus Infections/epidemiology , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Respiratory Tract Infections/epidemiology , Travel , Adolescent , Adult , Aged , Child , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Female , Humans , Male , Middle Aged , Netherlands/epidemiology , Respiratory Tract Infections/prevention & control , Respiratory Tract Infections/virology , Saudi Arabia , Surveys and Questionnaires , Young Adult
19.
J Med Virol ; 87(3): 472-7, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25196311

ABSTRACT

Adenoviruses are a common cause of conjunctivitis. Genotypes are diverse and differ according to population and geographical distribution of the virus. There is limited data regarding ocular adenoviral infections and genotype distribution in Turkey. This study aimed to determine the adenovirus genotypes and their epidemiological features among patients with conjunctivitis between 2006 and 2010, in Izmir, Turkey. Adenoviral DNA was detected by PCR in 213 of 488 (44%) of the ocular samples collected from patients with viral conjunctivitis during the 5-year study period. Of these, 101 (47%) were randomly chosen and genotyped by sequence analysis. Seven genotypes were identified, including 3, 4, 8, 11, 19, 37, and 53. Genotype 8 and 4 were the dominant types detected in 67 (66.3%) and 25 (24.7%) of the samples, respectively. Other five genotypes (3, 11, 19, 37, 53) were detected in 9 (8.9%) samples. Genotype and seasonal differences observed throughout the study. Human adenoviruse (HAdV)-8 was the most frequent type, except 2008. The prevalence of genotype 4 increased starting from 2006, became dominant in 2008 and decreased in the following years. The peak season was mostly spring months, although it was possible to detect positive samples throughout the year. In conclusion, genotype 8 followed by genotype 4 was the most frequent adenoviral types causing conjunctivitis during the 5-year study period. Findings suggest that there is a slow shift between genotypes throughout the years.


Subject(s)
Adenoviridae Infections/epidemiology , Adenoviridae Infections/virology , Adenoviridae/classification , Adenoviridae/isolation & purification , Conjunctivitis, Viral/epidemiology , Conjunctivitis, Viral/virology , Adenoviridae/genetics , DNA, Viral/genetics , Genotype , Humans , Polymerase Chain Reaction , Prevalence , Seasons , Sequence Analysis, DNA , Turkey/epidemiology
20.
Blood ; 122(6): 1079-86, 2013 Aug 08.
Article in English | MEDLINE | ID: mdl-23794068

ABSTRACT

Hepatitis E virus (HEV) is increasingly acknowledged as a cause of hepatitis in healthy individuals as well as immunocompromised patients. Little is known of HEV infection in recipients of allogeneic hematopoietic stem cell transplantation (alloHSCT). Therefore, we set out to study the incidence and sequelae of HEV as a cause of hepatitis in a recent cohort of 328 alloHSCT recipients. HEV RNA was tested in episodes of liver enzyme abnormalities. In addition, HEV RNA and HEV serology were assessed pre- and post-alloHSCT. We found 8 cases (2.4%) of HEV infection, of which 5 had developed chronic HEV infection. Seroprevalence pre-alloHSCT was 13%. Four patients died with HEV viremia, with signs of ongoing hepatitis, having a median time of infection of 4.1 months. The 4 surviving patients cleared HEV after a median period of 6.3 months. One patient was diagnosed with HEV reactivation after a preceding infection prior to alloHSCT. Although the incidence of developing acute HEV post-alloHSCT is relatively low, the probability of developing chronic hepatitis in severely immunocompromised patients is high. Therefore, alloHSCT recipients should be screened pretransplantation by HEV serology and RNA. Furthermore, a differential diagnosis including hepatitis E is mandatory in all alloHSCT patients with severe liver enzyme abnormalities.


Subject(s)
Hematologic Neoplasms/complications , Hematopoietic Stem Cell Transplantation/adverse effects , Hepatitis E virus/isolation & purification , Hepatitis E/complications , Adolescent , Adult , Aged , Cross-Sectional Studies , Female , Hematologic Neoplasms/therapy , Hematologic Neoplasms/virology , Humans , Immunocompromised Host , Liver/enzymology , Male , Middle Aged , RNA, Viral/isolation & purification , Retrospective Studies , Seroepidemiologic Studies , Transplantation, Homologous , Treatment Outcome , Young Adult
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