György Szűcs

Characterization and zoonotic potential of endemic hepatitis E virus (HEV) strains in humans and animals in Hungary.

BACKGROUND Hepatitis E virus (HEV) is a common cause of acute, fecally transmitted hepatitis in developing countries. Identification of HEV in indigenous human infection and in domestic pig raising the possibility that HEV infection is also a zoonosis. OBJECTIVES/STUDY DESIGN Molecular detection and epidemiology of HEV in humans (South-East Hungary) with acute hepatitis and in domestic (pig, cattle) and wild (boar and roe-deer) animals (countrywide) by ELISA and RT-PCR. RESULTS Between 2001 and 2006, a total of 116 (9.6%) of 1203 human sera were positive by HEV IgM ELISA and 13 (24.5%) of 53 samples were also confirmed by RT-PCR and sequencing. Forty-two (27.3%) of 154, 11 (34.4%) of 32 and 9 (12.2%) of 74 samples were RT-PCR-positive from swine (feces: 22.7%; liver: 30.8%), roe-deer (liver) and wild boar (liver), respectively. Except for an imported infection caused by genotype 1, 19 sequences (human: 12, swine: 4, roe-deer: 1, wild boar: 2) belong to genotype 3 HEV. Genetically identical strains were detected in human and roe-deer and in 2 other human clusters. CONCLUSIONS HEV is an endemic agent in Hungary. Consumption of raw or undercooked meat-products is one of the possible sources of the indigenous HEV infections. Cross-species infection with genotype 3 HEV potentially involves a food-borne transmission route in Hungary.

Detection of hepatitis E virus in samples of animal origin collected in Hungary.

Hepatitis E virus (HEV) is an enterically transmitted human pathogen. HEV infections are mainly associated with acute, self-limited, icteric hepatitis with an average mortality rate of 1%. Animal reservoirs are considered to play an important role in the maintenance of the virus and in the spread of HEV to humans. HEV-induced seroconversion was described in several species, however clinical hepatitis in animals has not been observed to date. HEV strains from animals are genetically closely related to human HEV isolates, which supports the opinions on the zoonotic transmission of the virus. In this expansive study the occurrence of HEV was investigated in Hungarian wild and domesticated animal samples. HEV RNA was detected by reverse transcription-polymerase chain reaction in liver samples of wild boars, roe deer, and deer. The investigations of domestic swine samples detected HEV in 39% of the investigated Hungarian pig farms. Simultaneous investigation revealed no definite difference between liver and faeces samples of domestic pigs in the frequency of HEV positivity. The highest (36%) incidence of HEV infection was found among the 11-16-week-old pigs. Samples from domestic cattle and rodents collected in pig farms, forests and meadows were tested negative for HEV RNA. Phylogenetic analysis of partial sequences amplified within the ORF1 and ORF2 regions of selected strains revealed that the detected viruses belong to three subgroups of the third genogroup of HEV, and are closely related to human and swine HEV strains detected in different countries. The investigations revealed widespread distribution of HEV in Hungarian wild ungulate and domesticated swine populations, with considerable genetic diversity among the strains.

Detection and quantification of group C rotaviruses in communal sewage.

ABSTRACT Group C rotaviruses have been recognized as a cause of acute gastroenteritis in humans, cattle, and swine, although the true epidemiologic and clinical importance of this virus in these hosts has not yet been fully established. A real-time PCR assay based on a broadly reactive primer pair was developed and used to quantitatively determine the viral load of group C rotaviruses in environmental samples. A total of 35 raw and 35 treated sewage samples collected at the same sampling time in four Hungarian sewage treatment plants during a survey in 2005 were tested for the presence of group C rotaviruses. The overall detection rates were 91% (32 of 35) for the influent and 57% (20 of 35) for the effluent samples. Molecular characterization of the amplified partial VP6 gene revealed the cocirculation of human and animal (i.e., bovine and porcine) strains that were easily distinguishable by melting curve analysis. Human strains yielded relatively high viral loads (mean, 1.2 × 107; median, 6.9 × 105 genome equivalents per liter influent sewage) and appeared to display seasonal activity over the study period, whereas animal strains appeared to circulate throughout the year at much lower average titers (bovine strains mean, 9.9 × 104; median, 3.0 × 104; porcine strains mean, 3.9 × 104; median, 3.1 × 104 genome equivalents per liter influent sewage). Our findings suggest that monitoring of communal sewage may provide a good surrogate for investigating the epidemiology and ecology of group C rotaviruses in humans and animals.

Novel NSP4 genotype in a camel G10P[15] rotavirus strain

In this study a Kuwaiti camel rotavirus strain, RVA/Camel-wt/KUW/s21/2010/G10P[15], is characterized by sequencing and phylogenetic analysis. The strain had multiple genes with high nucleotide sequence similarities to ovine and bovine strains (VP2, ≤ 96%; NSP2 and NSP5, ≤ 97%, NSP3, ≤ 94%), or, to porcine strains (VP1, ≤ 89%). Other genes had moderate sequence similarities (VP4, ≤ 87%; VP6, ≤ 81%; VP7, ≤ 82%) with reference strains from ruminants. The NSP4 gene shared limited sequence identity (≤ 71%) with other mammalian and avian rotavirus NSP4 types, and was designated a novel genotype, E15. This study demonstrates genetic diversity in the outer capsid and some backbone genes of an old-world camelid rotavirus strain and uncovers its common evolutionary roots with strains from other ruminants.

Genetic drift of norovirus genotype GII-4 in seven consecutive epidemic seasons in Hungary

BACKGROUND Noroviruses are common pathogens in human gastroenteritis outbreaks worldwide. They belong to a genetically diverse group of RNA viruses with multiple genogroups (G) and genotypes. Genotype GII-4 norovirus (Lordsdale) is the predominant agent in epidemics. OBJECTIVES To investigate the genetic variation in GII-4 strains isolated during seven epidemic seasons in Hungary from November 2000 to June 2007. STUDY DESIGN Using the prospective epidemiological surveillance of norovirus outbreaks in Hungary, GII-4 strains were selected for further genetic analysis. After phylogenetic analysis, RNA-polymerase (open reading frame 1; ORF1), capsid (ORF2) and the ORF1/ORF2 junction were analysed by RT-PCR and sequencing. RESULTS Three hundred and seventy-seven (76.8%) of 491 confirmed norovirus outbreaks were caused by genotype GII-4. GII-4 was the predominant genotype in six of the seven epidemic seasons. Four main GII-4 variants--epidemic point mutants--(GII-4-2000, GII-4-2002, GII-4-2004 and GII-4-2006b) were detected, with each variant predominating in two consecutive epidemic seasons. CONCLUSIONS Genotype GII-4 was confirmed as the predominant genetic type in epidemic norovirus seasons in Hungary. Genetic drift successfully promotes the re-emergence of GII-4 variants in the population. The elevated number of norovirus outbreaks in the population predicts the emergence of new GII-4 genetic variants as part of an international epidemic.

Surveillance of human rotaviruses in 2007–2011, Hungary: Exploring the genetic relatedness between vaccine and field strains

BACKGROUND The availability of rotavirus vaccines has resulted in an intensification of post vaccine strain surveillance efforts worldwide to gain information on the impact of vaccines on prevalence of circulating rotavirus strains. OBJECTIVES In this study, the distribution of human rotavirus G and P types in Hungary is reported. In addition, the VP4 and VP7 genes of G1P[8] strains were sequenced to monitor if vaccine-derived strains were introduced and/or some strains/lineages were selected against. STUDY DESIGN The study was conducted in 8 geographic areas of Hungary between 2007 and 2011. Rotavirus positive stool samples were collected from diarrheic patients mostly <5 years of age. Viral RNA was amplified by multiplex genotyping RT-PCR assay, targeting the medically most important G and P types. When needed, sequencing of the VP7 and VP4 genes was performed. RESULTS In total, 2380 strains were genotyped. During the 5-year surveillance we observed the dominating prevalence of genotype G1P[8] (44.87%) strains, followed by G4P[8] (23.4%), G2P[4] (14.75%) and G9P[8] (6.81%) genotypes. Uncommon strains were identified in a low percentage of samples (4.12%). Phylogenetic analysis of 318 G1P[8] strains identified 55 strains similar to the Rotarix strain (nt sequence identities; VP7, up to 97.9%; VP4, up to 98.5%) although their vaccine origin was unlikely. CONCLUSIONS Current vaccines would have protected against the majority of identified rotavirus genotypes. A better understanding of the potential long-term effect of vaccine use on epidemiology and evolutionary dynamics of co-circulating wild type strains requires continuous strain surveillance.

The goose reovirus genome segment encoding the minor outer capsid protein, σ1/σC, is bicistronic and shares structural similarities with its counterpart in muscovy duck reovirus

Reoviruses have recently been shown to be associated with disease in young geese and to be involved in epizooties of severe outcome in Hungary. To assess the genetic variability among these pathogenic goose reoviruses (GRVs), we sequenced the S4 genome segment of five GRV strains isolated from different diseased flocks. We found that the GRV S4 genome segment, consisting of two partially overlapping open reading frames (ORFs), shares substantial structural similarity with its counterpart in muscovy duck reoviruses (DRVs). ORF1 is predicted to encode a polypeptide highly similar to the p10 polypeptide of DRV, and ORF2 supposedly encodes the minor outer capsid protein, σ1/σC. In one of the five GRV strains examined, we identified a single uracil base insertion close to the middle of ORF2. This insertion resulted in a frameshift and in concomitant acquisition of a termination codon (UAA) a few codons downstream, apparently causing truncation of the C-terminal part of the protein. The functional consequences of this assumed mutation, which would result in loss of more than a half of the protein, have yet to be determined. Nonetheless, the sequence and structural similarities between the genome segment encoding σl/σC in GRVs and DRVs suggest that these viruses belong to a species distinct from other established species within subgroup 2 of orthoreoviruses.

First Detection of P[6],G9 Rotaviruses in Hungary—An Imported Strain From India?

EuroRotaNet was launched to monitor rotavirus strain prevalence during and after introduction of rotavirus vaccines in Europe. In early 2007, we detected P[6],G9 rotaviruses to appear in Hungary, representing the first documented occurrence of this strain in our surveillance area. Epidemiologic data suggested that this strain was introduced from India.

First detection of Tula hantaviruses in Microtus arvalis voles in Hungary

Tula hantavirus (TULV) is a member of the genus Hantavirus, family Bunyaviridae and is mainly carried by the European common vole (Microtus arvalis). In order to detect TULV, we tested Microtus arvalis (MAR) and Microtus subterraneus (MSU) voles captured in two different locations of the Southern Transdanubian region of Hungary. The viral genome was detectable in 37% of the tested MAR voles but, interestingly, was absent in all MSU. Phylogenetic analysis performed with a partial coding sequence of the capsid gene showed that Hungarian TULV strains clustered with viruses detected in western Slovakia and in the Czech Republic. To the best of our knowledge, this is the first report on the identification of TULV detected in MAR voles in the Transdanubian region of Hungary.

Adenovirus gastroenteritis in Hungary, 2003–2006

The incidence and type distribution of enteric human adenoviruses (HAds) among diarrheic children in south-western Hungary was investigated from 2003 through 2006. Laboratory studies were conducted using commercial antigen detection tests (latex agglutination or immunochromatography), polymerase chain reaction (PCR) amplification, single-strand conformation polymorphism, and sequencing and phylogenetic analysis of a conservative region of the HAd hexon gene. The overall rate of HAd infection in childhood gastroenteritis cases during the 4-year study was 8.1%, with a gradual decrease in detection rates from 11.7% in 2003 to 5.7% in 2006. Molecular studies of a subset of HAd-positive samples found that enteric HAd type 40 strains were identified only in 2003 and 2004, while HAd type 41 strains were identified throughout the 4-year study. Higher detection rates of non-enteric HAds was documented during the first half of the study period when latex agglutination was used in our laboratory for detection. Our study suggests that the choice of diagnostic method may profoundly influence the epidemiologic picture and disease burden attributed to enteric HAd infections.