First whole genome sequencing and analysis of human parechovirus type 3 causing a healthcare-associated outbreak among neonates in Hungary.

PURPOSE: In November 2023, the National Reference Laboratory for Enteroviruses (Budapest, Hungary) received stool, pharyngeal swab and cerebrospinal fluid samples from five newborns suspected of having human parechovirus (PEV-A) infection. The neonates were born in the same hospital and presented with fever and sepsis-like symptoms at 8-9 days of age, and three of them showed symptoms consistent with central nervous system involvement. PEV-A positivity was confirmed by quantitative reverse transcription polymerase chain reaction. METHODS: To determine the PEV-A genotype responsible for the infections, fecal samples of four neonates were subjected to metagenomic sequencing. For further analyses, amplicon-based whole genome sequencing was performed directly from the clinical samples. RESULTS: On the basis of whole genome analysis, sequences were allocated to PEV-A genotype 3 (PEV-A3) and consensus sequences were identical. Two ambiguities were identified in the viral protein 1 (VP1) region of all sequences at a frequency of 17.7-53.7%, indicating the simultaneous presence of at least two quasispecies in the clinical samples. The phylogenetic analysis and similarity plotting showed that all sequences clustered without any topological inconsistencies between the P1 capsid and P2, P3 non-capsid regions, suggesting that recombination events during evolution were unlikely. CONCLUSION: Our findings suggest that the apparent cluster of cases were microbiologically related, and the results may also inform future investigations on the evolution and pathogenicity of PEV-A3 infections.

Distribution of enterovirus genotypes detected in clinical samples in Hungary, 2010-2018.

This report provides the findings of a retrospective surveillance study on the emergence and circulation of enteroviruses with their associated clinical symptoms over a nine-year period detected at the National Enterovirus Reference Laboratory in Hungary between 2010-2018.Enterovirus (EV) detection and genotyping were performed directly from clinical samples. From 4,080 clinical specimens 25 EV types were identified with a median age of patients of 5 years and 68% of all cases affected children aged 10 years or younger, although infections occurred in all age-groups. In 130 cases neurological symptoms were recorded, in 123 cases the infection presented in skin related signs including hand, foot, and mouth disease (HFMD), herpangina and rash. In 2010 EV-A71 was found to cause the majority of diagnosed EV infections while in 2011 and from 2014-2018, Coxsackievirus (CV)-A6 was identified most often. Echovirus E6 accounted for the most cases in 2012 and Echovirus 30 dominated in 2013. EV-D68 was identified only in 2010 and 2013.Widespread circulation of several EV-A and EV-B viruses with occasional occurrence of EV-C and EV-D was detected. The ability of EVs to cause severe infections in sporadic cases and regular outbreaks highlight the importance of continued monitoring of circulating EV types.

Extraordinary increase in West Nile virus cases and first confirmed human Usutu virus infection in Hungary, 2018.

BackgroundDuring the 2018 WNV transmission season, similarly to other endemic areas in Europe, a large number of human West Nile virus (WNV) infections were reported in Hungary.AimsWe summarise the epidemiological and laboratory findings of the 2018 transmission season and expand experiences in flavivirus differential diagnostics.MethodsEvery patient with clinical suspicion of acute WNV infection was in parallel tested for WNV, tick-borne encephalitis virus and Usutu virus (USUV) by serological methods. Sera, whole blood and urine samples were also tested for the presence of viral nucleic acid.ResultsUntil the end of December 2018, 215 locally acquired and 10 imported human WNV infections were notified in Hungary. All reported cases were symptomatic; most of them exhibited neurological symptoms. In a large proportion of tested individuals, whole blood was the most appropriate sample type for viral nucleic acid detection, but because whole blood samples were not always available, testing of urine samples also extended diagnostic possibilities. In addition, the first human USUV infection was confirmed in 2018 in a patient with aseptic meningitis. Serological cross-reactions with WNV in different serological assays were experienced, but subsequent molecular biological testing and sequence analysis identified Europe lineage 2 USUV infection.ConclusionCareful interpretation and simultaneous application of different laboratory methods are necessary to avoid misdiagnosis of human USUV cases. Expansion of the laboratory-confirmed case definition criteria for detection of viral RNA in any clinical specimens to include urine samples could increase diagnostic sensitivity.

Are we protected? Imported measles - on the way to eradication.

In accordance with the 2015 regional goal for measles and rubella elimination of the WHO European Region, only a few imported cases have been documented of both diseases in Hungary for years.This paper presents a case of a Hungarian woman, born in 1975, who received measles vaccination at age of 12 months and later at age of 11 years, according to her certificate of vaccination. In 2009, after arriving home from a vacation in Ireland, she developed acute measles infection with clinical symptoms. It was confirmed by the detection of measles specific IgM, IgA and IgG antibodies, and by detection of viral nucleic acid from throat swab in virus transport medium.Additionally, an outbreak occurred in December of 2011 among a family emigrated from Romania to Hungary. No new measles cases were diagnosed among the contact persons of neither the young Hungarian woman returning from Ireland, nor the family emigrated from Romania. This observation refers to the effectiveness of the Hungarian vaccination program.

Serologic evidence of West Nile virus infection in patients with exanthema in Hungary.

The presence of WNV in Europe has been well known for decades, although the first human infections and avian outbreaks were diagnosed in Hungary only in 2003. An annual average of 6-8 cases of the neuroinvasive form of WNV infection has been detected in the region since then, but a higher number (17) of WNV associated neuroinvasive disease occurred in 2008. In 2004, a surveillance system was established for monitoring WNV-associated meningo-encephalitis cases in Hungary, but a milder type of illness (with fever, rash and/or influenza like symptoms) is not followed. Fifty-two sera of 45 patients with mild clinical symptoms (fever, exanthema) were tested for anti-WNV antibodies in 2008 in a retrospective study by immunofluorescence test and ELISA. Seven patients had antibodies against WNV, serologic evidence of recent WNV infection was found in 4 out of the 7 patients. Infections could be acquired predominantly in August and in September, which seems to be a risk period for WNV in Hungary. The possibility of a recent WNV infection should be taken into consideration in the occurrence of fever and rush at late summer. Differential diagnosis of exanthematous patients should include WNV serology tests and should be done routinely.

Interference among viruses circulating and administered in Hungary from 1931 to 2008.

Viral interference was discovered about 60 years ago. Molecular epidemiology revealed that this phenomenon possesses important biological implications, it can reduce the epidemic spread of certain viruses from time to time (influenza and enteroviruses) and the efficiency of live vaccination can be impaired, too. Phenomena observed during the last 80 years in Hungary are analyzed. It is suggested to concentrate the distribution of MMR vaccines to seasons of limited influenza and enterovirus circulation. Interference seems to impair the progress of wild poliovirus eradication in the endemic tropical countries. It is recommended to enhance enterovirus surveillance in the region of European countries, since the exchange of the oral poliovirus vaccine to the enhanced inactivated polio vaccine might result in enhanced circulation of non-polio enteroviruses leading to the increase in the number of type I (juvenile) diabetes patients.

Detection of human bocavirus from fecal samples of Hungarian children with acute gastroenteritis.

OBJECTIVES: Human bocavirus (HBoV), a newly identified member of the Parvoviridae family is associated with respiratory tract and gastroenteric infections, mostly of young children. HBoV infections show a seasonal distribution with the peak in temperate areas being in the winter months. METHODS: In our study, 35 throat swabs from children under 5 years with acute respiratory symptoms and 61 stool samples from children (<5 years) with acute gastroenteritis were collected in the period of October 2007-March 2008. A HBoV-specific polymerase chain reaction for detection of the virus, and sequence analysis for identification of virus variants were performed. RESULTS: Although respiratory samples were all negative, 3.3% of stool samples (2/61) proved to be positive for HBoV. The virus carrier children were 3 and 5 years old. The ratio of HBoV positive samples is similar to international results (2.1-5.5%). CONCLUSIONS: According to the result of sequence analysis of HBoV, the occurrence of genotype 2 of HBoV in Hungary is confirmed.