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Acta Microbiologica et Immunologica Hungarica
Authors: Orsolya Nagy, Anna Nagy, Szilvia Tóth, Bernadett Pályi, Anita Vargáné Koroknai, and Mária Takács

Zika virus is a mosquito-borne flavivirus with significant public health concern due to its association with neurological symptoms and intrauterine malformations. Although it is endemic in tropical and subtropical areas, sexual transmission raises the possibility of autochthonous spreading elsewhere. We describe the first laboratory diagnosed imported Zika-infections of Hungary, to highlight the challenges of microbiological identification of the pathogen, caused by serological cross-reactivity and short viremia. Serological examination was carried out using indirect immunofluorescent assay and enzyme-linked immunosorbent assay. Plaque-reduction neutralization test was used for verification purposes. A wide range of clinical specimens: serum, whole-blood, urine, saliva, and semen were analyzed by molecular methods, and sequencing was applied in case of PCR positive results to identify the virus strain. Zika-infected patients with previous vaccination against flaviviruses or possible flavivirus infection in the past showed high serological cross-reactivity, and even cross-neutralizing antibodies were observed. Zika virus RNA could be detected in urine specimen in case of two patients, and in EDTA-anticoagulated whole-blood sample of one patient. The detected strains belong to the Asian lineage of the virus. We presume that serological investigation of imported Zika virus could be altered by infections, vaccination of endemic flaviviruses in Hungary and vice versa.

Open access

A szennyvíz alapú epidemiológia jelentősége a COVID–19 járványban és azon túl

The importance of wastewater-based epidemiology in the COVID-19 pandemic and beyond

Scientia et Securitas
Authors: Tamás Pándics, Eszter Róka, Bernadett Khayer, Zoltán Kis, Luca Bella Kovács, Nóra Magyar, Tibor Málnási, Orsolya Oravecz, Bernadett Pályi, Eszter Schuler, and Márta Vargha

Összefoglaló. A szennyvízalapú epidemiológia módszere a jelenlegi világjárványban egyre inkább előtérbe kerül. Mivel a szennyvízhálózatot szinte mindenki használja, ezzel a módszerrel gyorsan és olcsón lehet reprezentatív egészségügyi információhoz jutni, az így keletkező adatok pedig támogatást és visszajelzést nyújthatnak a döntéshozatalban. A Nemzeti Népegészségügyi Központ 2020 júniusa óta működteti a COVID–19 előrejelző rendszert. A mintavételek hetente történnek Budapest három szennyvíztisztítójából, valamint a megyeszékhelyekről. A kapott adatok hazánkban is előrejelzik az esetszám alakulását, az eredmények gyors kommunikációja pedig lehetővé teszi a járványhelyzetre történő felkészülést. A szennyvízalapú epidemiológia alkalmazása a jövőben más területeken is megfontolandó hazánkban is.

Summary. Wastewater based epidemiology (WBE) is an emerging method in the current COVID-19 pandemic. Since almost everyone uses the sewerage system, wastewater is technically a composite sample representing the entire population of the area serviced by a wastewater plant. This community sample contains pathogens and compounds excreted by the human body through feces or urine, and can be used to obtain information on the health status of the community. It was successfully used previously for confirming the eradication of poliovirus and tracking legal and illegal drug consumption.

The etiological agent of COVID-19, the SARS-CoV-2 virus is an enveloped, single strand RNA coronavirus. Although it is a respiratory virus, it is also shed in feces both in symptomatic and asymptomatic infections. Wastewater therefore can be used to estimate outbreak trends and support outbreak management.

Wastewater monitoring efforts in Hungary started in June 2020, first in Budapest, then gradually extended to a national surveillance system. Weekly samples are collected in the three wastewater treatment plants servicing Budapest, and from every county seat. The analyzed 22 samples represent approximately 40 % of the population. Raw sewage samples are centrifuged to remove the debris and concentrated by membrane ultrafiltration. RNA is extracted from the concentrate and SARS-CoV-2 is quantified by RT-qPCR. Results are normalized to Enterococcus counts to correct for the bias of dilution from precipitation.

The first results in June reflected the decline of the first wave of the outbreak. During the summer, viral RNA concentrations were low, mainly below the limit of detection. The increase of RNA in the sewage preceded the resurge of cases by 2 weeks. Trends of viral concentration followed the same pattern as the number of infections in the second and third wave. SARS-CoV in sewage shows statistically significant association with the number of new cases in the following weeks, thus it can be used as an early warning system.

Results are communicated weekly to the governance board responsible for outbreak management, or more frequently in case of outstanding results or when it is necessary for decision support. Weekly information is also made available to the public. To inform the public, concentration categories (low, medium, elevated and high) were defined, representing orders of magnitude of the viral RNA concentration. Trends (increasing, stagnating or decreasing) are also indicated.

The establishment of a long-term wastewater surveillance system would provide an opportunity for early recognition of future emerging infections, tracking seasonal influenza, drug use or even the detection of certain bioterror attacks. It would be an important addition to maintaining the health and safety of the Hungarian population.

Open access
Acta Microbiologica et Immunologica Hungarica
Authors: S. Younes, Márta Csire, Bernadett Pályi, G. Mikala, I. Vályi-Nagy, I. Cseh, Márta Benczik, Cs. Jeney, T. Takács, Éva Simon, V. Fülöp, G. Berencsi, Gy. Fekete, and Mária Visy

Pregnant women were examined following healthy pregnancies at term. Amniotic fluids were sampled before arteficial rupture of membranes using closed vacutainer system. Blood samples were also taken from the pregnants simultaneously.Endotoxin concentrations of amniotic fluids were tested by the semiquantitative Limulus amebocyte lysate. Both amniotic fluids and blood samples were tested for the presence of DNA of lymphotropic human herpesviruses. The DNA of human papillomaviruses were tested only in the amniotic fluid samples.One-third of the amniotic fluids tested were found to contain measurable amounts of endotoxin. Lymphotropic herpesvirus DNA was deteced in every fourth amniotic fluid sample and in every 8 th blood sample. The prevalence of papillomaviruses was 7 of 96 samples.No significant correlation was found between the presence of endotoxin and viruses in the amniotic fluids. Epstein-Barr virus, human cytomegalovirus and human herpesvirus type 7 were found more frequently in the amniotic fluids than in blood samples (7 to 1). The prevalence of human herpesvirus 6 and 8 was higher in the blood samples than that in the amniotic fluids.The mean weight of the neonates were not impaired significantly by the presence of either viruses or endotoxin. Possible post partum consequences, i.e. partial immunotolerance to viruses is discussed.

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