Authors:Gyula Dura, Péter Rudnai, Mihály Kádár, and Márta Vargha
High concentration of naturally-occurring arsenic in groundwater poses a significant risk to human health if this water is a drinking water resource. Chronic arsenic ingestion has been linked mainly to skin cancer, and a wide variety of non-cancer health impacts. Research conducted in Hungary shows that there is an excessive risk of arsenic-related diseases in populations consuming water that exceeds the 10 microgram/liter limit value. It is therefore important to understand the significance of reduction of arsenic concentration in drinking water and the size of the exposed population.
Authors:Zsófia Barna, Mihály Kádár, Emese Kálmán, Eszter Róka, Anita Sch. Szax, and Márta Vargha
Nosocomial legionellosis is a growing concern worldwide. In Hungary, about 20% of the reported cases are health-care associated, but in the absence of legal regulation, environmental monitoring of Legionella is not routinely performed in hospitals. In the present study, 23 hospitals were investigated. The hot water distribution system was colonized by Legionella in over 90%; counts generally exceeded the public health limit value. Hot water temperature was critically low in all systems (<45 °C), and large differences (3–38 °C temperature drop) were observed within buildings, indicating insufficient circulation. Most facilities were older than 30 years (77%); however, new systems (n = 3) were also shown to be rapidly colonized at low hot water temperature. Vulnerable source of drinking water, complex distribution system, and large volume hot water storage increased the risk of Legionella prevalence (OR = 28.0, 27.3, 27.7, respectively). Risk management interventions (including thermal or chemical disinfection) were only efficient if the system operation was optimized. Though the risk factors were similar, in those hospitals where nosocomial legionellosis was reported, Legionella counts and the proportion of L. pneumophila sg 1 isolates were significantly higher. The results of environmental prevalence of legionellae in hospitals suggest that the incidence of nosocomial legionellosis is likely to be underreported. The observed colonization rates call for the introduction of a mandatory environmental monitoring scheme.
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
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
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