Giardiasis (lambliasis) in Poland in 2020.

OBJECTIVE: Assessment of the epidemiological situation of giardiasis in Poland in year 2020. MATERIAL AND METHODS: The assessment of the epidemiological situation of giardiasis in Poland in 2020 was performed on the basis of aggregated data from the annual bulletins "Infectious diseases and poisoning in Poland" for the years 2006-2020, data on individual cases collected for the purposes of epidemiological surveillance in the EpiBaza system, and data from food-borne outbreak investigations recorded in the Registry of Epidemic Outbreaks (ROE). RESULTS: The number of new cases of giardiasis reported in Poland in 2020 amounted to 358 cases (incidence rate 0.9 per 100,000 population) and was about 2 times lower than in 2019 (784 cases) and 2.5 times lower than in 2018 (928 cases). In 2020, there was a further decrease in the number of registered cases, but it was much more pronounced than in the preceding years. As in previous years, no deaths from giardiasis were recorded. The downward trend in hospitalizations continued and in 2020 they accounted for approximately 12.6% of all cases, in 2019 the percentage was 15.2% and in 2018 - 19.4%. Most cases met the definition of a confirmed case, with 1 patient meeting the criteria of a probable case. In 2020, 6 outbreaks of giardiasis were reported, which is a decrease compared to 2019 (12 outbreaks) and thus means a reversal of the upward trend occurring at least since 2017. CONCLUSIONS: Data for 2020 should be interpreted taking into account the effect of the COVID-19 pandemic, which could have resulted in changes in long-term trends, but in particular contributed to a strong decrease in the number of cases not only of giardiasis, but also of other infectious diseases. In 2020, almost all EU/EEA countries reported a decrease in the incidence of giardiasis similar to that in Poland. However, as in 2019, in 2020 Poland differed from other EU/EEA countries in terms of incidence by age and sex.

Infectious diseases in Poland in 2020.

OBJECTIVE OF THE WORK: The article reviews the main problems of the epidemiology of infectious diseases in Poland in 2020. It summarizes relevant findings from the national infectious disease surveillance system. MATERIAL AND METHODS: The data contained in this article come from the reports collected by the State Sanitary Inspection on cases of notifiable infectious diseases notified by clinicians and/or laboratories. These are supplemented by mortality data published by the Statistics Poland. RESULTS AND THEIR DISCUSSION: The epidemiology of infectious diseases was highly impacted by the COVID-19 pandemic. There were 1,306,983 cases notified in 2020 and 41,451 deaths attributed to COVID-19 (according to Statistics Poland). The reported incidence of other infections decreased by 10-98%. We noted especially high decreases in the incidence of viral gastrointestinal infections (by over 70%). The incidence of influenza and influenza-like infections decreased by 34% and tuberculosis by 36% as compared to 2019. However, important decreases were also noted for other diseases under surveillance, which could point to disruption of diagnosis services and reporting due to lockdowns and high workload on the public health services.

Foodborne infections and intoxications in Poland in the years 2018-2020.

AIM: The purpose of this study is to assess the epidemiological situation of foodborne infections and intoxications in Poland in the years 2018-2020. MATERIALS AND METHODS: The evaluation was based on the analysis of information sent to Department of Epidemiology NIPH NIH - NRI through ROE (pol. Rejestr Ognisk Epidemicznych) - an electronic system created for uploading, transfer and analysis of data acquired during the outbreak investigations. Additional sources for the analysis were NIPH NIH - NRI annual bulletins (Czarkowski MP et al. "Infectious diseases and poisonings in Poland", 2014-2020. Warsaw, NIPH NIH and GIS). RESULTS: In the years 2018-2020 a total number of 2,108 foodborne outbreaks were reported in which 52,175 persons were exposed and 17,023 got sick (in 2016 n=916, in 2019 n=918, in 2020 n=274). In 2020 over 3 fold decrease in the number of outbreaks comparing to 2019 and over 4 fold decrease in the number of cases in those outbreaks was observed. Among outbreaks which took place in 3 most frequent settings (private household, food facility and hospital) the steepest decrease was in 12th week of 2020 (ISO 2020-W12). The most frequent etiological agent of outbreaks in the years 2018-2020 was Salmonella sp. (38.3% of outbreaks in 2018, 32.7% in 2019 and 47.8% in 2020) and specifically serotype Enteritidis (38.3%, 27% and 39.4% accordingly). The most frequent setting of outbreaks was private household (59.7% outbreaks in 2018, 66% in 2019 and 62% in 2020), followed by hospital (17.4%, 18.3% i 19.7% accordingly). Up until 2019 an increasing trend in the number of small outbreaks (up to 4 cases) caused by Salmonella sp. was observed (in 2018 - 605 and in 2019 - 612 were reported). CONCLUSIONS: Decrease in the number of outbreaks in selected settings from 12th ISO week of 2020 might have been due to introduction of restrictions during COVID-19 pandemic and enhancement of personal hygiene practices. An increase in identified and registered small outbreaks caused by Salmonella sp. comparing to the median of the number of those outbreaks from 2014-2016 could partly be a result of routine surveillance enhancement after introducing System for Registry of Epidemiological Interviews (pol. SRWE).

Yersiniosis in Poland in 2018-2020.

AIM: The aim of the study was to assess the epidemiological situation of yersiniosis in Poland in 2018-2020 and compare it to previous years. MATERIAL AND METHODS: To assess the epidemiological situation of yersiniosis in Poland, data from individual case reports prepared by Sanitary Epidemiological Stations as part of routine epidemiological surveillance were used. Incidence, number of cases and data on hospitalizations by voivodship included in the bulletins "Infectious Diseases and Poisons in Poland" for 2015-2020 were also used. RESULTS: In 2018-2020, a total number of 542 cases of yersiniosis were registered, including 456 intestinal and 86 extraintestinal forms. The incidence in 2018 was 0.53/100,000 in 2019 0.59/100,000 and in 2020 0.29/100,000. The number of cases in 2020 compared to 2019 decreased by 52%, and compared to 2018 by 45.8%. The percentage of hospitalizations in each year was at a similar level of 65.5% in 2018, 62.4% in 2019, and 60% in 2020. The highest incidence was noted in the 0-4 age group at 44.7% of cases in 2018, 42.9% in 2019 and 55.6% in 2020, respectively (all cases of the intestinal form). The predominant species was Y. enterocolitica in both intestinal and extraintestinal forms. The most common serotype was serotype O:3, which was identified in 34 isolates in 2018, 43 isolates in 2019 and 9 isolates in 2020. SUMMARY AND CONCLUSIONS: Since 2009, Poland has had a decreasing trend in the incidence of yersiniosis. In 2020, both Poland and Europe saw a sharp decline in the number of cases compared to previous years. This is a result of the occurrence of the COVID-19 pandemic in March 2020, during which many measures were introduced to limit the spread of the SARS-CoV-2 virus, which may also have affected the number of other infections. Although the numbers of cases and incidence of yersiniosis among children under the age of 5 are the highest compared to other age groups, the highest number of hospitalizations was reported in the 10-19 age group, which most likely reflects the decreasing number of laboratory tests ordered on an outpatient basis with age and the significant underreporting of cases in this and older age groups.

Salmonellosis in Poland in 2020.

AIM: The aim of the study is to assess the epidemiological situation of salmonellosis in Poland in 2020 compared with previous years. MATERIAL AND METHODS: The epidemiological situation was assessed on the basis of data provided to the Department of Epidemiology of Infectious Diseases and Surveillance of the NIPH NIH-NRI by sanitary-epidemiological stations through the EpiBaza System and the Registry of Epidemic Outbreaks System (ROE), as well as on the basis of data published in the annual bulletin "Infectious Diseases and Poisoning in Poland in 2020" (NIPH NIH-NRI, GIS, Warsaw, 2021) and from information received from laboratories of sanitary-epidemiological stations and data from the Demographic Research Department of the Statistics Poland. RESULTS: In Poland in 2020, in the sanitary-epidemiological surveillance registered a total of 5,470 cases of salmonellosis, 5,302 cases of intestinal salmonellosis, and the remaining 168 cases of extra-intestinal salmonellosis. The incidence per 100,000 population was 14.3 for total salmonellosis, 13.8 for intestinal salmonellosis and 0.44 for extra-intestinal salmonellosis. Sanitary-epidemiological stations registered 5,349 confirmed cases and 121 probable cases of salmonellosis. Due to intestinal salmonellosis, 63.9% of all patients were hospitalized, while for extra-intestinal salmonellosis 153 patients or 91.1% of cases, were hospitalized. The increase in the number of salmonellosis cases in 2020 started in June, while the peak of the incidence was in August. Among the voivodeships, the highest incidence of salmonellosis was registered in the Podkarpackie voivodeship 33.3/100,000 population, the lowest in Zachodniopomorskie 6.1/100,000 population. Cases in the 0-4 age group accounted for 45.2% of all salmonellosis cases in 2020. Among extra-intestinal salmonellosis, 63.1% were people aged 60+. Sanitary-epidemiological stations registered 131 food poisoning outbreaks caused by Salmonella bacilli in the ROE system, 108 of these outbreaks were caused by the Enteritidis serotype. In 2020, the most common serotypes were S. Enteritidis 70% of all recorded salmonellosis, S. Typhimurium 1.9%, and S. Infantis 0.54%. There were 9 deaths due to Salmonella infection. CONCLUSIONS: The COVID-19 pandemic and the associated restrictions introduced in the country, as well as increased hygiene through more frequent washing and disinfection of hands, could have contributed to a reduction of almost 69% in the number of salmonellosis cases registered in 2020, in Poland, compared to 2019. This is a 82% decrease in relation to 2018. There was also a decrease in the number of food poisoning outbreaks caused by Salmonella bacilli, while at the same time their percentage in the total number of outbreaks increased. On the one hand, the implemented restrictions could have had an impact on the decrease in the number of cases and outbreaks, on the other hand, worse access to medical care and diagnostics, most likely deepened the underestimation of these cases in the country observed for years, and distorted the real picture of the situation.

Healthcare workers highly affected during the COVID-19 epidemic wave in Poland prior to vaccination availability: seroprevalence study.

BACKGROUND: The aim of the study was to assess seroprevalence of anti-SARS-CoV-2 antibodies among healthcare workers (HCW) before introduction of vaccination, in selected areas in Poland as well as to identify potential risk factors and estimate the cumulative incidence of COVID-19 infections in this population. MATERIAL AND METHODS: The authors conducted a sero-epidemiological, cross-sectional study among HCW of 5 non-COVID-19 hospitals in Poland. The recruitment took place in December 1-23, 2020, all HCW at selected hospitals could volunteer into the study. All persons were screened with rapid SARS-CoV-2 IgM/IgG tests in capillary blood. In case of positive result, 5 ml of venous blood was drawn for confirmatory testing with ELISA assay. The authors estimated prevalence of laboratory confirmed anti-SARS-CoV-2 antibody presence and examined factors associated with positive result. Cumulative incidence was estimated applying 2-source capture-recapture method to serology results and self-report of past infection. RESULTS: Out of 1040 HCW included in the analysis, one-fourth (25.2%) received a positive result for anti-SARS-CoV-2 antibodies by ELISA test, the prevalence among women was 25.3% (95% CI: 22.5-28.4) and 24.6% (95% CI: 19-31.2) among men. The prevalence of anti-SARS-CoV-2 antibodies was the highest among respondents who declared home contact with a confirmed COVID-19 case, 43.9% (95% CI: 32.4-56.1). It was also elevated among those who indicated contact with patients with COVID-19, 32.5% (95% CI: 26.7-38.8) and business contacts, including at the workplace, 28.9% (95% CI: 22.5-36.3). The estimated cumulative incidence of COVID-19 infections in the population, using the capture-recapture method was 41.2% (95% CI: 38.1-44.2). CONCLUSIONS: Healthcare workers remained at increased risk of infection largely due to work-related contacts with infected patients, although home exposure was also common. Estimated cumulative incidence is higher than the antibody prevalence, which indicates the need to monitor HCW for possible immunity waning, also post-immunization immunity. Med Pr. 2022;73(2):109-23.

Data-driven case fatality rate estimation for the primary lineage of SARS-CoV-2 in Poland.

After more than one and a half year since the COVID-19 pandemics outbreak the scientific world is constantly trying to understand its dynamics. In this paper of the case fatality rates (CFR) for COVID-19 we study the historic data regarding mortality in Poland during the first six months of pandemic, when no SARS-CoV-2 variants of concern were present among infected. To this end, we apply competing risk models to perform both uni- and multivariate analyses on specific subpopulations selected by different factors including the key indicators: age, sex, hospitalization. The study explores the case fatality rate to find out its decreasing trend in time. Furthermore, we describe the differences in mortality among hospitalized and other cases indicating a sudden increase of mortality among hospitalized cases at the end of the 2020 spring season. Exploratory and multivariate analysis revealed the real impact of each variable and besides the expected factors indicating increased mortality (age, comorbidities) we track more non-obvious indicators. Recent medical care as well as the identification of the source contact, independently of the comorbidities, significantly impact an individual mortality risk. As a result, the study provides a twofold insight into the COVID-19 mortality in Poland. On one hand we explore mortality in different groups with respect to different variables, on the other we indicate novel factors that may be crucial in reducing mortality. The later can be coped, e.g. by more efficient contact tracing and proper organization and management of the health care system to accompany those who need medical care independently of comorbidities or COVID-19 infection.

Estimated number of deaths directly averted in people 60 years and older as a result of COVID-19 vaccination in the WHO European Region, December 2020 to November 2021.

Since December 2019, over 1.5 million SARS-CoV-2-related fatalities have been recorded in the World Health Organization European Region - 90.2% in people ≥ 60 years. We calculated lives saved in this age group by COVID-19 vaccination in 33 countries from December 2020 to November 2021, using weekly reported deaths and vaccination coverage. We estimated that vaccination averted 469,186 deaths (51% of 911,302 expected deaths; sensitivity range: 129,851-733,744; 23-62%). Impact by country ranged 6-93%, largest when implementation was early.

COVID-19 module in SRWE system - application and use in epidemiological surveillance and reporting to international institutions.

The new SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) coronavirus causing acute respiratory disease COVID-19 (2019 coronavirus disease) detected in China in 2019 very quickly revealed its epidemic potential and was recognized as a global health problem. The situation caused by the rapidly increasing number of new cases and deaths due to COVID-19 required the rapid development of international recommendations and procedures to limit the spread of infections and ongoing monitoring of the epidemiological situation. In the field of epidemiological surveillance of COVID-19 cases, international organizations - WHO and regionally ECDC, have developed basic requirements for reporting data on newly detected cases of infection. In order to ensure the possibility of reporting new cases and activities undertaken by sanitary-epidemiological services in the country and to fulfill the obligation to report data to the European surveillance network, it was necessary to adapt the electronic system supporting epidemiological surveillance operations, for registration of suspected and confirmed cases of SARS-CoV-2 infections. This work presents the characteristics of the new COVID-19 module created as part of the central Epidemiological Case Reporting System and a preliminary evaluation of its usefulness for the purposes of combating COVID-19. CONCLUSIONS. The Epidemiological Case Reporting System is an efficient and adequate tool that can be adapted to newly emerging threats. In order to use the module to monitor the current epidemiological situation, it is necessary to integrate it with other systems collecting data about COVID-19 patients - ie. EWP and the clinical patient register.