Surveillance Program of Clinical Samples for Polio and Non-Polio Enteroviruses in the Slovak Republic during the 1958-2020 Period.

Enteroviruses (EVs) are associated with a wide spectrum of diseases involving various organs. Our aim was to give a historical overview of the genesis of clinical sample processing for EVs in the Slovak Republic (SR) during the 1958-2020 period, within the framework of the World Health Organization (WHO) polio program. Further, analyses were made of the data obtained from the archives of processed clinical sample surveillance using statistical methods. We used generalized additive models (GAM) with binomial distribution and logit link functions and an autoregressive moving average (ARMA) to analyze the data obtained during this 63-year period. Our results show trends in the composition of EV strains circulating in the population. Furthermore, statistically significant increasing trends of the non-polio enteroviruses (NPEVs) were observed over the studied time, represented by echoviruses (E) and coxsackieviruses A and B (CVA and CVB), with a cyclical pattern of occurrence. The most prevalent serotype over this period was CVB5, which became significantly more prevalent after 2000. While PVs, CVB1, and CVB3 were present in the second half of the studied period, CVA10, CVA16, E3, E25, and E30 appeared more frequently.

History of the Wastewater Assessment of Polio and Non-Polio Enteroviruses in the Slovak Republic in 1963-2019.

We describe the genesis of poliovirus (PV) and non-polio enterovirus (NPEV) surveillance program of sewage wastewaters from its inception to the present in the Slovak Republic (SR). Sampling procedures and evolution of the methodology used in the SR for the detection of PVs and NPEVs are presented chronologically. For statistical data processing, we divided our dataset into two periods, the first period from 1963 to 1998 (35 years), and the second period from 1999 to 2019 (21 years). Generalized additive models were used to assess temporal trends in the probability of occurrence of major EV serotypes during both periods. Canonical correspondence analysis on relative abundance data was used to test temporal changes in the composition of virus assemblages over the second period. The probability of occurrence of major viruses PV, coxsackieviruses (CVA, CVB), and Echoviruses (E)) significantly changed over time. We found that 1015 isolated PVs were of vaccine origin, called "Sabin-like" (isolates PV1, PV2, PV3). The composition of EV assemblages changed significantly during the second period. We conclude that during the whole period, CVB5, CVB4, and E3 were prominent NPEVS in the SR.

Coxsackievirus B4 sewage-isolate induces pancreatitis after oral infection of mice.

Numerous serotypes which belong to the genus Enterovirus (EV) show variability in their virulence and clinical manifestations. They are also known to undergo changes caused by mutations and recombination during their circulation in the environment and the population. Various EV serotypes are prevalent in groundwater, wastewater and surface waters. Our previous studies showed that oral infection induces pancreatitis depending on specific conditions, such as gravidity, in an outbred murine model. Our aim in the present study was to further explore the pancreatic histopathology in an outbred mouse model following oral infection with clinical isolates from a patient who had aseptic meningitis and an isolate from a treated-sewage sample recovered from the residential area of the patient. The isolates were identified as coxsackievirus B4 (CVB4) in tissue culture. The CVB4 sewage-isolate induced pancreatitis after oral infection. In contrast, pancreatitis was absent following infection with the clinical isolates. Comparison of polyprotein sequences showed that the treated-sewage strains differed from the patient's isolates by 9 and 11 amino acids. We conclude that the isolates of clinical and environmental origin differed in their pathogenic properties and showed genetic variation.

Should Enteroviruses Be Monitored in Natural Recreational Waters?

Enteroviruses (EVs) infections occur worldwide. Although, infections by these viruses are often asymptomatic and go unnoticed, they can be shed in stool for several weeks. The EVs are associated with sporadic outbreaks and a wide range of clinical symptoms, occasionally accompanied with fatal consequences. Presently in the Slovak Republic (SR) recreational waters are tested only for bacterial indicators. Our aim was to monitor EVs in recreational waters. Water samples were collected during the years 2012-2014 from different recreational natural lakes in Central and West regions of SR. The samples were concentrated by centrifugation using the two-phase separation method recommended by the World Health Organization (WHO) used for EVs surveillance in the treated sewage waste water. Each of the two phases collected from the samples was analysed by polymerase chain reaction for detection of EVs and primary sequencing was done. Our study demonstrated presence of EVs in three localities consecutively for three years, indicating a probability of constant local source of faecal contamination. This is the first monitoring report on the occurrence of EVs in the natural recreational waters in SR.

Factors affecting the success of influenza laboratory diagnosis.

Influenza is one of the most common human infectious diseases, and has profound health and economic consequences. The laboratory diag- nosis of influenza virus infections plays an important role in the global surveillance of influenza. Therefore, there is a growing demand for highly sensitive and rapid methods for detecting influenza. The performance of particular diagnostic methods is affected by various factors. In this study, we assess the effects of patients' age and time to diagnosis on the probability of detecting influenza using four diagnostic methods (virus isolation, rapid test, RT-PCR and real-time RT-PCR). We examined 3,546 samples from central and eastern Slovakia during the influenza seasons from 2005-2006 to 2010-2011. In general, the probability of influenza detection significantly decreased with the time from onset of illness to sample collection (T1) as well as with patients' age (AGE). On the contrary, time from sample collection to delivery (T2) did not play a role in the prob- ability of influenza detection. As judged by odds ratios, the virus isolation method was most sensitive to T1, followed by the rapid test and RT-PCR methods. For the effect of AGE, the rapid test and virus isolation methods were more sensitive than PCR-based methods. The effects of T1 and AGE were independent of each other. Laboratories which participate in inifluenza surveillance should use several methods to enable rapid and accurate influenza A and B virus detection.

Polymerase chain reaction (PCR)--an efficient tool for diagnosis of influenza and acute respiratory illnesses during influenza season.

Many severe diseases of the respiratory tract lead to hospitalisation. These diseases are often caused by viral infections and may cause increased mortality. The most common viral pathogens involved in these cases, which are also associated with significant morbidity and mortality during the influenza seasons are influenza viruses. Rapid differential diagnosis of influenza viruses is therefore of great importance. Classical diagnosis of these viruses involves virus cultures. Of the rapid diagnostic methodologies which have been developed are RT-PCR, multiplex PCR, real-time PCR. In the present study we have monitored clinical samples from patients of different age groups from selected regions in Slovakia and compared the effectiveness of the classical and molecular biological diagnostic methods. The molecular biological methods proved to be rapid, accurate and effective. Application of these techniques in diagnosis of the respiratory illnesses should help in the prevention, therapy and disease control.