SUMMARYThe objective of the study is to analyze molecular epidemiologic surveillance for norovirus infection in Belarus over the past five years (2009)(2010)(2011)(2012)(2013). Laboratory diagnostics was carried out by RT-PCR in 684 patients. Two regions of norovirus genome, localized in RNA-polymerase and capsid protein genes, were used for phylogenetic analysis.Noroviruses were predominant causative agents in adults and second only to rotaviruses in children, they also prevailed among aetiological agents of outbreaks (66.7% of outbreaks). In 2009-2013, the major norovirus genotype was GII.4 (58.3% of all genotyped isolates). Genovariant GII.4 2006b circulated in 2009 and 2010, genovariant GII.4 2009 New Orleans -in 2010and 2012. In addition to GII.4, genotypes GII.6 (16.6%), GII.2 (4.1%), GII.3 (2.2%), and recombinant genotypes GII.g-GII.12 and GII.g-GII.1 (10.4% and 8.3%, respectively) circulated in Belarus.The findings indicate a significant contribution of noroviruses in development of sporadic morbidity and outbreaks of acute gastroenteritis in Belarus. Outbreaks or prominent increases of sporadic morbidity were mostly due to the emergence of a new genotype, or an epidemic genovariant.

Background and Aims Polyomaviruses (PyV) are ubiquitous human viral pathogens. BKV and JCV representing this viral family are common causative agents of viral complications among kidney recipients. Viral load higher than 1 × 107 copies/ml in urine (viruria) or 1 × 104 copies/ml in serum (viremia) in posttransplantation period may lead to polyomavirus-associated nephropathy (PVAN), hemorrhagic cystitis (HC) or even kidney transplant failure. The aim of the study was to assess PyV reactivation frequency in patients during 12 months after renal transplantation (RT) and to identify molecular subtypes of BKV and JCV. Method We examined 3207 samples of biological material (serum and urine) of 763 adult (>18 years) patients who underwent renal transplantation (RT) at the State Institution “Minsk Scientific and Practical Center for Surgery, Transplantology and Hematology”, Healthcare institutions “Brest Regional Clinical Hospital”, “Vitebsk Regional Clinical Hospital Belarus”, “Mogilev Regional Clinical Hospital”. These patients were divided into 2 groups: group 1 included 394 patients examined only for BKV infection, group 2 – 356 recipients examined for both BKV and JCV infection. Serum and urine samples for regular monitoring were collected from patients before RT, every 2 weeks first 3 months, then at 6, 9, 12 months after RT. In the case of complication development samples from patients were collected later then 1-year monitoring period. PyV DNA was detected by real-time PCR. Viral DNAs from 17 BKV-positive and 11 JCV-positive patients were molecular typed by partial sequencing of VP1 genome region. Confidence intervals for the proportions were calculated using Wald's method. Results Results showed that BKV detection total frequency in the group 1 was 14.47% [11.32%; 18.3%], almost all patients developed viruria, only 2.54% [1.32%; 4.67%] had viremia. In the group 2 PyV DNA was detected in 46.07% [40.96%; 51.26%] of recipients: 19.10% [15.34%; 23.52%] had BKV infection, 19.94% [16.11%; 24.42%] – JCV, 7.02% [4.76%; 10.2%] – BKV+JCV mixed infection. Frequency of viremia was 6.74% [4.53%; 9.87%] in this group. Maximal BKV viral load levels reached 1.2 × 1012 copies/ml in urine and 5.9 × 107 copies/ml in serum. JCV loads were up to 3 × 109 copies/ml in urine and 1.2 × 108 copies/ml in serum. Then we analyzed frequency of PyV detection before RT and during the first year after RT among the 102 recipients. Results displayed on the Fig. 1 showed that the peak of PyV infection registration and the higher risk for patient had a place on the 1.5-2.5 months after RT. Quantitative monitoring of viral load in posttransplant period was the basis for the correction of the applied immunosuppressive therapy regimens in relation to the recipients with a high viral load (higher than 1 × 107 copies/ml in urine or 1 × 104 copies/ml in serum). The results of molecular typing showed that 17 BKV isolates belonged to subgroups Ib-2 and IVc-2 (12 and 5 isolates, respectively). Within subgroups Ib-2 isolates formed 3 clusters corresponding 3 separate genovariants. JCV isolates belonged to subtype 1A, 1B and 2A (7, 3 and 1 of isolates, respectively). The last one had 99% nucleotide sequence similarity with Greece and South Korea isolates. Conclusion Our data demonstrated an importance of PyV DNA monitoring of kidney recipients in the posttransplant period starting from the first days after RT to predict development of PyV complications as PVAN, HC or others by correcting the immunosuppressive therapy.

Enteroviruses are widespread human pathogens characterized by a high level of a genetic diversity. They cause different clinical forms of infection. The aim of the present study was to analyze the molecular epidemiology of enterovirus infection in the application to the structure of its clinical forms in 2016–2017.ECHO viruses predominated among patients with aseptic meningitis and were prevailing group of enteroviruses in 2016 (all ECHO viruses – 58%, including ECHO 9 – 26%, ECHO 6 –14%, ECHO 16 – 10%). In 2017, Coxsackieviruses prevailed (68%), that were including Coxsackievirus B5 (31%), Coxsackievirus B1, Coxsackievirus B4 and Coxsackievirus A6 (9% of each serotype). Coxsackieviruses were detected more frequently in patients with vesicular pharyngitis and unspecified enterovirus infection. The results of the molecular epidemiological analysis indicated that the prevalence of ECHO viruses in 2016 and Coxsackieviruses B in 2017 was due to the emergence of numerous new genovariants of these viruses.

Background: Human herpesvirus (HHV)-7 is usually associated with febrile seizures. Later onset and higher frequency of seizures are characteristic of pediatric HHV-7, compared with HHV-6 infection. The HHV-7-related severe neurological disorders are predominantly observed in immunocompromised individuals. Reports of healthy individuals with HHV-7 infection and diverse neurological disorders are limited. Patient Description: We present a case of HHV-7-related epilepsy in an immunocompetent 11-year old boy and extensive infectious and autoimmune testing positive only for HHV-7 in the cerebrospinal fluid. The patient made a good recovery after treatment with intravenous immunoglobulin and methylprednisolone. Discussion: This is the first reported case of epilepsy associated with HHV-7 in a previously healthy individual. It also demonstrates that intravenous immunoglobulin and steroids may be used in the course of this disorder and may be beneficial for recovery.

Background. Individual cases of viral hepatitis E are recorded in the Republic of Belarus annually indicating the need for the pathogen monitoring at both the population and reservoir levels. Objective. To consolidate the monitoring data on hepatitis E virus over the period of 2018 - 2021, as well as to work out an effective algorithm for its laboratory screening. Material and methods. As part of the study, 345 samples were analyzed, including 227 human biological samples, 37 samples of biological materials of domestic pigs, 22 samples of food and 59 samples of waste water. Results. According to the results of serum diagnostics, in the group of kidney recipients (n = 29), the detection rate of IgM and IgG to hepatitis E virus was 6.9% [0.85%; 23.03%] and 17.2% [7.13%; 35, 02%] respectively; in the group of patients with pregnancy pathology (n = 44) - 6.8% [1.68%; 18.89%] and 11.4% [4.5%; 24.43%] respectively. In patients with acute hepatitis of unknown etiology (n = 26), antiviral IgM was not detected, while the frequency of antiviral IgG detection reached 7.7% [1.02%; 25.26]. In control group (blood donors, n = 53) IgM and IgG were detected in 1.9% [0.6%; 10.88%] and 5.7% [1.35%; 15.97] of those examined respectively. Hepatitis E virus RNA was detected in 8 human biological samples (3.8%) from kidney recipients. The identified hepatitis E viruses were represented by genotype GIII and belonged to a previously unidentified subgenotype (GIIIa - GIIIi). In the studied samples of biological material from pigs, as well as in samples of food and waste water, hepatitis E virus RNA was not detected. Conclusions. An algorithm for hepatitis E virus laboratory screening has been developed and tested. Its section concerning the diagnosis of viral hepatitis E is set out in the Instructions for use "Algorithm for laboratory diagnosis of viral hepatitis E" (No. 148-1220 from January 28, 2021).