Molecular Evolution and Epidemiological Characteristics of SARS COV-2 in (Northwestern) Poland

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) evolved into a worldwide outbreak, with the first Polish cases in February/March 2020. This study aimed to investigate the molecular epidemiology of the circulating virus lineages between March 2020 and February 2021. We performed variant identification, spike mutation pattern analysis, and phylogenetic and evolutionary analyses for 1106 high-coverage whole-genome sequences, implementing maximum likelihood, multiple continuous-time Markov chain, and Bayesian birth–death skyline models. For time trends, logistic regression was used. In the dataset, virus B.1.221 lineage was predominant (15.37%), followed by B.1.258 (15.01%) and B.1.1.29 (11.48%) strains. Three clades were identified, being responsible for 74.41% of infections over the analyzed period. Expansion in variant diversity was observed since September 2020 with increasing frequency of the number in spike substitutions, mainly H69V70 deletion, P681H, N439K, and S98F. In population dynamics inferences, three periods with exponential increase in infection were observed, beginning in March, July, and September 2020, respectively, and were driven by different virus clades. Additionally, a notable increase in infections caused by the B.1.1.7 lineage since February 2021 was noted. Over time, the virus accumulated mutations related to optimized transmissibility; therefore, faster dissemination is reflected by the second wave of epidemics in Poland

Prevalence of F5 1691G>A, F2 20210G>A, and MTHFR 677C>T polymorphisms in Bosnian women with pregnancy loss

The relationship between genetic risk factors of thrombophilia and pregnancy loss (PL) is being discussed. The focus has been on F5 1691G>A, F2 20210G>A, and MTHFR 677C>T polymorphisms that may predispose women to microthrombosis during the stages of embryo implantation and placentation. Although, the frequencies of these polymorphisms were reported in different populations, such studies have not yet been performed in Bosnian population. In this study, we determined the prevalence of F5 G>A (rs6025), F2 G>A (rs1799963) and MTHFR C>T (rs1801133) polymorphisms in Bosnian women. A total of 154 women with PL, mean age 33 (±5.4) years, were enrolled in the study. As a control group, 154 mothers [mean age 31.4 (±6.7) years] with at least one live-born child were included. We used real-time polymerase chain reaction (PCR) to determine the frequencies of F5 G>A and F2 G>A genotypes, and PCR-restriction fragment length polymorphism (RFLP) for analyzing MTHFR C>T genotypes. The frequency of heterozygotes for F5 and F2 was significantly higher in women with venous thrombosis (VT) compared to women without VT (p = 0.047 and p = 0.001, respectively). There was no significant difference in the distribution of MTHFR genotypes and alleles between these two groups. In addition, we observed no significant differences in the genotype and allele frequencies between the group with PL and control group, for all investigated polymorphisms. The allele frequencies for 1691A (F5), 20210A (F2), and 677T (MTHFR) reported in this study are consistent with the data obtained for other European countries, however, we were not able to confirm the association between the three polymorphisms and PL in Bosnian women