Samra Uzicanin

Bio: Samra Uzicanin is an academic researcher from Canadian Blood Services. The author has contributed to research in topics: Ferritin & Hepatitis C virus. The author has an hindex of 7, co-authored 15 publications receiving 163 citations.

Molecular Detection Method for All Known Genotypes of TT Virus (TTV) and TTV-Like Viruses in Thalassemia Patients and Healthy Individuals

Abstract: High sequence diversity among TT virus (TTV) and TTV-like viruses (TTLVs) is an obstacle to PCR detection of the entire spectrum of existing genotypes. To determine which primers are needed to detect all know genotypes of these viruses, an alignment of commonly used primer sequences with sequences

Research initiatives of blood services worldwide in response to the covid-19 pandemic.

Abstract: BACKGROUND AND OBJECTIVES: While coronavirus (COVID-19) is not transfusion-transmitted, the impact of the global pandemic on blood services worldwide is complex. Convalescent plasma may offer treatment, but efficacy and safety are not established. Measuring seroprevalence in donors would inform public health policy. Here, we survey blood services around the world to assess the different research programmes related to COVID-19 planned or in progress. MATERIALS AND METHODS: Blood collection services were surveyed in June 2020 to determine whether they were participating in serosurveys or convalescent plasma collection and clinical trials. RESULTS: A total of 48 countries (77% of those contacted) responded. Seroprevalence studies are planned or in progress in 73% of countries surveyed and in all continents, including low- and middle-income countries. Most aimed to inform public health policy. Convalescent plasma programmes have been initiated around the globe (79% of surveyed), about three quarters as clinical trials in high-, middle- and low-income countries. CONCLUSION: Blood services around the world have drawn upon their operational capacity to provide much-needed seroprevalence data to inform public health. They have rapidly implemented preparation of potential treatment when few treatments are available and mostly as clinical trials. At the same time, they must continue to provide blood products for recipients despite challenges of working in a state of emergency. It is important to track and coordinate research efforts across jurisdictions to gain a composite evidence-based view that will influence future practice and preparative strategies.

Human anelloviruses: an update of molecular, epidemiological and clinical aspects

Abstract: Human torque teno viruses (TTVs) are new, emerging infectious agents, recently assigned to the family Anelloviridae. The first representative of the genus, torque teno virus (TTV), was discovered in 1997, followed by torque teno mini virus (TTMV) in 2000, and torque teno midi virus (TTMDV) in 2007. These viruses are characterized by an extremely high prevalence, with relatively uniform distribution worldwide and a high level of genomic heterogeneity, as well as an apparent pan-tropism at the host level. Although these viruses have a very high prevalence in the general population across the globe, neither their interaction with their hosts nor their direct involvement in the etiology of specific diseases are fully understood. Since their discovery, human anelloviruses, and especially TTV, have been suggested to be associated with various diseases, such as hepatitis, respiratory diseases, cancer, hematological and autoimmune disorders, with few arguments for their direct involvement. Recent studies have started to reveal interactions between TTVs and the host’s immune system, leading to new hypotheses for potential pathological mechanisms of these viruses. In this review article, we discuss the most important aspects and current status of human TTVs in order to guide future studies.

History of discoveries and pathogenicity of TT viruses.

Abstract: Since 1997, groups of novel nonenveloped DNA viruses with a circular, single-stranded (negative sense) DNA genome of 3.6–3.9 kb, 3.2 kb, or 2.8–2.9 kb in size have been discovered and designated Torque teno virus (TTV), Torque teno midi virus (TTMDV), and Torque teno mini virus (TTMV), respectively, in the floating genus Anellovirus . These three anelloviruses frequently and ubiquitously infect humans, and the infections are characterized by lifelong viremia and great genetic variability. Although TTV infection has been epidemiologically suggested to be associated with many diseases including liver diseases, respiratory disorders, hematological disorders, and cancer, there is no direct causal evidence for links between TTV infection and specific clinical diseases. The pathogenetic role of TTMV and TTMDV infections remains unknown. The changing ratio of the three anelloviruses to each other over time, relative viral load, or combination of different genotype(s) of each anellovirus may be associated with the pathogenicity or the disease-inducing potential of these three human anelloviruses. To clarify their disease association, polymerase chain reaction (PCR) systems for accurately detecting, differentiating, and quantitating all of the genotypes and/or genogroups of TTV, TTMDV, and TTMV should be established and standardized, as should methods to detect past infections and immunological responses to anellovirus infections.

Prevalence of swine Torque teno virus in post-weaning multisystemic wasting syndrome (PMWS)-affected and non-PMWS-affected pigs in Spain.

Abstract: The present study was designed to investigate the prevalence of swine Torque teno virus (TTV) in post-weaning multisystemic wasting syndrome (PMWS)-affected and non-affected Spanish swine. Nested PCR (nPCR) assays to detect two distinct TTV genogroups were applied. A significantly higher prevalence of TTV infection was found in sera from PMWS-affected animals (97 %) than in sera from non-PMWS-affected animals (78 %). Whilst PMWS-affected pigs (91 %) were more likely to be infected with TTV from genogroup 2 than non-PMWS-affected swine (72 %), no such difference was observed with genogroup 1. Nucleotide sequences of nPCR products were 91–99 % identical between strains within a genogroup. In contrast, inter-genogroup sequence identities were 49–58 %. Phylogenetic analyses demonstrated that genogroups form different clusters without association with PMWS or porcine circovirus type 2 infection status of the animals. These results indicate a high prevalence of both swine TTV genogroups in Spain, being present more frequently in PMWS-affected animals than in non-PMWS-affected animals.