Molecular identification of the emerging Human Gemykibivirus-2 (HuGkV-2) among Brazilian blood donors.

Human gemykibivirus-2 (HuGkV-2) belonging to the Gemykibivirus genus (Genomoviridae family) is an emerging DNA virus which has been described as a component of the virome of a wide variety of samples including clinical ones. So far, the HuGkV-2 DNA prevalence in the human population as well as its clinical impact are completely unknown. The objective of this study was to investigate the HuGkV-2 DNA prevalence among Brazilian healthy blood donors from three different geographic regions. A total of 450 blood samples were screened for HuGkV-2 DNA (150 samples were from the Brazilian Amazon, 150 from Midwest Brazil and 150 from South Brazil). The overall HuGkV-2 DNA prevalence was 7.8 %. Considering the examined regions, the highest prevalence was observed in the Brazilian Amazon (city of Macapa, state of Amapa), 15.3 %, followed by the Midwest Brazil (city of Brasilia, Federal District) (6.0 %) and South Brazil (city of Santa Maria, Rio Grande do Sul State) (2.0 %). This study gives preliminary insights on the molecular prevalence of HuGkV-2 DNA among Brazilian blood donors, highlighting that the highest HuGkV-2 prevalence was recorded in the Brazilian Amazon. However, more studies regarding the prevalence, transmission routes and any possible clinical effects appear to be crucial in order to understand the impact of this emerging viral agent.

Merkel cell polyomavirus (MCPyV) DNA prevalence in Brazilian blood donors.

Merkel cell polyomavirus (MCPyV) is an oncogenic virus that has been etiologically linked to Merkel cell carcinoma. Low levels of MCPyV DNA have been detected in blood donors with unclear impact on transfusion. The prevalence of MCPyV DNA in Brazilian blood donors is unclear. Therefore, the objective of this study was to evaluate the MCPyV DNA prevalence among Brazilian blood donors. We examined the presence of MCPyV DNA by real-time PCR (qPCR) in a total of 450 serum samples obtained from blood donors from three Brazilian regions (North, Central-West and South). The overall estimated MCPyV DNA prevalence was 1.1% (CI = 95%, 0.16-2.06%). Divided by region, in North Brazil (city of Macapa, state of Amapá) and South Brazil (city of Santa Maria, state of Rio Grande do Sul), the MCPyV prevalence was the same: 1.33% (CI = 95%, range 0.0-3.14%). In Central-West Brazil (city of Brasilia), the MCPyV prevalence was 0.6% (CI = 95%, 0.0-1.96%). All MCPyV positive samples showed a high cycle threshold (median Ct = 35.5), most probably related to the low viral load. More studies are necessary to unveil the impact of this oncogenic virus on transfusion medicine and if such exists, especially in regards of its infectivity and transmission potential.

Metavirome composition of Brazilian blood donors positive for the routinely tested blood-borne infections.

Viral metagenomics is widely applied to characterize emerging viral pathogens but it can also reveal the virome composition in health and disease. The evaluation of the virome in healthy blood donors can provide important knowledge on possible transfusion threats. Currently, there is still a paucity of information regarding the virome of blood donors who test positive for routinely tested blood-borne infections. Such analysis may reveal co-infections which in turn appear to be crucial for transfusion medicine and for patient management. The aim of this study was to evaluate the metavirome in blood donors who tested positive for routinely tested blood-borne infections, the information for which is important for transfusion medicine and blood donor management. For this purpose, we analyzed 18 blood donations obtained from HIV and HBV-infected blood donors from the Brazilian Amazon (Amapa state) and 11 HIV, HBV, HCV, syphilis and Chagas disease - positive blood donations obtained from blood donors sampled in South Brazil (Rio Grande do Sul state). We additionally included a control group of 20 blood donors obtained from Southeast Brazil (State of São Paulo). Samples were assembled in pools and sequenced by the Illumina NovaSeq 6000 platform. To link a given virus with geographic region or type of blood donor, we performed supervised machine learning classification (fingerprint analysis). The virome of both locations was predominantly composed of commensal viruses. However, in HBV-infected blood donors from the Brazilian Amazon, the Human Pegivirus-1 (HPgV-1) reads were prevailing, while in HIV-infected donors from the same location, the torque teno virus (TTV) reads expressive abundance. In blood donors from South Brazil, the most abundant reads were classified as Human endogenous retrovirus K (HERV-K). Putative emerging viruses like the Human gemykibivirus-2 (HuGkV-2) were exclusively identified in samples from the Brazilian Amazon. The fingerprint analysis demonstrated that the HERV-K, TTV-7, 13, and 15 were statistically important for the infected blood donors, while TTV-5, 12 and 20 were linked to geographic localization. Our study revealed differences in the viral composition among blood donors who tested positive for routinely tested blood-borne infections from two different Brazilian regions and indicated the presence of putative emerging viruses in samples obtained from the Amazon. Together our results show that the presence of specific commensal viruses may be related donor infection status but additional investigations including larger study groups and samples from other Brazilian regions are needed to confirm this hypothesis.

Molecular evolution pattern of Merkel cell polyomavirus identified by viral metagenomics in plasma of high-risk blood donors from the Brazilian Amazon.

Merkel cell polyomavirus (MCPyV) is a common human skin pathogen, shows high seroprevalence and is considered the etiologic agent of Merkel cell carcinoma. However, studies which detect MCPyV DNA in blood products may reveal the importance of this virus for the transfusion medicine. In this study we analyzed by viral metagenomics 36 plasma samples obtained from blood donors positive for the common blood transmitted infections from the city of Macapá (Brazilian Amazon). The generated raw data were were analyzed through a specific bioinformatics pipeline aimed at discovery of emerging viruses. The genomes of interest were analyzed phylogeographically and phylogenetically. MCPyV complete genome was recovered from one HBV-positive pool with high coverage (~ 223×) indicating acute viremia or reactivated infection. Interestingly, the phylogeographic position of the identified strain suggests its ancestry compared to MCPyV isolate from Colombian Amazon which hypothesizes that viral dissemination in the Amazon may have originated from Brazil. In conclusion, this study brings information for the genetic relationships of MCPyV isolated from blood donors from the Brazilian Amazon and demonstrates the possible phylogeographic behavior of our strain in relation to the other findings. We also demonstrated a strong evidence of viremic MCPyV phase in blood donations, however, more studies are necessary in order to understand the MCPyV impact on transfusion therapy.

Seroprevalence of Chikungunya virus in blood donors from Northern and Southeastern Brazil.

BACKGROUND: Chikungunya virus, an arbovirus that belongs to the Alphavirus genus of the Togaviridae family, causes a febrile illness accompanied by rash and arthralgia. It is estimated that during outbreaks, the prevalence of Chikungunya virus RNA in viremic blood donations varies between 0.4 and 2.1%; therefore, this virus may be transmitted by transfusion. In Brazil, Chikungunya virus has been claimed to cause extensive outbreaks, however, the seroprevalence of anti-Chikungunya virus IgG among Brazilian blood donors is unknown. METHODS: Eight hundred and ninety-seven blood samples were collected from volunteer blood donors in two distant localities long after the Chikungunya virus first appeared in Brazil. In 2015, 442 samples were collected from the Hemotherapy Service of Macapá, Amapá in the northern Brazilian Amazon. To evaluate the dissemination course of the virus in Brazil, in 2016, 455 blood samples were collected from the southeastern region (Blood Center of Ribeirão Preto, Ribeirão Preto, São Paulo). All samples were tested for the presence of anti-Chikungunya virus IgG and viral RNA. RESULTS: One sample (0.2%) obtained from the Hemotherapy Center of Macapá tested positive for anti-Chikungunya virus IgG and no sample from the Blood Center of Ribeirão Preto was seroreactive to anti-Chikungunya virus IgG. All blood donations were Chikungunya virus RNA negative. CONCLUSIONS: This study, performed during 2015-2016, indicates that the transfusion risk of Chikungunya virus in this period was low. However, due to the constant advance of this virus in Brazil, further studies during outbreaks are needed to evaluate the presence of Chikungunya virus RNA in blood donations and the respective transfusion-transmission risk.

Seroprevalence of Chikungunya virus in blood donors from Northern and Southeastern Brazil

ABSTRACT Background: Chikungunya virus, an arbovirus that belongs to the Alphavirus genus of the Togaviridae family, causes a febrile illness accompanied by rash and arthralgia. It is estimated that during outbreaks, the prevalence of Chikungunya virus RNA in viremic blood donations varies between 0.4 and 2.1%; therefore, this virus may be transmitted by transfusion. In Brazil, Chikungunya virus has been claimed to cause extensive outbreaks, however, the seroprevalence of anti-Chikungunya virus IgG among Brazilian blood donors is unknown. Methods: Eight hundred and ninety-seven blood samples were collected from volunteer blood donors in two distant localities long after the Chikungunya virus first appeared in Brazil. In 2015, 442 samples were collected from the Hemotherapy Service of Macapá, Amapá in the northern Brazilian Amazon. To evaluate the dissemination course of the virus in Brazil, in 2016, 455 blood samples were collected from the southeastern region (Blood Center of Ribeirão Preto, Ribeirão Preto, São Paulo). All samples were tested for the presence of anti-Chikungunya virus IgG and viral RNA. Results: One sample (0.2%) obtained from the Hemotherapy Center of Macapá tested positive for anti-Chikungunya virus IgG and no sample from the Blood Center of Ribeirão Preto was seroreactive to anti-Chikungunya virus IgG. All blood donations were Chikungunya virus RNA negative. Conclusions: This study, performed during 2015-2016, indicates that the transfusion risk of Chikungunya virus in this period was low. However, due to the constant advance of this virus in Brazil, further studies during outbreaks are needed to evaluate the presence of Chikungunya virus RNA in blood donations and the respective transfusion-transmission risk.