Viral metagenomics performed in patients with acute febrile syndrome during Toxoplasma gondii outbreak in south Brazil

ABSTRACT Toxoplasmosis is a zoonotic infection caused by the protozoan parasite Toxoplasma gondii. The infection is widely disseminated in the human population and is usually benign or asymptomatic. Systemic T. gondii infection presents risks for pregnant women and AIDS patients. Although rare, T. gondii can cause outbreaks in urban centers. The origin of these outbreaks is not completely understood but probably results from introduction of zoonotic T. gondii strains in the population. During such outbreaks other pathogens which mimic T. gondii acute febrile syndrome may also circulate; therefore, detailed investigation of the outbreak is of extreme importance. In this study we performed viral metagenomics next-generation sequencing (mNGS) in patient samples obtained during T. gondii outbreak in Santa Maria city, South Brazil. Specific bioinformatics pipelines specialized in virus discovery were applied in order to identify co-circulating vial agents. Epstein Barr virus and Parvovirus B19 contigs were assembled and these viruses can cause symptoms similar to toxoplasmosis. In conclusion, our findings show the importance of Metagenomics next generation sequencing (mNGS) use to help characterize the outbreak more completely and in the management of the affected patients.

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.

Molecular and clinical evaluation of the acute human parvovirus B19 infection: comparison of two cases in children with sickle cell disease and discussion of the literature

Human parvovirus B19 is a well-known cause of severe conditions in patients with sickle cell disease, but the molecular mechanisms of the infection are insufficiently understood. The different clinical outcome of the acute parvovirus B19 infection in two pediatric patients with sickle cell disease has been examined. One of them developed life-threatening condition requiring emergency transfusions, while the other had asymptomatic infection, diagnosed occasionally. Both cases had high viral load and identical subgenotype, indicating that the viral molecular characteristics play a minimal role in the infection outcome.