Genetic variability of Leishmania (Leishmania) infantum causing human visceral leishmaniasis in the Southeastern Brazil

ABSTRACT Leishmania infantum is a protozoan that causes visceral leishmaniasis (VL) in the Americas and some regions of Europe. The disease is mainly characterized by hepatosplenomegaly and fever, and can be fatal. Factors related to the host and parasite can contribute to the transmission of Leishmania and the clinical outcome. The intraspecific genetic variability of L. infantum strains may be one of these factors. In this study, we evaluated the genetic variability of L. infantum obtained from bone marrow smear slides from patients in the Sao Paulo State, Brazil. For this, the minicircle of the kDNA hypervariable region was used as target by Sanger sequencing. By analyzing the similarity of the nucleotides and the maximum likelihood tree (Fasttree), we observed a high similarity (98%) among samples. Moreover, we identified four different profiles of L. infantum. In conclusion, L. infantum strains from Sao Paulo State, Brazil, showed low diversity measured by minicircle of the kDNA hypervariable region.

Coxsackievirus A6 strains causing an outbreak of hand-foot-and-mouth disease in Northeastern Brazil in 2018

ABSTRACT Hand-foot-and-mouth disease (HFMD) is a highly contagious viral disease commonly associated to Enteroviruses (EV). During 2018, Brazil faced massive HFMD outbreaks spread across the country. This study aimed to characterize the EV responsible for the HFMD outbreak that occurred in Paraiba State, Brazilian Northeastern region, in 2018, followed by a phylogenetic analysis to detail information on its genetic diversity. A total of 49 serum samples (one from each patient) collected from children ≤ 15 years old, clinically diagnosed with HFMD were tested for EV using conventional RT-PCR and RT-qPCR. EV infection was confirmed in 71.4% (35/49) of samples. The mean and median ages were 1.83 years and one year old, respectively. Twenty-two EV-positive samples were successfully sequenced and classified as EV-A species; 13 samples were also identified with the CV-A6 genotype. The phylogenetic analysis (VP1 region) of three samples revealed that the detected CV-A6 strains belonged to sub-lineage D3. The CV-A6 strains detected here clustered with strains from South America, Europe and West Asia strains that were also involved in HFMD cases during the 2017-2018 seasons, in addition to the previously detected Brazilian CV-A6 strains from 2012 to 2017, suggesting a global co-circulation of a set of different CV-A6 strains introduced in the country at different times. The growing circulation of the emerging CV-A6 associated with HFMD, together with the detection of more severe cases worldwide, suggests the need for a more intense surveillance system of HFMD in Brazil. In addition, this investigation was performed exclusively on serum samples, and the analysis of whole blood samples should be considered and could have shown advantages when employed in the diagnosis of enteroviral HFMD outbreaks.

The rare enterovirus c99 and echovirus 29 strains in Brazil: potential risks associated to silent circulation

Human enteroviruses (EVs) are associated with a wide spectrum of human diseases. Here we report the complete genome sequences of one EV-C99 strain and one E29 strain obtained from children suffering from acute gastroenteritis, without symptoms of enteroviral syndromes. This is the first report of EV-C99 in South America, and the second E29 genome described worldwide. Continuous surveillance on EVs is vital to provide further understanding of the circulation of new or rare EV serotypes in the country. The present study also highlights the capacity of EVs to remain in silent circulation in populations.

Human sapovirus GI. 2 and GI. 3 from children with acute gastroenteritis in northern Brazil

Human sapoviruses (HSaV) are considered important causative agents of acute gastroenteritis in humans worldwide. However, knowledge of the genetic characteristics of the whole genome of HSaV in Brazil is limited. Here we report the complete genome sequences of six HSaVs GI.2 and two GI.3 strains obtained from children with acute gastroenteritis in the Northern region of Brazil. Next generation sequencing was used to obtain the full genome and molecular characterization of the genome was performed. Phylogenetic analysis of the genome was also performed. Only one complete HSaV GI.2 genome characterization in the country precedes that of the present study. This is the first complete genome sequence of genotype GI.3 in Brazil. The data obtained in this investigation can contribute to the augmentation of the database on the molecular diversity of HSaVs strains circulating in Brazil, and to the improvement of current typing protocols.

Frequency of human bocavirus respiratory infections among at-risk patients in São Paulo, Brazil / Frequência de bocavírus humano em infecções respiratórias entre pacientes de risco na cidade de São Paulo, Brasil

BACKGROUND AND OBJECTIVES: Human Bocavirus (HBoV) has been described since 2005 as an etiological agent of respiratory virus infections. From 2001 to 2008 we investigated the etiology of HBoV among adults and children in different groups at risk of presenting complications arising from acute respiratory infection, the investigation was carried out in a tertiary hospital health care system in Brazil. METHODS: HBoV DNA was assayed in 598 respiratory samples from community and hospitalized patients by PCR. RESULTS: Of the 598 tested samples, 2.44% (8/328) of children, including five children with heart disease, and 0.4% (1/270) of adult bone-marrow-transplant were HBoV positive. CONCLUSIONS: These data suggested lower HBoV frequency among different at-risk patients and highlights the need to better understand the real role of HBoV among acute respiratory symptomatic patients.

INTRODUÇÃO E OBJETIVOS: O bocavírus humano (HBoV) tem sido descrito desde 2005 como agente etiológico de infecções respiratórias virais. O presente estudo tem como objetivo investigar a etiologia da infecção respiratória pelo HBoV em pacientes adultos e crianças de diferentes grupos de risco para complicação de infecções respiratórias agudas desde 2001 até 2008 em um hospital terciário no Brasil. PACIENTES E MÉTODOS: O HBoV foi investigado, através de reação em cadeia da polimerase, em 598 amostras respiratórias coletadas de pacientes hospitalizados e não hospitalizados. RESULTADOS: Das 598 amostras testadas o HBoV foi detectado em 2,44% (8/328) das crianças, incluindo cinco crianças portadoras de cardiopatia congênita, e 0,4% (1/270) dos adultos em programa de transplante de células tronco hematopoiéticas. CONCLUSÃO: Os dados do presente estudo sugerem baixa freqüência de detecção do HBoV entre pacientes de risco, e destaca a necessidade de novos estudos para um melhor entendimento do verdadeiro papel desse agente em infecções respiratórias agudas em pacientes sintomáticos.

Viral etiology among the elderly presenting acute respiratory infection during the influenza season / Etiologia viral de infecção respiratória aguda entre idosos, durante a temporada de gripe

INTRODUCTION: Acute respiratory tract infections are the most common illness in all individuals. Rhinoviruses have been reported as the etiology of more than 50 percent of respiratory tract infections worldwide. The study prospectively evaluated 47 elderly individuals from a group of 384 randomly assigned for acute respiratory viral infections (cold or flu) and assessed the occurrence of human rhinovirus (HRV), influenza A and B, respiratory syncytial virus and metapneumovirus (hMPV) in Botucatu, State of São Paulo, Brazil. METHODS: Forty-nine nasal swabs collected from 47 elderly individuals following inclusion visits from 2002 to 2003 were tested by GenScan RT-PCR. HRV-positive samples were sequenced for phylogenetic analysis. RESULTS: No sample was positive for influenza A/B or RSV. HRV was detected in 28.6 percent (14/47) and hMPV in 2 percent (1/47). Of 14 positive samples, 9 isolates were successfully sequenced, showing the follow group distribution: 6 group A, 1 group B and 2 group C HRVs. CONCLUSIONS: The high incidence of HRV during the months of the influenza season requires further study regarding HRV infection impact on respiratory complications among this population. Infection caused by HRV is very frequent and may contribute to increasing the already high demand for healthcare during the influenza season.

INTRODUÇÃO: Infecções agudas do trato respiratório estão entre as doenças mais comuns em todas as pessoas. Os rinovírus têm sido descritos como agente etiológico de mais de 50 por cento das infecções do trato respiratório ao redor do mundo. O objetivo deste trabalho foi avaliar a ocorrência de rinovírus humano (HRV), influenza vírus A e B, vírus respiratório sincicial humano e metapneumovírus (hMPV) em uma população de idosos que apresentava sintomas de gripe ou resfriado, e que residiam na Cidade de Botucatu, Estado de São Paulo, Brasil. MÉTODOS: Foram coletados swabs nasais de 47 idosos após visitas de inclusão, entre os anos de 2002 e 2003 e que foram testadas através de GeneScan RT-PCR. RESULTADOS: HRV foi detectado em 28.6 por cento (14/47) e hMPV em 2 por cento (1/47). De 14 amostras positivas para HRV, 9 foram sequenciadas, mostrando a seguinte distribuição de grupos: grupo A: 6 amostras, grupo B: 1 amostra e grupo C: 2 amostras. CONCLUSÕES: A alta incidência de HRV durante os meses de ocorrência de gripe necessita de estudos posteriores para avaliar o impacto desse vírus entre os idosos. A alta frequência de HRV pode contribuir para o aumento da demanda por serviços de saúde durante a estação de influenza.

Detecçäo do provirús da imunodeficiência felina em gatos domésticos pela técnica de reaçäo em cadeia da polimerase / Detection of feline immunodeficiency provirus in domestic cats by polymerase chain reaction

A infecçäo de gatos domésticos pelo Vírus da Imunodeficiência Felina (FIV) é um dos modelos mais promissores para o estudo da infecçäo pelo vírus da imunodeficiência humana (HIV) que causa a Síndrome de Imunodeficiência Adquirida (AIDS). O FIV causa, em gatos, uma enfermidade similar àquela observada em pacientes com AIDS, sobretudo no que diz respeito ao aumento da susceptibilidade a infecções oportunistas. No presente estudo, utilizou-se a Reaçäo em Cadeia da Polimerase (PCR), com o objetivo de detectar o provírus do FIV em gatos com sinais clínicos de imunodeficiência. O fragmento de DNA escolhido como alvo para amplificaçäo situa-se no gene gag do lentivírus felino, o qual é conservado entre as diferentes amostras do vírus. O DNA utilizado foi extraído a partir de amostras de sangue e de tecidos de animais com suspeita clínica de imunodeficiência. Das 40 amostras analisadas, 15 foram positivas, das quais 4 foram submetidas à hibridizaçäo, confirmando a especificidade dos fragmentos amplificados. Esses resultados demonstram a presença do FIV na populaçäo de gatos domésticos do Rio Grande do Sul, Brasil.

Viral diseases and human evolution

The interaction of man with viral agents was possibly a key factor shaping human evolution, culture and civilization from its outset. Evidence of the effect of disease, since the early stages of human speciation, through pre-historical times to the present suggest that the types of viruses associated with man changed in time. As human populations progressed technologically, they grew in numbers and density. As a consequence different viruses found suitable conditions to thrive and establish long-lasting associations with man. Although not all viral agents cause disease and some may in fact be considered beneficial, the present situation of overpopulation, poverty and ecological inbalance may have devastating effects on human progress. Recently emerged diseases causing massive pandemics (e.g., HIV-1 and HCV, dengue, etc.) are becoming formidable challenges, which may have a direct impact on the fate of our species