Akemi Suzuki

Probable transfusion-transmitted Zika virus in Brazil

Zika virus (ZIKV) is an emerging arthropod‐borne flavivirus transmitted by Aedes mosquitoes. Recent commentaries regarding ZIKV routes of transmission describe a potential transmission by transfusion. Herein, we report a probable case of transfusion‐transmitted ZIKV infection through a platelet transfusion that was detected from postdonation information.

Identifying Rodent Hantavirus Reservoirs, Brazil

Bolomys lasiurus and Oligoryzomys nigripes are rodent reservoirs of Araraquara-like and Juquitiba-like hantaviruses, which cause HPS in Brazil.

Hantavirus Pulmonary Syndrome, Central Plateau, Southeastern, and Southern Brazil

This syndrome is an increasing health problem because of human encroachment into habitats of rodent reservoirs.

St. Louis encephalitis vírus: first isolation from a human in São Paulo state, Brasil

This paper reports the isolation of St. Louis encephalitis virus (SLEV) from a febrile human case suspected to be dengue, in Sao Pedro, Sao Paulo State. A MAC-ELISA done on the patients acute and convalescent sera was inconclusive and hemagglutination inhibition test detected IgG antibody for flaviviruses. An indirect immunofluorescent assay done on the C6/36 cell culture inoculated with the acute serum was positive for flaviviruses but negative when tested with dengue monoclonal antibodies. RNA extracted from the infected cell culture supernatant was amplified by RT-PCR in the presence of NS5 universal flavivirus primers and directly sequenced. Results of BLAST search indicated that this sequence shares 93% nucleotide similarity with the sequence of SLEV (strain-MSI.7), confirmed by RT-PCR performed with SLEV specific primers. Since SLEV was identified as the cause of human disease, it is necessary to improve surveillance in order to achieve early detection of this agent in the state of Sao Paulo and in Brazil. This finding is also an alert to health professionals about the need for more complete clinical and epidemiological investigations of febrile illnesses as in the reported case. SLEV infections can be unrecognized or confused with other ones caused by an arbovirus, such as dengue.

Detection of a new yellow fever virus lineage within the South American genotype I in Brazil.

Nucleotide sequences of two regions of the genomes of 11 yellow fever virus (YFV) samples isolated from monkeys or humans with symptomatic yellow fever (YF) in Brazil in 2000, 2004, and 2008 were determined with the objective of establishing the genotypes and studying the genetic variation. Results of the Bayesian phylogenetic analysis showed that sequences generated from strains from 2004 and 2008 formed a new subclade within the clade 1 of the South American genotype I. The new subgroup is here designated as 1E. Sequences of YFV strains recovered in 2000 belong to the subclade 1D, which comprises previously characterized YFV strains from Brazil. Molecular dating analyses suggested that the new subclade 1E started diversifying from 1D about 1975 and that the most recent 2004–2008 isolates arose about 1985. J. Med. Virol. 82:175–185, 2010.

Dengue Virus Type 4 Phylogenetics in Brazil 2011: Looking beyond the Veil

Dengue Fever and Dengue Hemorrhagic Fever are diseases affecting approximately 100 million people/year and are a major concern in developing countries. In the present study, the phylogenetic relationship of six strains of the first autochthonous cases of DENV-4 infection occurred in Sao Paulo State, Parana State and Rio Grande do Sul State, Brazil, 2011 were studied. Nucleotide sequences of the envelope gene were determined and compared with sequences representative of the genotypes I, II, III and Sylvatic for DEN4 retrieved from GenBank. We employed a Bayesian phylogenetic approach to reconstruct the phylogenetic relationships of Brazilian DENV-4 and we estimated evolutionary rates and dates of divergence for DENV-4 found in Brazil in 2011. All samples sequenced in this study were located in Genotype II. The studied strains are monophyletic and our data suggest that they have been evolving separately for at least 4 to 6 years. Our data suggest that the virus might have been present in the region for some time, without being noticed by Health Surveillance Services due to a low level of circulation and a higher prevalence of DENV-1 and DENV- 2.

Mayaro virus: imported cases of human infection in São Paulo State, Brazil

Mayaro virus (MAYV) is an arbovirus (Togaviridae: Alphavirus) enzootic in tropical South America and maintained in a sylvan cycle involving wild vertebrates and Haemagogus mosquitoes. MAYV cases occur sporadically in persons with a history of recent activities inside or around forests. This paper reports three cases of MAYV fever detected in men infected in Camapuã, MS, Brazil. Serum samples collected at four days and two months after the onset of the symptoms and examined by hemagglutination inhibition test, revealed monotypic seroconversion to MAYV. Isolation of the virus was obtained from one of the samples by inoculation of the first blood samples into newborn mice. A suspension of the infected mouse brain was inoculated into C6/36 cells culture and the virus was identified by indirect immunofluorescent assay with alphavirus polyclonal antibodies. RT-PCR, performed with RNA extracted from the supernatant of C6/36 infected cells in the presence of alphavirus generic primers as well as specific MAYV primers, confirmed these results. The reported cases illustrate the importance of laboratory confirmation in establishing a correct diagnosis. Clinical symptoms are not always indicative of a disease caused by an arbovirus. Also MAYV causes febrile illness, which may be mistaken for dengue.

Reemergence of yellow fever: detection of transmission in the State of São Paulo, Brazil, 2008

INTRODUCTIONnFollowing yellow fever virus (YFV) isolation in monkeys from the São José do Rio Preto region and two fatal human autochthonous cases from the Ribeirão Preto region, State of São Paulo, Brazil, two expeditions for entomological research and eco-epidemiological evaluation were conducted.nnnMETHODSnA total of 577 samples from humans, 108 from monkeys and 3,049 mosquitoes were analyzed by one or more methods: virus isolation, ELISA-IgM, RT-PCR, histopathology and immunohistochemical.nnnRESULTSnOf the 577 human samples, 531 were tested by ELISA-IgM, with 3 positives, and 235 were inoculated into mice and 199 in cell culture, resulting in one virus isolation. One sample was positive by histopathology and immunohistochemical. Using RT-PCR, 25 samples were processed with 4 positive reactions. A total of 108 specimens of monkeys were examined, 108 were inoculated into mice and 45 in cell culture. Four virus strains were isolated from Alouatta caraya. A total of 931 mosquitoes were captured in Sao Jose do Rio Preto and 2,118 in Ribeirão Preto and separated into batches. A single isolation of YFV was derived from a batch of 9 mosquitoes Psorophora ferox, collected in Urupês, Ribeirão Preto region. A serological survey was conducted with 128 samples from the municipalities of São Carlos, Rincão and Ribeirão Preto and 10 samples from contacts of patients from Ribeirão Preto. All samples were negative by ELISA-IgM for YFV.nnnCONCLUSIONSnThe results confirm the circulation of yellow fever, even though sporadic, in the Sao Paulo State and reinforce the importance of vaccination against yellow fever in areas considered at risk.

Perinatal transmission of yellow fever, Brazil, 2009

To the Editor: Although urban cases of yellow fever have not been reported in Brazil since 1942, sylvatic yellow fever is still endemic to the northern and middle-western states. In the past decade, the endemic area has spread southward and eastward, approaching most populated states (1). In 2009, there was an outbreak of sylvatic yellow fever in Sao Paulo State that caused 28 cases and 11 deaths. In the affected area, there had been no reports of yellow fever since the 1930s (2). In the outbreak setting, a case of perinatal yellow fever transmission was diagnosed. n nThe mother was a 30-year-old woman exposed to yellow fever in late pregnancy in a sylvatic area near Piraju (23°11′44′′S, 49°22′54′′W), a city 100 km from Botucatu. The patient had not received yellow fever vaccine and had not traveled to yellow fever–endemic regions in the previous months. The exposure to yellow fever occurred during regular walks in a sylvatic area, a habit that continued until late pregnancy. She had fever, headache, and jaundice on March 14, 2009. Three days later, on March 17, she delivered a female infant through vaginal partum in a hospital in her hometown. n nThe mother´s symptoms were mild. She was admitted to Botucatu Medical School Hospital 7 days after delivery; she had fever, jaundice, and conjunctival suffusion. Liver enzymes were elevated (aspartatexa0aminotransferase [AST] 246 U/L, alanine transaminase [ALT]xa0324 U/L, γ-glutamyl transpeptidasexa0221 U/L, and alkaline phosphatasexa0338 U/L). She was mildly anemic (hemoglobin levelxa010.2 g/dL), but leukocyte and platelet counts were within reference ranges. There were no other laboratory abnormalities. She was discharged after 7 days with complete recovery. n nThe infant girl was born asymptomatic on March 17, with a birthweight of 3,800 g and Apgar scores of 9–10. She was discharged from the hospital after 2 days of exclusive breast-feeding. On the third day of life, she had fever and cyanosis and was readmitted to the local hospital with suspected pneumonia. She received antimicrobial drugs but showed no improvement. On the 8th day of life, she had hematemesis, melena, bleeding at venipuncture sites, hypoglycemia, and oliguria. n nThe newborn was transferred to the Neonatal Intensive Care Unit at Botucatu Medical School Hospital. At admission, she had hypotension, tachycardia, cutaneous paleness, jaundice, hepatomegaly, and melena. The initial diagnostic hypothesis was congenital or hospital-acquired sepsis, but the mother´s diagnosis prompted doctors to investigate possible yellow fever. The infant was intubated for ventilatory support and received volume expansion, vasoactive amines, antimicrobial drugs, blood components (erythrocytes, platelets, fresh frozen plasma, cryoprecipitate), and drugs to control bleeding. Liver enzymes values were initially high (ASTxa04,072 U/L, ALTxa01,420 U/L) but fell abruptly within 3 days (ASTxa0150 U/L, ALTxa0114 U/L). n nDespite the therapy, the newborn experienced liver and renal failure, disseminated intravascular coagulation, seizures, and finally coma. She died on the 12th day of life (4th day of hospitalization in the neonatal intensive care unit). Autopsy specimens showed massive liver necrosis, pulmonary hemorrhage, and acute tubular necrosis (Figure). n n n nFigure n nMicroscopy findings of autopsy specimens from a 12-day-old girl with yellow fever, Brazil, 2009. A) Massive liver necrosis, with proliferation of ductular-like structures around portal tracts (arrow); B) hepatocytes with microvesicular fatty changes (arrows); ... n n n nThe mother had serologic tests (immunoglobulin M antibody capture ELISA) done on the 11th day of disease. Test results were positive for yellow fever and negative for dengue fever. The newborn had similar results from serum samples collected 5 days after onset of symptoms with confirmation by reverse transcription PCR (RT-PCR). RT-PCR was performed as described by Deubel et al. (3). Nucleotide sequencing showed a wild yellow fever virus belonging type I of South American genotype 1E, according to the classification proposed by Vasconcelos et al. (4). RT-PCR performed with samples of the mother´s serum did not amplify yellow fever virus sequences. However, the serum was collected on the 11th day post symptoms when the sensitivity of the test is low. n nThe vertical transmission of arboviruses has been documented. Pouliot et al. reviewed direct and indirect evidence for vertical transmission of dengue virus (5). Vertical transmission has also been reported for West Nile encephalitis and western equine encephalitis (6). This is not the case for yellow fever. Reports of yellow fever during pregnancy are scarce (7), and we found none that describe vertical transmission to newborns. However, vaccine virus was isolated from asymptomatic newborns from pregnant women who were inadvertently administered 17D vaccines (8). Still, mother-to-child transmission in late pregnancy or during delivery is a likely explanation for this newborn infection. The possibility of acquiring the virus through a mosquito bite is unlikely because urban cases of yellow fever have not occurred in Brazil in the past 50 years and were not reported in the present outbreak. n nThe timing of the newborn’s symptoms also argues against the possibility of transmission from a mosquito. We cannot rule out transmission through breast-feeding, which has been reported for the yellow fever vaccine virus (9). However, this would presuppose a short incubation period. In conclusion, this case points out to the possibility of vertical transmission of yellow fever. We imagine that similar cases can occur in yellow fever–endemic settings and may be identified by improved surveillance.

Arbovírus Ilheus em aves silvestres (Sporophila caerulescens e Molothrus bonariensis)

OBJETIVO: Relatar o isolamento do virus Ilheus no Estado de Sao Paulo e avaliar o seu impacto para a saude publica. METODOS: O isolamento de virus foi realizado em camundongos albinos Swiss, a partir de sangue de aves silvestres, capturadas com redes de espera tipo mist net, armadas no nivel do solo, no Parque Ecologico do Tiete, Sao Paulo. A identificacao das cepas isoladas foi feita pelos testes de inibicao da hemaglutinacao, fixacao de complemento e neutralizacao em camundongos. Amostras de plasma de aves e de mamiferos silvestres foram submetidas a pesquisa sorologica para deteccao de anticorpos inibidores de hemaglutinacao. RESULTADOS: Foram isoladas duas cepas do virus Ilheus em sangue de aves das especies Sporophila caerulescens e Molothrus bonariensis e detectados anticorpos em aves das especies Columbina talpacoti, Geopelia cuneata, Molothrus bonariensis e Sicalis flaveola, em saguis das especies Callithrix jacchus e Callithrix penicillata e no quati Nasua nasua. CONCLUSOES: O isolamento do virus Ilheus e a deteccao de anticorpos especificos em aves residentes, migratorias e de cativeiro, em saguis e quatis, comprovam a presenca desse agente no Parque Ecologico do Tiete. O comportamento migratorio de aves silvestres pode determinar a introducao do virus em outras regioes. Considerando-se a patogenicidade para o homem e a confirmacao da circulacao desse agente viral em area urbana, frequentada para atividade de lazer e de educacao, o risco de ocorrencia de infeccao na populacao humana nao pode ser descartado.