Inquérito soroepidemiológico para pesquisa de infecções por arbovírus em moradores de reserva ecológica

Rev. Soc. Bras. Med. Trop.

et al. 2020

Introduction: The study of the landscape ecology, biological microhabitat, and epidemiological implications for the distribution of the main vectors Aedes aegypti and Aedes albopictus contribute to the prevention and control actions regarding the diseases they transmit. Methods: This study sought to assess data on positive properties of the vector control program activities from 1998 to 2010. An entomological survey was also carried out on a sample of buildings collecting larvae and pupae from containers between October and April (spring / summer) from 2002 to 2005. We assessed the physico-chemical data of the water in 20% of positive containers. The vegetation and urbanization were assessed with the aid of satellite images and microenvironments were classified as urbanized, woods, and shrubs. The data were analyzed using statistical and geoprocessing software. Results: Ae. aegypti and Ae. albopictus colonized all types of microhabitats and microenvironments, predominantly in the urbanized area, in isolation and in coexistence. The microhabitat of Ae. aegypti showed a temperature gradient greater than that of Ae. albopictus, and there was an association with urbanized areas for the first species and wooded areas for the last species. Conclusions: Landscape ecology and intra-urban differences favor different microclimates, which contribute to the coexistence of species in the urban environment in an area close to the forest, raising the risk of other arbovirus infections in urban areas. The ecological niche should be considered for Ae. albopictus. Entomological and virologic monitoring are suggested as arbovirus surveillance actions in urban infested centers near preserved forests.

Section: /10mentioning

confidence: 99%

Importance of microenvironment to arbovirus vector distribution in an urban area, São Paulo, Brazil

Arduíno

Mucci

Rev. Soc. Bras. Med. Trop.

et al. 2020

“…FERREIRA et al 7 found monotypic hemagglutination inhibition (HI) antibodies to SLEV in 49 species of wild birds from the Atlantic forest belonging to 19 families, many of them with migratory habits. Serological inquiries conducted by ROMANO-LIEBER & IVERSSON 21 in the Ribeira Valley in 1990 showed, the prevalence of SLEV neutralizing antibodies in residents of ecological reserve Juréia-Itatins. No other isolations were obtained until 1993 when the virus was recovered from Anopheles triannulatus and Culex This work reports the first isolation of SLEV in the State of São Paulo from the blood of a human case and the results of the laboratory investigations in relation to the case.…”

Section: Introductionmentioning

confidence: 98%

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

Rocco

Rev. Inst. Med. trop. S. Paulo

Bisordi

et al. 2005

This paper reports the isolation of St. Louis encephalitis virus (SLEV) from a febrile human case suspected to be dengue, in São Pedro, São Paulo State. A MAC-ELISA done on the patient's 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 São 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.

“…The lack of systematic epidemiological surveillance activities toward arboviruses of minor importance compared to Yellow fever, Dengue fever, and Rocio encephalitis, for instance, may partially explain the few number of clinical cases of Saint Louis encephalitis reported both in Brazil and tropical America. Others factors including the attenuation of viral strains that was observed in rodent strains isolated in São Paulo and Argentina (Monath et al 1980) and the early acquisition and accumulation of human immunity, revealed among residents in the Amazon region (Pinheiro et al 1986, Vasconcelos et al 1998) and in different areas of the state of São Paulo (Iversson et al 1981, Romano-Lieber & Iversson 2000 as well as in several Argentina counties (Sabattini et al 1998) may be also considered.…”

Section: Discussionmentioning

confidence: 99%

Genetic characterization of St. Louis encephalitis virus isolated from human in São Paulo, Brazil

Mem. Inst. Oswaldo Cruz

Sallum

Franco

et al. 2006

(Calisher et al. 1989). The genome of flaviviruses contains a single-stranded positive sense RNA, about 10,800 nucleotides long that encodes 10 distinct proteins in a single reading frame (Chambers et al. 1990). SLEV is the etiologic agent of St. Louis encephalitis, a disease of epidemiological importance in North America. This virus was first isolated in the United States of America (US) in 1933, during an outbreak, which occurred in St. Louis and Kansas City, Mo. (Muckenfuss et al. 1934). In the US intermittent and unpredictable epidemics have been occurring during the last decades. The majority of SLEV infections is sub clinical or result in mild illness. The severity of infections is strongly dependent on the age of a patient, and the case fatality rate during epidemics ranges from 2% in young adults to more than 22% in the elders (Monath & Heinz 1996). In spite of being endemic in Central and South America, causing sporadic illness, occurrence of SLEV outbreaks is unknown (Spence 1980, Monath & Heinz 1996.The biological cycle of SLEV in nature involves primarily wild birds and several mosquito species; humans and other mammals are considered to be incidental hosts (Monath & Heinz 1996). In the US, Culicinae mosquitoes and birds, Passeriformes and Columbiformes, are involved in the dynamics of SLEV transmission. The transmission Financial support: Fapesp (no. 2004/07819-6) and CNPq (no. 305339/2003-6) cycle varies regionally, depending on the biology of mosquito species, virulence of SLEV strains and susceptibility to infection of vertebrate hosts (Monath & Tsai 1987, Day 2001, Reisen 2003. In Central and South America SLEV transmission cycle is not well defined, but it may include mosquito species of the genera Culex, Mansonia, Haemagogus, and Sabethes. A variety of bird taxa, including herons, egrets, and cormorant may be virus reservoirs (Spence 1980, Monath & Heinz 1996, Reisen 2003.The occurrence of SLEV in Brazil was recorded in 1953, by the finding of antibodies to this virus in residents of the Amazon Valley (Causey & Theiller 1958). A pool of mosquito Sabethes belisarioi, captured along the Belém-Brasília highway, was the source for the first isolation of a SLEV strain (Causey et al. 1964). Later in 1970 and 1978 two strains were recovered from human blood in Amazon region. In both cases the patients developed a febrile illness with jaundice, neither of them presenting neurological involvement (Pinheiro et al. 1981, Vasconcelos et al. 1998. SLEV was also found in the Southeast region of Brazil where it was isolated from wild birds, rodents, and sentinel mice during a surveillance program on arbovirus activity carried out in the state of São Paulo from 1967 to 1969 (Lopes et al. 1979).In the summer of 2004, after more than two decades of the last human Brazilian report, a clinical case of infection by SLEV was detected in the state of São Paulo. Epidemiologic data about the SLEV case was fully detailed by Rocco et al. (2005). Briefly, a patient, suffering from severe uncharacterized febrile illnes...