An Epidemic of Sylvatic Yellow Fever in the Southeast Region of Maranhao State, Brazil, 1993–1994: Epidemiologic and Entomologic Findings

Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil/ Institut Français de Recherche Scientifique pour le Developpement. Marseille, France.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil / Institut Français de Recherche Scientifique pour le Developpement. Marseille, France.Ministério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, BrasilMinistério da Saúde. Fundação Nacional de Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Yellow fever virus transmission was very active in Maranhao State in Brazil in 1993 and 1994. An investigation was carried out to evaluate the magnitude of the epidemic. In 1993, a total of 932 people was examined for yellow fever from Maranhao: 70 were positive serologically, histopathologically, and/or by virus isolation, and another four cases were diagnosed clinically and epidemiologically. In Mirador (17,565 inhabitants), the incidence was 3.5 per 1,000 people (case fatality rate [number of deaths/number of cases diagnosed] = 16.4 percent), while in a rural yellow fever risk area (14,659 inhabitants), the incidence was 4.2 and the case-fatality rate was 16.1 percent (10 of 62). A total of 45.2 percent (28 of 62) asymptomatic infections were registered. In 1994, 49 serum samples were obtained and 16 cases were confirmed (two by virus isolation, two by seroconversion, and 12 by serology). No fatal cases were reported. In 1993, 936 potential yellow fever vectors were captured in Mirador and a single strain was isolated from a pool of Haemagogus janthinomys (infection rate = 0.16 percent). In 1994, 16 strains were isolated from 1,318 Hg. janthinomys (infection rate = 1.34 percent) and one Sabethes chloropterus (infection rate = 1.67 percent). Our results suggest that this was the most extensive outbreak of yellow fever in the last 20 years in Brazil. It is also clear that the lack of vaccination was the principal reason for the epidemic, which occurred between April and June, during the rainy season, a period in which the mosquito population in the forest increases

Malpais spring virus is a new species in the genus vesiculovirus

BACKGROUND: Malpais Spring virus (MSPV) is a mosquito-borne rhabdovirus that infects a variety of wild and feral ungulates in New Mexico, including horses and deer. Although, initial serologic tests and electron microscopy at the time of isolation nearly 25 years ago provided evidence that MSPV is a novel virus, possibly related to vesiculoviruses, the virus still has not been approved as a new species. FINDINGS: Use of the illumina platform allowed us to obtain the complete genome of MSPV. Analysis of the complete 11019 nt genome sequence of the prototype 85-488NM strain of MSPV indicates that it encodes the five common rhabdovirus structural proteins (N, P, M, G and L) with alternative ORFs (> 180 nt) in the N, M and G genes, including a 249 nt ORF in the G gene predicted to encode a 9.26 kDa highly basic transmembrane protein. Although antigenically very distant, phylogenetic analysis of the L gene indicates that MSPV is most closely related to Jurona virus, also isolated from mosquitoes in Brazil, as well as a number of other vesiculoviruses. CONCLUSIONS: In sum, our analysis indicates MSPV should be classified as a member of the genus Vesiculovirus, family Rhabdoviridae. The complete genome sequence of MSPV will be helpful in the development of a reverse genetics system to study the unique aspects of this vesiculovirus in vivo and in vitro, and will assist development of specific diagnostic tests to study the epidemiology of MSPV infection

Two New Rhabdoviruses (Rhabdoviridae) Isolated from Birds During Surveillance for Arboviral Encephalitis, Northeastern United States

Two novel rhabdoviruses were isolated from birds during surveillance for arboviral encephalitis in the northeastern United States. The first, designated Farmington virus, is a tentative new member of the Vesiculovirus genus. The second, designated Rhode Island virus, is unclassified antigenically, but its ultrastructure and size are more similar to those of some of the plant rhabdoviruses. Both viruses infect birds and mice, as well as monkey kidney cells in culture, but their importance for human health is unknown

Oropouche Virus Isolation, Southeast Brazil

An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription–polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama

Serologic Evidence of Various Arboviruses Detected in White Tailed Deer (\u3ci\u3eOdocoileus virginianus\u3c/i\u3e) in the United States

White-tailed deer (Odocoileus virginianus) are an abundant mammal with a wide geographic distribution in the United States, which make them good sentinels for monitoring arboviral activity across the country. Exposure to various arboviruses has been detected in white-tailed deer, typically in conjunction with another diagnostic finding. To better assess the exposure of white-tailed deer to seven arboviruses, wetested 1,508 sera collected from 2010 to 2016 for antibodies to eastern equine encephalitis (2.5%), Powassan (4.2%), St. Louis encephalitis, (3.7%), West Nile (6.0%), Maguari (19.4%), La Crosse (30.3%), and bluetongue (7.8%) viruses. At least one arbovirus was detected in 51.3%, and exposure to more than one arbovirus was identified in 17.6% of the white-tailed deer sampled

Limited evolution of West Nile virus has occurred during its southwesterly spread in the United States

AbstractAnalysis of partial nucleotide sequences of nine West Nile virus strains isolated in southeast Texas during June–August 2002 revealed a maximum of 0.35% nucleotide variation from a New York 1999 strain. Two sequence subtypes were identified that differed from each other by approximately 0.5%, suggesting multiple introductions of virus to this area. Analysis of sequences from cloned PCR products for one strain revealed up to 0.6% divergence from the consensus sequence at the subpopulation level. The presence of unique patterns of small numbers of mutations in North American West Nile strains studied to date may suggest the absence of a strong selective pressure to drive the emergence of dominant variants

Venezuelan Equine Encephalitis Virus Infection of Cotton Rats

VEEV killed 2 allopatric populations of cotton rats but not a sympatric population from Florida

Experimental Infection of Prairie Dogs with Monkeypox Virus

Infected prairie dogs can transmit monkeypox virus by respiratory and mucocutaneous contact with susceptible animals and humans

Tickborne Arbovirus Surveillance in Market Livestock, Nairobi, Kenya

Numerous tickborne viruses, including Dhori virus and foot-and-mouth disease virus, were isolated