Oropouche Virus

Abstract

Urban epidemics of Oropouche (ORO) fever in three municipalities in Pará, Brazil were studied in 1975. Culicoides paraensis (Goeldi) were collected during each of the epidemics and there was a positive correlation, by study areas within the city of Santarém, between human seropositivity to ORO virus and population densities of C. paraensis and Culex quinquefasciatus Say. The best numerical correlation was with populations of C. paraensis. The relative absence of other species in the areas of high disease attack rates was further evidence C. paraensis were the probable vectors of ORO virus. These biting midges were found to bite readily inside of houses, with an indoor/outdoor ratio of 29%, and were most active around 1700-1800 hours. Other biological observations on C. paraensis are presented.

Transmission of Oropouche Virus from Man to Hamster by the Midge Culicoides paraensis

“…Since concentrations of specific organic compounds in the natural pool are extremely low, there is no direct analytical evidence for net entry of organic substrates at the submicromolar levels characteristic of natural waters. Furthermore, it has been impossible to exclude completely a possible role of heterotrophic microorganisms, which have been present in the experimental systems studied to date (6). We report here that net entry of specific organic solutes from natural waters has been established by direct chemical analysis.…”

“…215, 5 MARCH 1982 Osawa, W. L. Duax, Biochemistry 15, 4730 (1976). 6 illness with rash, and (iii) meningitis or meningismus. Although no fatalities have been attributed to the disease, many patients become severely ill, some to the point of prostration.…”

“…Two insect species have been implicated as potential vectors in the urban cycle through epidemiological studies made during outbreaks: the ceratopogonid midge Culicoides paraensis and the mosquito Culex p. quinquefasciatus (6,7). In laboratory transmission studies of both the suspect vectors the former was found to be the more efficient of the two, but hamsters were used in these experiments as the donor and recipient hosts (8).…”

Oropouche Fever: A Review

“…The larvae of C. paraensis develop in various habitats capable of remaining moist enhancing larvae feeding in dry periods, like rainforests, riverbanks, damp soil, tree holes, decaying organic matter of plant origin such as rotting banana and plantain stalks, stumps and cacao husks [ 27 , 28 , 29 , 30 ]. C. paraensis prefer biting indoors during day and night, more often by late afternoon, with a reported indoor/outdoor ratio of 29% [ 31 ], during light to torrential rains [ 30 ]. In addition, C. paraensis bites have been reported to be implicated in common allergic reactions and skin irritation, like dermatitis, eczema or scars [ 19 ].…”

Iquitos Virus: A Novel Reassortant Orthobunyavirus Associated with Human Illness in Peru

“…ORO virus has been isolated from mosquitoes ( Coquillettidia venezuelensis in Trinidad [9]; Ochlerotatus serratus and Culex quinquefasciatus in Brazil [20]) and frequently from the midge Culicoides paraensis [9], [21], [22]. High population densities of this midge have been found during epidemics of ORO virus [23].…”