Arbovirus growth in Aedes aegypti mosquitoes throughout their viable temperature range

Bunyavirus development in arctic and Aedes aegypti mosquitoes as revealed by glucose oxidase staining and immunofluorescence

Northway virus replication has been detected in salivary glands of wild-caught Culiseta inornata and Aedes communis mosquitoes from the western Canadian Arctic after incubation at 4 degrees C for 9 to 11 months, and after incubation at 13 degrees C for 3 to 4 months after they received virus by oral ingestion or intrathoracic injection. Aedes hexodontus supported Northway virus replication after incubation at 13 degrees C for one month after intrathoracic injection. Aedes aegypti supported Northway virus replication after incubation at 13 degrees C or 23 degrees C for 6 to 28 days following intrathoracic injection. A larval isolate of California encephalitis virus (snowshoe hare subtype) multiplied in all 3 species of arctic mosquito after incubation at 13 degrees C for 1 to 3 months after virus was administered by oral ingestion or intrathoracic injection. Virus was detected in salivary glands of Cs. inornata after 329 days incubation at 4 degrees C after intrathoracic injection. Bunyavirus antigens in salivary glands of arctic and domestic mosquitoes were detected by the glucose oxidase immunoenzyme technique somewhat less frequently than by assay for virus infectivity.

Transmission of Northway and St. Louis encephalitis viruses by arctic mosquitoes

Transmission of a Canadian arctic isolate of Northway virus has been demonstrated after incubation of arctic Aedes communis mosquitoes at 13 degrees C for 27 days after intrathoracic injection of 300 plaque forming units of virus. Replication has also been demonstrated after intrathoracic injection of domestic A. aegypti mosquitoes of this virus. Virions of Northway virus, 84--92 nm diameter were morphologically typical of a bunyavirus after propagation in salivary glands of A. communis or in tissue cultures of baby hamster kidney (BHK-21) cells. An Ontario isolate of St. Louis encephalitis was transmitted by bites of A. communis after 27 days incubation at 13 degrees C after oral ingestion of 3 or 30 mouse LD50 virus. This mosquito species transmitted virus after 13 to 76 days incubation at 13 degrees C following intrathoracic injection of 3 mouse LD50 or higher virus doses.

California encephalitis virus transmission by arctic and domestic mosquitoes

A zero passage arctic mosquito isolate of California encephalitis (CE) virus (showshoe hare subtype) was transmitted by wild-caught Aedes communis mosquitoes after 13 days incubation at 13 degrees and 23 degrees C, AFTER 20 days incubation at 13 degrees C, when mosquitoes imbibed 1 mouse LD50 in a blood meal. Transmission occurred after 20 days incubation at 13 degrees and 23 degrees C when mosquitoes were injected intrathoracially with 1 or 0.1 mouse LD50. Virus was also transmitted by A. aegypti 13 days after infection with 100 mouse LD50 by feeding or intrathoracic injection, and incubation at 13 degrees C. Virus antigen was detected in salivary glands of 42 percent virus-positive A communis mosquitoes by direct immunofluorescence, and in 50 percent or less of A aegypti mosquitoes by immunoperoxidase and immunofluorescence, with somewhat greater regularity by the indirect than the direct technique.