Laboratory vector competence of black flies (Diptera:Simuliidae) for the Indiana serotype of vesicular stomatitis virus.

This research article presents results suggesting that both colonized and wild black flies could potentially transmit the Indiana serotype of vesicular stomatitis virus (VSV-IN), based on testing with a 1998 equine isolate of the virus.

Research Context

• The research builds upon previous experiments, where black flies showed competence in laboratory conditions for transmitting different isolates of vesicular stomatitis virus, particularly, the New Jersey serotype (VSV-NJ).
• VSV is an infectious and volatile virus that can affect animals, particularly livestock such as horses, cows, and swine. It can also indirectly affect human industries through impact on livestock health. Different serotypes refer to variations of the virus, in this case, Indiana (VSV-IN) and New Jersey (VSV-NJ) serotypes.

The Experiment Testing Vector Competence

• The researchers used an equine isolate of VSV-IN from 1998 for their experiment.
• This experiment infected different species of black flies (Simulium vittatum and S. notatum) with this virus isolate.
• After a 10-day incubation period, saliva from the infected flies was collected individually and tested for the virus.

Results and Implications

• The virus was detected in the saliva of both Simulium species, which suggest they are competent vectors for VSV-IN, at least under laboratory conditions.
• The presence of the virus in fly’s saliva implies that black flies can potentially transmit VSV-IN to their biting hosts, just as they had shown with VSV-NJ.
• The research indicates that the black fly gut might exert evolutionary pressures on VSV. This means that the virus might change or evolve based on the internal environment of the black fly, although the nature and implications of these potential changes would need further investigation.