Volume 35, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



, a putative mosquito vector of western equine encephalomyelitis (WEE) virus, is susceptible to peroral infection by WEE virus. The nonvector mosquito, , has a very high peroral threshold of infection and is considered to be refractory. By parenteral inoculation, both mosquito species are equally susceptible. Thus, and represent an excellent model system to examine the mechanisms for the mesenteronal infection barrier to WEE virus.

Diethylaminoethyl (DEAE)-dextran (1.6 mg/ml), when added to a pledget bloodmeal that contained high concentrations of WEE virus, enhanced peroral infection rates of . In , a reduction in infection rates was observed when low WEE concentrations of virus were ingested. DEAE-dextran had no apparent effects on the dissemination of WEE after infection of either mosquito species. It is suggested that the peroral enhancement of WEE viral infection observed with may be related to random, nonspecific mechanisms of infection, since it requires high titers of ingested WEE virus. Interference with specific binding of WEE virus to cellular receptor sites is suggested to explain the reduction in WEE viral infection rates in .

Altering the pH of the ingested infectious bloodmeal did not affect the WEE viral infection rate of , within the range of 6.0–8.5. was optimally infected when the infectious bloodmeal was pH 8.0, and the infection rate was significantly reduced when the infectious blood was at either extreme of the pH range tested. This is again interpreted to indicate that different mechanisms control the peroral infection of and with WEE virus.

The mesenteronal infection barrier to WEE virus in is associated with an inability of the virus to adsorb and/or penetrate mesenteronal epithelial cells when administered perorally. The barrier is not related to an inability of the mesenteronal epithelial cells to support viral multiplication since these cells become infected when the virus is administered parenterally.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error