Western equine encephalitis surveillance in Utah.

This article examines the history of Western Equine Encephalitis (WEE) surveillance in Utah, beginning with a 1933 outbreak and the resulting development of a surveillance program. According to the study, recent years have demonstrated a lack of WEE activity.

Background

• The article starts by going through the history of Western Equine Encephalitis (WEE) surveillance in the region of Utah. This surveillance started after an outbreak in 1933, which affected 3,958 horses and resulted in a realization of the need for a more structured and objective surveillance program.
• Western Equine Encephalitis is a mosquito-borne viral disease that affects horses and humans and can lead to severe neurological disorders or even death.

The Utah Mosquito Abatement Association surveillance program

• Following the outbreak, the Utah Mosquito Abatement Association systematically started a surveillance program in 1957. The program was developed gradually, seemingly in response to the need for better control and prevention measures against WEE.
• The article discusses in detail the step-by-step establishment of this program from its inception in 1957 to the present.

Results of recent surveillance

• The study reports on the expansion of a sentinel chicken flock surveillance program that was carried out in Utah during the years 1983, 1984, and 1985.
• Sentinel chickens are used in the program as they can develop antibodies to WEE if bitten by an infected mosquito, which can then be detected through blood tests, without necessarily showing any symptoms of the disease themselves. Thus, they serve as an early warning system for WEE presence in a specific area.
• In 1983, there were three sero-conversions recorded in September, a sign that WEE was present in the region at this time.
• However, in 1984 and 1985, there was no reported sero-conversion, indicating an absence or very low level of WEE activity in the area under observation during these two years.