Skunk rabies surveillance in Illinois

Area of Science:

• Veterinary epidemiology
• Wildlife disease ecology
• Zoonotic disease surveillance

Background:

• Surveillance data revealed a notable increase in skunk rabies incidence in Illinois between 1979 and 1980.
• This rise was not explained by changes in reporting or laboratory submission rates for skunks.

Purpose of the Study:

• To investigate the factors contributing to the increased incidence of skunk rabies.
• To test the hypothesis that an increased skunk population density facilitated rabies transmission.

Main Methods:

• Analysis of surveillance data for skunk rabies cases.
• Examination of road-kill data to assess skunk population trends.
• Temporal analysis of rabies incidence to identify seasonal and secular patterns.

Main Results:

• Road-kill data indicated a preceding increase in the skunk population.
• A hypothesis was proposed: increased skunk density facilitated virus transmission.
• Rabies incidence exhibited a bimodal seasonal cycle (spring and fall) and a potential 6-8 year secular cycle.

Conclusions:

• The study suggests that an elevated skunk population density was a probable driver for the increased skunk rabies incidence.
• Findings highlight the importance of skunk population dynamics in rabies epidemiology.
• The identified seasonal and secular cycles provide insights for rabies control and prevention strategies.