Statistical sensitivity for detection of spatial and temporal patterns in rodent population densities

Area of Science:

• Ecology
• Epidemiology
• Wildlife Disease

Background:

• Hantavirus Pulmonary Syndrome (HPS) outbreaks in the U.S. Southwest necessitate understanding rodent population dynamics.
• Small mammals serve as reservoirs for hantaviruses, directly influencing human disease risk.
• Effective monitoring is crucial for predicting and mitigating HPS outbreaks.

Purpose of the Study:

• To evaluate a long-term monitoring program for rodent density and hantavirus infection rates.
• To assess the program's sensitivity in detecting population changes and potential biases.
• To determine the program's utility in identifying conditions associated with increased human disease risk.

Main Methods:

• Long-term monitoring of rodent density and hantavirus infection rates in small-mammal reservoirs.
• Statistical analysis of spatial and temporal rodent density variations.
• Assessment of trap-related mortality bias on population estimates.
• Correlation analysis between rodent density, infection rates, and human disease outbreaks.

Main Results:

• The monitoring program successfully detected species-specific spatial and temporal rodent density differences for multiple genera (Peromyscus, Reithrodontomys, Neotoma, Dipodomys, Perognathus).
• Trap-related deaths did not significantly impact long-term population estimates.
• A short-term rodent density increase was detected in the winter of 1997-98.

Conclusions:

• The monitoring program is statistically sensitive and reliable for tracking rodent populations relevant to hantavirus ecology.
• The program effectively identifies periods of elevated risk for human hantavirus exposure.
• This monitoring approach provides valuable data for public health interventions in hantavirus-endemic regions.