West Nile virus pool tests for female *Culex pipiens* in the Sacramento Metropolitan Area

A dataset of PCR-tested mosquito pools used to summarize infection for female *Culex pipiens* in the Sacramento Metropolitan Area (Sacramento, Placer, El Dorado counties, California, USA). Each row represents a tested pool at a specific location and date, with an estimated pool size.

Usage

data(infect_sma)

Format

A data frame with one row per tested pool (for a total of 596 pools) and 5 variables:

lon: Numeric. Longitude in decimal degrees (WGS84).
lat: Numeric. Latitude in decimal degrees (WGS84).
est_pool_n: Integer. Estimated number of mosquitoes in the pool (see Details).
wnv_pos: Logical. Whether the pool tested positive for West Nile virus (TRUE/FALSE).
date: Date. Pool collection date (local).

Source

Constructed from sample_collections in the vectorsurvR R package.

Details

Derived from the vectorsurvR sample datasets by:

Filtering to female Culex pipiens pools with WNV testing within the SMA using point-in-polygon against the union of Sacramento, Placer, and El Dorado counties.
Estimating pool size est_pool_n for each pool by:
- Summing total female counts from nearby collection points within the same week and within a spatial radius (e.g., 2 km) to obtain \(T_{\mathrm{near}}\).
- Counting nearby pools within the same week/radius to obtain \(m_{\mathrm{near}}\).
- Setting est_pool_n = round(max(1, T_near / m_near)); if no nearby collections are found, a conservative fallback (default 25) is used.
Coordinates are kept as WGS84 (EPSG:4326).

Important: est_pool_n is an estimate for demonstration and pooled-modelling examples; it is not the recorded laboratory pool size.