Table 1 Factors purported to influence heartworm prevalence
From: Forecasting United States heartworm Dirofilaria immitis prevalence in dogs
Factor | Data period | Scale | Notation | Numerical scale of data | |
|---|---|---|---|---|---|
Climate factors | Annual temperature | 1895–2015 | Climate Division | X s,1(t) | Continuous |
Annual precipitation | 1895–2015 | Climate Division | X s,2(t) | ||
Annual relative humidity | 2006–2015 | Climate Division | X s,3(t) | ||
Geographic factors | Elevation | 2012 | County | X s,4(t) | Continuous |
Percentage forest coverage | 2012 | County | X s,5(t) | ||
Percentage surface water coverage | 2010 | County | X s,6(t) | ||
Societal factors | Population density | 2011–2014 | County | X s,7(t) | Continuous |
Median household income | 1997–2014 | County | X s,8(t) | ||
Mosquito species | Aedes aegypti | 2008 | County | X s,9(t) | X s,k = 1 if present, and X s,k = 0 otherwise |
Aedes albopictus | 2012 | County | X s,10(t) | ||
Aedes canadensis | 2004 | County | X s,11(t) | ||
Aedes sierrensis | 2004 | County | X s,12(t) | ||
Aedes trivittatus | 2004 | County | X s,13(t) | ||
Anopheles punctipennis | 2004 | County | X s,14(t) | ||
Anopheles quadrimaculatus | 2004 | County | X s,15(t) | ||
Culex quinquefasciatus | 2004 | County | X s,16(t) |