Table 4. Results of the explanatory variables associated with highly pathogenic avian influenza infection at municipal level, South Korea

Variable	Negative binomial regression
	RR	95% CI	P value
Poultry LPAI	6.867	2.980 - 15.820	<0.001
Wild bird HPAI	1.174	0.880 - 1.566	0.276
River density	7.258	0.029 - 1,788.521	0.481
Agricultural land density	0.822	0.166 - 4.062	0.810
Chicken density	1.618	1.403 - 1.866	<0.001
Duck density	10.252	2.120 - 49.566	0.004
Livestock vehicle	1.134	1.001 - 1.283	0.048