Incidence of and risks associated with Giardia infections in herds on dairy farms in the New York City Watershed

Table 2 Factors that affect the intensity of shedding Giardia in dairy herds in the New York City Watershed.

Risk Factor	Regression Coefficient	Standard Error	Pr > \|t\|
Age	-0.0142	0.000980	<0.0001
Age ²	0.000015	1.367E^-6	<0.0001
Prior Infection Status
High risk	0
Low Risk	0.2201	0.0840	0.0089
Intermediate Risk	-0.0288	0.0539	0.5939
Season of Infection
Summer	0
Winter	-0.0554	0.0464	0.2324
Spring	-0.1205	0.0495	0.0151
Constant	3.4949	0.0684	<0.0001

Low risk= Herds shedding neither Giardia or Cryptosporidium prior to start of the study
Intermediate risk= Herd shedding Giardia only prior to the start of the study
High risk= Herd shedding both Giardia and Cryptosporidium prior to the star of the study
Winter= November through March
Spring= April through June
Summer= July through October

ISSN: 1751-0147