Table 1.

Summary of predictor variables included in the analysis.

Predictor list	Predictor categorya	Scale of analysis	Years available	Variable type
Bovine type (water buffalo vs. cow)	Physical/biological	Individual	2007, 2010	Binary
Bovine sex	Physical/biological	Individual	2007, 2010	Binary
Bovine age	Physical/biological	Individual	2007, 2010	Continuous
Number of hatch testsb	Physical/biological	Individual	All	Discrete
County of residence	Physical/biological	Household	All	Binary
Prevalence of human infection in village	Potential human sources	Village	All	Continuous
Number of infected human household members	Potential human sources	Household	All	Discrete
Percent of households with improved sanitation	Socio-economic indicators	Village	All	Continuous
Household has improved sanitation (y/n)c	Socio-economic indicators	Household	All	Binary
Village mean asset score (0–9)	Socio-economic indicators	Village	All	Continuous
Household asset score (0–9)	Socio-economic indicators	Household	All	Discrete
Percent of households that own cats	Animal reservoirs/sources	Village	All	Continuous
Household cat ownership	Animal reservoirs/sources	Household	All	Binary
Percent of households that own dogs	Animal reservoirs/sources	Village	All	Continuous
Household dog ownership	Animal reservoirs/sources	Household	2007, 2010	Binary
Mean number of pigs per household	Animal reservoirs/sources	Village	2010, 2016	Continuous
Household pig ownership	Animal reservoirs/sources	Household	2010	Discrete
Mean number of bovines per household	Animal reservoirs/sources	Village	All	Continuous
Household owns other bovines	Animal reservoirs/sources	Household	All	Discrete
Mean area of rice planted per household	Agricultural risk factors	Village	All	Continuous
Area of rice planted by household	Agricultural risk factors	Household	All	Continuous
Mean area of dry summer crop planted per household	Agricultural risk factors	Village	All	Continuous
Area of dry summer crop planted by household	Agricultural risk factors	Household	All	Continuous
Mean area of winter crop planted per household	Agricultural risk factors	Village	All	Continuous
Area of winter crop planted by household	Agricultural risk factors	Household	All	Continuous
Mean number of buckets of night soil used on rice crops	Agricultural risk factors	Village	All	Continuous
Number of buckets of night soil used on rice crops	Agricultural risk factors	Household	All	Discrete
Mean number of buckets of night soil used on dry summer crops	Agricultural risk factors	Village	All	Continuous
Number of buckets of night soil used on dry summer crops	Agricultural risk factors	Household	All	Discrete
Mean number of buckets of night soil used on winter crops	Agricultural risk factors	Village	All	Continuous
Number of buckets of night soil used on winter crops	Agricultural risk factors	Household	All	Discrete

^aPredictors were grouped into five categories relevant to bovine Schistosoma japonicum infection risk probability: i) physical/biological characteristics (e.g. old-age); ii) potential human sources of environmental schistosomes (e.g. human S. japonicum infection prevalence in the bovine’s household); iii) socio-economic indicators (e.g. prevalence of improved sanitation systems in the surround village); iv) potential animal reservoirs/sources of infections (e.g. prevalence of dog ownership in the surrounding village); v) agricultural risk factors (e.g. a household’s total rice crop area).

^bBecause not all bovines produced three stool samples, and examination of a greater number of stool samples can increase the probability of detecting infection, the number of hatch tests used on a given bovine was also included as a predictor.

^cImproved sanitation was defined as access to an improved toilet in the household, including a biogas digester or a three-compartment toilet.