Table II. Epidemiological covariates in the various PPF groups.

a) Arithmetic means (SEM); b) Alcohol intake: 6 classes were defined for drinking behaviour: no drinking, occasionally drinking, 50 ml/day, 100-150 ml/day, 200 ml/day or more; c) Praziquantel treatments in the last twenty years: none, 1-2, 3-6, 7-9, >10 treatments.

Sex	Epidemiological covariates	PPF A,B,C,CLL	PPF CLM	PPF CLH,D,E,F
Male subjects	N	42	32	21
	Age	48.5 (1.8)	48.4 (2)	45.5 (2.6)
	Living on a boat (%)	13.5	31	11.1
	Living on island (%)	81.1	62	77.8
	Years of fishing	33.6 (1.9)	32.6 (1.9)	41.5 (2.6)
	Net fishing (%)	90.2	70.7	67.8
	Electric fishing (%)	7.3	58.5	32.1
	Drinking (median)	Occasionally	Occasionally/50 ml	Occasionally
	Praziquantel treatments (median)	1-2	1-2	3-6
Female subjects	N	16	3	6
	Age	45.5 (2.6)	48.5 (1.8)	44 (6.4)
	Living on a boat (%)	27.2	100	100
	Living on island (%)	72.7	0	0
	Years of fishing	26.1 (1.9)	33.6 (1.8)	29.9 (5.2)
	Net fishing (%)	76.4	100	85.7
	Electric fishing (%)	23.5	0	14.3
	Drinking (Median)	Occasionnally	no	no
	Praziquantel treatments (median)	3-6	1-2	1-2