Detection and Quantification of Total and Pathogenic Vibrio parahaemolyticus in Anadara subcrenata in the Zhoushan Archipelago

Table 7

Prevalence of contamination of pathogenic Vibrio parahaemolyticus in Anadara subcrenata among different seasons and markets.

Seasons	Aqua farm			Retail market			χ^2 value	P value
	Number of samples	Positive rate %	Median of tdh or tlh positive samples (MPN/g)	Number of samples	Positive rate %	Median of tdh or tlh positive samples (MPN/g)
Spring	5	23.81	21	5	15.15	1.1	2.667	0.072
Summer	5	13.16	30	3	5.00	3	2.457	0.087
Autumn	6	19.35	9.25	1	2.63	7.4	4.726	<0.05
Winter	0	0	0	0	0	0	—	—
χ^2 value		2.115			3.021
P value		0.099			<0.05

The positive rate of pathogenic V. parahaemolyticus between different markets was significantly different only in autumn ().