A Google Earth-based surveillance system for schistosomiasis japonica implemented in the lower reaches of the Yangtze River, China

Table 3 Surveillance results in relation to type of site

Type of site	Number of sites	Year	Sites positive^a	Snail distribution^b	Snail density^c	Infection rate (%)^d	Worm burden^e
Shipyard	7	2009	1	0.00	-	0.30 (2/663)	1.00
		2010	1	10.00	3.14	1.15 (7/611)	4.00
Ferry terminal	10	2009	3*	3.51	0.49	0.41 (4/969)	1.00
		2010	0	-	-	0.00 (0/853)	-
Fishing centre	12	2009	3	44.13	1.47	0.25 (3/1177)	1.67
		2010	1	13.00	2.82	0.50 (5/1009)	2.80
New sand bank	3	2009	1	40.29	0.08	0.34 (1/294)	1.00
		2010	0	-	-	0.00 (0/263)	-
River port	6	2009	3	32.10	1.86	2.25 (13/578)	3.31
		2010	0	-	-	0.00 (0/529)	-
Other	7	2009	0	-	-	0.00 (0/689)	-
		2010	0	-	-	0.00 (0/578)	-
Total	45	2009	11	120.03	0.88	0.53 (23/4370)	2.39
		2010	2	23.00	2.97	0.31 (12/3843)	3.50

^aDeemed to be positive based on infection found in sentinel mice. ^bEstimated size of snail-infested area (hm²). ^cAverage number of snails/m². ^dNumber of infected sentinel mice/total number of mice used. ^eAverage number of worms per infected mouse. *No snails found in one of the sites.

ISSN: 1756-3305