Spatio-temporal variations of emerging sites infested with schistosome-transmitting Oncomelania hupensis in Hunan Province, China, 1949–2016

Table 4 Cluster of emerging snail-infested sites in hills from 1949 to 2016

Clusters	Radius (km²)	Time frame	Duration of cluster (years)	Observed number	Expected number	Observed/expected	P-value
1	27.52	1960–1965	6	587	142.33	4.12	< 0.01
2	11.84	1958	1	298	51.45	5.79	< 0.01
3	22.75	1955–1956	2	406	100.51	4.04	< 0.01
4	11.07	1957	1	104	3.41	30.54	< 0.01
5	17.78	1996–1998	3	136	8.69	15.65	< 0.01
6	34.57	1970–1984	15	135	15.54	8.69	< 0.01

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