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Table 1 Predicted impact of the Three Gorges Dam on the distribution of Oncomelania snails and transmission of S. japonicum

From: The Three Gorges Dam: Does it accelerate or delay the progress towards eliminating transmission of schistosomiasis in China?

Segment of Yangtze River

Water level rising

Water level decreasing

Oncomelania snails

S. japonicum

Refs.

Height (m)

Months

Height (m)

Months

Hubei (Jianghan Plain)

0.06–1.5

Jan – May

1.8–2.4

Nov, Dec

New habitats for Oncomelania snails would appear.

The probability of humans and livestock becoming infected would increase.

[17, 20, 23, 24]

Hunan (Dongting Lake)

0.06–1.5

Jan – May

1.6–2.6

Nov, Dec

The distribution of snails would not be significantly affected, however, the reproduction of snails would be effectively curbed.

The probability of humans and livestock becoming infected would increase and schistosomiasis epidemics would worsen.

[17, 20, 23, 25]

Jiangxi (Poyang Lake)

0.11–0.90

Jan – Mar

0.07–0.13

Dec

The reproduction and distribution of snails would be unaffected or the density of snails would increase, or the density of snails would decrease in the autumn.

The epidemiology of schistosomiasis would be very limitedly affected.

[17, 20, 23, 58, 59]

Anhui

0.14–0.76

Jan – Apr

0.06–1.26

Oct – Dec

The distribution of snails would not be significantly affected, however, some new habitats for snails would appear.

The probability of humans and livestock becoming infected would increase.

[17, 20, 24, 27, 60–62]

Jiangsu

0.15–0.40

Feb – Apr

0.32–0.75

Oct, Nov

The distribution of snails would be not affected and the density of snails would decrease.

The incidences of schistosome infections in people and livestock would increase.

[17, 20, 25, 27, 58]