登革热不治疗会怎样 广州引入食蚊鱼抗击登革热

广州引入食蚊鱼抗击登革热  

The southern Chinese city of Guangzhou has introduced a fish that eats mosquito larvae
in an effort to control its worst-ever dengue fever outbreak
state news media have reported. Some scientists have warned that use of the nonnative mosquito fish could have unexpected consequences
while others say that mosquito fish are already found in Guangdong waters and the environmental impact might not be significant
but that the effectiveness of the fish may also be limited.
As of Monday
the number of dengue cases in Guangdong Province this year had reached 41
155
the local health authorities reported
with six deaths. The province has seen 200 to 300 new cases a day in recent days. That is lower than the more than 400 per day last week and the more than 1
000 per day the week before that
offering some hope that the outbreak is beginning to ease.
Guangzhou
the capital of Guangdong and China’s third-largest city
has seen the most cases
with more than 34
000 reported infections and one death
followed by the city of Foshan
with more than 3
000 cases and one death.
中国第三大城市、广东省省会广州市的疫情最严重，已有超过34
000个报告的感染病例、一人死亡，其次是佛山市，有3
000多个病例、一人死亡。
The dengue virus
which is carried by Aedes mosquitoes
can cause extreme fever
headaches
and muscle and joint pain in infected humans
though death is rare when proper treatment is provided. China has traditionally not seen large-scale outbreaks
but widespread urbanization and climate change have made warmer coastal areas increasingly hospitable to the mosquitoes that spread the virus.
Officials
blaming the outbreak this year on inadequate mosquito control efforts
have increased the application of pesticides in Guangzhou in an effort to reduce the insect population. The city’s water bureau also announced on Oct. 15 that it had introduced mosquito fish from North America to “controllable static waters
” Xinhua
the state-run news agency
reported.
That move prompted criticism from some experts who suggested it could upset the ecological balance in Guangdong waterways.
“The best solution to the dengue problem is to improve the overall environment
” Li Yanliang
chairman of the National Aquatic Wildlife Conservation Association
told Xinhua. “Introducing foreign species must be meticulous. The impacts must be controlled.”
Liu Hansheng
an official with the Administration of Oceans and Fisheries
told Guangzhou Daily that the fish were invasive and that their introduction should be carefully controlled.
“Previously the nation brought them in to help control mosquitoes
but afterward they spread
” Mr. Liu told the newspaper. “Whether or not this leads to a disaster
the city of Guangzhou at present doesn’t have enough data to say.”
Guangzhou Daily reported that the small
finger-length fish were first brought to China in 1924 and introduced to West Lake in Hangzhou. The fish then spread to other bodies of water
and since 2006 they have been introduced to parks in Guangzhou to control mosquitoes.
“Mosquito fishes are already widespread all over southern Guangdong
and I would doubt very much that adding any more would have much effect — either on the mosquitoes or on the ecology of the receiving waters
” David Dudgeon
a professor of ecology and biodiversity at the University of Hong Kong
wrote in an email.
Scientific opinion on the effectiveness of the mosquito fish is divided
Dr. Dudgeon said. While the fish do eat mosquitoes
the insects are not the fish’s preferred food. And the mosquito fish can have a harmful effect by eating the eggs and larvae of other native species. If mosquitoes are breeding in flower pots
puddles and other small bodies of water where the fish aren’t introduced
then their effect will be further limited.