聯合國環境規劃署(UNEP)發表一份新報告指出,全球溼地的消失,迫使可能感染禽流感的野生鳥類來到農場、池塘及稻田,而這些場所將使牠們跟雞、鴨及鵝有接觸的機會。撰寫該報告的加拿大科學家拉波特(David Rapport)表示,提供野生鳥類偏好的棲息地,復育已消失及萎縮的溼地,將有助於降低禽流感流行的威脅。
拉波特說,當前人們多投注巨大的心力在「隔離、檢疫、撲殺與施藥」等方面,但這些努力最終很可能只是帶來侷限而短暫的用處。他的報告建議各國政府、聯合國以及公共衛生專家關注在中長期的環境措施上,以遏止高致病性H5N1禽流感等疾病的傳播。
目前在歐亞非三大洲的45個國家都已證實發現H5N1病毒,在亞洲,至今約有108個人死於此病毒。大多數死於處理病疫的家禽之後。
野鳥與家禽的密集接觸,已公認是引發禽流感散佈的主要原因之一。拉波特建議,把集約式家禽養殖場遷離候鳥的飛行遷徙路線上,會是較為審慎的做法。
「讓集約家禽養殖場蓋在候鳥遷徙路線上的做法,無法保障鳥類賴以維生之生態系統的健康,而且也會增加病原體在候鳥與本土禽鳥間傳播的風險。」他也建議,為了減少野鳥以及家禽的接觸機會,最好把家畜作業場所遠離人群或豬隻等哺乳類動物。
3月31日甫於巴西閉幕的生物多樣性公約締約方雙年會中,與會代表即指出,超過80%的已知鳥種,包括遷移性及非遷移性的,都有可能處險境,而其中烏鴉及禿鷹類更須特別加以注意。
生物多樣性公約執行秘書朱格拉夫(Ahmed Djoghlaf)博士說:「候鳥常被看成病毒帶原者,牠們常是最先的犧牲者,也因此可看到人們提出一些不良的因應做法如撲殺或抽乾溼地等。較好的做法應該是:保護生態系統、生物與基因資源的良好與多樣性,以可緩和此類疾病的傳播。」
The loss of wetlands around the world is forcing wild birds that may have avian influenza onto alternative sites like farm ponds and paddy fields, where they come into contact with chickens, ducks, and geese, finds a new report commissioned by the United Nations Environment Programme.
Restoring lost and degraded wetlands could help reduce the threat of an avian flu pandemic by providing wild birds with their preferred habitat, , according to the report authored by Dr. David Rapport of Canada.
Current "heroic efforts" focusing on "isolation, quarantine, culls and medications" are likely to be quick fixes offering only limited short term benefits, finds Dr. Rapport. His report recommends that governments, the United Nations and public health experts back environmental measures over the medium and longer term to counter the spread of diseases like the highly pathogenic strain of bird flu, H5N1.
The H5N1 virus has been confirmed in 45 countries on three continents - Asia, Europe and Africa. To date, the virus has killed 108 people, all in Asia. Most died after handling diseased poultry.
Close contact of wild birds and poultry species is believed to be a major cause behind the spread of bird flu. Clearing intensive poultry rearing units from the flyways of migratory birds would be prudent, Rapport suggests.
"Intensive poultry operations along migratory wild bird routes are incompatible with protecting the health of ecosystems that birds depend upon. They also increase the risks of transfer of pathogens between migrating birds and domestic fowl," he writes. He also suggests reducing contact between wild birds and poultry by shifting livestock production away from humans and other mammals such as pigs.
During their biannual meeting that ended March 31 in Brazil, the Conference of Parties to the Convention on Biological Diversity (CBD) delegates concluded that over 80 percent of known bird species, both migratory and nonmigratory, may also be at risk, with members of the crow and vultures families of particular concern.
"Often seen as the vectors of the virus, migratory birds are first and foremost its victims. Some responses to this, such as culling birds or draining wetlands, have been ill advised," CBD Executive Secretary Dr. Ahmed Djoghlaf said. "Better responses, involving the protection of the well-being and diversity of ecosystems, species and genetic resources, can mitigate against the spread of such diseases."