最新一期《科學》期刊內容指出,非洲羅西禁獵區週邊的伊波拉疫情嚴重,至今已奪去約5000隻低地大猩猩的性命,這較先前所估計的數據更多。科學家指出猿類間的傳染是疫情擴散的主要原因,而商業狩獵行為更使得這瀕絕動物的生計雪上加霜。
剛果共和國位於剛果民主共和國(薩伊)西方,疫情爆發在剛果共和國西北部的羅西禁獵區,這已經不是伊波拉病毒第一次奪去低地大猩猩性命。
自2002年8月到2003年,估計禁獵區一帶一半以上大猩猩(約600隻)死於伊波拉病毒。另一份調查則指出,禁獵區附近一塊2000平方英里的棲地裡,大猩猩巢穴數量減少96%。
研究羅西禁獵區大猩猩長達12年的靈長動物學家貝梅荷(Magdalena Bermejo)表示,「薩伊型病毒是伊波拉病毒4種病毒株之一,加彭和剛果已有人類受感染。」
專家估計,全世界四分之一的大猩猩已死於伊波拉出血熱,不過他們強調,已感染死亡數量和仍存活猩猩的確切數目,則難以確定。
每次人類爆發疫情,附近森林就會出現成堆的大猩猩和黑猩猩屍體。伊波拉是致命率最高的病毒之一,一旦感染伊波拉出血熱,根據世界衛生組織(WHO)統計,死亡率高達50%到90%。自1976年出現首例,伊波拉出血熱已造成超過1200人死亡。
WHO表示,伊波拉病毒是透過血液、分泌物、器官接觸或其他體液直接接觸而傳染。
貝梅荷博士等人的研究指出,伊波拉是透過猿猴間傳染,從一個大猩猩族群傳染至另外一個族群,但詳細傳遞機制仍未明朗。 科學家推測伊波拉病毒的傳染窩是同樣棲息在剛果雨林以水果維生的蝙蝠,實驗室讓蝙蝠感染伊波拉病毒後後,並未造成蝙蝠死亡,因此,蝙蝠可能是伊波拉病毒存在於熱帶雨林中的重要關鍵。科學家仍在剛果和多彭持續進行更多生態和病毒研究,以確認出伊波拉的傳染窩為何。
The Ebola virus has wiped out as many as 5,000 lowland gorillas in the region surrounding the Lossi Sanctuary in Africa, a much higher number than previous estimates, according to new research published today. The scientists propose that ape-to-ape transmission is a major factor in the spread of the disease among the endangered animals.
This Ebola outbreak is not the first to devastate gorillas in and around the Lossi Sanctuary in the northwestern Republic of Congo near the Gabon border. The Republic of Congo is the country to the west of the larger nation of Congo, formerly known as Zaire.
Beginning in August 2002 and continuing in 2003, about half of the previously estimated population of 1,200 gorillas living in and around the sanctuary were found to have died from Ebola infection. A survey of nesting sites used by gorillas in a 2,000 square mile area around the sanctuary found that the number of occupied nests had fallen by 96 percent .
The Zaire strain, one of four viral subtypes, has infected humans in Gabon and Congo, said primatologist Magdalena Bermejo, who has been studying the gorillas of the Lossi Sanctuary since 1994.
The researchers estimate that one-fourth of the world's gorillas have died from the disease since then, but they stress that no one knows precisely how many gorillas still exist and how many have died of Ebola infection.
Each time there is a human outbreak, carcasses of gorillas and chimpanzees have been found in nearby forests. One of the most deadly viruses known, Ebola hemorrhagic fever causes death in 50 to 90 percent of all clinically ill cases, according to the World Health Organization, WHO. Since the disease was discovered in 1976, it has caused over 1,200 human deaths.
WHO says the virus is transmitted among people by direct contact with the blood, secretions, organs or other bodily fluids.
Dr. Bermejo and her colleagues indicate in their paper that the virus appears to be spreading from one gorilla group to another in a manner consistent with ape-to-ape transmission. But exactly how gorillas pick up the infection is still unknown.
Scientists speculate that the natural reservoir is fruit eating bats that also inhabit the dense Congolese rainforests. Laboratory observation has shown that bats experimentally infected with Ebola do not die, and this has raised the possibility that these mammals may play a role in maintaining the virus in the tropical forest. Extensive ecological studies are underway in the Republic of Congo and Gabon to identify the Ebola's natural reservoir.