Ebola Virus Threatens Great Ape Population - Science Daily

[hatrack]

"The Ebola virus causes epidemics that wreak havoc in some tropical forest areas in Central Africa. Its control is therefore a major public health priority. The virus, transmitted to humans mainly by carcasses of gorillas, chimpanzees and duikers (Bovidae), provokes haemorrhagic fever which is usually fatal. IRD researchers and co-workers from partner organizations (1) have just shown that these animals can also be victims of Ebola epidemics. Such outbreaks appear to result from multiple simultaneous transmission events starting from an as-yet unidentified animal reservoir, triggering a drastic decline in great ape populations which has been observed in these areas of Africa. These findings, published in the journal Science, indicate clearly that the animal Ebola epidemics often precede the human ones. The occurrence of infected animal carcasses found in an area would therefore be an indicator of a forthcoming outbreak about to hit nearby villages. Such finds could therefore aid in attempts at more effective prevention of Ebola virus transmission to humans.

EDIT

A further discovery came from an organized count of carcasses found in the forest coupled with calculations of rates of presence of these animals (from occurrence of dung, tracks, nests, and so on). There have been large increases in mortality in some animal species before and during the human epidemics. The populations of gorillas and duikers plummeted 50% between 2002 and 2003 in the Lossi animal sanctuary (320 km2) in the Republic of Congo and Chimpanzee numbers fell by 88%. Hundreds or even thousands of animals may well have died during the latest epidemics that hit the region. Laboratory analyses of samples taken from animal carcasses during human epidemics confirmed that these carcasses were Ebola-virus infected. The rapid decline in animal populations in this part of Africa could therefore be due to Ebola epidemics. Gene analyses conducted on the samples have also shown the involvement of several infecting viral strains, as has been found in humans.

Ebola virus epidemics in the large apes hence appear not to stem from propagation of a single epidemic from one individual to another, but rather from massive simultaneous infections of these primates from the original carrier animal facilitated by a particular set of environmental conditions. Infection of humans occurs in a second phase, usually by contact with animal carcasses. The discovery of infected carcasses can therefore be taken as a warning sign of a human epidemic. Detection and diagnosis of Ebola infection on these carcasses could help define Ebola human transmission prevention and control programmes before any human epidemics arise, and thus increase the possibilities for containing or avoiding them. Outbreaks among the great apes seem to hit mainly at times of seasonal changes. However, the exact environmental conditions that foster their emergence are not known. Neither is the host, the natural reservoir of the virus, which contaminates the animals. Research is under way to identify the factors involved."

EDIT/END

http://www.sciencedaily.com/releases/2004/01/040116075934.htm

[gate of the sun]

1. I read about this in National Geographic

very sad