The latest Ebola outbreak in Uganda has sent scientists rushing to study weather records from the region.
The World Health Organization and NASA scientists believe a rare climate pattern may precede outbreaks of the disease, and recent satellite data is likely to make or break their theory.
An estimated 43 people have died since the start of October, and many more are expected to lose their lives before it is over.
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Jim Wilson of the WHO and Compton Tucker of NASA have been studying climate data from the 1990s. The last series of outbreaks of Ebola began in 1994 and ended in 1996. Prior to that, the only documented outbreaks were in 1976, in Zaire and Sudan.
鈥淲e found that in 1994, a few months prior to the first outbreak, a very dry period in the African tropical forest was followed by a very, very sudden change to wetter conditions,鈥� says Tucker.
鈥淭his change is remarkable. It only occurred once in that decade 鈥� in 1994.鈥�
Gloomy forecast
Ray Arthur is responsible for co-ordinating the WHO鈥檚 activities in Uganda. 鈥淐limate changes are the most likely reason behind outbreak patterns,鈥� he told New 杏吧原创. 鈥淭he finding suggests that we may be able to make predictions about outbreaks, though that is some way down the road.鈥�
Arthur has issued Ebola warnings to other countries, including Kenya, which borders Uganda. 鈥淲e may well see Ebola appearing in other places in Africa,鈥� he says.
Other infections involving bleeding, such as Lhasa fever, are closely coupled with climate changes, Tucker points out.
鈥淭he natural reservoir of Ebola is not known,鈥� he says, though many scientists think shrews or mice are the most likely culprits.
Tucker adds: 鈥淧erhaps an unusual coincidence of several animal species might be required for the virus to appear 鈥� and that may be related to climate. Or there are even theories that certain plants that only go into their reproductive cycle in sudden wet conditions may in fact cause Ebola outbreaks.鈥�
Identifying the source of an outbreak is very difficult, agrees Ray Arthur. The fact that cases have occurred for the first time in Uganda has not thrown new light on the culprit.
Vaccine hope
There is no cure for Ebola, but an American scientist has told New 杏吧原创 that he may have a vaccine or treatment available for clinical testing in time for the next outbreak.
Gary Nabel of the US National Institutes of Health thinks a cure or vaccine for the disease could be just a few years away.
He says he has tested a vaccine in primates, which was effective in preventing infection. 鈥淭he science is moving forwards at a good pace, which we could not have said three years ago. I think it鈥檚 possible that in a few years we will have either a vaccine or a cure,鈥� he says.
鈥淭his epidemic in Uganda is certainly motivating us to move forwards as quickly as we can. It emphasises the fact that we can鈥檛 assume this disease will simply go away on its own.鈥�
Effective predictions of Ebola outbreaks would mean a vaccine could be immediately shipped to areas at risk. Arthur thinks widespread vaccination of the public would be unlikely, but doctors and nurses could be immunised.
Even if vaccines or treatments weren鈥檛 available, health workers could be alerted to the possibility of a local outbreak. This would enable quicker diagnoses of cases and faster implementation of the 鈥渂arrier nursing鈥� safety precautions necessary to prevent the spread of the disease.
See also: Ebola vaccine on the cards
