New York, Dec 11 (IANS): No one really knows whether the deadly Ebola virus can survive on glass surfaces or countertops and cause infection or how long it remains active in water, wastewater, or sludge, say researchers.

The Ebola virus travels from person to person through direct contact with infected body fluids.

"The World Health Organization has been saying you can put (human waste) in pit latrines or ordinary sanitary sewers and that the virus then dies," said Kyle Bibby, assistant professor at University of Pittsburgh in the US.

"But the literature lacks evidence that it does. They may be right but the evidence is not there," Bibby added.

Knowing how long the deadly pathogen survives on surfaces, in water, or in liquid droplets is critical to developing effective disinfection practices to prevent the spread of the disease, the researchers pointed out.

Currently, the World Health Organization guidelines recommend to hospitals and health clinics that liquid wastes from patients be flushed down the toilet or disposed of in a latrine.

However, Ebola research labs that use patients' liquid waste are supposed to disinfect the waste before it enters the sewage system.

As researchers scoured scientific papers for data on how long the virus can live in the environment, they found a dearth of published studies on the matter, indicating that no one really knows how long the virus can survive.

The study appeared in the journal Environmental Science & Technology Letters.