KAMPALA, Aug. 15 (Xinhua) -- Three alert cases recorded in the western part of Uganda have tested negative for Ebola, the World Health Organization (WHO) said Wednesday.

The global health body said samples taken from two alert cases from Democratic Republic of the Congo (DRC) that were registered in the border district of Kasese tested negative.

Samples from the third alert case -- a pregnant woman who died at Kaganda hospital in Kasese district due to ante-partum hemorrhage -- also turned out negative.

The samples were tested at the Uganda Virus Research Institute, 40 km south of the capital Kampala.

Yonas Tegegn Woldemariam, WHO Representative in Uganda, told Xinhua that there was no confirmed case of ebola in Uganda though the threat is real.

"Uganda and DRC have a porous border so people will come and go for trade and business. I think having a good screening at the border is important and there are a lot of efforts to do that. Getting the health workers trained and get ready to respond is high and is ongoing," he said.

The ebola virus is highly contagious and can cause a range of symptoms including fever, vomiting, diarrhea, generalized pain and in many cases internal and external bleeding.

Mortality rates of ebola fever, according to WHO, are high, with the human case fatality rate ranging from 50 percent to 89 percent, depending on viral sub-type.