The World Health Organization (WHO) says two people in Ghana who later died tested positive for the Marburg virus, which causes a highly contagious disease similar to Ebola. Tests carried out in Ghana were positive, but those results must be confirmed by a laboratory in Senegal for the cases to be considered confirmed, the WHO said in a statement on Thursday. The two patients in the southern Ashanti region both had symptoms including diarrhoea, fever, nausea and vomiting before they died in hospital, the statement said. If the cases are confirmed, this would be only the second outbreak of Marburg in West Africa. The first case of the virus was detected last year in Guinea, with no other cases detected. “Preparations for a potential response to the outbreak are being made rapidly as further investigations are underway,” the WHO said. There have been twelve major outbreaks of Marburg since 1967, mostly in southern and eastern Africa. Marburg virus is usually associated with exposure to caves or mines that host colonies of Rousettus bats. Once contracted by a human, the virus is spread through contact with bodily fluids of infected individuals or contaminated surfaces and materials, according to the WHO. The disease begins suddenly, with high fever, severe headache and malaise. Fatality rates range from 24 percent to 88 percent in previous outbreaks, depending on the strain of the virus and case management, according to the WHO. Although there are no approved vaccines or antiviral treatments, oral or intravenous hydration and treatment of specific symptoms improve survival rates, he said.