1. Ebola virus disease
What it is: The Ebola virus disease is a serious disease that can be fatal if left untreated. In most cases, it causes haemorrhaging from internal organs and bodily orifices. Although there is no known cure, the symptoms are treated with supportive care. Ebola belongs to a group of haemorrhagic diseases, which includes Marburg disease.
How is it contracted? Ebola is believed to be carried by fruit bats from the Pteropodidae species, but once an Ebola epidemic has started, the transmission of the virus between humans occurs via body fluid and needles contaminated by infected secretions.
Signs and symptoms: The incubation period for the Ebola virus can be three to eight days. The onset of the symptoms are sudden and include fever, severe headache, fatigue, nausea, diarrhoea, abdominal pain, and in the most severe case, bleeding from the gastrointestinal tract and other orifices.
When and where: According to the WHO, the most recent outbreak occurred in the Democratic Republic of the Congo in May 2017. In 2014 to 2016, the outbreak mostly involved West Africa in major urban and rural areas.