Ebola virus or ebola hemorrhagic fever is a severe illness in humans caused by a virus. Here's what you need to know.
Dengue virus is estimated to infect up to 400 million people globally each year. The World Health Organisation ranks it as the most important mosquito-borne viral disease in the world.
Scientific advances have helped us understand and limit the impact of pandemics but we still cannot deliver the simple measures needed to control them for the benefit of all.
Brazil's Health Ministry says that cases of chikungunya are soaring this year in Latin America's biggest country.