The information contained in this factsheet is intended for the purpose of general information and should not substitute individual expert advice and judgement of healthcare professionals.
Yellow fever (YF) is a mosquito-borne infection, distributed in west, central and east Africa and in South America. The disease can cause a wide spectrum of symptoms, from mild to fatal. In severe cases there may be spontaneous haemorrhage. Mortality of these clinical cases can be as high as 80%, on a par with Ebola, Marburg and other haemorrhagic viral infections.
Most Zika virus infections are either asymptomatic or cause a mild illness with a transient maculopapular rash. However, there is scientific consensus that Zika virus is a cause of microcephaly, congenital nervous system malformations and Guillain-Barré syndrome.
Coronaviruses are viruses that circulate among animals. Some coronaviruses can infect humans. Many human coronaviruses come from bats which are considered natural hosts of these viruses.
A pandemic is the rapid spread of a new human influenza around the world. Influenza pandemics happen when a new strain of a flu virus appears which can infect humans, to which most people have no immunity and which can transmit efficiently from human to human.
Swine influenza is a respiratory disease of pigs caused by type A influenza viruses that regularly cause outbreaks of influenza in pigs. Influenza viruses that commonly circulate in swine are called “swine influenza viruses” or “swine flu viruses.” Like human influenza viruses, there are different subtypes and strains of swine influenza viruses.
Hepatitis B is a liver disease that results from infection with the hepatitis B virus (HBV) and is spread through contact with infected body fluids or blood products. Following acute infection with HBV, some people go on to develop a chronic infection.