Key facts Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease. The virus is transmitted through contact with the blood or other body fluids of an infected person. Two billion people worldwide have been infected with the virus and about 600 000 people die every year due to the consequences of hepatitis B.
Since March, the Ebola virus outbreak has infected 5,864 people and caused 2,811 deaths in West Africa. With no proven treatment, the World Health Organization (WHO) is scrambling to halt an epidemic its officials say is unparalleled in severity, complexity, and scale-which is likely underreported.
Key facts The Ebola virus causes severe viral haemorrhagic fever (VHF) outbreaks in humans. Viral haemorrhagic fever outbreaks have a case fatality rate of up to 90%. Ebola haemorrhagic fever outbreaks occur primarily in remote villages in Central and West Africa, near tropical rainforests.
As world health officials struggle to respond to the Ebola epidemic, Pakistan has passed a grim milestone in its efforts to combat another major global health crisis: the fight against polio. Over the weekend, Pakistan logged its 200th new polio case of 2014, the nation's highest transmission rate in more than a dozen years.
Key facts Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes. The "yellow" in the name refers to the jaundice that affects some patients. Up to 50% of severely affected persons without treatment will die from yellow fever. There are an estimated 200 000 cases of yellow fever, causing 30 000 deaths, worldwide each year.
Key facts Rabies occurs in more than 150 countries and territories. More than 55 000 people die of rabies every year mostly in Asia and Africa. 40% of people who are bitten by suspect rabid animals are children under 15 years of age. Dogs are the source of the vast majority of human rabies deaths.
Key facts HIV is one of the world's leading infectious killers, claiming more than 25 million lives over the past three decades. There were approximately 34.2 million people living with HIV in 2011. HIV infection can be diagnosed through blood tests detecting presence or absence of antibodies and antigens.
Key facts Influenza is an acute viral infection that spreads easily from person to person. Influenza circulates worldwide and can affect anybody in any age group. Influenza causes annual epidemics that peak during winter in temperate regions. Influenza is a serious public health problem that causes severe illnesses and deaths for higher risk populations.
Key facts Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected mosquitoes. In 2010, malaria caused an estimated 655 000 deaths (with an uncertainty range of 537 000 to 907 000), mostly among African children. Malaria is preventable and curable.