What Is Bird Flu? Bird flu, or avian influenza, is a viral infection spread from bird to bird. Currently, a particularly deadly strain of bird flu -- H5N1 -- continues to spread among poultry in Egypt and in certain parts of Asia. Technically, H5N1 is a highly pathogenic avian influenza (HPAI) virus. It's deadly to most birds.
Chickenpox is a very contagious disease caused by the varicella-zoster virus (VZV). It causes a blister-like rash, itching, tiredness, and fever. The rash appears first on the stomach, back and face and can spread over the entire body causing between 250 and 500 itchy blisters.
How a Common Cold Starts You can catch it from another person who is infected with the virus. This can happen by direct physical contact with someone who has a cold, or by touching a surface contaminated with their germs -- like a computer keyboard, doorknob or spoon --- and then touching your nose or mouth.
Cytomegalovirus (CMV) is a common virus that can infect almost anyone. Once infected, your body retains the virus for life. Most people don't know they have CMV because it rarely causes problems in healthy people. But if you're pregnant or have a weakened immune system, CMV is cause for concern.
Outbreaks of Ebola and Marburg virus infections started in Central and West Africa, probably because the infections are common in wild animals there. Such outbreaks are rare and, in the past, have not spread very far because they typically occurred in isolated, rural areas.
Bacterial and viral infections have many things in common. Both types of infections are caused by microbes -- bacteria and viruses, respectively -- and spread by things such as: Coughing and sneezing. Contact with infected people, especially through kissing and sex. Contact with contaminated surfaces, food, and water.