Chickenpox taking them to "chickenpox parties". Doctors counter that children are safer getting the vaccine, which is a weakened form of the virus, rather than getting the disease, which can be fatal. Humans are the only known species that the disease affects naturally. However, chickenpox has been caused in other animals, such as primates, including chimpanzees and gorillas. Chickenpox Chickenpox, also known as varicella, is a highly contagious disease caused by the initial infection with varicella zoster virus (VZV). The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over. It usually starts on the
Foreign animal disease Foreign animal disease A Foreign animal disease (FAD) is an animal disease or pest, whether terrestrial or aquatic, not known to exist in the United States or its territories. When these diseases can significantly affect human health or animal production and when there is significant economic cost for disease control and eradication efforts, they are considered a threat to the United States. Another term gaining preference to be used is Transboundary Animal Disease (TAD), which is defined as "those epidemic diseases which are highly contagious or transmissible and have the potential for very rapid spread, irrespective of national borders, causing