Chicken pox is most common in places with a warmer climate. It thrives in warm weather, but is weakened in cold weather. Under these conditions, the places with the highest amount of chicken pox virus cases reported are in South America, parts of the United States, and Africa. South America is very hot. It also gets a lot of precipitation which allows the many plants they have there to thrive. South America also has many unique animals which are known to carry many diseases, but not the chicken pox.