By Newsbreak Producer Matthew Veeran - Every July for the past four years, epidemiologists at the United States have noted a sudden spike in Covid-19 cases and hospitalisations, an annual trend which has been dubbed "the summertime surge". Taking North America into account, Covid-19 rates are reportedly particularly high in Arizona, California, Hawaii and Nevada. In these western states, the number of positive tests reached 15.6% in the first week of July, a significant increase on the previous week. The investigations show that viral rates in wastewater are also on the rise once again. In this week's Medical Monitor, I find out more about this seasonal trend and what it means going forward...