Vaccinations have helped decrease the number of cases of infectious diseases in the last 110 years.
The bubble chart on the left shows the number of cases of infectious diseases in the United States in the 1900s. Even though diseases like measles, pertussis, mumps, and rubella that used to infect hundreds of thousands of people have not disappeared, nowadays they infect a much lower number of people thanks to the use of vaccines, as shown on the bubble chart on the right.
Source: Vaccines.com
Right now it is flu season in the northern hemisphere. The flu (influenza) is a contagious respiratory disease caused by influenza viruses.
Google Trends created the map shown above, based on aggregate data generated by users searching for the word “flu” and related terms, in order to estimate flu activity worldwide. According to data captured by Google Trends, flu activity is very intense in the U.S. at the moment. Canada, Russia, Norway, Poland, the Netherlands and Japan show high flu activity as well.
The Centers for Disease Control and Prevention (CDC) tracks the geographical spread of flu across the United States, however, the collected data does not reflect intensity of influenza activity.
As can be seen in the map, the flu has spread relatively quickly in the last three weeks throughout the continental United States. California, Mississippi and the District of Columbia show local influenza activity at the moment.