The optical microscope is regularly used to identify bacteria and viruses. In 1918 the Spanish Flu infected almost one third of the world and was thought to be caused by bacteria. However, a virulent virus was the cause of the Spanish Flu. From what we have learned throughout this lab on microscopy, why weren't scientists able to identify the Spanish Flu with a microscope?

In 1918, one of the deadliest pandemics in history took place, known as the Spanish flu. The flu infected almost 500 million individuals globally, that is, about 33 percent of the world's population. Due to the Spanish flu, the death of about 20 to 50 million people took place.  

The general symptoms of the first wave of Spanish flu were fever, chills, and fatigue. However, during the second wave, the people started to die within hours after the development of the signs, due to the development of a fluid taking place within the lungs resulting in suffocation.  

At the time of the Spanish flu pandemic, not much was known regarding the composition of the virus. The scientists at that time were not able to make a difference between a bacteria and a virus. This made it tough for scientists to determine the Spanish flu with the help of a microscope.