DENVER (KDVR) — Bacterial meningitis is a highly dangerous disease, but it is relatively rare.

FOX31 has learned that a third teacher with the Cherry Creek School District has passed away. Freshman baseball coach and Willow Creek Elementary physical education teacher Scott Nash died over the weekend. His cause of death has not been released, but the district said it does not believe it is related to the bacterial meningitis death of another teacher in the district.

Bacterial meningitis is only one kind of meningitis and is spread mainly through saliva or spit. Meningitis is only one kind of what is called a “meningococcal disease” – any illness caused by a type of bacteria called Neisseria meningitidis, the two most common of which are meningitis and septicemia.

Rates of meningococcal disease in the U.S. have been falling for decades and are now at historic lows. In the 1990s, there was one case per every 100,000 people. In 2020, there was one case per million people. Infants under one year of age have the highest rates of illness.

According to Colorado Department of Public Health and Environment data, there was not a single case of meningitis in Colorado between 2015 and 2018, the most recent publicly available data, though there have been half a dozen meningococcal infections.

However, there was an outbreak of meningitis in the early 2010s that claimed the lives of two Fort Collins hockey players, among others.

Bacterial meningitis is a dangerous disease with relatively high rates of fatality and long-term damage. According to the CDC, between 10 and 15 people out of 100 people with the affliction will die even with treatment. About 20% of survivors will have long-term disabilities such as limb loss, deafness, nervous system problems or brain damage.