Keeping the Germs Away! Disease Control by Susan H. Gray

"Ouch," whimpered Brandon.

"It'll be okay," Alex told his little brother. "This will help you not get sick, right, Dr. Devi?"

"Absolutely. You should feel lucky," the doctor said. "That little pinch was a vaccine--a lot better than some of the diseases people used to get!"

"Like what?" asked both boys.

The list of widespread human diseases is long and the story of how most of them came under control is the subject of Susan H. Gray's Disease Control (21st Century Skills Innovation Library: Innovation in Medicine) (Cherry Lake Publishing). Author Gray covers ancient views of the mysterious waves of sickness that people have dealt with over history. For millennia people thought weather and bad spirits made people sick, but even a thousand years ago they noticed that some diseases seem to sicken not just one person who got the "evil eye" but many of the people in a community or a whole area. Sometimes the disease came when a ill person entered the group, but sometimes if a healthy stranger came into the group, he or she got sick too, so there had to to be something that moved from person to person or place to place that made them sick. People in Italy called the fever that came in warm, humid seasons "malaria," bad air, until one physician figured out that with warm, rainy weather came warm puddles of water from which mosquitoes hatched to transmitted the disease by biting their victims.

In another famous case, Joseph Jenner noticed that dairy workers often had a minor sickness called "cow pox," but were never sick during epidemics of the deadly smallpox. He tried "vaccinating" a boy by transferring some of the fluid in a cowpox lesion to a small scratch on the skin of the healthy boy, who got a mild sickness but was then immune to smallpox.

And when a deadly cholera epidemic struck London during the rule of Queen Victoria, a young doctor named John Snow noticed that victims only complained about pain in the digestive system and concluded that the cause must be something in food or water. People were eating many different foods, but everyone was drinking water, and Dr. Snow traced the source of the epidemic to one water pump in all of London, and when the authorities closed that well, the disease quickly disappeared. Dr. Snow found the cause to be in sewage found in the water from that pump, and as London's new health department worked to provide clean water to all, the cholera vanished.

From those discoveries the science of epidemiology gained three of its major tools, tracking and mapping victims, finding the vector, and stopping the transmission became one of medicine's most useful tools for stopping an epidemic. Preventing harmful cases of a deadly disease by inducing a minor exposure from a harmless but related disease or a weakened (attenuated) or killed version of the disease particles, soon called "germs," prevented transmission and ended epidemics.

Humankind is in a on-going war on disease. For middle readers who love a real-life mystery and those who are interested in medical mysteries, Disease Control (21st Century Skills Innovation Library: Innovation in Medicine) provides both basic background information and how medical science works to stop an epidemic or a pandemic like COVID-19. Author Gray points out that the roles once played by Dr. Jenner and Dr. Snow are still being played out on an individual, national and international levels in agencies like the Center for Disease Control (CDC) and the World Health Organization (WHO). These agencies provide protective information and research, from "wash your hands" to the development of vaccines that bring new diseases under control or even, as in the case of smallpox, to become as extinct as the dinosaurs.

Other intriguing books in this Innovation in Medicine series are Emergency Care (Innovation in Medicine), Vision (Innovation in Medicine), and Transplants (Innovation in Medicine).