Germs are a major threat to anyone with Rheumatoid Arthritis. Since we take immunosuppressant drugs, our immune systems cannot fight against germs the way people with a healthy immune system can.
The drugs suppress the immune system so it cannot attack the joints, thereby reducing pain and permanent damage. If the immune system is suppressed, it also cannot fight other forms of inflammation, such as the common cold. Anyone with a suppressed immune system is already more susceptible to any type of germ, and they will take longer to recover from an illness than a healthy person.
If you (you being a generally healthy person with a robust immune system) catch a cold, it might take about a week for you to recover. You might take some cold medicine, perhaps stay in the whole weekend and rest. It might be a slight inconvenience, and while nobody enjoys being sick, it's usually not the end of the world if you catch a cold from somebody.
If I catch a cold, I have to stop taking my medications, which will allow my immune system to fight the germs but also allow the pain and joint inflammation to return (possibly initiating a flare). I may or may not be able to take cold medication to alleviate the symptoms. I'll likely be sick for twice as long as a person without RA, because my immune system needs more time to fight back. It actually is a major life disruption if I catch a cold. I also have a greater risk of developing complications, such as developing bronchitis and taking over two months to recover (true story).
Germs - immunosuppressant drugs = more pain/joint inflammation = feeling like major you-know-what
So how do people with RA avoid germs, pain and general misery? First rule of remaining as healthy as possible: WASH YOUR HANDS. All the time, every day, with soap and water, before you eat, after using the restroom, just keep your hands clean. Seriously. I carry a mini hand sanitizer with me everywhere and I use it constantly.
Other germ avoidance techniques include, but are certainly not limited to: avoiding any person with a cough, a sniffle or a generally gross vibe; wearing a face mask over your nose and mouth (yes, you'll feel dumb); wearing warm clothing in a cold climate; opening doors with your mind instead of your hands; not breathing; and avoiding all people and public places regardless of how clean and germ-free they appear.