Hi Kathy and Welcome back!
Allergies are not contagious. Though...when you do have allergies and your body is trying to fight that off your resistance is lowered somewhat and you may pick up "what's going around" more easily.
Is your Husband in good health otherwise? I would recommend that he goes to his Dr. and asks for a recommendation for something to help contain his allergies. It could be a prescription or something he recommends OTC. Sometimes the salt/saline nasal sprays help out - my daughter's used them before and had pretty good success with them. Right now she takes Zyrtec 10 mg. per night and Flonase, a nasal spray, and she is 95% controlled. Everyone's different! :)
I don't know what to tell re your children becoming ill at the same time? Coincidence? Perhaps they have similar allergies? Using lysol, or small amt. of bleach mixed with your laundry detergent, just be careful with that
or alcohol used to wipe off a countertops, telephone, door handles.
Remember to wash hands a lot - that's the worse offender in aiding the spread of disease.
Wishing you all the best and good health!