Aug 24, · Ear infections can be caused by viruses, bacteria, or rarely virginxx.xyz are three areas in the ear where ear infections can occur in adults and children.. Outer ear infections (swimmer's ear): An outer ear infection (otitis externa) most commonly experienced is often known as “swimmer’s ear.”This infection usually is due to bacterial infection of the skin tissue covering the ear canal. Aug 27, · Viruses or bacteria in the middle ear can cause ear infections. Ear infections can occur in both children and adults. Some reasons and contributing factors that cause ear infections are a wax buildup, food allergies, environmental allergies, upper respiratory infections, fetal alcohol syndrome, genetics, internal injuries and nutritional deficiencies.