It takes significant exposure to an infected individual to become infected. It is less likely that a person would become infected by someone who was merely exposed to pertussis and is not having any symptoms. If children have been significantly exposed to pertussis they may be incubating the infection, and not yet able to test positive. If your child is likely to be infected, or has tested positive, it will take 5 days for the antibiotics to reduce the risk of spreading infection. My antibiotics are making me sick.
Some individuals have difficulty taking erythromycin.
If the symptoms cannot be tolerated, contact your medical provider to prescribe one of several other choices. It is important to complete a full course of antibiotics. My child is receiving antibiotics. Antibiotic therapy will reduce the infectiousness of pertussis. Unfortunately, antibiotics will not reduce the severity of the illness.