HENDERSONVILLE, N.C. -- Whooping cough is spreading in one western North Carolina county where the number of cases more than doubled in a week. 

Health officials in Henderson County tell multiple media outlets that the number of reported cases was 45 on Friday, up from 21 on Dec. 8. 

Whooping cough, or pertussis, is a serious respiratory infection that affects the lungs and breathing tubes. It spreads easily when an infected person coughs or sneezes. 

The first case of pertussis was reported Nov. 16 at an elementary school. In the month since, the respiratory infection has spread beyond the schools. 

People who have been vaccinated can contract whooping cough though the symptoms may be milder for them. 

The health department has created a webpage with resources and more information here .