Health care officials have confirmed 4 cases of whooping cough in Farmington since the start of November.

Camelot Skilled Nursing and Rehabilitation informed the St. Francois County Health Center and Missouri Department of Health and Senior Services of a first case of pertussis earlier this month.

Both entities are continuing to monitor the treatment of the infected and working with Camelot to prevent the spread of the illness.

Experts believe whooping cough is again common in the U.S. because of better diagnosis tests and vaccines having short-term affects.