Local health officials report that as of midday Monday the number of confirmed pertussis cases in Missoula County has reached 100.
The Missoula City-County Department had previously told MTN News that confirmed whooping cough cases had been reported in 18 schools from preschools to high schools.
Health Department officials have identified more than 1,000 close contacts but say that number is creeping up to about 2,000 close contacts.
The Health Department along with area school nurses continue to screen students and are working with families and employers who may have been in close contact with an infected person.
The ongoing Missoula County whooping cough outbreak has local health officials seeking some extra help.
The Missoula City-County Health Department is looking for nurses to work short term as the pertussis outbreak continues to expand.
The Florence Carlton School and Frenchtown School districts have also reported confirmed whooping cough cases.