Another county health department reports an outbreak of an illness that can kill infants. Last week, Black Hawk County officials reported more than 20 cases of whooping cough in the Waterloo area. Now, at least 21 cases of that disease are reported in Davenport. Scott County Health Department spokeswoman Roma Taylor gives two possible explanations for the whooping cough outbreak, also called pertussis. Taylor says the whooping cough vaccine begins to wane when children reach adolescence. Also, doctors in the community are being made more aware of pertussis so they’re testing patients for it more frequently. Taylor says it’s vital that doctors -do- take that action and check patients for whooping cough. Pertussis can be very contagious and it’s spread through the air. When someone who has it is coughing, they could be spreading it to anyone else who’s nearby, in the same house, office or classroom. Taylor says if you’re hacking a lot over several days, don’t wait until it gets worse — get into the doctor’s office now. Symptoms include a severe cough, low-grade fever, sneezing and sometimes a runny nose. While whooping cough can be fatal in infants, it can also be severe for people of any age, particularly the elderly.