Could Severe Raspy Cough With White Mucus And Low Grade Fever Indicate Pertussis?

my 78yo mom has symptoms of severe raspy cough, white mucous production, low grade temp. after 5 days, i took her ED. she had blood cultures, cbc, cxr, and flu swab done, all were negative. O2 sat was 94%. her cxr did show COPD. she quit smoking in the '80's but lives w/ 2 smokers. could this be pertussis?