NM whoop cough cases up as fewer get shots May 16, 2012 at 8:59 PM CDT - Updated June 27 at 3:44 AM ALBUQUERQUE, N.M. (AP) - Health officials say a three-fold increase in the number of New Mexico children exempt from required vaccinations may be a factor in the state's jump of whooping cough cases. Albuquerque Journal reports that a recent New Mexico Department of Health report shows the number of New Mexico children exempt from required vaccinations has tripled since 1999 to nearly 3,400. Meanwhile, the state has seen a spike in pertussis, or whooping cough, from 85 cases in 2009 to 274 cases in 2011. About 112 pertussis cases were reported this year through May 5. Pertussis is a highly contagious bacterial illness that attacks the respiratory system. New Mexico law allows parents to exempt their children from required vaccinations by claiming a religious or personal belief that forbids vaccinations.