In a study to identify the organisms that cause cough similar to whooping cough, it was found that chand "a part of pertussis-like cough in children can be caused by adenovirus, parainfluenza virus, respiratory syncytial virus and Mycoplasma. Differential diagnosis of pertussis-like cough by laboratory methods should include these infections, especially in vaccinated children ... A total of 149 of 1179 children (12,6%) had no laboratory evidence of B. pertussis infection. Serological evidence of other infections was found in 56% (83 out of 149). Adenovirus (33), parainfluenza virus 1, 2 and 3 (18), Mycoplasma pneumoniae (15), and respiratory syncytial virus (14) were the most common. Of this group, 48% had been vaccinated against whooping cough ”.