4
Severe respiratory syncytial virus pulmonary infection in a patient treated with fludarabine for chronic lymphocytic leukemia .
 Severe respiratory syncytial virus pulmonary infection, fludarabine
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: adverse effect 
Text: {0} 
Answer:
 Severe respiratory syncytial virus pulmonary infection, fludarabine