请问这句怎么分析句子结构？

大家好，我在规培英语手册上看到这样一句话：Fever may be present in many different conditions,commonly in infections,connective tissue disorders,cancer or drug-reaction of certain drugs are the common clinical reasons of fever.我有疑问：后面有are，前面又用了commonly in，是不是有误？请大神帮忙解疑，谢谢！