1860
The HBV viral loads for mono - infected and co - infected patients ranged from 3 . 32 x 10 ( 2 ) to 3 . 82 x 10 ( 7 ) and < 200 to 4 . 40 x 10 ( 3 ) copies / ml , respectively .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 None