In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Compared with hepatitis E virus ( HEV ) and non - A non - E - induced ALF , ATT - ALF patients had nearly similar presentations except for older age and less elevation of liver enzymes .
### Output Text:
Compared with hepatitis E virus ( HEV ) and non - A non - E - induced ALF , ATT - ALF patients had nearly similar presentations except for older age and less elevation of liver enzymes . 