You are correct. Version 1.3 tested and confirmed working for TF2.
Possible enhancements to consider:
1. Add percentage chance to get virus on spawn. That way the virus can happen without Admin.
2. Add a check to see if '[TF2] Roll the Dice Revamped' plugin by Phil25 is running. If so, add random RTD effects during the cough. Example:
https://forums.alliedmods.net/showpo...&postcount=251