Modifiers matching std:

• bacterial,
• inflammatory,
• serious,
• chronic,
• common,
• major,
• nasty,
• prevalent,
• viral,
• ulcerative,
• infectious,
• protozoal,

Simple categories matching prevalent:

• virus,
• symptom,
• disease,
• condition,
• infection,
• trauma,
• disorder,
• dermatosis,
• cancer,
• pathology,
• state,
• problem,
• std,
• difficulty,
• illness,