Sore throat or throat irritation that lasts longer than 5 to 7 days, especially, in people with low immunity, must be evaluated by physician.
HIV infection can sometimes cause a chronic sore throat, due not to HIV itself but to a secondary infection that can be extremely serious.
Sinusitis, that wasn't treated with antibiotic easily can progress to chronic form.
Post nasal drip due to sinusitis is very common reason for feeling of throat irritation.
Frequent episodes of acid reflux may result in throat irritation, too.
If you are prone to allergies like seasonal ones, you may have post nasal drip and throat irritation.

Try to find some medical program for free for HIV positive people!
Best wishes!
Marija