Travel clinic for lyme disease in Belgrade

Hi,

I'm hoping there is someone out there who could give me some advice. I know someone who has been monitoring a recent swelling and thinks she may have picked up Lyme's Disease weeks ago somewhere else. She's now trying to go seek medical help to diagnose what she has. Does anyone know of a good English speaking travel clinic she might be able to see? I'd be grateful for any advice anyone could provide. -Kev