You didn't in the end include any URL in your post.
Looking here
https://www.immigration.govt.nz/opsm....htm?35154.htm, you'll see that HIV is one of the conditions considered a 'no'. However, here
https://www.immigration.govt.nz/opsm....htm?35154.htm is the page about medical waivers, and indeed, waivers can be given to someone applying under the family stream. But these days, there is no route for anyone in NZ to sponsor in their adult sibling, so this would only apply to the partner or child of a resident or citizen.
Those links are to the INZ operational manual, which is the official summary of all the regulations, so can be relied upon.