[php] Removing a Precise Characters and replacing them

I want to

"Thomas;Abramse;2-7-1985;;;;;;;;;;;;; Maurits;van Actena;27-3-1983;;;;;;;;;;;;; Roeland;Aeijelts Averink;11-11-1974;;;;;;;;;;;;; "

to:

"Thomas;Abramse;2-7-1985+ Maurits;van Actena;27-3-1983+ Roeland;Aeijelts Averink;11-11-1974+ "