If you are absolutely positively sure and certain that there will be no ';;' anywhere inside the fields, then you can use split to good effect

use Modern::Perl;
use Text::CSV;

my $csv = Text::CSV->new( { eol => "\n" } )
  or die "Cannot use CSV: " . Text::CSV->error_diag();
open my $fh, '>', './new.csv' or die "new.csv: $!";

while (<DATA>) {
    chomp;
    $csv->print( $fh, [ split /;;/ ] );
}

close $fh or die "new.csv: $!";

__DATA__
abd;;sasa;;trre,dsa;;sdas;;dsss
123;;456,789;;include some spaces and ; once;;55555+;;abc
[download]

Output:

abd,sasa,"trre,dsa",sdas,dsss
123,"456,789","include some spaces and ; once",55555+,abc
[download]