Like this.

my %count;
while(<DATA>) {
    chomp;
    tr/,/\t/;
    $count{$_}++;
}
foreach(sort keys %count) {
    print "$count{$_}\t$_\n";
}

__DATA__
abcd,US
abee,UK
abcd,US
adee,US
[download]

Replace <DATA> with "<>" to run it for real, and either pipe in the data file or pass the filename as an argument to the script.