Shell Programming and Scripting

Gurus,

Need little guidance.
I have A.txt and B.txt file. B.txt file contains Unique strings.
Sample content of B.txt file for which i cut the fourth column uniquely and output directed to B.txt file
And A.txt file contains the above string as a fourth column which is last column.
So A.txt file fourth column content is

Code:

while read line
    do
    COUNT=`grep "$line" A.txt | wc -l`
    echo $line "," $COUNT >> output.txt
    done < B.txt

Output.txt file displays output
Here ghjjj should display 1 instead 2...
Can anybody guide me the better way to get this.

Thanks in advance!!!