Jalpaiguri, Sept. 22: A laboratory here has changed the blood group of a man after 13 years.

Sushil Roy, a resident of Ghughudanga village in Jalpaiguri sadar, was puzzled when he discovered that his blood group was A+ and not O+ as tested by a clinic more than a decade ago.

Roy, a constable in his late twenties, first discovered that he was A+ at the annual police health camp. A surprised Roy decided to go for a re-test at the same private clinic near Kadamtala Girls? High School that had tested him O+ on December 19, 1991.

?The report, which had the signature of a pathologist on it, then stated that I was O+. At that time I had undergone the test for my driving licence,? said Roy.

A few years later, Roy underwent another test after joining the police services. This time it was the annual health camp of the police.

?There I found out that my blood group was A+. Since then, I have been confused. I had also restrained myself from donating blood as there was a discrepancy regarding my group,? he said.

This year, Roy decided to clear the confusion. On August 26, 2004, he underwent another blood group test at the same private laboratory.

?When they handed me the report, signed by the same pathologist who had identified my blood group 13 years ago, I was amazed to find it read A+. I asked them if a man?s blood group could change. They told me that the earlier test was a printing mistake,? he said. ?How do I know that this report is not wrong?? he added.

Debajit Sarkar, one of the owners of the laboratory, admitted the mistake. ?He came to us with both the reports. When he showed us the earlier report, we told him that it was a typo error. We tested his blood twice this time and it is A+,? Sarkar said.

Bhusan Chakrobarty, the chief medical officer of health of Jalpaiguri, has blamed the absence of adequate medical infrastructure in private laboratories as the main reason for errors in pathology reports. ?This is not an isolated case. We will, however, go for an on-the-spot inquiry and take necessary action,? said Chakrobarty.