28 January 2011
By Umesh Isalkar
Diagnosing HIV in infants and children has taken a giant leap forward. A new method, using filter paper, allows high–end polymerase chain reaction (PCR) test to be performed equally effectively on small spots of dried blood rather than a whole blood sample with equal amount of sensitivity and specificity.
"The PCR is a high–end test which is used to diagnose babies born to HIV–positive mothers. Traditionally, the test requires a liquid blood sample, which if taken in a rural area and transported to a testing facility, needs to be kept refrigerated. However, the dried blood spots (DBS) method is easy to prepare in a resource–limited setting and can be stored and shipped to testing facilities without refrigeration. The method has been tested successfully at the seven referral centres," said Sayan Chatterjee, director–general of NACO, on Thursday.
The PCR test using DBS method has proven to be as effective as the PCR using liquid blood samples, with good amount of sensitivity and specificity, he added. The city–based National AIDS Research Institute (NARI) and the B J medical college are among the seven referral centres where the samples were tested with the help of this newer diagnosis method in the last one year.
"Out of the 9,000 children, 460 were found to be HIV–positive. In order to reconfirm the results, tests were also conducted al on the whole blood samples to substantiate the findings," prosaid B B Rewari, NACO’s nationgramme officer. If not treated, an HIVpositive child has a 35 per cent chance of dying by his/her first birthday and a 53 per cent chance of dying before the age of two. But if the baby receives prophylactic antibiotics soon after birth and antiretroviral therapy (ART) as soon as it is medically indicated, he/she has a good chance of surviving childhood and living a long, healthy life.
"The challenge in resourcelimited settings is identifying HIV–positive infants and providing early access to this lifesaving medicine," Rewari said. The National AIDS Control Organisation has now formulated technical and operational guidelines on care of HIVexposed infants and children below 18 months of age.
The 2010 World sation guidelines recommend that all HIV–positive infants, under two Health years of age, begin antiret–Organi– roviral treatment regardless of CD4 count or disease stage. Without antiretroviral treatment, an estimated 50 per cent of the children with HIV will die before the age of two. HIV DNA testing is necessary to make a definitive diagnosis in children below 18 months because of the persistence of maternal antibodies until this age.