Now, HIV detection in newborns

There’s good news for HIV-infected mothers-to-be. A new testing technique to be introduced by the National Aids Control Organisation (Naco) from April 1 will help detect HIV infection among newborns in only six weeks. So far, it could be detected after 18 months when the antibodies of the HIV-infected
mother disappeared from the babies’ blood.

As part of Naco’s annual plan, the advanced testing technique called Deoxyribonucleic Acid (DNA) Polymerase Chain Reaction (PCR) will be introduced at 230 shortlisted centres across the country. Areas where the prevalence of mother to child transmission of the virus is more will have additional centres. In Maharashtra, the Kasturba hospital in Mumbai and the National Aids Research Institute in Pune will have high-tech DNA-PCR laboratories.

“The technique was known for many years. However, there were lots of policy decisions to be taken before it could be implemented. The cost factor also had to be worked out because the DNA-PCR test is costly as well as complicated. A test costs between Rs2,000-3,000,” Dr SS Kudalkar, project officer, Mumbai District Aids Control Society (MDACS) said, adding that it will be conducted free of cost at all centres.

Since the earlier tests could only detect antibodies, in several instances the babies would show false signs of being HIV positive.

This was because the test picked up the antibodies from the mother. The DNA-PCR test directly detects the antigens which carry the virus thereby excluding any chances of false diagnosis.

An early diagnosis not only helps in treating the infant early, but also controlling the spread of the virus.

According to Kudalkar, 33% babies test positive for HIV in cases where the infected women are not given Nevirapine, a drug which lessens the chances of transmission of the virus to the newborn. In cases where Nevirapine is given to HIV positive women before delivery, only 5% babies test positive for the virus.

In addition to HIV, PCR also permits early diagnosis of malignant diseases such as leukemia and lymphomas, which is currently the highest developed in cancer research and is already being used routinely. PCR assays can be performed directly on genomic DNA samples to detect translocation-specific malignant cells at a sensitivity which is at least 10,000 fold higher than other methods.
PCR also permits identification of non-cultivatable or slow-growing microorganisms such as mycobacteria, anaerobic bacteria, or viruses from tissue culture assays and animal models.

The basis for PCR diagnostic applications in microbiology is the detection of infectious agents and the discrimination of non-pathogenic from pathogenic strains.