A patient is suspected of carrying a viral pathogen, but the concentration of the pathogen in the body is extremely low and no visible disease symptoms are present. Which of the following techniques is most appropriate for the early diagnosis of this infection?

Step-by-step solution

Early diagnosis of a disease is not possible using conventional methods of diagnosis like serum and urine analysis, as they require a higher concentration of the pathogen to yield a positive result. When the concentration of a pathogen (like bacteria or viruses) is very low and no symptoms of the disease are visible, it can still be detected by the amplification of its nucleic acid using Polymerase Chain Reaction (PCR). PCR is routinely used to detect HIV in suspected AIDS patients. The Widal test is a specific ser