Coronavirus death toll in China has reached 2,118 and the total confirmed cases of infection have increased to 74,576. Amidst the havoc caused by the deadly virus, China has revised the diagnostic methodology sixth time. The country has changed the diagnostic and counting methodology twice in almost one and a half weeks. The change in the diagnostic method now excludes patients from Hubei Province, who have been diagnosed using clinical methods such as CT scan and by assessment of symptoms. Now they will be re-tested by the new diagnostic method adopted by China before they are declared infected. This has drastically brought down the cases of new infections in the country.
Last week China adopted a counting method based on clinical tests such as scanning the lungs of patients. Later it was realized that the clinical methods, though faster, may give erroneous results. It was found out that the clinical results may even conclude ordinary seasonal flu as pneumonia infection, thus increasing the counting of Coronavirus infected patients. To control the error in counting now the country has switched to specialized Nucleic Acid-Based identification methods.
Nucleic Acid-Based identification methods detect virus-specific DNA sequences, which are extracted from the microorganism. These tests are considered specific and highly sensitive. The government of China has said that from now onwards, the “confirmed” and “suspected” cases will be differentiated only based on such genetic tests. In this manner, the false cases may be discarded, and a more realistic number may come into the picture.
The Nucleic Acid-Based tests have their shortcomings, as they are difficult to be conducted and take at least two days for processing the test data. Several public health professionals are pessimistic about adopting the genetic testing method for Coronavirus, as it has also produced wrong results in the past.