<p>Karnataka on Thursday officially recognised a new category of patients with "Covid-19 Like Syndrome", who test negative for Covid-19 in RT-PCR but are later found to have serious Covid-like illness through high-resolution CT (HRCT) scan.</p>.<p>In a new circular to diagnose 'Covid-19 probable' cases, the government suggested a four-pronged approach to identify such patients: Clinical, radiological, blood investigations and nasal and throat swab.</p>.<p>The state will employ Covid-19 Reporting And Data (CORAD), a new method to assess the risk factor of such patients. CORAD score is a CT scan-based system that is used to assess the suspicion of pulmonary involvement in Covid-19. A score ranging from 3 to 6 means the level of suspicion is 'equivocal' to 'very high', meaning 'features are compatible with Covid-19' or are 'typical of Covid-19'.</p>.<p>Based on the official assessment, DH on October 15 highlighted that up to 5% of total Covid cases may test negative in RT-PCR but are found to have serious infections through HRCT and later test positive for the disease.</p>.<p>Noting that identifying such false-negative patients was crucial to prevent mortality and infection, the government has stressed the need to conduct an HRCT scan.</p>.<p>Now, if a patient has clinical features suggestive of Covid-19, a CORAD of 5 and blood investigations suggest markers above certain values, and an RT-PCR negative report, then he/she will be considered a 'Covid-19 Probable Case'.</p>.<p>"With the increase in the spread of Covid-19 and increase in the number of tests every day, the percentage of False Negative Reports are increasing and it's expected to increase further in future," the circular stated.</p>.<p>It goes on to say, "And many times, in spite of clinical-radiological features suggestive of Covid-19 disease, the RTPCR test, which is considered as Gold Standard Test, maybe negative." With sensitivity and specificity of RT-PCR tests for nasal and throat swab ranging between 60-70%, we may miss many positive cases, i.e., get false negative reports.</p>.<p>Rapid Antigen Detection test, which is recommended by the ICMR has shown sensitivity (ability to detect true positives) ranging from 50.6% to 84% and specificity (ability to detect true negatives) of 99.3% to 100%, after two independent evaluations. Additionally, several retrospective studies have shown that CT Thorax (chest) has greater sensitivity (86%-98%) and lower false-negative rate than RT-PCR.</p>.<p>Hence, a proxy syndrome, called "Covid-19 Like Syndrome" (or) Covid-19 Probable case, has to be used to identify such cases with a correlation of clinical features, CT Thorax findings and laboratory investigations, to initiate treatment similar in lines to Covid-19 confirmed cases as early as possible.</p>.<p>All government and private health establishments treating Covid-19 should strictly adhere to the above approach, in the larger interest of reducing mortality due to Covid-19, the circular said.</p>
<p>Karnataka on Thursday officially recognised a new category of patients with "Covid-19 Like Syndrome", who test negative for Covid-19 in RT-PCR but are later found to have serious Covid-like illness through high-resolution CT (HRCT) scan.</p>.<p>In a new circular to diagnose 'Covid-19 probable' cases, the government suggested a four-pronged approach to identify such patients: Clinical, radiological, blood investigations and nasal and throat swab.</p>.<p>The state will employ Covid-19 Reporting And Data (CORAD), a new method to assess the risk factor of such patients. CORAD score is a CT scan-based system that is used to assess the suspicion of pulmonary involvement in Covid-19. A score ranging from 3 to 6 means the level of suspicion is 'equivocal' to 'very high', meaning 'features are compatible with Covid-19' or are 'typical of Covid-19'.</p>.<p>Based on the official assessment, DH on October 15 highlighted that up to 5% of total Covid cases may test negative in RT-PCR but are found to have serious infections through HRCT and later test positive for the disease.</p>.<p>Noting that identifying such false-negative patients was crucial to prevent mortality and infection, the government has stressed the need to conduct an HRCT scan.</p>.<p>Now, if a patient has clinical features suggestive of Covid-19, a CORAD of 5 and blood investigations suggest markers above certain values, and an RT-PCR negative report, then he/she will be considered a 'Covid-19 Probable Case'.</p>.<p>"With the increase in the spread of Covid-19 and increase in the number of tests every day, the percentage of False Negative Reports are increasing and it's expected to increase further in future," the circular stated.</p>.<p>It goes on to say, "And many times, in spite of clinical-radiological features suggestive of Covid-19 disease, the RTPCR test, which is considered as Gold Standard Test, maybe negative." With sensitivity and specificity of RT-PCR tests for nasal and throat swab ranging between 60-70%, we may miss many positive cases, i.e., get false negative reports.</p>.<p>Rapid Antigen Detection test, which is recommended by the ICMR has shown sensitivity (ability to detect true positives) ranging from 50.6% to 84% and specificity (ability to detect true negatives) of 99.3% to 100%, after two independent evaluations. Additionally, several retrospective studies have shown that CT Thorax (chest) has greater sensitivity (86%-98%) and lower false-negative rate than RT-PCR.</p>.<p>Hence, a proxy syndrome, called "Covid-19 Like Syndrome" (or) Covid-19 Probable case, has to be used to identify such cases with a correlation of clinical features, CT Thorax findings and laboratory investigations, to initiate treatment similar in lines to Covid-19 confirmed cases as early as possible.</p>.<p>All government and private health establishments treating Covid-19 should strictly adhere to the above approach, in the larger interest of reducing mortality due to Covid-19, the circular said.</p>
