A Case Series of Patients Suspected to Have Covid-19 Based on Clinical Features, Laboratory Markers and Imaging Studies but Who Were RT-PCR Negative

Abstract

BACKGROUND Real-time reverse transcription polymerase chain reaction (rRTPCR) test is the gold standard assay to diagnose Covid-19 in-spite of few concerns. The disease is suspected in patients presenting with clinical features suggestive of Covid-19 supported by laboratory markers and imaging studies. We describe a case series of ten patients suspected to have SARS CoV-2 infection but RTPCR negative. METHODS We carried out a retrospective observational study of patients who presented with clinical features suggestive of Covid-19 but were RTPCR negative. As dedicated Covid hospitals, RTPCR negative patients were not admitted because of overload. We admitted such patients in isolation ward in non Covid hospitals, evaluated them further with laboratory biomarkers, and imaging studies. All patients were categorised in disease severity and were managed according to guidelines of Ministry of Health and Family Welfare (MoHFW) India. RESULTS Our case series included ten patients with a mean age of 55.1 years and the male to female ratio was 1.5:1. All patients (100 %) were suspected to have SARS CoV2 infection. Commonest symptom was fever in all (100 %) and least common was diarrhoea in 30 % patients. Mean SpO2 was 92.5 % on pulse oximeter (range 91 to 94 %). The laboratory findings showed (median): white blood cell count 9400 / cumm, N / L ratio 3.78, C-reactive protein (CRP) 46.21 mg / L, D-dimer 465 ng / mL, lactate dehydrogenase 499.59 U / L, serum ferritin 160.55 ng / mL, interleukin 6 31.6 pg / mL. Chest radiograph showed patchy non homogenous opacities in lungs in 6 (60 %) out of 10 patients, high resolution computed tomography (HRCT) chest revealed peripheral ground glass opacities (GGOs) in 10 (100 %) patients, Coronavirus Disease 2019 Reporting and Data System (CORADS) score was 5 in 8 (80 %) patients and less than 5 in 2 (20 %) patients. CONCLUSIONS In current pandemic, patients presenting with clinical features suggestive of Covid19, but RT-PCR negative should be suspected to have SARS CoV-2 infection, further evaluation with laboratory markers and imaging study help in diagnosis. Managing and monitoring according to MoHFW guidelines show good clinical recovery. KEYWORDS Corona Virus Disease (Covid-19), Real-Time Reverse Transcription Polymerase Chain Reaction (RT-PCR), High Resolution Computed Tomography (HRCT), Chest X-Ray (CXR)