key: cord-0994468-0j0zlhs0
authors: Raveendran, A.V.
title: Long COVID-19: Challenges in the diagnosis and proposed diagnostic criteria
date: 2020-12-15
journal: Diabetes Metab Syndr
DOI: 10.1016/j.dsx.2020.12.025
sha: 51d66331839c48dc4fccce7ca0f9e06b22467332
doc_id: 994468
cord_uid: 0j0zlhs0

nan

Reports from various parts of the world show that significant proportion of people who recovered from COVID-19 suffers from various health issues which are collectively called "long COVID-19" or post COVID-19 syndrome. The common symptoms include fatigue, breathlessness, cough, joint pain, chest pain, muscle aches, headaches and so on. Even though collectively called long COVID-19, researchers identified that it is a collection of at least 4 distinct clinical entities which are post-intensive care syndrome, post-viral fatigue syndrome, permanent organ damage, and long-term COVID-19 syndrome [1] . In our experience in addition to these we identified that drug related side effects, complications of COVID-19 (like pneumothorax, pneumomediastinum, vascular thrombosis leading to pulmonary thromboembolism, myocardial infarction, stroke etc), post-COVID-19 psychological issues and other infections (bacterial ,other viral ,fungal or re-infection with SARS-CoV-2 itself) can also cause similar symptoms in COVID-19 recovered patients. Careful evaluation to rule out causes unrelated to COVID-19 is important to offer correct treatment.

In people infected with SARS-CoV-2, 80% of infections are mild or asymptomatic, 15% are severe infection and 5% are critical infections [2] . Usually in people with mild disease symptoms resolve within 2 weeks, where as in severe illness it may persist for 3-6 weeks [3] . Presence of long COVID-19 challenges the assumption that "mild" disease recover within 2 weeks [4] .

There are lots of challenges in the diagnosis of long COVID-19. Those who had history of typical symptoms of acute COVID-19 with positive throat swab RT-PCR, presenting with long duration symptoms, the diagnosis of long COVID is straight forward. But those with acute COVID-19 symptoms and negative throat swab RT-PCR, presenting with long symptoms pose real challenge in day to day clinical practice. Significant proportions of SARS-CoV-2 infected individuals are asymptomatic. And development of long COVID-19 symptoms in those asymptomatic individuals adds to the diagnostic confusion. Similarly the duration of acute symptoms vary in patients again adding confusion to differentiate acute COVID-19 from long COVID-19. Based on our experience and after reviewing relevant literature, we are proposing criteria for the diagnosis of long COVID-19 (table 1) . Anytime in doubtful cases (Note: Those who did not undergo throat swab RT-PCR or antibody testing also considered as test negative)

Clinical criteria ( symptoms of Long COVID-19) after defined time period in presence of essential criteria ( evidence of preceding SARS-CoV-2 infection ) helps to categorise long COVID-19 as confirmed, probable, possible or doubtful long COVID-19 syndrome (table 2) . 

Living with covid-19. A dynamic review of the evidence around ongoing covid-19 symptoms (often called long covid)

Clinical features of patients infected with 2019 novel coronavirus in Wuhan

World Health Organization (WHO)

World Health Organization

Long covid could be four different syndromes, review suggests

J o u r n a l P r e -p r o o f