Self-Reported Symptom Study of COVID-19 Chemosensory Dysfunction in Malaysia

Abstract

Alterations in the three chemosensory modalities – smell, taste, and chemesthesis – have been implicated in Coronavirus Disease 2019 (COVID-19), yet emerging data suggest a wide geographic and ethnic variation in the prevalence of these symptoms. Studies on chemosensory disorders in COVID-19 have predominantly focused on Caucasian populations whereas Asians remain understudied. We conducted a nationwide, multicentre cross-sectional study using an online questionnaire on a cohort of RT-PCR-confirmed adult COVID-19 patients in Malaysia between 6 June to 30 November 2020. The aim of our study was to investigate their presenting symptoms and assess their chemosensory function using self-ratings of perceived smell, taste, chemesthesis, and nasal blockage. In this cohort of 498 patients, 41.4% reported smell and/or taste loss when diagnosed with COVID-19, which was the commonest symptom. Blocked nose, loss of appetite, and gastrointestinal disturbances were independent predictors of smell and/or taste loss on multivariate analysis. Self-ratings of chemosensory function revealed a reduction in smell, taste, and chemesthesis across the entire cohort of patients that was more profound among those reporting smell and/or taste loss as their presenting symptom. Perceived nasal obstruction accounted for only a small proportion of changes in smell and taste, but not for chemesthesis, supporting viral disruption of sensorineural mechanisms as the dominant aetiology of chemosensory dysfunction. Our study suggests that chemosensory dysfunction in COVID-19 is more widespread than previously reported among Asians and may be related to the infectivity of viral strains. Study Registration: NMRR-20-934-54803 and NCT04390165

Smell, taste and chemesthesis disorders in patients with the SARS-CoV-2 Omicron variant in China

“…The questionnaire was adapted from existing online questionnaires developed by the Global Consortium for Chemosensory Research (GCCR) (5) . The GCCR core questionnaire has been implemented in 10 languages as of April 18, 2020, and used or adapted in many other research studies (4,26,27) . Data collected included demographic information, COVID-19-related characteristics, and patient chemosensory situations, before and during infection.…”

“…There are reports that chemosensory disorders are important symptoms of COVID-19 infection (3–5) . Studies from the United States, Europe, Malaysia, and Singapore demonstrated that 12%– 88% of COVID-19-infected patients have olfactory and taste disorders (4,6–8) , while studies from China reported that 5%–25% of patients have smell and/or taste disorder (9,10) . The Omicron variant of SARS-CoV-2 was first detected in South Africa in November 2021, and became the main epidemic strain in the world by 15 January 2022 (11,12) .…”