Evolution of olfactory and gustatory dysfunctions in COVID-19 patients in India

The ongoing coronavirus disease 19 (COVID-19) pandemic is spreading at an alarming rate across the globe. Sudden onset loss of smell and/or taste has been increasingly reported as a symptom of COVID-19. However, prevalence of these symptoms, and its severity varies widely between studies, with little data on its duration and recovery rate. Since this significantly impacts the quality of life of patients, there is a need for a study to provide insight into the loss of smell or taste in terms of its correlation with other upper respiratory tract symptoms, natural history and resolution rates.

This cross-sectional study included 718 mild to moderately symptomatic adult patients (≥ 18 years), admitted consecutively to Kalinga Institute of Medical Sciences (KIMS), Odisha, India between June 25 and July 24, 2020, who tested positive for SARS-CoV-2 by polymerase chain reaction on nasopharyngeal and throat swabs. Prevalence, severity, duration and factors associated with altered smell or taste sensation, and their follow-up were recorded.

Of the 718 patients included in the study at baseline [563 (78%) men; median age 34 years], 101 (14%) patients experienced either altered smell or taste, with 52 (7%) experiencing both altered smell and taste. Seventy-seven (10.7%) patients had altered smell and 76 patients had altered taste (10.5%). Of these, 71 (92%) and 73 (96%) regained their sense of smell and taste, respectively, by 14 days after their swab tested positive. Presence of fever (OR = 5.4, 95% CI = 2.7-10.6, p < 0.001), cough (OR = 2.3, 95% CI = 1.2-4.2, p = 0.009) and nasal obstruction (OR = 3.1, 95% CI = 1.4-6.7, p = 0.006) were independently associated with increased likelihood of experiencing both altered taste and smell in multivariable models.

The prevalence of altered smell and taste in Indians was much lower compared to Europeans and similar to East Asians. Majority regained these senses by 2 weeks. Identification of these symptoms can help in early detection of the disease in suspected individuals.