Simultaneously complete but not partial taste and smell losses were associated with SARS-CoV-2 infection

OBJECTIVES: The aim of this study was to investigate the association between taste and smell losses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and to elucidate whether taste preference influences such taste loss. METHODS: A matched case–control study was conducted in 366 Thai participants, including 122 who were confirmed SARS-CoV-2-positive by RT-PCR (case group) and 244 who were SARS-CoV-2-negative (control group). Taste, smell, and appetite changes were assessed by self-reported visual analog scale. Preference for sweet, salty, umami, sour, bitter, and spicy were judged using the validated TASTE-26 questionnaire. RESULTS: Partial taste and smell losses were observed in both groups, while complete losses (ageusia and anosmia) were detected only in the case group. Moreover, only ageusia and anosmia were associated with SARS-CoV-2 positivity (P < 0.001, odds ratio of 14.5 and 27.5, respectively). Taste, smell, and appetite scores were more severely reduced in the case group (P < 0.0001). Multivariate analysis showed that anosmia and ageusia were the best predictors of SARS-CoV-2 positivity, followed by appetite loss and fever. Simultaneous losses of taste and smell but not taste preferences were associated with SARS-CoV-2 positivity (P < 0.01, odds ratio 2.28). CONCLUSIONS: Complete, but not partial, losses of taste and smell were the best predictors of SARS-CoV-2 infection. During the current COVID-19 pandemic, healthy persons with sudden simultaneous complete loss of taste and smell should be screened for COVID-19.