Research on loss of smell and taste due to COVID-19

A loss of the capacity to smell and taste has been identified by the World Health Organization (WHO) and the Netherlands National Institute for Public Health and the Environment (RIVM) as a possible symptom of COVID-19, the disease caused by the new coronavirus SARS-CoV-2. While loss of flavor perception has been mentioned by patients in a number of small-scale studies by doctors, no reliable figures are available to date on how often these symptoms occur and at what stage of the disease. It is also unclear which sensory system the virus affects: the sense of smell in the nose, or the taste buds on the tongue.

Worldwide data collection

The Global Consortium of Chemosensory Research (GCCR) aims to answer these questions by collecting data in a uniform manner worldwide on the symptoms of anyone who may have had COVID-19 in the past two weeks.

“With statistically reliable information, we may be able to use the loss of smell and taste in the early diagnosis of COVID-19 and thus as a means to prevent its spread,” says Sanne Boesveldt, coordinator of the study in the Netherlands and associate professor at Wageningen University & Research. “Once we have this information, we may know enough to immediately guide people with these symptoms into home isolation or to a dedicated department in the hospital.”

Questionnaire

The GCCR invites everyone who thinks they have had COVID-19 in the past two weeks to complete the questionnaire, which consists of questions such as: ‘Do you find chili pepper to be more or less spicy?’ 'Does garbage smell less bad than usual?' and 'Have you been diagnosed with COVID-19?' In addition, participants are asked whether they suffer from other conditions that may be associated with a loss of smell and taste, such as hay fever or diabetes – this is to ensure that the symptoms are in fact caused by COVID-19. 

Answering the questions takes about 10 minutes. The questionnaire is available in more than 20 languages, including Dutch, on https://gcchemosensr.org/. The questions can also be answered on a smartphone via a QR code. The survey will be complemented with a home test before the summer: this will allow people to use products from their kitchen or bathroom cupboard to assess whether their smell and taste have improved or worsened.