The Malaysian COVID-19 Anosmia Study is a nationwide multicentre observational study to investigate the prevalence and characteristics of olfactory and gustatory/taste disturbances in COVID-19 infection in Malaysia, and to evaluate the predictive value of screening for these symptoms in COVID-19 infection. This study consists of two phases: the first phase is a cross-sectional study and the second phase is a case-control study. The case-control study is described here (the cross-sectional study is described in a separate ClinicalTrials.gov record).
The world is currently in the midst of the Coronavirus 2019 (COVID-19) pandemic that is
caused by a novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).
According to published cohort studies on COVID-29 infected patients, the most prevalent
symptoms consist of fever, dry cough, dyspnoea, sputum production, myalgia, arthralgia,
headache, diarrhoea, and sore throat. Recently, there have been concerns of significant viral
transmission through asymptomatic, pre-symptomatic or even mildly symptomatic patients.
There is increasing anecdotal evidence from patients and healthcare professionals
highlighting isolated loss of sense of smell (anosmia) and taste disturbances (dysgeusia) as
atypical symptoms of COVID-19 infection in otherwise asymptomatic patients. In parallel,
expert statements from the British Association of Otorhinolaryngology-Head & Neck Surgery
(ENT UK), British Rhinological Society, and the American Association of Otolaryngology-Head &
Neck Surgery (AAO-HNS) have suggested that olfactory and taste disturbances could be a
clinical feature of COVID-19 infection.
Rapidly emerging evidence from Europe, the United Kingdom and the United States have found
olfactory and taste disturbances to be highly prevalent in patients diagnosed with COVID-19.
In contrast, there is currently limited evidence from Asia on the prevalence of these
symptoms in COVID-19 infection. Additionally, there is also limited evidence on the
predictive value of screening for olfactory and taste disturbance in COVID-19 patients with
subclinical symptoms.
The aim of this case-control study is to study the predictive value of screening for
olfactory and taste disturbance in patients with COVID-19 infection in Malaysia. The cases
will be selected from the cohort of COVID-19 positive patients recruited from participating
Malaysian Ministry of Health-designated COVID-19 treating hospitals across the country (from
Phase 1 of the Malaysian COVID-19 Anosmia Study). Controls will be recruited from healthy
volunteers who will will answer the an online questionnaire to evaluate and characterise
their olfactory and taste symptoms. This is the same questionnaire that is answered by the
COVID-19 patients in case cohort.
Other: Patient-Reported Online Questionnaire on Olfactory & Taste Disturbances
This is an online patient-reported questionnaire that examines the presence or absence of olfactory and taste disturbances, the onset of olfactory and taste disturbances in relation to other COVID-19 symptoms, and the temporal evolution of the severity of olfactory and taste disturbances. The occurrence of ear symptoms in COVID-19 infection will also be evaluated in this questionnaire as a secondary outcome. The questionnaire will also have questions relating to the patient's underlying health conditions, risk factors for COVID-19 infection, and demographics.
Inclusion Criteria:
1. Age at least 18 years old
2. For Cases: Laboratory confirmed COVID-19 infection [Reverse Transcription Polymerase
Chain Reaction (RT-PCR)]
3. Patients clinically able to answer the questionnaire
Exclusion Criteria:
1. Patients with olfactory or taste/gustatory disorders before the COVID-19 epidemic
2. For Cases: Patients without a laboratory-confirmed COVID-19 diagnosis
3. For Cases: Patients in intensive care unit at the time of study
Hospital Enche' Besar Hajjah Khalsom
Kluang, Johor, Malaysia
Hospital Sultanah Bahiyah
Alor Setar, Kedah, Malaysia
Hospital Raja Perempuan Zainab II
Kota Bharu, Kelantan, Malaysia
Hospital Tuanku Jaafar
Seremban, Negeri Sembilan, Malaysia
Hospital Tengku Ampuan Afzan
Kuantan, Pahang, Malaysia
Penang Hospital
George Town, Penang, Malaysia
Hospital Raja Permaisuri Bainun
Ipoh, Perak, Malaysia
Hospital Tuanku Fauziah
Kangar, Perlis, Malaysia
Hospital Queen Elizabeth
Kota Kinabalu, Sabah, Malaysia
Sarawak General Hospital
Kuching, Sarawak, Malaysia
Hospital Sungai Buloh
Sungai Buloh, Selangor, Malaysia
Hospital Sultanah Nur Zahirah
Kuala Terengganu, Terengganu, Malaysia
Kuala Lumpur General Hospital
Kuala Lumpur, Malaysia
Hospital Melaka
Melaka, Malaysia
Siti Sabzah Mohd Hashim, MD MS
+604 740 7335
dr_ctsabzah@yahoo.com
Shen-Han Lee, MB PhD MRCS
+6016 474 0088
shen-han.lee@cantab.net
Siti Sabzah Mohd Hashim, MD MS, Study Chair
Hospital Sultanah Bahiyah