Recent smell loss is the best predictor of COVID-19 among individuals with recent respiratory symptoms

In a preregistered, cross-sectional study we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC=0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0-10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4<10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable

Evaluation de l’applicabilité du "Sniffin’Stick test" dans la population africaine sub-saharienne du Sud-Kivu (R.D.Congo)

The olfactory disorders, formerly neglected, were recognized worldwide with the COVID-19 outbreak. Management of olfactory disorders requires appropriate tools of investigation. The Sniffin`Sticks test is widely used in Europe as a standard test to assess olfaction. However, up to now, there is no version adapted to Sub-Saharan African populations. This PhD thesis aimed at assessing the applicability of the Sniffin`Sticks test in the population of South-Kivu. Overall, we conducted three studies. In the first study, we selected odours that were poorly recognised in the identification test with the standard version of the Sniffin'stick test and proposed to replace them with culturally appropriate odours in an adapted version. In the second study, we found that the adapted version led to a higher rate of correctly identified odours and we defined normative values for the South Kivu population. In the third study, using the adapted version, we found that hyposmia predominated when the cause was an upper respiratory tract infection, while anosmia predominated when the cause was non-infectious. Our results point to the necessity of adapting the Sniffin`Sticks test by using both adapted odors and normative values specific to this population.Les troubles olfactifs, autrefois négligés, ont été reconnus dans le monde entier avec l'épidémie de COVID-19. La prise en charge des troubles olfactifs nécessite des outils d'investigation adaptés. Le Sniffin`Sticks test est largement utilisé en Europe comme test standard pour évaluer l'olfaction. Cependant, à ce jour, il n'existe pas de version adaptée aux populations d'Afrique subsaharienne. Cette thèse de doctorat visait à évaluer l'applicabilité du Sniffin`Sticks test dans la population du Sud-Kivu. Dans l'ensemble, nous avons mené trois études. Dans la première étude, nous avons sélectionné des odeurs mal reconnues lors du test d'identification avec la version standard du Sniffin’stick test et avons proposé de les remplacer par des odeurs culturellement appropriées dans une version adaptée. Dans la deuxième étude, nous avons constaté que la version adaptée conduisait à un taux plus élevé d'odeurs correctement identifiées et nous avons défini des valeurs normatives pour la population du Sud-Kivu. Dans la troisième étude, en utilisant la version adaptée, nous avons constaté que l'hyposmie prédominait lorsque la cause était une infection des voies respiratoires supérieures, alors que l'anosmie l'était lorsque la cause était non infectieuse. Nos résultats soulignent la nécessité d'adapter le Sniffin`Sticks test en utilisant à la fois des odeurs adaptées et des valeurs normatives propres à cette population.(MED - Sciences médicales) -- UCL, 202

Assessing olfactory function in patients with smell disorders in the South Kivu province of the Democratic Republic of Congo

Objective: Olfactory disorders may be associated with different etiologies, including upper respiratory infections, sinonasal conditions, head injuries, exposure to toxins, and congenital anosmia. This study aimed to evaluate the prevalence of different etiologies for olfactory dysfunction as observed in a sub-Saharan African population. Methods: This descriptive cross-sectional study was conducted in a series of 116 consecutive patients with an olfactory disorder who lived in the city of Bukavu in the South Kivu province of the Democratic Republic of the Congo. The study was conducted from June 1, 2016 to May 30, 2017. We used the Sniffin’ Sticks test, adapting the identification (I) test to our population but retaining the standard threshold (T) and discrimination (D) tests. The patients were classed as anosmic if their composite T + D + I score was 30. Informed consent was obtained in accordance with the Declaration of Helsinki II. We calculated proportions for each olfactory disorder. Results: Median age (minimum–maximum) in our 116 patients was 42.5 (18–83) years. Women made up 60% of our sample. It was observed that 70.7% of patients had anosmia and 29.3% hyposmia. In descending order, the main causes were upper respiratory infections (49.1%), congenital causes (34.5%), nasal polyps (6%), nose and/or sinus surgery (3.4%), head injuries (2.6%), metabolic causes (2.6%), and occupational exposure to toxins (1.7%). Hyposmia predominated when the cause was upper respiratory infection, whereas anosmia did when the cause was congenital and noninfectious. Conclusion: In our study population, upper respiratory infections were the main cause of dysosmia. The anosmic cases we observed tended to be congenital in nature, suggesting that there existed other etiological factors that require further investigation

Adaptation of the Sniffin’ Sticks Test in South-Kivu

AIM: The "Sniffin' Sticks" test is widely used in Europe as a standard test to assess olfaction. Several culturally-adapted versions have been developed. However, no version adapted to Sub-Saharan African populations exists. The aims of the present study were (1) to assess the applicability of the Sniffin' Sticks test in the population of South Kivu (DR Congo), and (2) to develop a culturally adapted version with normative values. MATERIALS AND METHODS: In a first study, 157 volunteers were tested with the original Sniffin' Sticks test. Based on these results, we selected odors that were poorly recognized in the identification test and replaced them by culturally adapted odors. In a second study, we assessed the modified version of the Sniffin' Sticks test in 150 volunteers and defined normative values. RESULTS: In the first study, we found that olfactory function (threshold-discrimination-identification: TDI score) significantly decreased with age and was better in females. Five odors were poorly recognized and were replaced by culturally adapted odors. In the second study, we found that this adapted version led to a higher rate of correctly identified odors. We defined normative values for the South-Kivu population (TDI score: 18-35 years: 30.4±6.0; 36-55 years: 26.2±5.3; >55 years: 25.6±5.0). CONCLUSION: This culturally adapted version of the Sniffin' Sticks test is culturally adapted to the South Kivu population. The normative values will provide the basis for clinical evaluation of pathologic subjects

The outcome of pectoralis major myocutaneous flap in the reconstruction of large defects in the lower face region after high velocity gunshot injury in the eastern part of DR Congo.

INTRODUCTION : Severe ballistic injuries to the face are common occurrence in South-Kivu province in the eastern Democratic Republic of the Congo (DRC) due to the 20 years’ unrest. High velocity ballistic injury creates large, complex and composite defects. Large soft tissue defects of the lower face actually rise concern as it is associated with cosmetic and functional deficits with that impact on patient's quality deeper than injuries in other areas of the body. [...

The best COVID-19 predictor is recent smell loss: a cross-sectional study

Background: COVID-19 has heterogeneous manifestations, though one of the most common symptoms is a sudden loss of smell (anosmia or hyposmia). We investigated whether olfactory loss is a reliable predictor of COVID-19. Methods: This preregistered, cross-sectional study used a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified singular and cumulative predictors of COVID-19 status and post-COVID-19 olfactory recovery. Results: Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both single and cumulative feature models (ROC AUC=0.72), with additional features providing no significant model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms, such as fever or cough. Olfactory recovery within 40 days was reported for ~50% of participants and was best predicted by time since illness onset. Conclusions: As smell loss is the best predictor of COVID-19, we developed the ODoR-19 tool, a 0-10 scale to screen for recent olfactory loss. Numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (10<OR<4), especially when viral lab tests are impractical or unavailable