Tropical Medicine Center, Federal University of Pará, Belém, Brazil.
Biological and Health Center, Pará State University, Belém, Brazil.
JAMA Netw Open. 2022 Sep 1;5(9):e2230637. doi: 10.1001/jamanetworkopen.2022.30637.
Determining the characteristics, type, and severity of olfactory dysfunction in patients with long COVID is important for the prognosis and potential treatment of the affected population.
To describe the sociodemographic and clinical features of patients with long COVID who develop persistent olfactory dysfunction.
DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study, conducted at a rehabilitation center at a public university in the Amazon region of Brazil between September 9, 2020, and October 20, 2021, comprised 219 patients with long COVID and self-reported neurologic symptoms. Of these 219 patients, 139 received a diagnosis of chronic olfactory dysfunction, as confirmed by the Connecticut Chemosensory Clinical Research Center (CCCRC) test.
Clinical diagnosis of long COVID.
Electronic case report forms were prepared for the collection of sociodemographic and clinical data. Patients' sense of smell was evaluated via a CCCRC test, and the association of olfactory dysfunction with aspects of daily life was recorded using a questionnaire.
Of the 219 patients included in the study, 164 (74.9%) were women, 194 (88.6%) were between 18 and 59 years of age (mean [SD] age, 43.2 [12.9] years), 206 (94.1%) had more than 9 years of education, and 115 (52.5%) had a monthly income of up to US $192.00. In the study group, 139 patients (63.5%) had some degree of olfactory dysfunction, whereas 80 patients (36.5%) had normosmia. Patients with olfactory dysfunction had a significantly longer duration of long COVID symptoms than those in the normosmia group (mean [SD], 242.7 [101.9] vs 221.0 [97.5] days; P = .01). Among patients with anosmia, there was a significant association between olfactory dysfunction and daily activities, especially in terms of impairment in hazard detection (21 of 31 patients [67.7%]), personal hygiene (21 of 31 patients [67.7%]), and food intake (21 of 31 patients [67.7%]). Univariable logistic regression analyses found that ageusia symptoms were associated with the occurrence of olfactory dysfunction (odds ratio [OR], 11.14 [95% CI, 4.76-26.07]; P < .001), whereas headache (OR, 0.41 [95% CI, 0.22-0.76]; P < .001) and sleep disorders (OR, 0.48 [95% CI, 0.26-0.92]; P = .02) showed an inverse association with the occurrence of olfactory dysfunction.
Olfactory dysfunction is one of the most important long-term neurologic symptoms of COVID-19, with the highest prevalence seen among women, adults, and outpatients. Patients with olfactory dysfunction may experience persistent severe hyposmia or anosmia more than 1 year from the onset of symptoms, suggesting the possibility of the condition becoming a permanent sequela.
确定长新冠患者嗅觉功能障碍的特征、类型和严重程度对于预测和潜在治疗受影响人群的预后非常重要。
描述出现持续性嗅觉功能障碍的长新冠患者的社会人口学和临床特征。
设计、地点和参与者：这是一项横断面研究，在巴西亚马逊地区一所公立大学的康复中心进行，时间为 2020 年 9 月 9 日至 2021 年 10 月 20 日，共纳入 219 名出现长新冠和自述神经症状的患者。其中 139 名患者通过康涅狄格化学感觉临床研究中心（CCCRC）测试被确诊为慢性嗅觉功能障碍。
长新冠的临床诊断。
通过电子病例报告表收集社会人口学和临床数据。通过 CCCRC 测试评估患者的嗅觉，使用问卷记录嗅觉功能障碍与日常生活方面的关联。
在纳入研究的 219 名患者中，164 名（74.9%）为女性，194 名（88.6%）年龄在 18 至 59 岁之间（平均[SD]年龄为 43.2[12.9]岁），206 名（94.1%）受教育年限超过 9 年，115 名（52.5%）月收入在 192 美元以下。在研究组中，139 名（63.5%）患者存在不同程度的嗅觉功能障碍，80 名（36.5%）患者嗅觉正常。嗅觉功能障碍患者的长新冠症状持续时间明显长于嗅觉正常组（平均[SD]，242.7[101.9]vs 221.0[97.5]天；P = .01）。在嗅觉丧失患者中，嗅觉功能障碍与日常活动之间存在显著关联，尤其是在危险察觉（31 名患者中的 21 名[67.7%]）、个人卫生（31 名患者中的 21 名[67.7%]）和食物摄入（31 名患者中的 21 名[67.7%]）方面。单变量逻辑回归分析发现，味觉障碍症状与嗅觉功能障碍的发生相关（比值比[OR]，11.14[95%CI，4.76-26.07]；P < .001），而头痛（OR，0.41[95%CI，0.22-0.76]；P < .001）和睡眠障碍（OR，0.48[95%CI，0.26-0.92]；P = .02）与嗅觉功能障碍的发生呈负相关。
嗅觉功能障碍是新冠病毒感染后最常见的长期神经症状之一，在女性、成年人和门诊患者中最为常见。嗅觉功能障碍患者在症状出现 1 年以上可能会持续出现严重的嗅觉减退或嗅觉丧失，提示该疾病可能成为永久性后遗症。
