GI symptoms plus loss of taste, smell, fever highly specific to COVID-19
While gastrointestinal symptoms like anorexia and diarrhea are common in both patients with COVID-19 and those without, these symptoms plus a loss of smell, taste and fever were 99% specific for COVID-19, according to a study published in Gastroenterology.
“Current testing guidelines should highlight the symptoms of loss of smell, taste, fever, anorexia and diarrhea as highly specific for COVID-19 infection,” Alan Chen, MD, from the Institute of Digestive Health and Liver Diseases at Mercy Medical Center and the department of medicine at the University of Maryland School of Medicine in Baltimore, and colleagues said.
Prevalence of GI symptoms in COVID-19
Chen and colleagues performed a prospective case-control study of 340 adult patients who tested positive (n = 101) or negative (n = 239) for COVID-19 by nasopharyngeal swab from March 9, 2020, to April 15, 2020. Investigators conducted a telephone survey to gather information on demographics, comorbid conditions, GI, respiratory, fever, gustatory, olfactory symptoms, and need for hospitalization using a predesigned questionnaire. The prevalence of GI symptoms in COVID-19 positive and negative patients served as the primary outcome. Other outcomes included determining the utility of GI symptoms for screening for COVID-19 and the correlation between GI symptoms and the need for hospitalization. Logistic regression was performed to assess risk factors of COVID-19. Then, the area under the receiver operating characteristic (AUROC) for COVID-19 was determined with the use of a combination of different symptoms.
Investigators reported COVID-19 patients were mostly men, had higher BMI and were less likely to smoke. However, comorbidities were similar between COVID-19 positive and negative patients. GI symptoms were more common among patients with COVID-19 compared with COVID-19 negative patients (74% vs. 53%). Anorexia (53% vs 26%) and diarrhea (50% vs 30%) were more likely seen in COVID-19 patients compared with negative patients. Nausea, vomiting, abdominal pain and hematochezia were similar between the groups. COVID-19 positive patients were more likely to have loss of smell or taste (67% vs. 14%) and fever (65% vs. 44%).
Combination of symptoms specific to infection
Results showed there was no significant difference between COVID-19 positive and negative patients regarding the median duration of symptoms before COVID-19 testing. Additionally, there was no significant difference in COVID-19 patients with or without any GI symptoms regarding hospitalization and mean days to testing.
According to multivariable analysis, African American (OR = 2.62; 95% CI, 1.38-4.99) and men (OR = 3.23; 95% CI, 1.68-6.2) tested positive more often for COVID-19. Symptoms more likely correlated with COVID-19 included loss of smell (OR = 8.29; 95% CI, 3.56-19.28) or taste (OR = 3.41; 95% CI, 1.53-7.61) and fever (OR = 2.14, 95% CI, 1.17-3.92). Multivariable analyses found diarrhea and anorexia alone were not specific symptoms for COVID-19 infection; however, the specificity for COVID-19 infection was 99% when patients had diarrhea and anorexia symptoms in addition to fever, loss of smell and taste. Moreover, the negative predictive value was 75%. Investigators found the specificity was marginally lower when patients had fever with a loss of smell or taste.
“Furthermore, patients without any symptoms of fever, loss of smell, taste, diarrhea and anorexia had a negative predictive value of 75% (specificity 99%) for not having COVID-19 infection,” the authors wrote. “The negative predictive value is likely to improve as the prevalence of disease decreases with increased testing making the screening of these symptoms even more important.”