CMAAO IMA HCFI Corona Myth Buster 21

Loss of Smell & Taste is not a screening test

NEJM: The American Academy of Otolaryngology — Head & Neck Surgery has proposed to add anosmia and dysgeusia to the list of screening items for potential COVID-19 disease.

Informally, these symptoms have been noted among some patients whove tested positive for COVID-19, and in some cases, anosmia was the only symptom.

Depression is uncommon in COVID-19

JAMA Network Open study of 1300 healthcare workers in China (mostly from Hubei) in late January and early February noted that 50% of the subjects had symptoms of depression, 45% had anxiety, 34% had insomnia, and 72% had symptoms of distress. Nurses, women, frontline workers, and those in Wuhan had more severe symptoms.

The infection rate is 3.4%

No. A report published in MMWR provides details of COVID-19 cases aboard cruise ships. On the Diamond Princess, 19% of the 3700 passengers and crew got infected. Nearly half were asymptomatic when they tested positive, although many developed symptoms later.

Cardiac injury is uncommon in COVID-19

No. Cardiac injury is a common complication among those hospitalized with COVID-19 and it is associated with significantly increased mortality as per a report in JAMA Cardiology.

Researchers studied over 400 patients hospitalized with COVID-19 in Wuhan, China. Around 20% had cardiac injury, defined as elevated cardiac biomarkers (e.g., high-sensitivity troponin).

Patients with cardiac injury were more likely than those without cardiac injury to require non-invasive ventilation (46% vs. 4%) and invasive ventilation (22% vs. 4%). Patients with cardiac injury also had a higher mortality rate (51% vs. 5%). After adjusting for confounders, including acute respiratory distress syndrome, cardiac injury was still a significant predictor of mortality.

We cannot predict the advantage of social distancing

A new study published in Lancet Infectious Diseases bolsters support for strict social distancing measures. Making use of simulation models, researchers in Singapore estimated the number of SARS-CoV-2 infections that would occur at 80 days after the first 100 cases of community spread were confirmed, assuming that 7.5% of infections were asymptomatic.

In a setting when the virus was least infectious (assuming each case infects another 1.5 people), a median 279,000 infections is estimated to occur by day 80. This would decrease with increasing social distancing measures, coming down to 1800 when all of the following were put into place: isolation of infected individuals and family quarantine, workplace distancing, and school closures.

Notably, assuming that the virus is more infectious (one case infects another 2.5 people), there would be over 1.2 million infections at day 80 with no social distancing measures — and 258,000 with all measures in place.

Italy’s 7.2% mortality is not true

JAMA viewpoint analyzed the high case-fatality rate in Italy — 7.2% as of mid-March.

The authors note that this could be attributed to three major factors: 1) nearly one-fourth of Italys population is 65 years of age and above; 2) some deaths may have been due to comorbid illness rather than the SARS-CoV-2 infection; and 3) mild and asymptomatic cases were rarely tested after late February and were therefore, not included in the denominator.

Still, the 7.2% rate in symptomatic cases is higher.

Undocumented COVID-19 Infections are linked to Transmission

No, it’s a hidden disaster. In China, undocumented infections fueled the rapid early spread of SARS-CoV-2. The number of individuals infected with SARS-CoV-2 with minimal symptoms is an important determinant of the pathogens pandemic potential, as these infections are likely to go undiagnosed.

Using mathematical modeling, investigators estimated the number of undocumented infections and their contribution to SARS-CoV-2 transmission in China.

Subjects were segregated into two groups: those with symptoms severe enough to elicit care-seeking and a documented COVID-19 diagnosis, and those with undocumented infections. The model also accounted for changes in human mobility between cities based on recent historic data adjusted for the escalating restrictions on such movement.

At the beginning of the epidemic, the estimated basic reproductive number (R0) was 2.38 and the percentage of undocumented infections was 86.0%. Undocumented infections were estimated to cause 86.2% of all infections.

Later in the epidemic and with increased testing, the proportion of undocumented infections fell to 35%, and the R0 dropped to 1.36 and then to 0.99 as restrictions on geographic movement tightened. (Science 2020 Mar 16)

Lung involvement is unilateral

No.  In a report from a hospital in Shanghai, investigators reviewed the key initial CT findings in 51 consecutive patients hospitalized due to COVID-19 disease. All patients had thin-section noncontrast scans. Mean age was 49 (range, 16–79), and median time from symptom onset to CT was 4 days. (Radiology 2020 Apr)

Almost all patients had extensive multifocal involvement; bilateral abnormalities were seen in 86% of cases. Lesions were seen in the lower lobes, posterior lung fields, and peripheral lung zones. Three quarters of patients had ≥3 involved lobes.

Various combinations of pure ground-glass opacities (GGOs), GGOs plus reticular or interlobular septal thickening, and GGOs plus consolidation were commonly noted. GGOs were predominant in patients whose symptoms started ≤4 days prior to CT, and areas of consolidation became increasingly evident in those with >4 days of symptoms.

Pleural effusion is common in COVID-19

No. Only four patients had pleural effusions. [Radiology 2020 Apr:]

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA

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