Evidence-based of conjunctival COVID-19 positivity: An Italian experience: Gemelli Against COVID Group

Abstract

Background: The possible transmission of severe acute respiratory coronavirus 2 (SARS-CoV-2) by tears and conjunctiva is still debated.

Methods: Main outcome was to investigate the agreement between nasopharyngeal swab (NPs) and conjunctival swabs (Cs) in patients with SARS-CoV-2 infection. We divided patients into four groups: (1) NPs and Cs both negative (C-NF-), (2) NPs positive and Cs negative (NFs+Cs-), (3) NPs negative and Cs positive (NFs-Cs+), and (4) NPs and Cs both positive (NFs-Cs+). The secondary outcomes were to correlate Cs results with systemic clinical parameters such as: oxygen saturation (SpO₂), dyspnea degree (DP), radiologic pulmonary impairment based on chest radiography (XR) or computed tomography (CT), blood chemistry as D-Dimer (D-Dimer), fibrinogen, ferritin, lactate dehydrogenase (LDH), and C-reactive protein (C-RP).

Results: A total of 100 conjunctival swabs in 50 patients with SARS-CoV-2 have been enrolled in this interventional clinical trials. Ocular signs (conjunctivitis) were present in five patients (10%). NPs and Cs highlighted a poor level of agreement (0.025; p = 0.404). Median SpO₂ levels are the highest in the NF-C- group (98%) and the lowest (90%) in the group NF+C+ (p = 0.001). Pulmonary impairment was statistically significantly different between NFs and Cs groups (p = 0.019). Pulmonary impairment score increased from NFs-Cs- group (3.8 ± 3.9), to NFs+Cs+ group (6.7 ± 4.1). Intensive care unit patients showed higher COVID-19 Cs positivity in conjunctiva (12.5%) against hospitalized ones (5.8%).

Conclusions: In patients hospitalized for SARS-CoV-2 the virus can be detected in conjunctival swab. Intensive care unit patients may reveal a higher COVID-19 presence in the conjunctiva. The most severe pulmonary impairment can be observed in NFs and Cs positivity.

Trial registration: Clinicaltrials.gov registration.

Ethical committee authorization: ID number: 0013008/20.

Keywords: COVID-19; Conjunctival swab; SARS-CoV-2; eye infection; ophthalmologists; personalized medicine; precautionary measures.

Figure 1.

Shows the procedure of conjunctival swabs: (a) the virus COVID-19 containing single-stranded (positive-sense) RNA associated with a nucleoprotein within a capsid comprised of matrix protein, (b) conjunctival swabs performed in personal protection equipment, (c) swabs of both eyes were taken by rolling cotton swabs across the lower fornix conjunctiva of both eyes, (d) both swabs, one for each eye, were introduced in the same virus-specific tube and delivered to the laboratory for analysis (e).

Figure 2.

Box-plot shows the SpO₂ (%) correlated to NFs−Cs patient status. Highest group was NFs−Cs− (98%) and the lowest (90%) was NFs+Cs+ group. The values were statistically significantly between groups H(2) = 13.062, p = 0.001; eta-squared = 0.482. Adjusted p-values was presented: (NFs−Cs−) versus (NFs+Cs+), p = 0.001; (NFs+Cs+) versus (NFs+Cs−), p = 0.024.

Figure 3.

Box plot reports the pulmonary impairment (score) correlated to NFs and Cs patient status. Statistically significantly differences among different patients status groups, F(2, 46) = 4.330, p = 0.019 has been observed. Pulmonary impairment score increased from the (NFs−Cs−) group (3.8 ± 3.9), to (NFs+Cs+) group (6.7 ± 4.1), to (NFs+Cs−) group (9.4 ± 4.2). Tukey post hoc analysis revealed that the difference between (NFs−Cs−) and (NFs+Cs−) was statistically significant (p = 0.019; 95%CI = [−10.3; −0.78]).