Detecting SARS‐CoV‐2 RNA in conjunctival secretions: Is it a valuable diagnostic method of COVID‐19?

Abstract

The main purpose of this study is to evaluate the presence of viral RNA of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) in conjunctival swab specimen of coronavirus disease 2019 (COVID‐19) patients with and without conjunctivitis to establish the diagnostic value of reverse transcription‐polymerase chain reaction (RT‐PCR) in each case and to describe its clinical characteristics. A cross‐sectional study was conducted at the Hospital Clinico San Carlos of Madrid, Spain. Thirty‐six subjects from the COVID admission unit with laboratory‐confirmed SARS‐CoV‐2 infection were included. Conjunctival swabs were collected from 18 patients with conjunctivitis and 18 patients without conjunctivitis and RT‐PCR was performed. Conjunctival swab was collected from both eyes of 36 patients (72 eyes), detecting SARS‐CoV‐2 RNA in conjunctival swab of two patients (5.5%). Among the 18 patients with conjunctivitis, only one of them (5.5%) showed positive results. Likewise, SARS‐CoV‐2 RNA was detected in one patient without conjunctivitis (5.5%). The mean age of the 36 patients was 67.9 years (range, 28‐92 years) and the male‐to‐female ratio was 0.44 (16:20). The mean days since the onset of COVID‐19 symptoms until conjunctivitis manifestation was 8 (range, 1‐24 days). The mean duration of the conjunctivitis was 3 days (range, 1‐7 days). SARS‐CoV‐2 RNA may be detected in conjunctival swabs of both patients with and without conjunctivitis. This study revealed the same rate of positive results amongst the group with and without conjunctivitis, suggesting that detecting SARS‐CoV‐2 in ocular fluids is not conditioned on the presence of conjunctivitis. The presence of SARS‐CoV‐2 RNA in ocular samples highlights the role of the eye as a possible route of transmission of the disease.

Anti-SARS-Cov-2 IgA Response in Tears of COVID-19 Patients

“…The possibility that the conjunctiva may be a site of virus replication has been indicated in several reports, in cross-sectional as well as monocentric studies or case reports [16,20,22,24,26,[31][32][33][34], posing an important concern for infection prevention in healthcare workers and the general population, and highlighting the need for eye protection in addition to respiratory protection. Despite the lack of frequent isolation of infectious SARS-CoV-2 from the conjunctiva [26], the eye is thus considered a potential portal of entry and spread for the virus.…”

<p>The Role of the Ocular Tissue in SARS-CoV-2 Transmission</p>

“…However, several studies suggested that the prevalence of ocular signs and symptoms in COVID-19 patients is relatively low. 9 Two separate metaanalyses on ocular manifestations estimated a pooled prevalence of 5.5% and <4%. 10,11 Another meta-analysis showed that the prevalence of conjunctivitis in 1167 COVID-19 patients was about 1%.…”

“…[13][14][15][16] Conjunctivitis may be unilateral or bilateral. 9 Two case reports describe the presence of pseudomembranes among severe cases of conjunctivitis. Salducci et al reported one COVID-19 patient with pseudomembranes of fibrin, inflammatory cells, and enlarged preauricular and submaxillary lymph nodes.…”

“…Importantly, none of the studies reported any associated changes in visual acuity of COVID-19 patients with ocular manifestations. 9,[21][22][23] There has been only one study showing retinal changes in COVID-19 patients. 23 Marinho et al examined 12 COVID-19 patients and found that all of them displayed hyper-reflective changes in retinal ganglion cell and inner plexiform layers binocularly using OCT. Four patients had cotton wool spots and microhemorrhages but no signs of intraocular inflammation.…”

Serial simultaneously self-swabbed samples from multiple sites show similarly decreasing SARS-CoV-2 loads in COVID-19 cases of differing clinical severity

“…However, this lower detection rate for conjunctival swabs (with or without overt conjunctivitis) is consistent with previous reports. 6 Thirdly, the relative SARS-CoV-2 viral loads from the URT decreased with time in the 1-2 weeks post-COVID-19 symptom onset, regardless of disease severity. This has been shown elsewhere, 7 though this is not always the case.…”