Conjunctival Secretions Research Articles

16S rRNA sequencing in chronic dacryocystitis

ABSTRACT Clinical relevance The pathogenesis of chronic dacryocystitis (CDC) is associated with a variety of bacteria. Investigating microflora has the potential to provide a theoretical basis for preventing and treating CDC. Background 16S rRNA sequencing is a sequence-based bacterial analysis. The application of 16S rRNA sequencing in CDC is rarely reported. Methods A case-control study of infected and healthy eyes diagnosed as CDC patients was conducted. Seventy-eight patients were divided into A (conjunctival sac secretions from healthy eyes), B (conjunctival sac secretions from affected eyes), and C (lacrimal sac secretions from affected eyes) groups. The flora of samples was analysed with 16S rRNA sequencing, and the data was analysed using QIIME, R, LefSE and other software. The potential functions were analysed by PICRUSt. Results A total of 1440 operational taxonomic units (OTUs) were obtained, 139 specific to group A, 220 specific to group B, and 239 specific to group C. There was no significant difference in α index between the three groups. The beta diversity and grouping analysis data indicated that the three groups of flora were similar in species richness and diversity, but there were some differences in composition. In group A, the abundance of Pseudomonadaceae, Chlorobacteria, Moraceae, Staphylococcaceae, Bacillariophyceae, Immunobacterium spp. and Bacillus spp. was higher; in group B, the abundance of Burkholderiaceae, Sphingomonas, Rhizobia, Stalked Bacteria, Sphingomonadaceae, Enterobacteriaceae, Shortwaveomonas spp. was higher; in group C, the abundance of Streptococcus digestiveis, Propionibacterium, Enterobacteriaceae, Anaerobacteriaceae, Propionibacteriaceae, Bacillus spp. Neisseria spp. and Shortactomonas spp. was higher. Six pathways were identified to assess the potential microbial functions. Conclusion Alterations in the microbiota of the conjunctiva and lacrimal sac are associated with the pathogenesis of CDC, which may provide certain guidance for antibiotic treatment of CDC.

Ocular Manifestation of Monkeypox: A Systematic Reviews

Introduction & Objectives : On July 23, 2022, the World Health Organization declared the monkeypox epidemic a global public health emergency. The majority of clinical studies on monkeypox have concentrated on its dermatological symptoms, but mounting data raises questions regarding its ocular side effects.
 Methods : Thirteen studies were found among the 541 distinct articles that were evaluated. Overall, ten studies were case reports, two studies of case series, and one observational cohort study. Ocular manifestations of monkeypox were vesicopapular lesions on the eyelid and conjunctiva, conjunctivitis, epiphora, photophobia, foreign body sensation, eye edema, vision changes, eye pain, itchy eyes, eye discharge, bilateral eye involvement, corneal involvement, keratitis, and subconjunctival nodules.
 Results : The most prevalent ocular symptoms of monkeypox were conjunctivitis, followed by eye pain and photophobia. It is still unknown whether the ocular involvement is due to self-inoculation or the systemic transmission of the virus during the early viral phase of the illness. Despite some theories involving the transit of monkeypox into the conjunctival secretions via the plasma compartment, this study also showed that conjunctival swab PCR is 100% positive, equal to skin lesion swabs.
 Conclusion : In conclusion, to the best of our knowledge, this is the first review with a larger sample and the newest study to report the ocular manifestations of monkeypox disease. The primary ocular symptoms were conjunctivitis, eye pain, and photophobia. In addition, it is advised that healthcare professionals, especially ophthalmologists, use eye protection goggles when close to patients.

Antimicrobial susceptibility of Moraxella catarrhalis in Russia: results of the PEGAS 2010–2021 multicenter study

Objective. To study the antimicrobial susceptibility profile of Moraxella catarrhalis isolates from different regions of Russia in 2010–2021. Materials and Methods. The study included 352 isolates of M. catarrhalis isolated in 11 cities of Russia (Volgograd, Irkutsk, Kazan, Kirov, Moscow, Murmansk, Perm, Seversk, Togliatti, Tomsk, and Ulan-Ude) in 2010–2021. Identification was done by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing was determined by broth microdilution method in accordance with the ISO 20776-1:2020. Interpretation of results was done in accordance with EUCAST guidelines (v.14.0). Results. Most of the isolates were isolated from respiratory specimens: 225 (63.9%) from sputum, 49 (13.9%) from nasal swabs, 41 (11.6%) from sinus aspirates, 17 (4.8%) from bronchoalveolar lavage, 8 (2.3%) from middle ear fluid, 6 (1.7%) from pharyngeal swabs, and 5 (1.4%) from conjunctival secretions. All tested isolates were susceptible to beta-lactams for which interpretive criteria have been established (amoxicillin-clavulanate, cefixime, ceftriaxone, cefuroxime). The susceptibility to clarithromycin and azithromycin was 99.7% and 100%, respectively. Ciprofloxacin, levofloxacin and moxifloxacin were active against 98.9%, 99.2% and 99.7% of isolates tested, respectively. Susceptibility to tetracycline was 99.7% and to trimethoprim-sulfamethoxazole was 99.4% (92% of isolates susceptible, 7.4% – susceptible at increased exposure). Conclusions. In the Russian Federation there is a favorable situation regarding the susceptibility of M. catarrhalis to antimicrobials. Amoxicillin-clavulanic acid, cefixime, ceftriaxone, azithromycin, clarithromycin, ciprofloxacin, levofloxacin, moxifloxacin and tetracycline retain high in vitro activity

Microbial distributions in the conjunctiva and lacrimal sacs of patients with chronic dacryocystitis in a tertiary hospital.

The aim was to clarify the distributions of bacteria in the conjunctival sac and lacrimal sac in patients with chronic dacryocystitis. In total, 297 (322 eyes) chronic dacryocystitis patients who underwent nasal endoscopic dacryocystorhinostomy (EN-DCR) were included. Conjunctival sac secretions from the affected eye were collected preoperatively, and lacrimal sac retention fluid from the affected side in the same patient was collected intraoperatively. Bacterial culture and drug sensitivity testing were performed to determine bacterial distributions. In total, 127 bacterial isolates (49 species) were detected in 123 eyes in the conjunctival group, with a positivity rate of 38.2% (123/322); 85 bacterial isolates (30 species) were detected in 85 eyes in the lacrimal sac group, with a positivity rate of 26.4% (85/322). The positivity rates were significantly different (P = 0.001) between two groups. The gram-negative bacilli proportion in the lacrimal sac group (36/85, 42.4%) was significantly higher than that in the conjunctival sac group (37/127, 29.2%) ( P = 0.047). Positive conjunctival sac secretion culture (123/322) was significantly associated with increased ocular secretion (281/322, 87.3%) (P = 0.002). Among the culture-positive bacteria in the conjunctival sac group and the lacrimal sac group, 30/127, 23.6% and 43/127, 26.7% and 21/85, 24.7% and 20/85, 23.5% were resistant to levofloxacin and tobramycin, respectively. This study illustrated differences in bacterial distributions between conjunctival sac secretions and retained lacrimal sac fluid in chronic dacryocystitis patients, with a higher proportion of gram-negative bacilli in lacrimal sac secretions. The ocular surface flora in chronic dacryocystitis patients is partially resistant to levofloxacin and tobramycin, which need to be considered by ophthalmologists.

Detection of SARS-CoV-2 in conjunctival secretion and tears in patients with COVID-19 in a tertiary care centre, South India. .

Aims and objectives: Purpose of this study is to detect the presence of SAR-CoV-2 viral RNA in conjunctival secretions of COVID-19 patients and to compare the RT-PCR positivity rate for SARS-CoV-2 in conjunctival and nasopharyngeal swab. Materials and method: Eighty hospitalised COVID-19 patients whose nasopharyngeal swab tested positive for SARS-CoV-2 by RT-PCR were included in the study. Conjunctival swab was collected from eyes of these patients and sent for detection of SARS-CoV-2 by RT-PCR method. Results: Among the eighty patients, 51 (63.7%) were males and 29 (36.3%) were females. The mean age of the patients was 55.93 ± 16.59. Six patients had ocular manifestations. Eleven (13.75%) patients tested positive on conjunctival swab for SARS-CoV-2 viral RNA and only one of them had ocular manifestations out of the eleven. Conclusion: In our study the presence of SARS-CoV-2 in conjunctival secretions of COVID-19 patients was detected and this was not dependent on presence of ocular manifestations or duration of disease. Though the conjunctival positivity is lower compared to the nasopharyngeal swab sampling, ocular surface and secretions can be a potential route of viral transmission.

RISK PREVENTION AND MAINTAINING ACCESS TO EFFECTIVE OPHTHALMOLOGY PRACTICE IN COVID-19 CONDITIONS AT LOZENETZ HOSPITAL SOFIA

During the Covid-19 pandemic, eye care professionals are at serious risk of contracting Sars-Cov-2. The reason for this is the specific examination course, requiring close contact with the patient's face, the presence of Sars-CoV-2 in the conjunctival secretions, the use of multiple instruments and equipment, which requires thorough and effective disinfection. The present paper describes the changes in the daily work of the Department of Ophthalmology at Lozenetz Hospital in Sofia for the period 2020-2022 carried out to provide a safe working environment for both medical staff and patients. The measures concern the reorganization of the offices and adjacent spaces, modification of the protocols for appointments, triage, follow-up, necessary procedures, especially for conditions with long-term control need - e.g., macular degeneration, glaucoma, diabetic retinopathy, etc. as well as rational management of medical personnel.

COVID-19 – OCULAR INVOLVMENT, FINDINGS AND THE RISK OF POTENTIAL TRANSMISSION

The coronavirus disease COVID-19 affects primarily the respiratory system in humans, but it also affects many other organs, including the eyes. The ocular surface is considered as a Sars-CoV-2 gateway; it also plays an important role in its spread through the conjunctival secretions. Conjunctival secretion swabs of 50 people were examined by real-time PCR methodology. All of them were hospitalized due to medium and moderately severe COVID-19 in Lozenetz Hospital Sofia during the period of October-November 2021. The results showed that the severity of clinical findings in the anterior eye segment and subjective complaints did not correspond to the presence of Sars-Cov-2 in conjunctival samples. Nevertheless, eye care specialists need to take notice while working in their ophthalmic practices in order to reduce the risk of virus transmission and diminish SarsCoV-2 infection among visiting patients and health care professionals. An effective program and specific precautions need to be exploited in order to effectively prevent disease spread.

Detection of SARS-CoV-2 in conjunctival secretion and tears in patients with COVID-19 in a tertiary care centre, South India. .

Aims and objectives: Purpose of this study is to detect the presence of SAR-CoV-2 viral RNA in conjunctival secretions of COVID-19 patients and to compare the RT-PCR positivity rate for SARS-CoV-2 in conjunctival and nasopharyngeal swab. Materials and method: Eighty hospitalised COVID-19 patients whose nasopharyngeal swab tested positive for SARS-CoV-2 by RT-PCR were included in the study. Conjunctival swab was collected from eyes of these patients and sent for detection of SARS-CoV-2 by RT-PCR method. Results: Among the eighty patients, 51 (63.7%) were males and 29 (36.3%) were females. The mean age of the patients was 55.93 ± 16.59. Six patients had ocular manifestations. Eleven (13.75%) patients tested positive on conjunctival swab for SARS-CoV-2 viral RNA and only one of them had ocular manifestations out of the eleven. Conclusion: In our study the presence of SARS-CoV-2 in conjunctival secretions of COVID-19 patients was detected and this was not dependent on presence of ocular manifestations or duration of disease. Though the conjunctival positivity is lower compared to the nasopharyngeal swab sampling, ocular surface and secretions can be a potential route of viral transmission.

Conjunctivitis with Monkeypox Virus Positive Conjunctival Swabs

A 39-year-old man consulted for unilateral red eye and itchiness (Fig A, C) 5 days after positive monkeypox virus (MPOX) cutaneous polymerase chain reaction (PCR) swab from chin and lip lesions (Fig B). Slit-lap examination showed conjunctival follicular reaction and the presence of small white vesicles on the nasal bulbar conjunctiva (Fig C, arrow). The rest of the anterior and posterior segment were normal, and the fellow eye remained uninvolved during follow up. Two separate conjunctival PCR swabs were positive for MPOX, confirming indirectly similar loads of the virus on conjunctival and eye secretions compared with cutaneous lesions (26.7 vs 24.8 [cycle threshold] respectively), raising the possibility of transmission via eye contact, i.e., during ophthalmologic examination.

Detection of coronavirus in tear samples of hospitalized patients with COVID-19.

PurposeTo assess the presence of viral RNA in conjunctival secretions and tears of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients in terms of a possible ocular transmission route and also to examine whether a difference between the patients with and without ocular surface positivity existed.MethodsA prospective cross-sectional study of 70 consecutive patients who were hospitalized in Haseki Training and Research Hospital with SARS-CoV-2 from February 1 to April 1, 2021, was performed. Tears and conjunctival secretions were collected within 24 h of nasopharyngeal sample collection and examined for SARS-CoV-2 using reverse transcription real-time polymerase chain reaction (qPCR). The clinical data, results of blood tests and nasopharyngeal and conjunctival swabs, and CT findings were evaluated for all patients.ResultsSeventy patients (37 males, 33 females) were included in this study. Tear–conjunctival samples from eight patients (11.42%) yielded positive PCR results although these eight patients had no eye symptoms or conjunctivitis. In patients with positive conjunctival PCR results, cycle threshold values for conjunctival samples were higher than those for nasopharyngeal samples. All findings (except gender) were similar between patients with either positive or negative conjunctival swab samples. All patients with positive conjunctival swab samples were male; however, the male ratio in patients with negative conjunctival swab samples was only 46.77%.ConclusionIn our study, the rate of conjunctival swab PCR positivity was 11.42%. It appears that even in the absence of ocular symptoms, SARS-CoV-2 virus may be present on the ocular surface; therefore, the ocular surface may be a significant viral transmission route.

Increased proinflammatory cytokines in tears correspond with conjunctival SARS-CoV-2 positivity in symptomatic COVID-19 patients

Tear fluid cytokine levels may serve as biomarkers of innate immune system response against SARS-CoV-2 infection. Therefore, our aim was to analyze panel of selected inflammatory cytokines in tears of COVID-19 patients in relation to presence of SARS-CoV-2 viral load in conjunctival secretions. In this study concentrations of TNF-α, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, GM-CSF, and IFN-γ were determined by a magnetic bead assay in tear film collected from 232 symptomatic COVID-19 patients. SARS-CoV-2 ocular infection was confirmed based on positive conjunctival swab-based RT-PCR testing. Viral RNA in conjunctival sac was detected in 21 patients (9%). No relation between presence and the duration of ophthalmic symptoms and SARS-CoV-2 infection detected in conjunctival secretions was found. The tear film concentrations of IFN-γ, TNF-α, IL-5, IL-8 and GM-CSF were found to be significantly greater among patients with positive conjunctival swab results as compared to the group negative for SARS-CoV-2 in conjunctival sac. Our current data depict a group of inflammatory mediators in human tears, which may play a significant role in ocular pathology of SARS-CoV-2 conjunctival infection.

Mystery of Shedding Coronavirus in Tears of Patients Affected with COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) caused 2019 new coronavirus illness (COVID-19) has spread globally, causing a pandemic. The WHO declared the outbreak a pandemic on January 31, 2020. 2020 has been marked as COVID pandemic year. SARSCoV2 caused a global outbreak of this infectious disease. A number of cases has continued to rise since then. Coronavirus is a highly infectious disease spread mostly by respiratory droplets and direct contact with affected individuals. Viral isolation and quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis confirm the diagnosis. While the pathways of virus transmission are still debated, several investigations have been conducted to identify tear film and conjunctiva as the mode of virus transmission. Multiple case reports have surfaced in which ophthalmic doctors were found to be infected during routine management. From January 26 to February 9, 2020, 30 confirmed novel coronavirus pneumonia (NCP) patients were recruited for a prospective interventional case series investigation at Zhejiang University's first affiliated hospital. Tear and conjunctival secretions were collected twice with disposable sample swabs at a 2-to-3 day interval for the reverse transcription polymerase chain reaction assay. Twenty-one individuals with NCP of the common type and nine patients with NCP of the severe kind were included in the study. The lone patient with conjunctivitis had two samples of tear and conjunctival secretions, both of which generated positive RTPCR results. A total of 58 samples from different patients were found to be negative.

Bacterial Culture of Tear Duct Infections Secondary to Congenital Nasolacrimal Duct Obstructions.

Purpose To investigate the microbial profile of congenital nasolacrimal duct obstruction (CNLDO) in Chinese children. Methods We retrospectively reviewed the medical records of 330 consecutive children (330 eyes) who were diagnosed with tear duct infections secondary to CNLDO and were admitted to the Children's Hospital of Fudan University from January 2013 to January 2020. Bacterial cultures were grown from tear duct samples of each patient. Samples from conjunctival secretions were cultivated on blood or chocolate agar. Clinically significant bacterial growth was reported. Results Of the 330 eyes considered, 62.7% (207/330) were associated with positive bacterial cultures. A total of 223 isolates were detected from 207 culture-positive eyes. Among the 223 isolates, 52.0% (116/223) were Gram-positive bacteria and 47.1% (105/223) were Gram-negative bacteria. The most prevalent Gram-positive bacteria were Streptococcus viridans (67 isolates, 30%), followed by Staphylococcus aureus (36 isolates, 16.1%) and Streptococcus pneumoniae (5 isolates, 2.2%). The most prevalent Gram-negative bacteria were Neisseria (nonpathogenic) (25 isolates, 11.2%), followed by Escherichia coli (16 isolates, 7.2%) and Haemophilus influenzae (16 eyes, 7.2%). Antibiotic susceptibility test results suggested that both Gram-positive and Gram-negative bacteria were highly sensitive to most of the tested antibiotics. Conclusions S. viridans and S. aureus are the most prevalent bacteria in tear duct infections secondary to CNLDO. Broad-spectrum antibacterial eye drops are suggested as empirical antibiotic treatments.

Assessment of Alteration in Aerobic Conjunctival and Meibomian Gland Microbial Flora after Cataract Surgery and its Association with Postoperative Meibomian Gland Dysfunction

Introduction: Combination of various commensal microorganism species is capable of protecting the ocular surface from colonization by potentially pathogenic microbes. These homeostatic microorganisms can be easily altered by environmental factors like cataract surgery. These may play a role in the development of postcataract surgery Meibomian Gland Dysfunction (MGD) whose exact pathogenesis is still unknown. Aim: To assess the change in aerobic bacterial flora of meibomian glands and conjunctiva and its association with the development of MGD after cataract surgery. Materials and Methods: This prospective study was conducted in Department of Ophthalmology at BPS Government Medical College for Women, Sonepat, Haryana, India, from June 2021 to February 2022. A total of 60 eyes of 60 patients who had undergone uncomplicated phacoemulsification surgery with intraocular lens implantation were selected. Conjunctival and Meibomian Gland (MG) secretions samples were collected preoperatively before starting antibiotics and at 6 weeks postoperatively. Aerobic bacteria isolated from the culture samples of patients before and after surgery were analysed for microbial flora change (MFC). At 6 weeks postoperative follow-up visit, the diagnosis of the MGD was made on slit lamp examination of lid margin and meibomian glands. Chi-square test was applied to assess the association between patients with MFC and patients with MGD. Results: There were 33 males and 27 females, with a mean age of 62.41 years. Preoperative conjunctival samples of 20 patients (33.33%) and MG samples of 27 patients (45%) were culture positive for aerobic bacteria. Most common microorganism isolated from preoperative samples was Coagulase Negative Staphylococci (CoNS). Isolation rate of Staphyloccus aureus increased postoperatively in both conjunctival and MG culture samples. Postoperative aerobic Microbial Flora Change (MFC) in culture samples of either conjunctival or MG or both was present in 30 patients (50%). Total 16 patients (26.6%) developed MGD out of which 13 patients (81.25%) had MFC. The association between MFC and MGD was statistically significant (p-value=0.004). Conclusion: There is alteration of ocular aerobic bacterial flora after cataract surgery and it has a statistically significant association with postcataract surgery MGD. Replenishment of ocular surface microflora can play a preventive and therapeutic role in the management of postcataract surgery MGD.

Detection of SARS-CoV-2 RNA in a conjunctival swab sample in real-time-polymerase chain reaction positive COVID-19 patients and its association with comorbidity and severity at a designated COVID-19 hospital in Central India.

Purpose:To evaluate the presence of SARS-CoV-2 RNA in the conjunctival swab sample of positive confirmed COVID-19 patients and to find out its association with comorbidity and severity of COVID-19 disease.Methods:We conducted an observational cross-sectional study at a dedicated tertiary COVID-19 hospital in central India for a period of 8 weeks from February 2021to March 2021. We included patients who tested positive for SARS-CoV-2 RNA through nasopharyngeal swab and were above 18 years of age. Swab samples have been collected within 48 h of admission. Conjunctival swab was taken from the lower fornix of both eyes and sent to microbiology laboratory for real-time- polymerase chain reaction (RT-PCR).Results:Out of 150 patients, conjunctival swab RT-PCR was positive in five patients (3.33%). Two patients had conjunctival manifestations in the form of conjunctivitis but conjunctival swab RT-PCR was negative in those patients. Among the RT-PCR positive patients, two (40%) were from mild, one (20%) was from moderate, and two (40%) were from severe category. No association could be established between conjunctival swab RT-PCR positivity and severity of the disease or associated comorbidity.Conclusion:Our study provides evidence that SARS-CoV-2 RNA could be detected in conjunctival secretions, and though the risk is relatively low, the eye may act as source of transmission. Extra caution should be taken by healthcare workers, and use of proper precautions like face shields and goggles should be encouraged.

SARS-CoV-2 in Conjunctiva and Tears and Ocular Symptoms of Patients with COVID-19.

This study investigates the presence of SARS-CoV-2 in conjunctival secretions and tears and evaluates ocular symptoms in a group of patients with COVID-19. We included 56 hospitalized patients with COVID-19 in this cross-sectional cohort study. Conjunctival secretions and tears were collected using flocked swabs and Schirmer strips for SARS-CoV-2 reverse-transcriptase polymerase chain reaction (RT-PCR). Assessment of ocular surface manifestations included an OSDI (Ocular Surface Disease Index) questionnaire. Patients had been admitted to hospital for an average of 2.4 days (range 0–7) and had shown general symptoms for an average of 7.1 days (range 1–20) prior to ocular testing. Four (7.1%) of 56 conjunctival swabs and four (4%) of 112 Schirmer strips were positive for SARS-CoV-2. The mean E-gene cycle threshold values (Ct values) were 31.2 (SD 5.0) in conjunctival swabs and 32.9 (SD 2.7) in left eye Schirmer strips. Overall, 17 (30%) patients presented ocular symptoms. No association was found between positive ocular samples and ocular symptoms. This study shows that SARS-CoV-2 can be detected on the conjunctiva and tears of patients with COVID-19. Contact with the ocular surface may transmit the virus and preventive measures should be taken in this direction.

Clinical Symptoms and Types of Samples Are Critical Factors for the Molecular Diagnosis of Symptomatic COVID-19 Patients: A Systematic Literature Review.

Background Currently, a novel coronavirus found in 2019 known as SARS-CoV-2 is the etiological agent of the COVID-19 pandemic. Various parameters including clinical manifestations and molecular evaluation can affect the accuracy of diagnosis. This review aims to discuss the various clinical symptoms and molecular evaluation results in COVID-19 patients, to point out the importance of onset symptoms, type, and timing of the sampling, besides the methods that are used for detection of SARS-CoV-2. Methods A systematic literature review of current articles in the Web of Science, PubMed, Scopus, and EMBASE was conducted according to the PRISMA guideline. Results Of the 12946 patients evaluated in this investigation, 7643 were confirmed to be COVID-19 positive by molecular techniques, particularly the RT-PCR/qPCR combined technique (qRT-PCR). In most of the studies, all of the enrolled cases had 100% positive results for molecular evaluation. Among the COVID-19 patients who were identified as such by positive PCR results, most of them showed fever or cough as the primary clinical signs. Less common symptoms observed in clinically confirmed cases were hemoptysis, bloody sputum, mental disorders, and nasal congestion. The most common clinical samples for PCR-confirmed COVID-19 patients were obtained from throat, oropharyngeal, and nasopharyngeal swabs, while tears and conjunctival secretions seem to be the least common clinical samples for COVID-19 diagnosis among studies. Also, different conserved SARS-CoV-2 gene sequences could be targeted for qRT-PCR detection. The suggested molecular assay being used by most laboratories for the detection of SARS-CoV-2 is qRT-PCR. Conclusion There is a worldwide concern on the COVID-19 pandemic and a lack of well-managed global control. Hence, it is crucial to update the molecular diagnostics protocols for handling the situation. This is possible by understanding the available advances in assays for the detection of the SARS-CoV-2 infection. Good sampling procedure and using samples with enough viral loads, also considering the onset symptoms, may reduce the qRT-PCR false-negative results in symptomatic COVID-19 patients. Selection of the most efficient primer-probe for target genes and samples containing enough viral loads to search for the existence of SARS-CoV-2 helps detecting the virus on time using qRT-PCR.

Investigation of SARS-CoV-2 in tear and conjunctival secretions of hospitalized patients with clinically-confirmed COVID-19 pneumonia

BackgroundThe aim of this study was to demonstrate the presence of the virus in tear and conjunctival secretions of clinically-confirmed COVID-19 pneumonia patients.MethodsThis prospective study was conducted at Bakirkoy Dr. Sadi Konuk Training and Research Hospital (2020/190). Nasopharyngeal and ocular samples were obtained by swab technique and investigated by RT-PCR.ResultsA total of 83 patients were included. The mean age was 61.88 ± 16.04 years. 28.92% of the patients had mild, 65.06% moderate and 6.02% severe pneumonia radiologically. RT-PCR was positive in 31 (37.35%) patients in the first nasopharyngeal swabs and in 19 (22.89%) in the second swabs. 17 of 19 patients had positive both first and second nasopharyngeal swabs; only the second swabs of two patients were positive. The first conjunctival swabs RT-PCR were positive in 5 out of 83 clinically-confirmed patients or 33 laboratory-confirmed patients (rates: 6.02% and 15.15%). There were no positives detected in the second conjunctival swabs.ConclusionsSARS-CoV-2 can be detected in the conjunctival swabs of patients with COVID-19 pneumonia.

SARS-CoV-2: is it present in the conjunctiva?

The Orthocoronavirinae family was discovered in the 1960s. These are enveloped viruses with positive single-stranded RNA, and their genome size varies approximately between 26 and 32 kb, being the largest genome for an RNA virus. In Mexico, the first reported case was that of a person from Italy. Taking this first case as day 1, the cases have been increasing and, at the time of writing this article, there were 133,974 infected people and 15,944 deaths. The conjunctiva has been proposed as a route of entry for SARS-CoV-2. However, in a search for coronavirus genetic material in tear and conjunctiva samples, patients who did not show conjunctivitis were negative for the presence of viral genetic material, and only one person was positive, both in tear and conjunctiva samples. Negative results for SARS-CoV-2 RNA in tears and conjunctival secretions could indicate that the virus does not replicate in conjunctival epithelia, but could be present in undetectable amounts, which does not rule out that it can be transmitted through the conjunctiva.

Evaluation and comparison of conjunctival swab polymerase chain reaction results in SARS-CoV-2 patients with and without ocular manifestations.

Purpose:The aim of this study was to evaluate and compare the presence of SARS-CoV-2 in tears of patients with and without ocular symptoms in SARS-CoV-2 positive patients.Methods:The prospective observational study conducted on 60 consecutive SARS-CoV-2 positive patients with ocular complaints was compared with 60 controls who had no ocular manifestations. The tear samples were taken within 48 h of admission from both the eyes of the enrolled patients for evaluating the presence SARS-CoV-2 by reverse transcription-polymerase chain reaction.Results:Eleven cases (18.33%) tested positive for SARS-CoV-2 in tears on RT-PCR from cojunctival swab compared to 10 (16.66%) controls. The difference was not statistical significant. The difference between mean age of patients who tested positive or negative was also without statistical significance (P = 0.652), but the difference between patients who tested positive or negative by conjunctival swab for SARS-CoV-2 was statistically significant in terms of severity of COVID-19 disease (P = 0.0011), presence of comorbidity (P = 0.0015), mean TLC (P = 0.00498), and mean d dimer (P = 0.00465).Conclusion:Though the percentage of patients with positive RT PCR from conjunctival secretions is significantly less than nasopharyngeal swabs, potential risk of transmission of SARS-Co-2 through tears cannot be ruled out. Moreover, SARS-CoV-2 can be present in tears irrespective of ocular involvement.