First parechovirus reported case in Saudi Arabia in hospitalized immunocompromised adult patient.

Human parechovirus, a member of the Picornaviridae family (PeVs), can lead to severe infections, including severe meningitis, meningoencephalitis, and sepsis-like syndrome. We report a case of human parechovirus-related encephalitis in a 52-year-old woman diagnosed with glioblastoma multiforme. She underwent surgical resection in June 2022. Unfortunately, her disease recurred, and she underwent a second resection in August 2022, followed by radiation therapy and Temozolomide therapy. She presented to the hospital with acute confusion followed by seizures, necessitating intubation for airway support. A cerebrospinal fluid (CSF) sample was obtained and processed using the Biofire FilmArray, which reported the detection of HSV-1. Despite being on Acyclovir, the patient did not show signs of improvement. Consequently, a second CSF sample was obtained and sent for next-generation sequencing (NGS), which returned a positive result for Parechovirus. In this presented case, the patient exhibited symptoms of an unknown infectious cause. The utilization of NGS and metagenomic analysis helped identify Parechovirus as the primary pathogen present, in addition to previously identified HSV. This comprehensive approach facilitated a thorough assessment of the underlying infection and guided targeted treatment. In conclusion, the application of NGS techniques and metagenomic analysis proved instrumental in identifying the root cause of the infection.

Stenotrophomonas riyadhensis sp. nov., isolated from a hospital floor swab.

During the analysis of a collection of Pseudomonas strains linked to an outbreak in an intensive care unit at King Faisal Specialist Hospital and Research Center in 2019, one isolate (CFS3442T) was identified phenotypically as Pseudomonas aeruginosa. However, whole-genome sequencing revealed its true identity as a member of the genus Stenotrophomonas, distinct from both P. aeruginosa and Stenotrophomonas maltophilia. The isolate demonstrated: (i) a significant phylogenetic distance from P. aeruginosa; (ii) considerable genomic differences from several S. maltophilia reference strains and other Stenotrophomonas species; and (iii) unique phenotypic characteristics. Based on the combined geno- and phenotypic data, we propose that this isolate represents a novel species within the genus Stenotrophomonas, for which the name Stenotrophomonas riyadhensis sp. nov. is proposed. The type strain is CFS3442T (=NCTC 14921T=LMG 33162T).

Changes in seasonal respiratory viral infections among pediatric population around the COVID-19 pandemic; 2019-2023.

PURPOSE: This study aims to describe the prevalence and the fluctuations of respiratory viral infections among the pediatric population in a tertiary care center during 2019-2023, parallel with the COVID-19 pandemic, and the specific preventative measures applied in the region during this time. METHODS: In this observational study, we extracted all respiratory virus PCR tests collected from pediatric patients (< 15 years old) between January 2019 and March 2023. Data on the positivity rate and prevalence of 18 respiratory viruses were presented over the study period. RESULTS: The lowest rate for the studied respiratory viruses was observed in 2020/2021 (during the COVID-19 pandemic), followed by a gradual increase in positive cases in the 2021/2022 season. Timing (seasonality) was altered during 2022/2023 with an early circulation of respiratory viruses in May-June followed by an early start of the usual respiratory viruses' season in September, leading to prolonged respiratory virus activity. Most respiratory viruses were circulating at unprecedented levels during the 2022/2023 season, with rhinovirus/enterovirus being the most commonly detected virus in all seasons. Other viruses that had atypical activity after the COVID-19 pandemic were influenza A(H3) virus, adenovirus, and parainfluenza 3 virus. CONCLUSION: Our study demonstrates the extended influence of the COVID-19 pandemic and its associated community restriction measures on the timing and distribution of other respiratory viruses. Continuous monitoring of changes in the circulation of respiratory viruses is crucial for the success of related public health measures such as vaccination distributions and epidemic preparedness.

Portable RT-PCR System: a Rapid and Scalable Diagnostic Tool for COVID-19 Testing.

Combating the ongoing coronavirus disease 2019 (COVID-19) pandemic demands accurate, rapid, and point-of-care testing with fast results to triage cases for isolation and treatment. The current testing relies on reverse transcriptase PCR (RT-PCR), which is routinely performed in well-equipped laboratories by trained professionals at specific locations. However, during busy periods, high numbers of samples queued for testing can delay the test results, impacting efforts to reduce the infection risk. Besides, the absence of well-established laboratories at remote sites and low-resourced environments can contribute to a silent spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These reasons compel the need to accommodate point-of-care testing for COVID-19 that meets the ASSURED criteria (affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free, and deliverable). This study assessed the agreement and accuracy of the portable Biomeme SARS-CoV-2 system against the gold standard tests. Nasopharyngeal and nasal swabs were used. Of the 192 samples tested using the Biomeme SARS-CoV-2 system, the results from 189 samples (98.4%) were in agreement with the reference standard-of-care RT-PCR testing for SARS-CoV-2. The portable system generated simultaneous results for nine samples in 80 min with high positive and negative percent agreements of 99.0% and 97.8%, respectively. We performed separate testing in a sealed glove box, offering complete biosafety containment. Thus, the Biomeme SARS-CoV-2 system can help decentralize COVID-19 testing and offer rapid test results for patients in remote and low-resourced settings.

Evaluation of riboflavin and ultraviolet light treatment against Klebsiella pneumoniae in whole blood-derived platelets: A pilot study.

BACKGROUND: Bacterial contamination of platelet concentrates (PCs) is the predominant cause of infectious transfusion reactions. The Pathogen Inactivation Mirasol system was implemented at the King Faisal Specialist Hospital (Saudi Arabia) to reduce the risk of transfusing contaminated PCs. This pilot study evaluated the effectiveness of Mirasol against Klebsiella pneumoniae, a pathogen associated with transfusion reactions, in whole blood-derived PCs. STUDY DESIGN AND METHODS: Whole blood (WB) units inoculated with one of six K. pneumoniae strains (five clinical isolates and ATCC-700603) at a concentration of 3-38 CFU/unit, were processed using the platelet-rich plasma (PRP) method. Each spiked PC was pooled with four unspiked units. The pooled PC was split into three Mirasol storage bags: an untreated unit (control), and two units treated with Mirasol at 26 and 32 h post-WB collection, respectively. PC samples obtained before and after Mirasol treatment were used for BacT/ALERT cultures and determination of bacteria quantification. Each experiment was repeated three independent times. RESULTS: Five strains were detected prior to PC treatment (24 h post-WB spiking), while one clinical isolate was not detected. Mirasol treatment after 26 h of WB collection resulted in complete inactivation of all K. pneumoniae strains. However, treatment 32 h post-WB collection resulted in the breakthrough of one clinical isolate in two of the three replicates with ~7.8 log10 CFU/unit detected on day 5 of PC storage. CONCLUSION: Delayed Mirasol treatment from 26 to 32 h post-WB collection, resulted in one breakthrough. These results highlight the importance of minimizing the time between WB collection and PI treatment.

Molecular characterisation and clinical outcomes of Candida auris infection: Single-centre experience in Saudi Arabia.

BACKGROUND: Candida auris is a difficult-to-diagnose multidrug-resistant yeast that can cause invasive infections with high mortality. Since emerging in 2009, this pathogen has been associated with numerous outbreaks around the world. Whole genome sequencing (WGS) is instrumental for understanding the emergence and local transmission of this pathogen. OBJECTIVES: To describe the clinical, molecular characteristics of Candida auris infection and clinical outcome in our centre. PATIENTS AND METHODS: Patients with positive cultures for Candida auris were identified in a microbiology database. Clinical characteristics and antifungal susceptibility were obtained. Isolates were sent to the US CDC for whole genome sequencing. RESULTS: Seven unique patients with eight different isolates were identified. Seven isolates were sent to the US CDC for whole genome sequencing. None of the patients had bloodstream infection. Thirty-day mortality was higher in infected patients compared with those who were colonised. Seven of the eight isolates were resistant to both fluconazole, and five were resistant to amphotericin B. WGS analysis demonstrated that the seven isolates belonged to the South Asian clade but formed two distinct subclades suggesting two independent introductions and ongoing transmission within the facility. CONCLUSIONS: Candida auris is associated with a high mortality rate in infected patients. Strict infection control measures and surveillance for asymptomatic cases are warranted to halt ongoing transmission.

Impact of Mycobacterium tuberculosis complex lineages as a determinant of disease phenotypes from an immigrant rich moderate tuberculosis burden country.

BACKGROUND: Growing evidences suggested that the Mycobacterium tuberculosis complex (MTBC) lineages can determine the clinical outcome of pulmonary and extra-pulmonary tuberculosis. However, limited data only available revealing such association of bacterial genotypes and clinical phenotypes from immigrant rich countries. METHODS: A multicenter study has been carried out on a collection of 2092 (1003 extrapulmonary and 1089 pulmonary) MTBC isolates. Genotyping of all the isolates were carried out by spoligotyping and 24 loci based MIRU-VNTR typing. RESULTS: Demographically domination of young Saudi nationals (61.4%) and men (61.2%) were found in this cohort. Lymph nodes (62.4%) and gastrointestinal sites (16.7%) were the most common anatomical sites of infection. The predominant lineages were Delhi/CAS (26.9%), EAI (14.2%) and Ghana (9.9%). Mycobacterium africanum type I and II were reported for the first time in the country among extrapulmonary cases. 'Ancestral' lineages M.bovis (OR-5.22; 95% CI-2.23-8.22, p- < 0.001) and Delhi/CAS (OR-0.57; 95% CI-0.411-0.734, p- < 0.001) were directly associated with lymph node tuberculosis and gastrointestinal tuberculosis (M. bovis-OR-0.33; 95% CI-0.085-0.567, p-0.001 and Delhi/CAS-OR-1.87; 95% CI-1.22-2.53, p- < 0.001) respectively. Among the 'Modern' lineages, EAI showed significant association to central nervous system tuberculosis (OR-1.98; 95% CI-0.76-3.19, p-0.04) and Uganda-I to gastrointestinal tuberculosis (OR-2.41; 95% CI-0.77-4.06, p-0.02). CONCLUSIONS: The findings substantially contribute to the emerging evidences that MTBC lineages influence disease phenotypes and epidemiological consequences.

Mycobacterium riyadhense in Saudi Arabia.

We explored in detail the nationwide existence of Mycobacterium riyadhense in Saudi Arabia. In 18 months, 12 new cases of M. riyadhense infection were observed, predominantly among Saudi nationals, as a cause of pulmonary disease. M. riyadhense may be emerging as a more common pathogen in Saudi Arabia.

Antibody Response and Disease Severity in Healthcare Worker MERS Survivors.

We studied antibody response in 9 healthcare workers in Jeddah, Saudi Arabia, who survived Middle East respiratory syndrome, by using serial ELISA and indirect immunofluorescence assay testing. Among patients who had experienced severe pneumonia, antibody was detected for >18 months after infection. Antibody longevity was more variable in patients who had experienced milder disease.

Temporal analysis of prevalence and antibiotic-resistance patterns in Stenotrophomonas maltophilia clinical isolates in a 19-year retrospective study.

Stenotrophomonas maltophilia is a nonfermenting gram-negative bacterium associated with multiple nosocomial outbreaks. Antibiotic resistance increases healthcare costs, disease severity, and mortality. Multidrug-resistant infections (such as S. maltophilia infection) are difficult to treat with conventional antimicrobials. This study aimed to investigate the isolation rates, and resistance trends of S. maltophilia infections over the past 19 years, and provide future projections until 2030. In total, 4466 patients with S. maltophilia infection were identified. The adult and main surgical intensive care unit (ICU) had the highest numbers of patients (32.2%), followed by the cardiology department (29.8%), and the paediatric ICU (10%). The prevalence of S. maltophilia isolation increased from 7% [95% confidence interval (CI) 6.3-7.7%] in 2004-2007 to 15% [95% CI 10.7-19.9%] in 2020-2022. Most S. maltophilia isolates were resistant to ceftazidime (72.5%), levofloxacin (56%), and trimethoprim-sulfamethoxazole (14.05%), according to our study. A consistent and significant difference was found between S. maltophilia-positive ICU patients and non-ICU patients (P = 0.0017) during the three-year pandemic of COVID-19 (2019-2021). The prevalence of S. maltophilia isolates is expected to reach 15.08% [95% CI 12.58-17.59%] by 2030. Swift global action is needed to address this growing issue; healthcare authorities must set priorities and monitor infection escalations and treatment shortages.

Whole genome sequencing of resistance and virulence genes in multi-drug resistant Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic bacterium that causes serious hospital-acquired infections. To assess the risk of clinically isolated P. aeruginosa to human health, we analyzed the resistance and virulence mechanisms of a collection of clinical isolates. METHODS: This was a retrospective study in which P. aeruginosa isolates collected from January 1, 2018 to August 31, 2019 were analyzed using phenotypic and whole-genome sequencing (WGS) methods. The analysis included 48 clinical samples. Median patient age was 54.0 (29.5) years, and 58.3% of patients were women. Data from the microbiology laboratory database were reviewed to identify P. aeruginosa isolates. All unique isolates available for further testing were included, and related clinical data were collected. Infections were defined as hospital acquired if the index culture was obtained at least 48 h after hospitalization. RESULTS: High-risk P. aeruginosa clones, including sequence types (STs) ST235 and ST111, were identified, in addition to 12 new STs. The isolates showed varying degrees of biofilm formation ability when evaluated at room temperature, along with reduced metabolic activity, as measured by metabolic staining, suggesting their ability to evade antimicrobial therapy. Most isolates (77.1%) were multidrug resistant (MDR), with the highest resistance and susceptibility rates to beta-lactams and colistimethate sodium, respectively. CONCLUSIONS: The MDR phenotypes of the examined isolates can be explained by the high prevalence of efflux-mediated resistance- and hydrolytic enzyme-encoding genes. These isolates had high cytotoxic potential, as indicated by the detection of toxin production-related genes.

Characteristics and clinical manifestations of patients, including organ transplant patients, during the surge of JN.1: Insights from Saudi Arabia.

BACKGROUND: Amidst the persistent global health threat posed by the evolving SARS-CoV-2 virus throughout the four-year-long COVID-19 pandemic, the focus has now turned to the Omicron variant and its subvariant, JN.1, which has rapidly disseminated worldwide. This study reports on the characteristics and clinical manifestations of patients during the surge of the JN.1 variant in Saudi Arabia; it also investigates the evolution of SARS-CoV-2 variants in organ transplant patients and identifies patient risk factors. METHODS: A total of 151 nasopharyngeal samples from patients with PCR-confirmed SARS-CoV-2 infection were collected between September 2023 and January 2024. Demographic and clinical data of the patients were obtained from electronic health records. All confirmed positive samples underwent sequencing using Ion GeneStudio and the Ion AmpliSeq™ SARS-CoV-2 panel. RESULTS: During the surge of the JN.1 variant, the average age of the patients was 40 years, ranging from 3 to 93 years, and nearly 50% of the patients were male. Our investigation revealed that the J.N variant predominantly infected patients with comorbidities or organ transplant recipients (57.6%). Moreover, patients with comorbidities or organ transplants exhibited a higher number of mutations. In our organ transplant cohort, an increased total number of spike mutations was associated with a lower risk of developing severe disease (OR = 0.96, 95% CI: 0.93-0.98). CONCLUSIONS: Although JN.1 may not prove to be particularly harmful, it is crucial to recognize the persistent emergence of concerning variants, which create new pathways for the virus to evolve. The ongoing evolution of SARS-CoV-2 is evident in the continuous divergence of these variants from the original strain that marked the onset of the pandemic nearly four years ago.

Donor respiratory multidrug-resistant bacteria and lung transplantation outcomes.

RATIONALE: Respiratory culture screening is mandatory for all potential lung transplant donors. There is limited evidence on the significance of donor multidrug-resistant (MDR) bacteria on transplant outcomes. Establishing the safety of allografts colonized with MDR bacteria has implications for widening an already limited donor pool. OBJECTIVES: We aimed to describe the prevalence of respiratory MDR bacteria among our donor population and to test for associations with posttransplant outcomes. METHODS: This retrospective observational study included all adult patients who underwent lung-only transplantation for the first time at King Faisal Specialist Hospital & Research Centre in Riyadh from January 2015 through May 2022. The study evaluated donor bronchoalveolar lavage and bronchial swab cultures. MAIN RESULTS: Sixty-seven of 181 donors (37%) had respiratory MDR bacteria, most commonly MDR Acinetobacter baumannii (n = 24), methicillin-resistant Staphylococcus aureus (n = 18), MDR Klebsiella pneumoniae (n = 8), MDR Pseudomonas aeruginosa (n = 7), and Stenotrophomonas maltophilia (n = 6). Donor respiratory MDR bacteria were not significantly associated with allograft survival or chronic lung allograft dysfunction (CLAD) in adjusted hazard models. Sensitivity analyses revealed an increased risk for 90-day mortality among recipients of allografts with MDR Klebsiella pneumoniae (n = 6 with strains resistant to a carbapenem and n = 2 resistant to a third-generation cephalosporin only) compared to those receiving culture-negative allografts (25.0% versus 11.1%, p = 0.04). MDR Klebsiella pneumoniae (aHR 3.31, 95%CI 0.95-11.56) and Stenotrophomonas maltophilia (aHR 5.35, 95%CI 1.26-22.77) were associated with an increased risk for CLAD compared to negative cultures. CONCLUSION: Our data suggest the potential safety of using lung allografts with MDR bacteria in the setting of appropriate prophylaxis; however, caution should be exercised in the case of MDR Klebsiella pneumoniae.

Genomic Surveillance and Mutation Analysis of SARS-CoV-2 Variants among Patients in Saudi Arabia.

The genome of severe acute respiratory coronavirus-2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), has undergone a rapid evolution, resulting in the emergence of multiple SARS-CoV-2 variants with amino acid changes. This study aimed to sequence the whole genome of SARS-CoV-2 and detect the variants present in specimens from Saudi Arabia. Furthermore, we sought to analyze and characterize the amino acid changes in the various proteins of the identified SARS-CoV-2 variants. A total of 1161 samples from patients diagnosed with COVID-19 in Saudi Arabia, between 1 April 2021 and 31 July 2023, were analyzed. Whole genome sequencing was employed for variant identification and mutation analysis. The statistical analysis was performed using the Statistical Analytical Software SAS, version 9.4, and GraphPad, version 9.0. This study identified twenty-three variants and subvariants of SARS-CoV-2 within the population, with the Omicron BA.1 (21K) variant (37.0%) and the Delta (21J) variant (12%) being the most frequently detected. Notably, the Omicron subvariants exhibited a higher mean mutation rate. Amino acid mutations were observed in twelve proteins. Among these, the spike (S), ORF1a, nucleocapsid (N), and ORF1b proteins showed a higher frequency of amino acid mutations compared to other the viral proteins. The S protein exhibited the highest incidence of amino acid mutations (47.6%). Conversely, the ORF3a, ORF8, ORF7a, ORF6, and ORF7b proteins appeared more conserved, demonstrating the lowest percentage and frequency of amino acid mutations. The investigation of structural protein regions revealed the N-terminal S1 subunit of the S protein to frequently harbor mutations, while the N-terminal domain of the envelope (E) protein displayed the lowest mutation frequency. This study provides insights into the variants and genetic diversity of SARS-CoV-2, underscoring the need for further research to comprehend its genome evolution and the occurrence of mutations. These findings are pertinent to the development of testing approaches, therapeutics, and vaccine strategies.

Invasive fungal infection due to Triadelphia pulvinata in a patient with acute myeloid leukemia.

Triadelphia pulvinata is a rare dematiaceous fungus found in soil. We report the first case of invasive disease in a patient with acute myeloid leukemia who had a bloodstream infection with possibly both lung and brain involvement. Identification was by combined phenotypic features and fungal ribosomal DNA sequence analysis.

Association of SARS-CoV-2 Nucleocapsid Protein Mutations with Patient Demographic and Clinical Characteristics during the Delta and Omicron Waves.

SARS-CoV-2 genomic mutations outside the spike protein that may increase transmissibility and disease severity have not been well characterized. This study identified mutations in the nucleocapsid protein and their possible association with patient characteristics. We analyzed 695 samples from patients with confirmed COVID-19 in Saudi Arabia between 1 April 2021, and 30 April 2022. Nucleocapsid protein mutations were identified through whole genome sequencing. 𝜒2 tests and t tests assessed associations between mutations and patient characteristics. Logistic regression estimated the risk of intensive care unit (ICU) admission or death. Of the 60 mutations identified, R203K was the most common, followed by G204R, P13L, E31del, R32del, and S33del. These mutations were associated with reduced risk of ICU admission. P13L, E31del, R32del, and S33del were also associated with reduced risk of death. By contrast, D63G, R203M, and D377Y were associated with increased risk of ICU admission. Most mutations were detected in the SR-rich region, which was associated with low risk of death. The C-tail and central linker regions were associated with increased risk of ICU admission, whereas the N-arm region was associated with reduced ICU admission risk. Consequently, mutations in the N protein must be observed, as they may exacerbate viral infection and disease severity. Additional research is needed to validate the mutations' associations with clinical outcomes.

SARS-CoV-2 spike gene Sanger sequencing methodology to identify variants of concern.

The global demand for rapid identification of circulating SARS-CoV-2 variants of concern has led to a shortage of commercial kits. Therefore, this study aimed to develop and validate a rapid, cost-efficient genome sequencing protocol to identify circulating SARS-CoV-2 (variants of concern). Sets of primers flanking the SARS-CoV-2 spike gene were designed, verified and then validated using 282 nasopharyngeal positive samples for SARS-CoV-2. Protocol specificity was confirmed by comparing these results with SARS-CoV-2 whole-genome sequencing of the same samples. Out of 282 samples, 123 contained the alpha variant, 78 beta and 13 delta, which were indicted using in-house primers and next-generation sequencing; the numbers of variants found were 100% identical to the reference genome. This protocol is easily adaptable for detection of emerging variants during the pandemic.

Epidemiological characteristics, clinical course, and laboratory investigation of pediatric COVID-19 patients in a tertiary care center in Saudi Arabia.

Background: Since the initial emergence of the novel SARS-CoV-2 coronavirus responsible for the 2019 coronavirus disease (COVID-19) pandemic, many studies have been exploring the nature and characteristics of this virus and its associated clinical manifestations. The present study aimed to describe the clinical presentation and outcomes of COVID-19 infections in pediatric patients. Methods: A retrospective review of findings associated with 143 pediatric patients (age <14 years) with a confirmed COVID-19 diagnosis who had undergone inpatient or outpatient treatment at King Faisal Specialist Hospital and Research Center in Riyadh, Saudi Arabia, between March 2020 and October 2020, was conducted. The analyzed data included patient demographic information, pre-existing medical conditions, symptoms, interventions, and outcomes. Results: The median age of this patient population was 7 years. Of these 143 patients, 67 (46.8%) had known pre-existing medical conditions including bronchial asthma (12.8%), chronic lung disease (CLD) (3%), congenital heart disease (CHD) (17%), primary immunodeficiencies (1.5%), malignancies (9.8%), and 7.5% were post-transplant patients. Thirty-seven patients (26%) were overweight or obese. Sixty-three of these patients (51%) were symptomatic, with the most common symptom being fever (55%). Ultimately, 45 patients (31%) required admission to the hospital, with a median duration of hospitalization of 9.6 days for admitted patients. There were no documented cases of infection-related mortality among this pediatric cohort, although 11 patients experienced post-infectious complications that primarily manifested as a loss of taste and smell. Conclusion: These findings suggest that pediatric COVID-19 patients tend to experience mild forms of the disease, without any significant differences in disease severity as a function of patient gender or immune status.

Epidemiology and Clinical Characteristics of People with Confirmed SARS-CoV-2 Infection during the Early COVID-19 Pandemic in Saudi Arabia.

This study provides epidemiologic and clinical characteristics of 492 consecutive patients diagnosed with SARS-CoV-2 infection at King Faisal Specialist Hospital and Research Centre in Saudi Arabia between March and September 2020. Data were collected from electronic case reports. The cohort was 54% male, with 20.4% aged >60 years, 19.9% aged 31−40 years, and 17% aged 41−50 years. The median incubation period was 16 days, with upper and lower 95% quartiles of 27 and 10 days, respectively. Most patients (79.2%) were symptomatic. Variables significantly different between symptomatic and asymptomatic patients were age, blood oxygen saturation percentage, hemoglobin level, lymphocyte count, neutrophil to lymphocyte (NTL) ratio, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level. Asymptomatic patients were mostly younger, with lower body mass index and ALT and AST levels but higher lymphocyte counts, NTL ratio, and CD4, CD8, natural killer cell, IgG, and IgM levels. Factors associated with increased risk of mortality were age (>42 years) and comorbidities, particularly diabetes mellitus and hypertension. Patients who were not given an antiviral regimen were associated with better prognosis than patients who received an antiviral regimen (HR, 0.07; 95% CI, 0.011−0.25). These findings will help clinicians and policymakers adopt best management and treatment options for SARS-CoV-2 infection.

Seroprevalence of SARS-CoV-2 antibodies in healthcare workers at a tertiary care hospital in Riyadh, Saudi Arabia.

Background: The SARS-CoV-2 pandemic has led to a strain on medical resources. The development of countermeasures to prevent its spread is evolving. Healthcare workers (HCWs) are at high risk for contracting and transmitting the disease. Methods: Serology testing of volunteer HCWs was performed at King Faisal Specialist Hospital and Research Center in Riyadh (the Center) in order to determine the prevalence of SARS-CoV-2 antibodies, as well as the associated risk factors, in the hope of implementing adequate prevention and control measures. Results: 1076 subjects participated in this study, of whom 24.3% were seropositive. The majority were nurses (379, 35%) or physicians (245, 22.2%). 392 (36.4%) of the 1076 subjects were caregivers for COVID-19 patients, and 463 (43.0%) reported contact with infected employees. There was a statistically significant association between taking care of COVID-19 patients and being diagnosed with COVID-19 (chi-square test, p = 0.046). There was a significant association between being in contact with infected employees and having a positive IgG result (chi-square test, p < 0.001). Conclusions: A baseline analysis of SARS-CoV-2 seropositivity in HCWs at a large tertiary care hospital in Riyadh was performed as the first part of a prospective study of HCWs. The reported seropositivity was 24.3% - higher than that of other hospitals in Riyadh. IgG testing was very useful in the detection of previous SARS-CoV-2 infection, as it has high negative predictive value.