De-isolation of vaccinated COVID-19 health care workers using rapid antigen detection test.

BACKGROUND: COVID-19 de-isolation guidelines of health care workers (HCW) were formulated based on evidence describing the duration of infectious viral shedding of the wild SARS-CoV-2 virus. During the periods of COVID-19 vaccination and variants, a test-based approach was recommended to end isolation of HCW, based on emerging data describing the viral kinetics of COVID-19 variants. While Rapid antigen detection tests (RADT) are increasingly used in the diagnosis of COVID-19, their use is limited in de-isolation. METHODS: We described the use of RADT in the de-isolation of COVID-19 vaccinated HCW with mild infection who were asymptomatic on day 7 post diagnosis in a single center retrospective cohort study during the Omicron surge. RESULTS: Of the 480 HCWs, 173 (36%) had positive RADT. The positivity rate of RADT was not different in HCW who received two doses versus three doses of vaccine (34.4% versus 40.3%, p = 0.239). CONCLUSIONS: A symptom based, test-based approach using RADT is a useful tool in the de-isolation of HCW, with mild disease, in the era of Omicron. Further studies are required to evaluate the role of RADT in de-isolation of patients with severe COVID-19 disease.

Active viral shedding in a vaccinated hospitalized patient infected with the delta variant (B.1.617.2) of SARS-CoV-2 and challenges of de-isolation.

In the era of SARS-CoV-2 variants and COVID-19 vaccination, the duration of infectious viral shedding and isolation in post vaccine breakthrough infections is challenging and depends on disease severity. The current study described a case of SARS-CoV-2 Delta variant pneumonia requiring hospitalization. The patient received two doses of BNT162b2 COVID-19 vaccines, and he had positive SARS-CoV-2 viral cultures 12 days post symptom onset. The time between the second dose of vaccine and the breakthrough infection was 6 months. While immunosuppression is a known risk factor for prolonged infectious viral shedding, age and time between vaccination and breakthrough infection are important risk factors that warrant further studies.

Outcome of COVID19 in Patients With Osteogenesis Imperfecta: A Retrospective Multicenter Study in Saudi Arabia.

Background: Although genetic diseases are rare, children with such conditions who get infected with COVID-19 tend to have a severe illness requiring hospitalization. Osteogenesis imperfecta (OI) is a rare genetic disorder of collagen resulting in fractures and skeletal deformities. Kyphoscoliosis, restrictive lung disease, and pneumonia worsen the prognosis of patients with OI. The use of bisphosphonate improves bone mineral density (BMD) and reduces fractures in OI. There is no literature describing the impact of COVID-19 in patients with OI. Methodology: A retrospective multi-center study was performed in three hospitals in Jeddah and Riyadh, Saudi Arabia, from March 1st, 2020, until August 31st, 2021, aiming to evaluate the outcome of COVID-19 in patients with OI. Demographics, vaccination status, underlying kyphoscoliosis, functional status, use of bisphosphonate, BMD, and COVID-19 severity, and course were recorded for all patients. Results: Twelve cases of confirmed COVID-19 were identified among 146 patients with OI. 9 (75%) of patients were less than 18 years, 6 (50%) were male, 5 (41%) had kyphoscoliosis, and 5 (41%) were wheelchair-bound. 6 (50%) received bisphosphonate, and 7(58%) had normal BMD. All patients had mild disease and did not require hospitalization. None of OI the patients with COVID-19 were fully vaccinated before the infection, and some were ineligible for vaccination. Conclusion: Patients with OI and COVID-19 in our study recovered without complications, unlike patients with other genetic diseases. Young age and mild illness contributed to the favorable outcome. Half of the patients received bisphosphonate and had normal BMD.

Outcome of SARS-CoV-2 variant breakthrough infection in fully immunized solid organ transplant recipients.

SARS-CoV-2 vaccination in solid organ transplant recipients is associated with suboptimal immune response and risk for breakthrough infection. It is not known whether they are at risk of severe post-vaccine breakthrough infections in the presence of SARSCoV-2 variant of concern. We describe a case series of four fully vaccinated solid organ transplant recipients who developed SARS-CoV-2 variants of concern breakthrough infections. Three patients received BNT162b2 mRNA (Pfizer-BioNTech) and one patient received ChAdOx1 (AZD12220) COVID-19 vaccines. The patients were infected with SARS-CoV-2 variants circulating in Saudi Arabia. Two patients were infected with Alpha variant and had severe pneumonia requiring intensive care admission and ventilatory support and subsequently died. The other two patients recovered; one patient was infected with Beta variant required low supplemental oxygen via nasal flow and the other patient was infected with Delta variant and required high supplemental oxygen nasal flow. Younger patients had a better outcome than older patients. Future large studies are required to confirm our observations and to compare the different vaccine efficacy among solid organ transplants in the era of SARS-CoV-2 variants of concern.

Test-based de-isolation in COVID-19 immunocompromised patients: Cycle threshold value versus SARS-CoV-2 viral culture.

BACKGROUND: Immunocompromised patients with coronavirus disease 2019 (COVID-19) have prolonged infectious viral shedding for more than 20 days. A test-based approach is suggested for de-isolation of these patients. METHODS: The strategy was evaluated by comparing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load (cycle threshold (Ct) values) and viral culture at the time of hospital discharge in a series of 13 COVID-19 patients: six immunocompetent and seven immunocompromised (five solid organ transplant patients, one lymphoma patient, and one hepatocellular carcinoma patient). RESULTS: Three of the 13 (23%) patients had positive viral cultures: one patient with lymphoma (on day 16) and two immunocompetent patients (on day 7 and day 11). Eighty percent of the patients had negative viral cultures and had a mean Ct value of 20.5. None of the solid organ transplant recipients had positive viral cultures. CONCLUSIONS: The mean Ct value for negative viral cultures was 20.5 in this case series of immunocompromised patients. Unlike those with hematological malignancies, none of the solid organ transplant patients had positive viral cultures. Adopting the test-based approach for all immunocompromised patients may lead to prolonged quarantine. Large-scale studies in disease-specific populations are needed to determine whether a test-based approach versus a symptom-based approach or a combination is applicable for the de-isolation of various immunocompromised patients.

Re-infection with a different SARS-CoV-2 clade and prolonged viral shedding in a hematopoietic stem cell transplantation patient.

Immunocompromised patients who have a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection pose many clinical and public health challenges. We describe the case of a hematopoietic stem cell transplantation patient with lymphoma who had a protracted illness requiring three consecutive hospital admissions. Whole genome sequencing confirmed two different SARS-CoV-2 clades. Clinical management issues and the unanswered questions arising from this case are discussed.

Seroprevalence of neutralizing antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare workers in Makkah, Saudi Arabia.

OBJECTIVE: The new coronavirus disease 2019 (COVID-19) is a major health problem worldwide. The surveillance of seropositive individuals serves as an indicator to the extent of infection spread and provides an estimation of herd immunity status among population. Reports from different countries investigated this issue among healthcare workers (HCWs) who are "at risk" and "sources of risk" for COVID-19. This study aims to investigate the seroprevalence of COVID-19 among HCWs in one of the COVID-19 referral centers in Makkah, Saudi Arabia using three different serological methods. METHODS: In-house developed enzyme-linked immunoassay (ELISA), commercially available electro-chemiluminescence immunoassay (ECLIA), and microneutralization (MN) assay were utilized to determine the seroprevalence rate among the study population. 204 HCWs participated in the study. Both physicians and nurses working in the COVID-19 and non COVID-19 areas were included. Twelve out of 204 were confirmed cases of COVID-19 with variable disease severity. Samples from recovered HCWs were collected four weeks post diagnosis. RESULTS: The overall seroprevalence rate was 6.3% (13 out of 204) using the in-house ELISA and MN assay and it was 5.8% (12 out of 204) using the commercial ECLIA. Among HCWs undiagnosed with COVID-19, the seroprevalence was 2% (4 out 192). Notably, neutralizing antibodies were not detected in 3 (25%) out 12 confirmed cases of COVID-19. CONCLUSIONS: Our study, similar to the recent national multi-center study, showed a low seroprevalence of SARS-Cov-2 antibodies among HCWs. Concordance of results between the commercial electro-chemiluminescence immunoassay (ECLIA), in-house ELISA and MN assay was observed. The in-house ELISA is a promising tool for the serological diagnosis of SARS-CoV-2 infection. However, seroprevalence studies may underestimate the extent of COVID-19 infection as some cases with mild disease did not have detectable antibody responses.