Seroprevalence of SARS-CoV-2 (COVID-19) among Healthcare Workers in Saudi Arabia: Comparing Case and Control Hospitals

Healthcare workers (HCWs) stand at the frontline for fighting coronavirus disease 2019 (COVID-19) pandemic. This puts them at higher risk of acquiring the infection than other individuals in the community. Defining immunity status among health care workers is therefore of interest since it helps to mitigate the exposure risk. This study was conducted between May 20th and 30th, 2020. Eighty-five hospitals across Kingdom of Saudi Arabia were divided into 2 groups: COVID-19 referral hospitals are those to which RT-PCR-confirmed COVID-19 patients were admitted or referred for management (Case-hospitals). COVID-19 nonaffected hospitals where no COVID-19 patients had been admitted or managed and no HCW outbreak (Control hospitals). Next, seroprevalence of severe acute respiratory syndrome coronavirus 2 among HCWs was evaluated; there were 12,621 HCWs from the 85 hospitals. There were 61 case-hospitals with 9379 (74.3%) observations, and 24 control-hospitals with 3242 (25.7%) observations. The overall positivity rate by the immunoassay was 299 (2.36%) with a significant difference between the case-hospital (2.9%) and the control-group (0.8%) (P value <0.001). There was a wide variation in the positivity rate between regions and/or cities in Saudi Arabia, ranging from 0% to 6.31%. Of the serology positive samples, 100 samples were further tested using the SAS2pp neutralization assay; 92 (92%) samples showed neutralization activity. The seropositivity rate in Kingdom of Saudi Arabia is low and varies across different regions with higher positivity in case-hospitals than control-hospitals. The lack of neutralizing antibodies (NAb) in 8% of the tested samples could mean that assay is a more sensitive assay or that neutralization assay has a lower detection limits; or possibly that some samples had cross-reaction to spike protein of other coronaviruses in the assay, but these were not specific to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Colonic basidiobolomycosis presenting with intestinal obstruction and a normal eosinophil count

Gastrointestinal basidiobolomycosis (GIB), caused by Basidiobolus ranrum, is a rare fungal infection with a limited geographic distribution. The majority of the cases are reported from the warm areas of Arizona in USA, Saudi Arabia and Iran.We report a middle aged patient who was admitted to hospital with suspected metastatic colonic carcinoma. He presented with constipation, anorexia and weight loss. Computed tomography scan disclosed a mass involving the mid and distal sigmoid colon and hypodense lesion in hepatic segment IV. Excised tissue during a Hartmann’s surgery showed an extensive eosinophil-rich transmural inflammation with mural necrotizing granulomas and several broad septated fungal hyphae. He was commenced on voriconazole following surgery. The diagnosis of basidiobolomycosis was established by histopathological examination. Since the diagnosis was not suspected preoperatively tissue culture for fungi was not collected. However molecular testing confirmed the diagnosis of GIB. Therapy involved a combination of surgical resection of the mass and prolonged voriconazole treatment. Increased awareness among physicians is needed for early diagnosis and treatment of GIB. Keywords: Fungal, Gastrointestinal, Basidiobolomycosis, Colon cance

Disseminated angioinvasive basidiobolomycosis with a favourable outcome

Basidiobolomycosis, a rare fungal infection, is of worldwide distribution but areas commonly involved include the tropical areas of Africa, USA and South East Asia. 88% of the cases are reported among patients younger than 20 years. Many of the case reports in Saudi Arabia are from Tohama area where our patient lives. The diagnosis tends to be overlooked as the presentation may mimic colonic carcinoma in adults or inflammatory bowel diseases and tuberculosis in both children and adults. Angioinvasion seen in our patient is extremely rare suggesting the diagnosis of mucormycosis and resulting in a delay in choosing the most appropriate treatment. We report this case to remind physicians and surgeons to consider this diagnosis in patients from endemic area presenting with such conditions. Keywords: Zygomycetes, Basidiobolomycosis, Mucormycosis, Eosinophilia, Angioinvasio

Development and Validation of Reverse Transcriptase Loop-Mediated Isothermal Amplification (RT-LAMP) as a Simple and Rapid Diagnostic Tool for SARS-CoV-2 Detection

Since the COVID-19 pandemic outbreak in the world, many countries have searched for quick diagnostic tools to detect the virus. There are many ways to design diagnostic assays; however, each may have its limitations. A quick, sensitive, specific, and simple approach is essential for highly rapidly transmitted infections, such as SARS-CoV-2. This study aimed to develop a rapid and cost-effective diagnostic tool using a one-step Reverse Transcriptase Loop-Mediated Isothermal Amplification (RT-LAMP) approach. The results were observed using the naked eye within 30&ndash;60 min using turbidity or colorimetric analysis. The sensitivity, specificity, and lowest limit of detection (LoD) for SARS-CoV-2 RNA against the RT-LAMP assay were assessed. This assay was also verified and validated against commercial quantitative RT-PCR used by health authorities in Saudi Arabia. Furthermore, a quick and direct sampling from the saliva, or buccal cavity, was applied after simple modification, using proteinase K and heating at 98 &deg;C for 5 min to avoid routine RNA extraction. This rapid single-tube diagnostic tool detected COVID-19 with an accuracy rate of 95% for both genes (ORF1a and N) and an LoD for the ORF1a and N genes as 39 and 25 copies/reaction, respectively. It can be potentially used as a high-throughput national screening for different respiratory-based infections within the Middle East region, such as the MERS virus or major zoonotic pathogens such as Mycobacterium paratuberculosis and Brucella spp., particularly in remote and rural areas where lab equipment is limited