COVID-19 Among Children With Chronic Renal Diseases in Qatar

In this retrospective study investigators will include all children and adolescents (≤ 18 years old) with pre-existing CKD and laboratory-confirmed SARS-CoV-2 infection who were treated at Hamad General Hospital, in Doha, Qatar during this pandemic using the electronic medical records from 1st March 2020 till January 20th, 2022. Indications for testing patients for SARS CoV-2 infection included: * Clinical features suggestive of COVID-19 (fever, cough, dyspnea, rhinorrhea, sore throat, diarrhea, myalgia, anosmia, or ageusia). * Close contact (within 6-ft of an infected person for 15 min or longer) within an individual diagnosed with SARS-CoV-2 infection. * Admission for management of the underlying disease. Testing for SARS-CoV-2 infection was performed on nasal and oropharyngeal swabs using reverse transcriptase polymerase chain reaction (RT-PCR) or rapid antigen test. Indications for hospital admission were: * symptomatic infection, particularly in an immunosuppressed host. * management of the underlying illness. * inability to ensure home isolation. Data on clinical and laboratory findings are reviewed from medical records for details of underlying disease, the severity of COVID-19 and associated complications, testing methods for SARS-CoV-2 virus and duration of RT-PCR positivity, therapy received, and duration of hospital stay. Underlying CKD was categorized as nephrotic syndrome, other kidney diseases with CKD stage 1-5. In patients with nephrotic syndrome, the presence of nephrotic-range proteinuria at evaluation at onset, relapse, or following non-response to immunosuppression, was considered as 'relapse'. The Patients will be followed up until discharge, death, or 4weeks after diagnosis of COVID-19, whichever was earlier, until 20 January. Hypertension was defined using standard guidelines. The estimated glomerular filtration rate (eGFR) was calculated using the modified Schwartz formula. Investigators will look for the clinical manifestations, radiological and laboratory findings, severity of COVID-19 infection, prevalence and difference between waves of the pandemic, median age, gender, and ethnic background. Underlying illness, renal treatment, reinfection, correlation with vaccination. Participants are divided into three groups; first wave, second wave, and third wave