RESUMO
The aetiologic agent of COVID-19 is a novel coronavirus, SARS-CoV-2. Like other coronaviruses, it generally induces enteric and respiratory diseases in animals and humans. COVID-19 may be subclinical, and symptomatic, ranging from mild-to-severe disease. The spectrum of presentation is the result of several factors ranging from the inoculum size, inherent host susceptibility, possible cross-reacting circulating antibodies. Subclinical viral infections are associated with widespread community transmission and in some cases like Polio, herd immunity. An understanding of the biology and immune behavior in subclinical coronavirus disease 2019 (COVID-19) might be useful in the quest for vaccine development as well as the current control efforts against the COVID-19 pandemic. We carried out a narrative review of the available literature on the biology, etiopathogenesis, clinical manifestation of SARS-CoV-2 viral infection, focusing on our current understanding of the disease mechanisms and its clinical manifestation, and the host immune response to the infection. We also highlighted some of the research gaps regarding subclinical infection in COVID-19 and its potential application for vaccine development and other preventive efforts toward containing the current COVID-19 pandemic.
RESUMO
BACKGROUND: Hemodialysis (HD) is the main form of renal replacement therapy available in Nigeria. However, this is still largely unaffordable by individuals with resultant poor outcomes. METHODS: This was a retrospective study of all patients with renal failure who had dialysis in the renal unit of Dalhatu Araf Specialist Hospital over the past 2 years. Information retrieved included sex, age, cause of renal failure, human immunodeficiency virus status, hepatitis B surface antigen status, antibodies to hepatitis C virus status, number of sessions, total duration on dialysis (in weeks), use of erythropoietin (EPO), common problems encountered on the dialysis machine, and the outcome of the patient. RESULTS: A total of 68 patients (50% males) were enrolled in the study. The mean age was 41 ± 15 years (17-75), and mean weight in kilograms was 64.3 ± 10.9 (42-87). Acute kidney injury was seen in 18 (26.5%), while 50 (73.5%) had end-stage renal disease (ESRD). Chronic glomerulonephritis was the leading cause of ESRD (46%) with autosomal dominant polycystic kidney disease being the least (2%). The mean packed cell volume at the start of dialysis was 25.7% ± 5.9%. Tunneled necklines were in 11 (16.8%) and femoral catheters were in 48 (70.6%). The median total number of sessions was 4.0 (1-136), while the median duration on dialysis was 1 week (1-48) with both sexes having the same duration on dialysis (P = 0.44). The average frequency of dialysis among those with ESRD was twice weekly. Only 15 (30.0%) of those with ESRD continued dialysis after 3 months. The median survival time for females was 5 weeks while that for the males was 20 weeks (P = 0.108). EPO use was in 12 (17.7%) being 4000 IU once weekly. Cramps complicated the first sessions of dialysis in 27 (39.7%) patients. CONCLUSION: The survival of patients on HD in our environment is poor due largely to poor affordability despite its availability.