COVID-19 Pandemic: Is Africa Different?

COVID-19 has now spread to all the continents of the world with the possible exception of Antarctica. However, Africa appears different when compared with all the other continents. The absence of exponential growth and the low mortality rates contrary to that experienced in other continents, and contrary to the projections for Africa by various agencies, including the World Health Organization (WHO) has been a puzzle to many. Although Africa is the second most populous continent with an estimated 17.2% of the world's population, the continent accounts for only 5% of the total cases and 3% of the mortality. Mortality for the whole of Africa remains at a reported 19,726 as at August 01, 2020. The onset of the pandemic was later, the rate of rise has been slower and the severity of illness and case fatality rates have been lower in comparison to other continents. In addition, contrary to what had been documented in other continents, the occurrence of the renal complications in these patients also appeared to be much lower. This report documents the striking differences between the continents and within the continent of Africa itself and then attempts to explain the reasons for these differences. It is hoped that information presented in this review will help policymakers in the fight to contain the pandemic, particularly within Africa with its resource-constrained health care systems.

Renal failure in HIV-positive patients-a South African experience.

BACKGROUND: Kidney disease is a major complication of HIV infection, with both acute kidney injury (AKI) and chronic kidney disease (CKD) contributing to morbidity and mortality. Incidence of AKI was reported as 5.9 per 100 patient years in ambulatory patients and ∼18% in hospitalized HIV-infected patients, an almost 3-fold higher risk compared with HIV uninfected patients in developed countries. CKD was reported in 6-48.5% of HIV-infected patients in Africa. There is a paucity of data regarding the prevalence and outcomes of AKI in HIV-infected patients in sub-Saharan Africa, the region most affected by HIV. METHODS: A retrospective review of 101 HIV-positive anti-retroviral therapy (ART)-naïve patients presenting with renal failure from 1 October 2005 to 30 September 2006 was undertaken. RESULTS: A total of 684 patients presented with renal failure, 101 (14.8%) of whom were HIV positive. Ninety-nine (98%) of HIV-positive patients were black and 56 (55%) were male, with mean age 38 ± 9.9 years (range 21-61 years). HIV-positive patients demonstrated severe immunosuppression, with mean CD4 count of 135 cells/µL (range 1-579 cells/µL). Fifty-seven (56%) HIV-positive patients presented with AKI, 21 (21%) with acute-on-chronic kidney disease and 23 (23%) with CKD; seven patients with AKI were excluded due to lack of records. The causes of AKI in the HIV-positive group included sepsis (60%), volume depletion and haemodynamic instability (19%), toxins (9%), urological obstruction (7%) and miscellaneous (14%). Forty-four per cent of HIV-positive and 47% of HIV-negative patients with AKI demised; P = 0.45. Hyponatraemia (P = 0.018), acidosis (P = 0.018), anaemia (P = 0.019) and hyperphosphataemia (P = 0.003) were predictors of mortality in HIV-positive patients with AKI. In comparison, predictors of mortality in the HIV-negative group were age (P = 0.023) and black ethnicity (P = 0.04). CONCLUSION: HIV-positive patients, compared with the HIV-negative group, presented with AKI at a younger age and at an advanced stage of immunosuppression. Appropriate support, including dialysis, resulted in similar outcomes in both groups.

Urinary screening abnormalities in antiretroviral-naive HIV-infected outpatients and implications for management--a single-center study in South Africa.

Few urinary screening studies have been performed to determine the incidence of urinary abnormalities in antiretroviral therapy-naive, HIV-infected outpatients. From published data, the incidence appears to be high, particularly when compared with populations outside sub-Saharan Africa. In South Africa, urinary screening in antiretroviral therapy clinics is not routinely practiced. The aim of this descriptive study was to screen antiretroviral therapy-naive, HIV-infected outpatients attending the HIV clinic for urinary abnormalities, namely leukocyturia, microscopic hematuria, and microalbuminuria/proteinuria. This study showed that 84% of the screened population had AIDS (CD4 count < 200 cells/ mm3), and the incidence of abnormalities on urinary dipstick testing was high: 30% had leukocyturia, 33% had microscopic hematuria, and 44% had microalbuminuria/proteinuria. In patients with leukocyturia, an infective organism was cultured in only 29.1% of cases, predominantly Escherichia coli (70%) with sterile leukocyturia comprising the remainder. There may be an association with tuberculosis (TB) or sexually transmitted infections (STI) in the sterile leucocyturia group, but this remains to be confirmed. In those with a culture positive result the most common organism was E. coli (70%), which exhibited 90% resistance to cotrimoxazole, demonstrating that cotrimoxazole prophylaxis is not effective to prevent urinary tract infection in this group. On the basis of these findings, it has been proposed that urinary screening be considered standard of care in HIV clinics in South Africa. An algorithm has been proposed for use in antiretroviral therapy clinics in South Africa to guide clinicians regarding the cost-effective management of urinary dipstick abnormalities.

Infection and glomerulonephritis.

Glomerular injury, occurring either as primary glomerular disease or as part of a systemic disease process, is usually a result of immune-mediated mechanisms. The morphologic reaction pattern has a diverse spectrum of appearance, ranging from normal by light microscopy in minimal change disease to crescentic forms of glomerulonephritis, with conspicuous disruption of the normal glomerular morphology. The mechanisms of glomerular immune deposit formation include trapping of circulating antigen-antibody complexes and the in situ formation of immune complexes within the glomerulus. While the majority of postinfectious immune-complex-mediated glomerulonephritides are believed to result from the deposition of circulating antigen-antibody complexes, preformed outside of the kidney and secondarily deposited in the kidney, the notion of forming in situ antigen-antibody complexes to either planted antigens or to integral structural components of the glomerulus, through "cross-reacting" autoimmune reactions, is gaining popularity in a variety of forms of glomerulonephritides. Patients with HIV infection may develop a spectrum of renal pathology, the glomerular manifestations of which include both antigen-antibody complex and nonimmune-complex-mediated pathogenetic mechanisms. Similarly, patients with Streptococcal infections, Hepatitis B virus, or Hepatitis C virus infection may develop a spectrum of glomerulonephritides, which are predominantly immune-complex-mediated. Therapy for glomerular diseases due to HIV, hepatitis B, or C virus infections remains a challenge.