Impact of rural versus urban setting on kidney markers: a cross-sectional study in South-Kivu, DRCongo.

BACKGROUND: Most studies of chronic kidney disease (CKD) in Sub-Saharan Africa (SSA) have been conducted in urban settings. They relied on GFR estimated from serum creatinine alone and on the inexpensive, convenient urinary dipstick to assess proteinuria. The dipstick for proteinuria has not been directly compared with the gold standard albumin-to-creatinine ratio (ACR) in a large-sized study in SSA. We hereby assessed the influence of rural versus urban location on the level, interpretation, and diagnostic performance of proteinuria dipstick versus ACR. METHODS: In a cross-sectional population-based study of CKD in both urban (n = 587) and rural (n = 730) settings in South-Kivu, Democratic Republic of Congo (DRC), we assessed the prevalence, performance (sensitivity, specificity, positive predictive value and negative predictive value) and determinants of a positive dipstick proteinuria as compared with albuminuria (ACR). Albuminuria was subdivided into: A1 (< 30 mg/g creatinine), A2 (30 to 299 mg/g creatinine) and A3 (≥ 300 mg/g creatinine). RESULTS: The overall prevalence of positive dipstick proteinuria (≥ 1+) was 9.6 % (95 % CI, 7.9-11.3) and was higher in rural than in urban residents (13.1 % vs. 4.8 %, p < 0.001), whereas the prevalence of albuminuria (A2 or A3) was similar in both sites (6 % rural vs. 7.6 % urban, p = 0.31). In both sites, dipstick proteinuria ≥ 1 + had a poor sensitivity (< 50 %) and positive predictive value (< 11 %) for the detection of A2 or A3. The negative predictive value was 95 %. Diabetes [aOR 6.12 (1.52-24.53)] was a significant predictor of A3 whereas alkaline [aOR 7.45 (3.28-16.93)] and diluted urine [aOR 2.19 (1.35-3.57)] were the main predictors of positive dipstick proteinuria. CONCLUSIONS: ACR and dipstick proteinuria have similar positivity rates in the urban site whereas, in the rural site, dipstick was 2-fold more often positive than ACR. The poor sensitivity and positive predictive value of the dipstick as compared with ACR makes it unattractive as a screening tool in community studies of CKD in SSA.

Prevalence of microalbuminuria and diagnostic value of dipstick proteinuria in outpatients from HIV clinics in Bukavu, the Democratic Republic of Congo.

BACKGROUND: Microalbuminuria is a marker of early kidney disease and high cardiovascular risk in various populations, including HIV positive patients. However, the diagnostic value of qualitative (dipstick) proteinuria and the burden of microalbuminuria in HIV positive patients living in sub-Saharan Africa are relatively unclear. METHODS: In a cross-sectional study, 235 HIV- positive outpatients were screened for proteinuria in 3 HIV-clinics in Bukavu. A spot urine sample from each subject was tested both by a dipstick and albumin-creatinine-ratio (ACR) assay. The performance of dipstick proteinuria exceeding 1+ was compared with that of microalbuminuria (≥ 30 mg/g creatinine). RESULTS: The prevalence of microalbuminuria and dipstick proteinuria ≥ (1+), ≥ (2+) and ≥ (3+) was 11%, 41%, 3.5% and 0.7%, respectively.Compared to microalbuminuria, the dipstick (proteinuria of 1+ or greater) had an overall sensitivity of 60% and a specificity of 61%. The positive predictive value was 15.4% and the negative predictive value 92.8%. CONCLUSION: Proteinuria is highly prevalent in HIV positive patients. The limited sensitivity and specificity of the dipstick to detect significant microalbuminuria make it unattractive as a screening tool in HIV positive patients.

APOL1 Renal Risk Variants and Sickle Cell Trait Associations With Reduced Kidney Function in a Large Congolese Population-Based Study.

Introduction: APOL1, GSTM1 risk variants, and sickle cell trait (SCT) are associated with chronic kidney disease (CKD) among African Americans (AAs). Nevertheless, such evidence remains scarce in sub-Saharan Africa (SSA) populations. Methods: In a cross-sectional study, we evaluated the prevalence of these risk variants and their association with estimated glomerular filtration rate (eGFR), albuminuria, and CKD in urban (n = 587) and rural (n = 730) adults from South-Kivu, DR Congo (DRC). Furthermore, we evaluated APOL1 recessive model (high risk [HR] vs. low risk [LR]), SCT carriage, and the active versus inactive GSTM1 genotypes. Results: The frequencies of the APOL1 G1 and G2 alleles were 8.7% and 9.1%, respectively, and 3.2% carried the HR genotype. SCT and GSTM1 null allele frequencies were 3.8% and 51.2%, respectively. APOL1 HR was associated with lower eGFR (P = 0.047, odds ratio [OR] = 4). Individuals with SCT exhibited lower eGFR (P = 0.018), higher albuminuria (P = 0.032), and 2.4× increased risk of CKD (P = 0.031). APOL1 HR and SCT were synergistically associated with lower eGFR (P interaction = 0.012). The GSTM1 null allele was not significantly associated with any renal outcomes. Conclusion: Our study highlighted the impact of APOL1 and SCT variants on poorer renal outcomes in the DRC and advocates for further genetic studies in SSA settings.

Atypical respiratory distress in eastern Democratic Republic of the Congo prior to the COVID-19 pandemic. A case report.

BACKGROUND: Predictions have been made that Africa would be the most vulnerable continent to the novel Coronavirus disease 2019 (COVID-19). Interestingly, the spread of the disease in Africa seems to have been delayed and initially slower than in many parts of the world. Here we report on two cases of respiratory distress in our region before the official declaration of the disease in December 2019, cases which in the present times would be suspect of COVID-19. CASE PRESENTATION: These two cases (one 55-year-old man and one 25-year-old woman) of acute respiratory distress secondary to atypical pneumonia were seen in Bukavu, in Eastern Democratic Republic of the Congo (DRC), between September and December 2019. One patient had returned from China and the other had close contacts with travellers from China in the 2 weeks prior to the onset of symptoms. In either case, the aetiology could not be accurately determined. However, the two cases presented a clinical picture (progressive dyspnoea, preceded by dry cough and fever) and laboratory changes (procalcitonin within the normal range, slight inflammation, and lymphopenia) compatible with a viral infection. The chest X-ray series of the first patient showed lesions (reticulations, ground glass, and nodules ≤6 mm) similar to those currently found in COVID-19 patients. In addition, unlike the 25-year-old female patient who had no comorbidity, the 55-year-old male patient who had hypertension as comorbidity, developed a more severe acute respiratory distress which progressed to death. CONCLUSION: These cases bring to the attention the fact that COVID-19-like syndromes may have already been present in the region months before the official beginning of the pandemic. This also brings to question whether a prior presence of the disease or infections with related virus may account for the delayed and less extensive development of the pandemic in the region.

Prevalence and Risk Factors of CKD in South Kivu, Democratic Republic of Congo: A Large-Scale Population Study.

BACKGROUND: The prevalence of chronic kidney disease (CKD) in African American individuals is high but whether this applies to native populations in sub-Saharan Africa is unclear. METHODS: In a cross-sectional study, we assessed the prevalence and risk factors of CKD in rural and urban adults in South Kivu, Democratic Republic of Congo. Glomerular filtration rate (GFR) was estimated using the CKD-Epidemiology Collaboration (CKD-EPI) equations based on serum creatinine (eGFRcr), cystatin C (eGFRcys), or both markers (eGFRcr-cys), without ethnic correction factor. CKD was defined as an eGFR <60 ml/min per 1.73 m2 and/or albuminuria (albumin-to-creatinine ratio ≥30 mg/g). RESULTS: A total of 1317 participants aged 41.1 ± 17.1 years (730 rural, 587 urban) were enrolled. The prevalence of hypertension (20.2%; 95% confidence interval [CI], 18-22.3), diabetes mellitus (4.3%; 95% CI, 3.2-5.4) and obesity (8.9%; 95% CI, 7.4-10.5) was higher in urban than rural participants (all P < 0.05). HIV infection prevalence was 0.41% (95% CI, 0.05-0.78). The prevalence of eGFRcr <60 ml/min per 1.73 m2 was 5.4% (95% CI, 4.2-6.7). The prevalence of albuminuria was 6.6% (95 % CI, 5.1-8.1). The overall prevalence of CKD was 12.2% (95% CI, 10.2-14.2) according to CKD-EPIcr. Factors independently associated with CKD-EPIcr were older age (adjusted odds ratio [aOR], 1.05 [1.04-1.07]), urban residence (aOR 1.86 [1.18-2.95]), female sex (aOR 1.66 [1.04-2.66]), hypertension (aOR 1.90 [1.15-3.12]), diabetes (aOR 2.03 [1.02-4.06]), and HIV infection (10.21 [2.75-37.85]). The results based on eGFRcys or eGFRcr-cys were largely consistent with the preceding. CONCLUSION: Overall, the burden of CKD is substantial (>11%), predominantly in the urban area, and largely driven by classic risk factors (gender, aging, HIV, hypertension, and diabetes).