Forgotten but not gone in rural South Africa: Urinary schistosomiasis and implications for chronic kidney disease screening in endemic countries [version 1; peer review: awaiting peer review]
Date
2023-02-10
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Abstract
Background: Urinary schistosomiasis caused by infection with
Schistosoma haematobium (S. haematobium) remains endemic in Africa
and is associated with haematuria and albuminuria/proteinuria.
Kidney Disease Improving Global Outcomes clinical guidelines
recommend evaluating proteinuria/albuminuria and glomerular
filtration rate for chronic kidney disease (CKD) diagnosis. The
guidelines are informed by population data outside of Africa but have
been adopted in many African countries with little validation. Our
study aimed to characterise the burden of urinary schistosomiasis in
rural South Africa (SA) and evaluate its relationship with markers of
kidney dysfunction with implications for CKD screening.
Methods: In this population-based cohort study, we recruited 2021
adults aged 20 – 79 years in the Mpumalanga Province, SA.
Sociodemographic data were recorded, urinalysis performed, and
serum creatinine and urine albumin and creatinine measured. Kidney
dysfunction was defined as an estimated glomerular filtration rate
(eGFR) <60ml/min/1.73m2 and/or urine albumin-creatinine ratio>3.0mg/mmol. S. haematobium infection was determined by urine
microscopy. Multivariable analyses were performed to determine
relationships between S. haematobium and markers of kidney
dysfunction.
Results: Data were available for 1226 of 2021 participants. 717 (58.5%)
were female and the median age was 35 years (IQR 27 – 47).
Prevalence of kidney dysfunction and S. haematobium was 20.2% and
5.1% respectively. S. haematobium was strongly associated with kidney
dysfunction (OR 8.66; 95% CI 4.10 – 18.3) and related to albuminuria
alone (OR 8.69; 95% CI 4.11 – 18.8), with no evidence of an association
with eGFR <90ml/min/1.73m2 (OR 0.43; 95% CI 0.05 – 3.59).
Discussion: The strong association between urinary schistosomiasis
and albuminuria requires careful consideration when screening for
CKD. Screening for, and treatment of, schistosomiasis should be a
routine part of initial work-up for CKD in S. haematobium endemic
areas. Urinary schistosomiasis, a neglected tropical disease, remains a
public health concern in the Mpumulanga province of SA.
Description
Keywords
Schistosomiasis, chronic kidney disease, proteinuria, albuminuria, neglected tropical diseases, South Africa, sub-Saharan Africa