Wednesday, February 26, 2014

Scratching the Surface of Kidney Disease in Sub-Sahara Africa

"John Stanifer is currently a 4th year resident in the Global Health Pathway of the Internal Medicine Residency at Duke and will be joining the Nephrology Fellowship this year. He is interested in first understanding the prevalence of chronic kidney disease (CKD) in Tanzania and then exploring the unique risk factors at play. I asked him to share his thoughts about this region of the world here on RFN so that others can learn from his unique experiences." -Matt Sparks 

I first traveled to Tanzania in 2012 where I realized the enormous need for increased clinical awareness of chronic diseases such as CKD. Global health nephrology may be a new idea for many people, but after practicing medicine and living in Tanzania, the idea has become second nature. It is known that acute kidney injury (AKI) and CKD account for a great deal of morbidity and mortality in this region. As in the developed world, this is not just related to kidney outcomes but importantly impact cardiovascular risk and outcomes. While we do have the capacity for peritoneal dialysis here at the hospital where I work in Tanzania, cost, training, and staff substantially limit its use. The biggest difficulty may actually be in pre-dialysis care. This applies not only to early- to mid-stage CKD but also in the non-dialysis management of AKI. We still have a lot to learn about the nature and impact of kidney disease in developing regions of the world such as Tanzania. We, as a nephrology community, can make a huge impact into helping people cope and potentially prevent kidney disease in a region where little research has been performed.

The United Nations adopted a resolution in 2011 acknowledging the growing global risk of non-communicable diseases such as CKD. In fact, CKD as a cause of death has doubled worldwide since 1990. As such, CKD continues to be an under-recognized burden worldwide. Our recent article in the Lancet Global Health, “The Epidemiology of Chronic Kidney Disease in Sub-Saharan Africa: A Systematic Review and Meta-Analysis” highlights how poor the state of renal research and care is in many low-income countries, and our efforts here in Tanzania are beginning to highlight the disparity between the dearth of data pertaining to renal disease and the magnitude of the problem.

First, we are beginning to understand practice patterns and healthcare utilization among patients with chronic disease such as CKD. Besides cost and access, there are numerous reasons that lead to failure of care for chronic diseases the most important of which may be the lack of understanding of ‘chronic disease’ itself. In a region where untreated malaria is considered the paradigm for ‘chronic disease’, informing patients that their diseases are lifelong and chronic (which often translates as incurable) most commonly results in isolation, fear, and treatment failure.

Secondly, CKD is unique in that it is related to both communicable and non-communicable disease: a point which is especially important in global health nephrology. The well-known and traditional risk factors such as diabetes, hypertension, and HIV are still apparent in this region. However, CKD in this part of the world is also associated with schistosomiasis, tuberculosis, untreated streptococcal infections (structural heart disease from Rheumatic Fever is exceedingly common), environmental contaminates such as lead and arsenic. The most troubling cause of CKD in this region is the pervasive use of traditional or herbal remedies, and one of the goals of our research is to catalogue the remedies that are nephrotoxic and education locals about them.

Third, our preliminary data suggest that the burden of CKD is likely to be as substantial (if not greater) than that of the US and Europe. Alarmingly, we are finding similar prevalence estimates for diabetes, hypertension, and obesity. Crude estimates indicate that the prevalence of CKD is about 12-16% and that diabetes is prevalent in 14-18% of the adult population. In light of these findings, the importance of CKD in the spectrum of non-communicable diseases must be stressed especially in the context of it as a cardiovascular risk factor and in context of the uniform fatality of ESRD in almost all low-income countries. CKD should no longer be viewed as a disease exclusive to the developed world.

After establishing the epidemiology of CKD in the region, our next steps will be to validate measures of renal function, study the genetics of CKD in Eastern Africa, and to establish chronic disease treatment and prevention programs.

John W Stanifer

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