In humans, infections are caused by two main species of roundworm, belonging to the genera Ancylostoma and Necator.The relationship between kidney disease and parasites dates back to ancient times. Hookworm infection is found in many parts of the world, and is common in areas with poor access to adequate water, sanitation, and hygiene. Hookworms are intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases.
Hookworms can cause redness, pain, and itching when they travel under the skin.EAJKD: How did you become interested in parasitic kidney disease?RB: Soon after I began practicing clinical nephrology in 1969, my colleagues and I at Cairo University and the Naval American Research Unit (NAMRU)-3 in Cairo encountered several cases of a full-blown nephrotic syndrome in patients with hepatosplenic schistosomiasis. Waste from pet dogs, cats, and raccoons is a common source of human infection. Helminths are transmitted to humans in many different ways ().The simplest is by accidental ingestion of infective eggs (Ascaris, Echinococcus, Enterobius, Trichuris) or larvae (some hookworms).Other worms have larvae that actively penetrate the skin (hookworms, schistosomes, Strongyloides).In several cases, infection requires an intermediate host vector.Hookworms and roundworms are tiny parasites that can be passed from animal feces to humans. The types of intestinal parasites range from a 6 foot intestinal worm, to tiny flukes (5 Transmission of Infection.
The prevalence of acute kidney injury (AKI) due to malaria is 10 fold that of all other causes of AKI. Literally, hundreds of millions are infected, and millions die every year as a direct result of those infections. Finally, we put together a histopathologic classification system of the different glomerular lesions in hepatosplenic schistosomiasis, and correlated them with clinical features and prognosis.EAJKD: Why is this topic important? Can you comment on the importance of these diseases for physicians in Western countries where they are not frequently seen in clinical practice?RB: According to the World Health Organization (WHO), one in four individuals living on our planet is infected with one or more parasites. We later identified a pathogenetic link, established a role of impaired hepatic macrophage function, and implicated Th2 cytokines, particularly IL-10, in the disease process. Our group published several papers on glomerulonephritis in hepatosplenic schistosomiasis, particularly when associated with salmonellosis—a well-known co-morbidity. We obtained kidney biopsies from these patients and found histologic lesions similar to those reported by Brazilian investigators.
Furthermore, the impact of parasitic infection has been seriously magnified by the growing immunocompromised populations including those with HIV infection, malignancy, and immunosuppression for organ transplantation. However, more and more parasitic diseases are being seen in the industrialized world owing to immigration of infected patients and vectors and exposure of Western populations through tourism and ex-partite appointments. Colleagues in the West are not commonly aware of the magnitude of this health problem, largely because of the containment of parasitic diseases in Africa, India, South-East Asia, and Central and South America.
With the implementation of mass treatment programs, this proportion fell to 8% according to the latest (2010) review of the same registry. Registry data of the Egyptian Society of Nephrology 4 decades ago blamed schistosomiasis as the cause of CKD in 29% of patients treated with regular dialysis. Taking the WHO data on the incidence of this type of malaria, the parasite would account for 1200 cases per million population, mostly in Africa, India, China, and South East Asia. It has been estimated that 1% of patients with falciparum malaria develop AKI. However, there is some relevant data that can assist us.
The data on filarial nephropathy are still weaker.EAJKD: How do we establish causality between a parasitic infection and a specific pattern of kidney disease (i.e., glomerulonephritis) beyond a simple temporal relationship?RB: There are three sets of data that establish this relationship: a) animal models where particular glomerular lesions can be induced by experimental infection in a dose-dependent manner (e.g., schistosomiasis) b) demonstration of parasitic antigens in early glomerular deposits by immunofluorescence or in-situ hybridization (all 4 parasites addressed in the article) c) parallel clustering of CKD in regions with highest prevalence of respective parasitic infection, with significant reduction in kidney disease paralleling parasite eradication programs (e.g., malaria, schistosomiasis).To view the article (freely available), please visit AJKD.org. According to the WHO, only one third of cases are officially reported, with less documentation of association with CKD.
0 kommentar(er)
