Chronic Leptospirosis Research Articles

Review Paper: Host-Pathogen Interactions in the Kidney during Chronic Leptospirosis

Pathogenic species of Leptospira cause leptospirosis, a global zoonotic disease. Leptospira colonize renal tubules of chronically infected maintenance hosts, from where they are shed in urine to the environment and survive in suitable moist conditions. Transmission of disease to new hosts is facilitated by contact with contaminated urine or water sources, because Leptospira can penetrate broken skin or mucosal surfaces of new hosts. Infection of new hosts may be asymptomatic, as with chronically infected maintenance hosts, or may result in an acute disease process in which clinical signs can include fever, jaundice, renal failure, and pulmonary hemorrhage. Those factors that determine if an animal will suffer an acute or a chronic infection are not fully understood but include host animal species, infecting serovar, and infecting dose. During chronic infection, renal colonization and leptospiruria persist despite cellular and humoral responses by the host. Tubulointerstitial nephritis is the most common lesion associated with chronic infection, and this may progress to fibrosis and subsequent renal failure. This review aims to address how Leptospira cause tubulointerstitial nephritis during chronic leptospirosis and to summarize the mechanisms by which Leptospira might evade host immune responses during chronic colonization of the renal tubule.

Urban rats as chronic carriers of leptospirosis: an ultrastructural investigation.

Kidneys of six wild-trapped, adult Norway rats with high agglutinating titers to Leptospira icterohaemmorhagiae were examined ultrastructurally. Although many leptospires were seen in the lumen of proximal kidney tubules, few changes in epithelial cells of this region were found. The predominant lesion in chronic rat leptospirosis was diffuse interstitial nephritis. Principal kidney lesions were proximal tubule cell basement membrane thickening with or without the presence of granular particles, and an interstitial response that varied from mixed hypercellular to chiefly plasmacytic. The association of leptospires with membrane-bound protein droplets of the proximal kidney tubules may be important in the maintenance of the chronic carrier state in rat leptospirosis.

Renal Histopathology of Leptospirosis Caused by Leptospira grippotyphosa in Farm Animals in Kenya

SUMMARY The renal histopathology of 12 cases of acute leptospirosis (4 bovine, 6 ovine and 2 caprine) and 34 cases of chronic leptospirosis (32 bovine, 1 ovine and 1 porcine) is compared with that of 5 cases of east coast fever. A peri-arteriolar lymphocytic infiltration was common to all. Where leptospires were seen in silver-stained sections they were localized mainly in ascending limbs of Henle and distal convoluted tubules. In chronic cases of leptospirosis syncytia and giant cells were seen. These had not been previously described in disease caused by Leptospira grippotyphosa. The main site of formation of these structures was the lower nephron; their probable sequence of development is outlined. Dilated descending Henle loops, many containing hyaline casts, were seen only in leptospirosis. The main macroscopic and microscopic differences between kidney lesions of chronic leptospirosis and of east coast fever are tabulated.

Streptomycin in the Treatment of Leptospira Carriers. Experiments with Hamsters and Dogs.

ConclusionsThe data here presented prove that chronic renal infections with leptospira in hamsters and dogs may be successfully cured with streptomycin. Although penicillin, as well as streptomycin, effectively influences the leptospiremia in experimental infections in guinea pigs, mice and hamsters, only streptomycin is capable of destroying the organisms found in the convoluted tubules.Canine leptospirosis is usually treated after the parasite has already disappeared from the blood. Obviously, penicillin is of little value. Streptomycin in oil and wax in a daily dose of 40 mg per kilo given intramuscularly should be used in the treatment of acute and chronic canine leptospirosis. In fact, this antibiotic may be employed in the prevention of this destructive disease in dogs. It is recommended that the urine of all dogs intended for breeding be examined for leptospira, and when infection is found, the dogs should be treated for 3 to 5 days with streptomycin a few days before the act of breeding.