Leptospirosis pathophysiology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; {{AE}Venkata Sivakrishna Kumar Pulivarthi M.B.B.S [2]
Pathophysiology
The disease leptospirosis involves a spectrum of symptoms ranging from subclinical infection to a severe syndrome of multiorgan infection with high mortality and Weil’s disease represents only the most severe presentation. Severe leptospirosis is frequently caused by serovars of the icterohaemorrhagiae serogroup. The presentation of leptospirosis is biphasic, with the acute or septicemic phase lasting about a week, followed by the immune phase, characterized by antibody production and excretion of leptospires in the urine.[1]
Reservoirs
The major reservoir for leptospirosis is rat.[2]
Transmission
Pathogenic leptospires live in the renal system and the genital tracts of domestic animals which act as sites of persistence.[3][4] Bacteria shed from the infected animals such as rodents and domesticat animals through urine. These animals may not show signs of disease, but humans shows signs of illness after contact with infected urine, or through contact with water, soil or food that has been contaminated and the outbreaks are associates with floodwaters. The major route of infection by leptospires is probably by transmission through indirect contact with leptospires secreted into the environment. Humans are considered dead end hosts, but sometimes they also act as carriers. Mammalian species (e.g. rodents, insectivores, dogs, pigs and cattle) act as the main carriers of the disease.[5] Leptospires are excreted in urine into the environment, where they can survive for several months, depending on favourable environmental conditions such as humid and temperate areas. Infection can occurs either by direct contact with the carrier’s urine or through indirect transmission via urine-contaminated environment. The pathogen may also be excreted in the products of abortion in mammalian animal species.[3]
Pathophysiology
Toxin Production | |
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Type of toxin production depends on the serovar
Hemolytic toxins: Hemolysins are produced from several serovars such as serovars ballum, hardjo, pomona, and tarassovi which are sphingomyelinases | |
Immunological Mechanism | |
Humoral Immunity | Innate Immunity |
Acute phase | Immune phase | |
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Anicteric leptospirosis | Icteric leptospirosis |
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Pathology
Pathology |
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Pathological findings of leptospirosis are due to the development of the following:
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Gross Findings |
Gross findings of various organ systems are present as:[10]
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Histopathological Findings |
Liver:
Kidney:
Heart: Leptospirosis is associate with interstitial myocarditis.[14][15][16][17]
Lungs: Common pulmonary presentation in leptospirosis are pulmonary congestion and hemorrhage.[10][17][18][19]
Skeletal muscle:
Brain:
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- ↑ Levett, P. N. (2001). "Leptospirosis". Clinical Microbiology Reviews. 14 (2): 296–326. doi:10.1128/CMR.14.2.296-326.2001. ISSN 0893-8512.
- ↑ Picardeau, M. (2013). "Diagnosis and epidemiology of leptospirosis". Médecine et Maladies Infectieuses. 43 (1): 1–9. doi:10.1016/j.medmal.2012.11.005. ISSN 0399-077X.
- ↑ 3.0 3.1 Ellis WA, O'Brien JJ, Cassells JA, Neill SD, Hanna J (1985). "Excretion of Leptospira interrogans serovar hardjo following calving or abortion". Res Vet Sci. 39 (3): 296–8. PMID 4081333.
- ↑ Ellis WA, McParland PJ, Bryson DG, Thiermann AB, Montgomery J (1986). "Isolation of leptospires from the genital tract and kidneys of aborted sows". Vet Rec. 118 (11): 294–5. PMID 3705357.
- ↑ Ganoza CA, Matthias MA, Saito M, Cespedes M, Gotuzzo E, Vinetz JM (2010). "Asymptomatic renal colonization of humans in the peruvian Amazon by Leptospira". PLoS Negl Trop Dis. 4 (2): e612. doi:10.1371/journal.pntd.0000612. PMC 2826405. PMID 20186328.
- ↑ Budihal, Suman Veerappa (2014). "Leptospirosis Diagnosis: Competancy of Various Laboratory Tests". JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. doi:10.7860/JCDR/2014/6593.3950. ISSN 2249-782X.
- ↑ BEESON PB, HANKEY DD (1952). "Leptospiral meningitis". AMA Arch Intern Med. 89 (4): 575–83. PMID 14902167.
- ↑ King SD, Urquhart AE (1975). "Laboratory investigations on four cases of leptospiral meningitis in Jamaica". West Indian Med J. 24 (4): 196–201. PMID 1224630.
- ↑ Silva MV, Camargo ED, Batista L, Vaz AJ, Ferreira AW, Barbosa PR (1996). "Application of anti-leptospira ELISA-IgM for the etiologic elucidation of meningitis". Rev Inst Med Trop Sao Paulo. 38 (2): 153–6. PMID 9071036.
- ↑ 10.0 10.1 10.2 10.3 AREAN VM (1962). "The pathologic anatomy and pathogenesis of fatal human leptospirosis (Weil's disease)". Am J Pathol. 40: 393–423. PMC 1949541. PMID 13862141.
- ↑ De Brito T, Machado MM, Montans SD, Hoshino S, Freymüller E (1967). "Liver biopsy in human leptospirosis: a light and electron microscopy study". Virchows Arch Pathol Anat Physiol Klin Med. 342 (1): 61–9. PMID 4298629.
- ↑ PENNA D, DE BRITO T, PUPO AA, MACHADO MM, AYROZA PA, DE ALMEIDA SS (1963). "KIDNEY BIOPSY IN HUMAN LEPTOSPIROSIS". Am J Trop Med Hyg. 12: 896–901. PMID 14072448.
- ↑ Sitprija, Visith; Evans, Hilary (1970). "The kidney in human leptospirosis". The American Journal of Medicine. 49 (6): 780–788. doi:10.1016/S0002-9343(70)80059-6. ISSN 0002-9343.
- ↑ De Biase L, De Curtis G, Paparoni S, Sciarra D, Campa PP (1987). "Fatal leptospiral myocarditis". G Ital Cardiol. 17 (11): 992–4. PMID 3446572.
- ↑ Brito, T. De; Morais, C. F.; Yasuda, P. H.; Lancellotti, Carmen P.; Hoshino-Shimizu, Sumie; Yamashiro, E.; Alves, V. A. Ferreira (2016). "Cardiovascular involvement in human and experimental leptospirosis: Pathologic findings and immunohistochemical detection of leptospiral antigen". Annals of Tropical Medicine & Parasitology. 81 (3): 207–214. doi:10.1080/00034983.1987.11812114. ISSN 0003-4983.
- ↑ AREAN VM (1957). "Leptospiral myocarditis". Lab Invest. 6 (5): 462–71. PMID 13464040.
- ↑ 17.0 17.1 Ramachandran S, Perera MV (1977). "Cardiac and pulmonary involvement in leptospirosis". Trans R Soc Trop Med Hyg. 71 (1): 56–9. PMID 871034.
- ↑ Nicodemo AC, Duarte MI, Alves VA, Takakura CF, Santos RT, Nicodemo EL (1997). "Lung lesions in human leptospirosis: microscopic, immunohistochemical, and ultrastructural features related to thrombocytopenia". Am J Trop Med Hyg. 56 (2): 181–7. PMID 9080878.
- ↑ Zaltzman M, Kallenbach JM, Goss GD, Lewis M, Zwi S, Gear JH (1981). "Adult respiratory distress syndrome in Leptospira canicola infection". Br Med J (Clin Res Ed). 283 (6290): 519–20. PMC 1507945. PMID 6790049.