Leptospirosis an update


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Leptospirosis an update

  1. 1. Leptospirosis update Dr.T.V.Rao MD Dr.T.V.Rao MD 1
  2. 2. Scientific Beginning• It was first described by Adolf Weil in 1886 when he reported an "acute infectious disease with enlargement of spleen, jaundice and nephritis". Leptospira was first observed in 1907 from a post mortem renal tissue slice. Dr.T.V.Rao MD 2
  3. 3. Leptospirosis - Zoonosis• Leptospirosis is an acute arthropod-zoonotic infection of worldwide significance caused by spirochete Leptospira interregnas which has 23 serogroups and >200 serovars. Various factors influencing the animal activity, suitability of the environment for the survival of the organism and behavioural and occupational habits of human beings can be the determinants of incidence and prevalence of the disease. Dr.T.V.Rao MD 3
  4. 4. What is leptospirosis?• Leptospirosis, also known as canicola fever, haemorrhagic jaundice, infectious jaundice, mud fever, spirochetal jaundice, swamp fever, swineherds disease, cavers flu or sewermans flu, is a bacterial infection resulting from exposure to the Leptospira interrogans bacterium. Dr.T.V.Rao MD 4
  5. 5. Leptospirosis also called as Weil’s Disease after its inventor. Dr.T.V.Rao MD 5
  6. 6. Weil’s disease signifies Leptospirosis• There is an acute form of human infection known as Weils disease, where the patient suffers from jaundice, though this term is often (incorrectly) used to describe any case of infection.. Dr.T.V.Rao MD 6
  7. 7. Leptospirosis 2011 Dr.T.V.Rao MD 7
  8. 8. SynonymsMud / Swamp fever Japanese 7 day feverRice Field Fever Spirochete JaundiceCanicola Fever Leptospiral JaundiceAutumn Fever Swineherd’s Disease Dr.T.V.Rao MD 8
  9. 9. The Causative BacteriumOrder Spirochaetales – Treponema, Borrelia, Leptospira Family – Leptospiraceae, susceptible to heat, cl, acid Genus – Leptospira, 26 serogroups, 250 serovars interrogans, biflex, ictero hemorrhagica, hebdomidis Corkscrew shaped, delicate, flexible spirochete, Gram -ve6 to 20 long & 0.1 thick, coiled, flagellate, actively motile Dr.T.V.Rao MD 9
  10. 10. Reservoirs• Wild and domestic animals rodents, livestock (cattle, horses, sheep, goats, swine), canines, and wild mammals are the reservoir for leptospirosis. Many animals have prolonged leptospiruria without suffering from the disease themselves. Dr.T.V.Rao MD 10
  11. 11. Classification:• Phylum: Spirochaetes• Class: Spirochaetes• Order: Spirochaetales• Species: Leptospira• Family: Leptospiraceae Dr.T.V.Rao MD 11
  12. 12. What causes Leptospirosis• Leptospirosis is a bacterial disease that affects humans and animals. Leptospira bacteria are found worldwide and there are many different types or serovars capable of causing disease. Disease caused by Leptospira bacteria is most common in temperate or tropical climates and appears to be rare in North America. Dr.T.V.Rao MD 12
  13. 13. Morphology• The Leptospira appear tightly coiled thin flexible Spirochetes 5 – 15 microns long.• Fine spiral of 0.1 – 0.2 microns• One end appears bent forms a hook.• Actively motile• Seen best with dark field Microscopy. Dr.T.V.Rao MD 13
  14. 14. Greater Understanding with Electron Microscopy• Electron Microscopy show thin axial filament and a delicate membrane• In dark field it may appear as chain of miniature cocci. Dr.T.V.Rao MD 14
  15. 15. Resistance and Disinfection• Leptospira species can be inactivated by 1% Sodium hypochlorite• 70%ethanol,• glutaraldehyde,• formaldehyde,• detergents and acid.• This organism is sensitive to moist heat (121 ° C for a minimum of 15 min))and is also killed by pasteurization. Dr.T.V.Rao MD 15
  16. 16. Leptospirosis – A Major Zoonotic Infection• Weils disease is comparatively rare, though mild cases of leptospirosis happen everywhere there are carriers, and it is believed that leptospirosis is one of the most common zoonotic infections in the world. Millions of people are infected each year, but information and treatment can be limited, especially in the developed world where cases are considered rare by the medical community. Dr.T.V.Rao MD 16
  17. 17. Dr.T.V.Rao MD 17
  18. 18. Animals spread LeptospirosisRats, Mice, Wild Rodents, Dogs, Swine, Cattle are principle source of infectionThe above animals excrete Leptospira both in active infection and Asymptomatic stage The Leptospira survive and remain viable for several weeks in stagnant water. Dr.T.V.Rao MD 18
  19. 19. Modes of Transmission1. Direct contact with urine or tissue of infectedanimal Through skin abrasions, intact mucusmembrane2. Indirect contact Broken skin with infected soil, water orvegetation Ingestion of contaminated food & water3. Droplet infection Dr.T.V.Rao MD 19 Inhalation of droplets of infected urine
  20. 20. Transmission Urine Tissue Contam Survive Infection FecesAnimal Source Environment Human Dr.T.V.Rao MD 20
  21. 21. Dr.T.V.Rao MD 21
  22. 22. Pathogenic Strains x Non pathogenic Leptospirosis• There are several species of Leptospira only few are pathogenic to Humans, rest to some Animals and Many in Nature as saprophytes• Leptospira Interrogans is Pathogenic there are 200 serovars.• Leptospira biflexa Non Pathogenic there are 60 serovars• Further classifications are made on shared antigens Dr.T.V.Rao MD 22
  23. 23. Genomic based classification• DNA – DNA hybridization studies proved more specific• The traditional serologic classification has limitations at Molecular level, but useful at Epidemiological studies. Dr.T.V.Rao MD 23
  24. 24. Comparative Morphology of Spirochetes Dr.T.V.Rao MD 24
  25. 25. Culturing of Leptospira• Leptospira grows best under aerobic conditions at 280 to 300c best demonstrated in Semisolid agar media• Optimal Media Fletchers Media Stuarts MediaOptimal growth after 1 – 2 weeks Dr.T.V.Rao MD 25
  26. 26. Growth requirements• Leptospira derive energy from oxidation of long chain fatty acids, and cannot use or carbohydrates or amino acids as major energy source. Dr.T.V.Rao MD 26
  27. 27. Antigenic structure• All isolates of L.inttterogans from different parts of the world are serologically related and exhibit cross reactions in serologic tests.• Overlapping of Antigens do occur in different species.• Outer envelop contains large amount of Lipopolysaccharides ( LPS )• Antigenic structure varies from one strain to other• This variation forms the basis of serologic classification Dr.T.V.Rao MD 27
  28. 28. Genome of Leptospira• L. interrogans serogroups Icterhaemorrhagiae consists of a 4.33 mega base large chromosome and a 359 kilo base small chromosome, totalling 4,768 predicted genes. A series of genes have been discovered that could potentially be related to adhesion. This genome differs from the two other pathogenic spirochete (Treponema palladium and Borrelia burgdorferi), though some similar genes are visible (CHGC, 2004). Dr.T.V.Rao MD 28
  29. 29. PATHOGENESIS• leptospira• skin,mucosa• Initial stage leptospiremia toxic symptoms• (1~3days) three symptoms:• fever,myalgia,fatigue;• three signs:• conjunctival suffussion;• muscle tenderness;• enlargement of lymphonodes; Dr.T.V.Rao MD 29
  30. 30. Pathogenesis• Leptospira are present in the water bodies• Enter through breaks in the skin ( cuts and abrasions ) and mucous membranes• Enters through Mouth – Nose – Conjunctive• Rarely enters though ingestion.• Incubation period 1 – 2 weeks• When multiples blood stream produces fever.• May establish organ involvement in Kidney and Liver,• May produce hemorrhage and necrosis in the tissues and initiates dysfunction of these organs Dr.T.V.Rao MD 30
  31. 31. Sequence of Leptospira Infection Dr.T.V.Rao MD 31
  32. 32. Clinical IllnessesTypes Anicteric (common 95% recover) Icteric ( Weil’s Syndrome) (rare, fatal) Hepato-renal syndrome Hemorrhagic syndrome with ARF Atypical pneumonia syndrome Aseptic meningo-encephalitis Myocarditis, Chronic uveitis
  33. 33. Clinical Presentation90% of Cases Anicteric Icteric Common, mild Rare, Severe < 2% Mortality 15% Mortality 10% of Cases Dr.T.V.Rao MD 33
  34. 34. May present with• Jaundice• Hemorrhage• Nitrogen retention• The Illness is Biphasic with initial temperature when the second phase comes with raise of IgM titers raise• Aseptic meningitis – initial headache, stiffness of neck, pleocytosis of Cerebro spinal fluid Dr.T.V.Rao MD 34
  35. 35. Pathogenesis of Severe Disease Damage to small Vasculitis blood vessels Leptospira Massive migration of fluid from Direct cytotoxic injuryIntravascular to interstitial compartment Immunological injury Renal dysfunction, vascular Injury to internal organs Dr.T.V.Rao MD 35
  36. 36. Presenting with Jaundice is significant and Important, Serious Manifestation Dr.T.V.Rao MD 36
  37. 37. May present with Major Complications• Nephritis• Hepatitis.• Manifestations in eye• Muscular lesions• Many infections are mild and subclinical Dr.T.V.Rao MD 37
  38. 38. Weil’s Syndrome• Weils syndrome is a severe form of leptospirosis that causes a continuous fever, stupor, and a reduction in the bloods ability to clot, which leads to bleeding within tissues. Blood tests reveal anaemia. By the third to sixth day, signs of kidney damage and liver injury appear. Kidney abnormalities may cause blood in the urine and painful urination. Liver injury tends to be mild and usually heals completely. Dr.T.V.Rao MD 38
  39. 39. May present asAtypical Pneumonia Dr.T.V.Rao MD 39
  40. 40. Hepatitis - Leptospirosis• Hepatitis is the frequent complication• Elevation of serum creatine phospholipase enzyme raise differentiates from Viral hepatitis where the enzyme is not raised Dr.T.V.Rao MD 40
  41. 41. Nephritis - Leptospirosis• Kidney involvement in animals produce chronic disease of the kidney and the infected animal starts shedding large number of Leptospira and main source of environmental contamination of bacteria and results I human infections• Human urine also contain Spirochetes in the second and third week of infection Dr.T.V.Rao MD 41
  42. 42. Complications• Azotemia• Oliguria• Hemorrhage• Purpura• Hemolysis• Gastrointestinal bleeding• Hypoprothrombinemia and Thrombocytopenia Dr.T.V.Rao MD 42
  43. 43. FeverDifferential Diagnosis Viral fever, Malaria, Typhus Jaundice Malaria, Viral hepatitis, Sepsis Renal Failure Malaria, Hanta virus, Sepsis Meningitis Bacterial / Viral causes Hemorrhagic Fever Dengue, Hanta virus, Typhus
  44. 44. Early and Prompt Diagnosis is Highly Essential• The development of simpler, rapid assays for diagnosis has been based largely on the recognition that early initiation of antibiotic therapy is important in acute disease but also on the need for assays which can be used more widely. Dr.T.V.Rao MD 44
  45. 45. Laboratory Tests• TC / DC / ESR / Hb / Platelet count• Serum Bilirubin / SGOT/ SGPT• Blood Urea, Creatinine & Electrolytes• Chest X-Ray; ECG• Tests for diagnosis of Leptospirosis – Culture for Leptospira: Positive – MAT; Sero conversion or 4 fold rise/ high titer – ELISA / MSAT : positive• MAT: Microscopic agglutination test• (M)SAT: Microscopic slide agglutination Test
  46. 46. Approach to Diagnosis Clinical Features Leptospiremic phase < Immune phase > 7days 7dBlood Culture PCR ELISA MSAT Repeat MAT Dr.T.V.Rao MD 46
  47. 47. Laboratory Diagnosis Specimens1 Blood to be collected in a heparin tube2 CSF, Tissues Microscopic examination3 Urine to be collected with great care to avoid contamination4 Serum for agglutination tests Dr.T.V.Rao MD 47
  48. 48. Leptospira under the Microscope Dark Field Microscopy FLLong, Thin, Highly Coiled Dr.T.V.Rao MD 48
  49. 49. Culturing LeptospiraBlood and Urine be cultured in Fletcher’s semisolid agar or other media chemically defined protein-free media for the growth of leptospires have been proposed. Dr.T.V.Rao MD 49
  50. 50. Time Relationship of Tests MAT1 week 1 month 2 months 1 year 5 years ELISA or SAT Dr.T.V.Rao MD 50
  51. 51. WHO Guide - Faine’s Criteria2 • Headache 5 • Rain fall2 • Fever 4 • Contaminate H202 • Temp > 39 F 1 • Animal contact4 • Conjn. suffusion 15 • ELISA IgM + ve4 • Meningism 15 • SAT positive4 • Muscle pain 15 • MAT high titer1 • Jaundice 25 • MAT rising titer1 • Alb, creatinine Definite • Culture positive Dr.T.V.Rao MD 51
  52. 52. Serology based Testing• Variety of serological tests other than MAT have been developed for the diagnosis of leptospirosis. Among them are the complement fixation test , several enzyme- linked Immuno-Sorbant assay formats , the macroscopic slide agglutination test , the microcapsule agglutination test , the indirect Haemagglutination assay , the dipstick assay , and other methods . Each assay has its own advantages, drawbacks, and limitations Dr.T.V.Rao MD 52
  53. 53. Serology• Agglutinating antibodies raise to very high titers 1 : 10,000 or higher occurs 5 – 10 weeks after onset of infection Dr.T.V.Rao MD 53
  54. 54. What is MAT Testing• Each serum sample was tested against 21 or as specified different serovars by MAT by the standard procedure . Agglutination was examined by dark-field microscopy at a magnification of ×100. The reported titer was calculated as the reciprocal of the highest dilution of serum that agglutinated at least 50% of the cells for each serovar used. Dr.T.V.Rao MD 54
  55. 55. What is MAT Confirmed Test• A MAT-confirmed case was defined as a fourfold increase in antibody titer or a single titer ≥1:200, according to the case definition of the Centres for Disease Control and Prevention Dr.T.V.Rao MD 55
  56. 56. Serology - ELISA• Several Immunoassays are available as commercial kits• Detection of IgM and razing titers of IgG will guide in association with clinical history will help in Diagnosis Dr.T.V.Rao MD 56
  57. 57. Newer and Rapid Methods in Diagnosis• Several rapid tests are evolved for the• diagnosis of leptospirosis. They are easy to perform and read, although needs to be scientifically evaluated with respect to sensitivity and specificity.• Dri-Dot test gave considerable sensitivity (67.7%)along with good specificity (78%)by Ig M ELISA. Dr.T.V.Rao MD 57
  58. 58. Treatment• Antibiotic of choice is Benzyl Penicillin given by injection in doses of 5 mega units in a day, for 5 days.• If the patients are genuinely hypertensive to Penicillin opted with Erythromycin 250mgs four times a day for a period of 5 days. Dr.T.V.Rao MD 58
  59. 59. Preferred treatment• Penicillin 6 million units daily I.V (10-14 days)• Amoxicillin, Erythromycin, & Doxycycline• Patients with MOF(Multi organ failure) to be observed and treated in intensive care unit Dr.T.V.Rao MD 59
  60. 60. Treatment - Other alternatives• The leptospirosis can be effectively treated with Doxycycline Ampicillin AmoxicillinSevere patients need administration Intravenous Penicillin or Amoxicillin Dr.T.V.Rao MD 60
  61. 61. Epidemiology• Rainfall; Contaminated environment• Poor Sanitation; Inadequate drainage facilities• Presence of rodents, cattle & stray dogs• Walking/ working bare foot poses high risk• Difficult to pinpoint the source of infection• Any person can get infected, if exposed to contaminated and environment Dr.T.V.Rao MD 61
  62. 62. Epidemiology• Leptospirosis causes several animal infections• Most wide spread zoonotic infection in Nature• Human infections are accidental associated with contamination of water, other materials contaminated with excreta and animal flesh.• Animal carriers often excrete upto 100million leptospirosis per ml of urine Dr.T.V.Rao MD 62
  63. 63. Epidemiology - Occupation Certain occupational groups such asagriculture workers in rice and cane fields, miners andsever cleaners are potential victims Dr.T.V.Rao MD 63
  64. 64. Leptospirosis – India’s Concern• The first of its kind in India was reported in the 1920s from Andaman and Nicobar Islands.• In 1993, a serosurvey of conservancy workers in Madras (using MAT) revealed a prevalence rate of 32.9%.• In 1994, an increase in the number of individuals with uveitis was noted at Aravind Eye hospital, Madurai, India after an epidemic of leptospirosis in South India; the epidemic followed severe flooding of the Tamil Nadu District in the autumn of 1993• In 1995, a seroprevalence rate of 12% leptospirosis was found among febrile and jaundice patients in Pondicherry Dr.T.V.Rao MD 64
  65. 65. How Man gets Infected• Water the great source Drinking Swimming Bathing, as the urine of Rodents chronically infected contaminate water sourcesChildren get infected when in contact with infected Dogs Dr.T.V.Rao MD 65
  66. 66. Control of Leptospirosis• Rodent control is most important.• Human’s should avoid contact with water contaminated with animal contact. Dr.T.V.Rao MD 66
  67. 67. ChemoprophylaxisDoxycycline 200mg orally once aweek is simple effectivemeasure. Whenheavy exposure is anticipated Dr.T.V.Rao MD 67
  68. 68. Vaccination in humans• Vaccination for humans is justified where they cannot be separated from animal sources or where the animals cannot be immunized successfully• Necessity of human vaccinated will arise where people live and work in proximity to rodents in wet, tropical conditions, in wet rice planting and harvesting, in military operations, or working in sewers.• Yet no universally accepted vaccine is available for humans Dr.T.V.Rao MD 68
  69. 69. Vaccination of Animals Vaccinating animals have a dual purpose 1 Protecting animals 2 Protecting humans who may contract leptospirosis from themIt is probably true as that immunization of animals will prevent leptospirosis in people in contact with them. It proved true in 1980 when extensive vaccination of dairy cows in New Zealand lead to marked decreased incidence in Humans. Animals immunized experimentally with polysaccharide derived from Leptospira LPS linked to diphtheria Toxoid were protected against challenges Several other vaccines in use to suit local needs. Dr.T.V.Rao MD 69
  70. 70. New Vaccine trails - Leptospira Dr.T.V.Rao MD 70
  71. 71. Walking in Flood Waters can Infect• With the rats comes the threat of illnesses such as Weils Disease, which is transmitted to humans via contaminated water and is carried by up to 30 per cent of the rodent population. Dr.T.V.Rao MD 71
  72. 72. PreventionPrevention is difficult due to wild animal infection Good sanitation, Immunization of live stock Personal hygiene, PPE, Water treatment No useful human vaccines – multiple serovarsDoxycycline 200 mg weekly for at risk groups Dr.T.V.Rao MD 72
  73. 73. Created for Health Awareness on Leptospirosis Email doctortvrao@gmail.com Dr.T.V.Rao MD 73