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Leptospirosis- Dr Ajay Tyagi

Leptospirosis an emerging public health problem. I have give an overview and skipped Pathogenesis & Surviellance. Tried to keep it short & informative.

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Leptospirosis- Dr Ajay Tyagi

  1. 1. Dr Ajay TyagiJR, Deptt. of community medicine, PGIMS, Rohtak
  2. 2. Contents History Introduction Epidemiology Disease situation in India Species Significance of Serovar concept Protective immunity Natural Maintenance hosts Modes of transmission Clinical Manifestations
  3. 3. Contents Faine’s Criteria & Modified Faine’s Criteria For Diagnosis of Leptospirosis Differential Diagnosis Treatment Prognosis Screening Prevention & control National Leptospirosis Control Programme Future perspective
  4. 4. History In 1907, Stimson described the micro-organism in renal tubules of a patient who died of so-called yellow fever. The spirochete was first isolated in Japan by Inada and co- workers in 1915, nearly 30 years after Weil described the clinical disease in 1886. Leptospirosis was probably known much earlier in China and Japan by names such as “rich harvest jaundice” and “autumn fever”.
  5. 5. Introduction Leptospirosis is an emerging zoonotic disease of public health importance. It is an infectious disease caused by pathogenic bacteria called leptospires, that are transmitted directly or indirectly from animals to humans (zoonosis). In humans, it can cause a wide range of symptoms, some of which may be mistaken for other diseases. Some infected persons, however, may have no symptoms at all. Without treatment, Leptospirosis can lead to kidney damage, meningitis, liver failure, respiratory distress, and even death.
  6. 6. Introduction It is Overlooked and underreported. Reasons for lack of recognition of leptospirosis are- – It may present with a wide variety of clinical manifestations. These may range from a mild “flu”-like illness to a serious and sometimes fatal disease (dengue fever and other viral haemorrhagic diseases). – Icterus (jaundice) is a relatively common symptom in leptospirosis but is also found in many other diseases involving the liver such as the various forms of hepatitis. – The diagnosis is confirmed by laboratory tests, but these are not always available, especially in developing countries.
  7. 7. Epidemiology Awareness has increased internationally over the past decade that leptospirosis is a globally important public health threat, both in developing countries and industrialized countries. (e.g. US, Ireland, Germany, India, Indonesia, Thailand, Sri Lanka etc.) Leptospirosis occurs worldwide but is most common in tropical and subtropical areas with high rainfall. Most countries in the SEA region are endemic for leptospirosis. The incidence of leptospirosis is often influenced by various socio-cultural, occupational, behavioural and environmental factors.
  8. 8. Epidemiology The risk is higher in rural areas where the animals are present in large numbers and the population is mainly involved in agriculture. Seasonal outbreaks have been reported in northern Thailand and Gujarat following heavy rainfall and flooding. Major outbreaks in South-East Asia were reported in the past due to cyclone in Orissa (1999), flooding in Jakarta (2002), Mumbai (2005) and in Sri Lanka (2008). Leptospirosis is known to be a possible cause of acute pyrexia of unknown origin (PUO) after flooding.
  9. 9. Epidemiology The annual incidence of leptospirosis is estimated from 0.1–1 per 100,000 in temperate climates to 10–100 per 100,000 in the humid tropics. A disease incidence of more than 100 per 100,000 is encountered during outbreaks and in high-exposure risk groups.
  10. 10. Epidemiology Epidemiological studies indicate that infection is commonly associated with certain occupational workers such as farmer, sewage worker, veterinarian, and animal handler. Leptospirosis can also be transmitted during recreational activities such as hiking, picnicking, swimming and canoeing. Leptospires can survive in untreated water for months or years, but cannot survive desiccation or salt water.
  11. 11. Disease situation in India Leptospirosis has been a significant problem in low lying areas of India that are densely populated and prone to flooding and water stagnation during monsoon. The outbreaks of leptospirosis are increasingly been reported from Kerala, Gujarat, Tamil Nadu and Karnataka. The Government of India has launched a pilot project on control of leptospirosis in Gujarat, Kerala, Tamil Nadu, Maharashtra & Karnataka(2011). NCDC is the nodal agency for this project. The main objective of the project is to reduce morbidity and mortality due to leptospirosis
  12. 12. Disease situation in India In a study at PGIMER, Chandigarh namely “Increasing Trends of Leptospirosis in Northern India: A Clinico-Epidemiological Study” – increasing trend in lab confirmed cases of Leptospirosis have been observed . Year No. of Cases Diagnosed at PGIMER, Chandigarh 2004 9 2005 17 2006 25 2007 74 2008 107
  13. 13. Disease situation in India
  14. 14. Species The genus Leptospira contains both pathogenic and nonpathogenic strains. Genus Leptospira is broadly divided into two species: Leptospira interrogans comprising all pathogenic strains, and Leptospira biflexa, containing the saprophytic (non- pathogenic) strains isolated from the environment. Species Leptospira interrogans, comprises of at least 250 antigenically distinct variants known as serovars belonging to 23 serogroups. Identification and classification of species of Leptospira is important because of different host specialities.
  15. 15. Significance of Serovar concept It is of epidemiological importance. A certain serovar may develop a commensal or comparatively mild pathogenic relationship with a certain animal host species. For instance, cattle are often associated with serovar hardjo, dogs with canicola and rats with icterohaemorrhagiae and copenhageni.
  16. 16. Protective immunity It is generally believed that serovar-specific antibodies are protective and that a patient is immune to reinfection with the same serovar as long as the concentration (titre) of specific antibodies is high enough. Antibodies provoked by an infection with a particular serovar do not necessarily protect against infection with other serovars.
  17. 17. Natural Maintenance hosts Certain vertebrate animal species have a commensal relationship with leptospires in which they are the natural hosts for pathogenic leptospires that live in their kidneys. Such leptospires do little or no detectable harm to these hosts but they maintain the infection and are therefore known as natural maintenance hosts. If other animals that are not natural maintenance hosts (including humans) are infected by the same pathogenic leptospires, they often become ill. In addition, if a maintenance host for a particular leptospire is infected with another serovar, it may develop symptoms and signs of leptospirosis.
  18. 18. Modes of transmission The bacteria that cause leptospirosis are spread through the urine of infected animals, which can get into water or soil and can survive there for weeks to months. This disease has been described as the most common zoonosis affecting many species of wild and domestic animals such as rodents, cattle, pigs, wild mammals, dogs and cats etc. The most frequent hosts are rodents, especially the common rat (Rattus norvegicus). Leptospires can survive for long periods in the renal tubules of infected animals without causing illness.
  19. 19. Modes of transmission Infected animals may continue to excrete the bacteria into the environment continuously or once in a while for a few months up to several years. Humans can become infected through: – contact with urine (or other body fluids, except saliva) from infected animals – contact with water, soil, or food contaminated with the urine of infected animals. – The bacteria can enter the body through skin or mucous membranes (eyes, nose, or mouth), especially if the skin is broken from a cut or scratch. Drinking contaminated water can also cause infection.
  20. 20. Modes of transmission Outbreaks of leptospirosis are usually caused by exposure to contaminated water, such as floodwaters. Person-to-person transmission is extremely rare since man is a dead-end host for leptospiral dissemination. Most human infections occur in young adult men and children and result from occupational or environmental exposure.
  21. 21. Clinical Manifestations In humans, Leptospirosis can cause a wide range of symptoms, including: – High fever – Jaundice (yellow skin and eyes) – Headache – Red eyes – Chills – Abdominal Pain – Muscle aches – Diarrhea – Vomiting – Rash Many of these symptoms can be mistaken for other diseases. In addition, some infected persons may have no symptoms at all.
  22. 22. Clinical Manifestations Illness usually begins abruptly with fever and other symptoms. Leptospirosis may occur in two phases: – after the first phase (with fever, chills, headache, muscle aches, vomiting, or diarrhea) the patient may recover for a time but may become ill again. – if a second phase occurs, it is more severe; the person may have kidney or liver failure or meningitis. This phase is also called Weils disease. The illness lasts from a few days to 3 weeks or longer. Without treatment, recovery may take several months.
  23. 23. Clinical Manifestations In its mild form, leptospirosis may present as an influenza-like illness with headache and myalgia. Severe leptospirosis, characterized by jaundice, renal dysfunction, and hemorrhagic diathesis, is referred to as Weil’s syndrome. Incubation Period: 2-26 days (usually 7-12 days) In general, clinical manifestation can be divided into two distinct clinical syndromes. 90% of patients present with mild anicteric febrile illness; 10% are severely ill with jaundice and other manifestations (Weil’s disease).
  24. 24. Clinical Manifestations Both anicteric and icteric leptospirosis may follow a biphasic course.
  25. 25. WHO GUIDELINES: Faine’s Criteria For Diagnosis of Leptospirosis Faine had evolved a criteria for diagnosis of leptospirosis on the basis of clinical, epidemiological and laboratory data (Parts A, B and C respectively) A presumptive diagnosis of leptospirosis may be made if: (i) Parts A and B score = 26 or more (Part C laboratory report is usually not available before fifth day of illness; thus it is mainly a clinical and epidemiologic diagnosis during early part of disease) (ii) Part A+B+C = 25 or more A score between 20 and 25 : Suggests a possible but unconfirmed diagnosis of leptospirosis
  26. 26. Modified Faine’s Criteria For Diagnosis Of Leptospirosis Shivakumar et al from Chennai have suggested modification on Faine’s criteria to include local factor (like rainfall) and newer investigations in the total scoring. As per this, epidemiological and laboratory criteria (Parts B and C) are modified only; no modification is made in the clinical criteria (Part A)
  27. 27. Faine’s criteria Modified Faine’s criteria Part A: Clinical data Part B: Epidemiological factors Part C: Bacteriological and Lab. findings
  28. 28. Diagnosis of Leptospirosis
  29. 29. Need for laboratory 1. Leptospirosis is difficult to distinguish from a number of other diseases on clinical grounds. Laboratory methods help to confirm leptospirosis where the disease is suspected on clinical grounds. 2. For epidemiological and public health reasons, namely to determine which serovar caused the infection, the likely source of infection and the potential reservoir and its location. This helps to guide control strategies.
  30. 30. Differential Diagnosis The differential diagnosis of leptospirosis depends on the epidemiology of acute febrile illnesses in the particular area. A high index of suspicion is needed in endemic areas, and leptospirosis must be considered when a patient presents with acute onset of fever, headache and myalgia. However, in locations where dengue fever or malaria is also present, the differentiation may be very difficult because of similar clinical manifestations. Laboratory confirmation is crucial, especially when these diseases are occurring simultaneously during the rainy season.
  31. 31. Differential Diagnosis Other conditions to be considered in the differential diagnosis include influenza, meningitis (or encephalitis), viral hepatitis, rickettsiosis, typhoid fever, septicemia, toxoplasmosis etc. When the patient presents with jaundice during or after an acute febrile illness, leptospirosis must be differentiated from other causes of febrile jaundice such as malaria, septicemia, alcoholic hepatitis and typhoid hepatitis. The high bilirubin level seen in Weil’s disease with mild to modest elevation of transaminases assists in differentiating it from viral hepatitis, which has usually a much higher elevation of transaminases. Further, a high serum creatinine phosphokinase (CPK) concentration or thrombocytopenia also favors a diagnosis of leptospirosis.
  32. 32. Treatment Early treatment with antibiotics. Severe cases usually treated with high doses of IV benzyl penicillin (30 mg/kg up to 1.2 g IV 6-hourly for 5-7 days). Less severe cases treated orally with antibiotics such as doxycycline (2 mg/kg up to 100 mg 12-hourly for 5-7 days), tetracycline, ampicillin or amoxicillin. Third-generation cephalosporins, such as ceftriaxone and cefotaxime, and quinolone antibiotics may also be effective. Monitoring and supportive care as appropriate, e.g. dialysis, mechanical ventilation.
  33. 33. Prognosis The prognosis of leptospirosis depends on the severity of the disease and the associated complications. Anicteric leptospirosis usually has a good prognosis. Without jaundice the disease is almost never fatal; however, fatal pulmonary hemorrhage and myocarditis have been reported occasionally in anicteric cases. The case fatality rate for Weil’s disease is 15-40%, and is higher for patients over 60 years of age.
  34. 34. Screening A number of tests such as the macroscopic slide agglutination test, the Patoc-slide agglutination test, the microcapsule agglutination test, latex agglutination tests, dipstick tests, and the indirect haemagglutination test are easy to perform and give results relatively rapid. Results of screening tests, whether positive or negative, should be confirmed by other tests and preferably by the MAT.
  35. 35. Prevention and Control The risk of acquiring leptospirosis can be greatly reduced by not swimming or wading in water that might be contaminated with animal urine, or eliminating contact with potentially infected animals. Protective clothing or footwear should be worn by those exposed to contaminated water or soil because of their job or recreational activities.
  36. 36. Prevention and Control Because of the large number of serovars and infection sources and the wide differences in transmission conditions, the control of leptospirosis is complicated and will depend on the local conditions. Control can be achieved by controlling the reservoir or reducing infection in animal reservoir populations such as dogs or livestock. Control of wild animals may be difficult. Preventive measures must be based on a knowledge of the groups at particular risk of infection and the local epidemiological factors
  37. 37. Prevention and Control Prevention and control should be targeted at : – (a) the infection source; – (b) the route of transmission between the infection source and the human host; or – (c) infection or disease in the human host. It is important to establish what animal species are the infection sources in a particular area. Control measures can then be targeted to the local reservoir species of animals.
  38. 38. Prevention and Control Such measures include: – the reduction of certain animal reservoir populations, e.g. rats; – the separation of animal reservoirs from human habitations by means of fences and screens; – the immunization of dogs and livestock; – the removal of rubbish and keeping areas around human habitations clean; – encouraging people not to leave food around, especially in recreational areas where rats may be present.
  39. 39. Prevention and Control Interruption of transmission – It is important to be aware of the risk factors for human infection and, if possible, the infection source. – Risk of infection is minimized by avoiding contact with animal urine, infected animals or an infected environment. – Where appropriate, protective clothing should be worn and wounds covered with waterproof dressings to reduce the chance of infection.
  40. 40. Prevention and Control Human protection— Much depends on detailed knowledge of how, where and when humans may become infected in a particular area.— One possibility is to increase awareness of the disease among the population, risk groups and health care providers, so that the disease can be recognized and treated as soon as possible.— In certain countries, vaccines for humans are available, but it should be remembered that they may only provoke immune responses to the serovars included in the vaccine. Vaccines are, in principle, suspensions of killed leptospires. Protection is largely serovar-specific. In areas where many serovars are causing leptospirosis, a vaccine must consist of different serovars matching those circulating locally.
  41. 41. National Leptospirosis Control Programme The Government of India has launched a pilot project on control of leptospirosis in Gujarat, Kerala, Tamil Nadu (March 2008) Maharashtra & Karnataka(2011). NCDC is the nodal agency for this project. The main objective of the project is to reduce morbidity and mortality due to leptospirosis The thrust areas of the project are- —Early diagnosis & treatment of Leptospirosis —Strengthening of lab & patient management facilities —Training of manpower —IEC in the community —Inter- sectoral coordination
  42. 42. Future perspectives Leptospirosis is easily overlooked and relatively little is known about it. Few studies are therefore carried out on it, and this, in turn, results in the disease being overlooked. There is need to increase awareness of it. Better diagnosis and surveillance programmes may break the vicious circle.
  43. 43. References Report of the Second Meeting of the Leptospirosis Burden Epidemiology Reference Group 2011 Leptospirosis situation in the WHO South-East Asia Region Sethi S, Sharma N, Kakkar N, Taneja J, Chatterjee SS, et al. (2010) Increasing Trends of Leptospirosis in Northern India: A Clinico- Epidemiological Study. PLoS Negl Trop Dis 4(1): e579. doi:10.1371/journal.pntd.0000579 A Global Research Agenda for Leptospirosis ER Cachay, JM Vinetz J Postgrad Med. Author manuscript; available in PMC 2008 March 20.Published in final edited form as: J Postgrad Med. 2005; 51(3): 174–178. Human leptospirosis: Guidance for diagnosis, surveillance and control 2003 Leptospirosis – An Overview: TK Dutta, M Christopher; JAPI , VOL. 53 • JUNE 2005, 545-51