Zoonotic tuberculosis in elephanths

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Tuberculosis hardly excuse anyone irrespective of its shape, size, colour, cast, creed, breed, species or genus having a little warmth in blood. Therefore, elephants e not exception, rather very prone for this disease which have taken many times more lives than any of the war.

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Zoonotic tuberculosis in elephanths

  1. 1. ZOONOTIC TUBERCULOSIS in ELEPHANTS Dr Sakshi Dubey, MVSc. Scholar, Epidemiology Dr. Bhoj R Singh, Principal Scientist & Head, Division of Epidemiolo IVRI, Izanagar, Bareilly, UP, India
  2. 2. Tuberculosis  One of the most ancient diseases of mankind and     animals A contagious zoonotic disease Aristotle was first to say that tuberculosis is an airborne disease. In 1865 Jean Antoine Villemin, put out the idea that TB was genetically inherited. In1882 Robert Koch proved Villemin wrong by discovering the bacterium causing the disease. It is caused by Mycobacterium spp.
  3. 3. Indian scenario  Endemic in most parts.  Holds about 21% of the total global TB cases  1000 Indians die from TB per day. (Krishnaswami, 2000)  One third of the population is suffering from TB.
  4. 4. Global Scenario  2nd most common infectious cause of deaths (WHO 2013)  Human TB (zoonotic 3-10%) - localized in High Burden Countries (India, China, Indonesia, Nigeria, Bangladesh, a nd Pakistan)  22 High Burden Countries including India house for 80 % of all new TB cases.  In developing countries ~10.5% of human cases are associated with M. Bovis (ILRI,2012).
  5. 5. The Global Burden of TB -2011 Estimated number of cases All forms of TB 8.7 million (8.3–9.0 million) Estimated number of deaths 1.4 million* (1.3–1.6 million) Multidrug-resistant TB 1.1 million (13%) 430,000 (1.0–1.2 million) HIV-associated TB (400,000–460,000) Up to 0.5 million Unknown, but probably > 150,000 Source: WHO Global Tuberculosis Report 2012 GLOBAL TB PROGRAMME * Including deaths attributed to HIV/TB
  6. 6. Incidence rates, 2011 ( WHO ) 0–24 25–49 50–149 150–299 ≥300 Per 100 000 population Highest rates in Africa, linked to high rates of HIV infection ~80% of HIV+ TB cases in Africa
  7. 7. Prevalence in Animal Overall, 7.4% of livestock Bovines: 8%, camels 11%, Sheep and goats 2% Pigs 15%, Wildlife 5% (ILRI,2012)
  8. 8. Tuberculosis in wild animals  A number of cases reported among wild animals worldwide.  In zoo primates TB is due to M. tuberculosis and M. bovis  In Larger land mammals (Ungulates), TB is mostly caused by M. bovis.  M. tuberculosis is the main cause of TB in Elephants, Rhinoceroses, Tapirs, and in some exotic bovine spp.
  9. 9. Tuberculosis in wild animals  TB in a chimpanzee at London zoo reported by Owen (1961)  TB in Tigers of Delhi and Darjeeling Zoos (Rathore and Khera, 1981)  TB in Lions of zoological garden Bombay (Das and Jayaro, 1986)  M. tuberculosis reported in some exotic carnivores and Psittacine birds.
  10. 10. Tuberculosis in wild animals Eurasian badger (Meles meles) UK White-tailed deer (Odocoileus virginianus) Wildlife Reservoirs of TB Wild boar (Sus scrofa) Sp Cape buffalo (Syncerus caffer) Africa (Wilson et al., 2009) Brush-tailed possum (Trichosurus vulpecula) New
  11. 11. Tuberculosis in Elephants  Described in Asian documents of over 2000 years old  1st report of TB in elephants made in London zoo in 1875  Sporadic TB in Asian elephants and 1st case in African elephant reported in mid 20th century (Gorovitz, 1962)  During 1997 transmission of TB between human and elephants reported (Michalak et al., 1998)
  12. 12. Epidemiology  Though it is also found in free ranging animals, tuberculosis found more commonly in captive animal worldwide.  In Asian elephants mostly M. tuberculosis and M. bovis are involved. (Abraham et al., 2010 and Mikota et al., 2007)  Female seems to be affected more than the male elephants (Karthik, 2012)  Prevalence of TB in Asian elephants is about 15% in India and 13% in Nepal (Abraham et al., 2010 and Mikota et al., 2007)  In United States of America (USA), its prevalence in elephants is 6.3%
  13. 13. Transmission to elephants  Humans activity can lead to an increased level of M. tuberculosis being shed into the environment and may result in the spillover of infection into wildlife populations (Mikota, 2008)
  14. 14. Development of TB Inhalation of bacteria Bacteria reach lungs, enter macrophages Bacteria reproduce in macrophages Lesion begins to form (caseous necrosis) Activated macrophages Bacteria cease to grow; lesion calcifies Immune suppression Lesion liquifies Spread to blood,organs reactivation death Bact coughed up in sputum
  15. 15. Clinical signs  No typical signs in elephant  Non specific signs includes:  Inappetance  Weight loss  Subcutaneous ventral oedema (Kay et. al. 2010)
  16. 16. Zoonotic aspects  By aerosolization my spread to:  Elephant handlers  Zoo employees, veterinarians  Other animals
  17. 17. Pathology  Involves primarily :  Lungs  Thoracic & Bronchial lymph nodes  Extra thoracic sites  Caseous and mucopurulent exudates in trunk Histological findings: Epethelioid granulomas with giant cell Pyelogranulomatous pneumonia
  18. 18. Diagnosis  Intra-dermal Tuberculin Test  Microscopic examination  Acid Fast Staining  Serological test  Elephant TB STAT-PAK® Assay  Multi-antigen print immunoassay (MAPIA)  ELISA  Molecular test PCR
  19. 19.  Isolation and identification of Mycobacterium species  Sample: Trunk wash, Blood/Serum  “Triple sample method”  Lowenstein Jensen medium
  20. 20. TREATMENT Dose and route of administration of Anti-Tubercular drugs in Elephants Route S. No. Drug Does Target conc. 1. 2. 3. 4. Ethambutol Isoniazid Pyrazinamide Rifampin (mg/kg) 30 5 30 10 Oral Oral/rectal Oral/rectal Oral (µg/ml) 2-5 3-5 20-60 8-24 (Guideline for control of tuberculosis, 2008 and Peloquin et al., 2006) • Standard protocol includes: • 2 months with Isoniazid, Rifampin, Pyranzinamide & Ethambutol • followed by 4 months of isoniazid and rifampicin (Daly et al., 2006)
  21. 21. Tuberculosis Management Options
  22. 22. Conclusion  TB is endemic in captive elephants  The role played by elephants in the spread of TB to humans needs to be addressed.  Regular screening of elephants for TB is required for control.  Research on tuberculosis in elephants is required

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