Tularemia “A Vector Borne Zoonosis”

1. POST-GRADUATE SEMINAR ON
DEPT. OF VETERINARY PUBLIC HEALTH & EPIDEMILOGY
COLLEGE OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY
ANAND AGRICULTURAL UNIVERSITY
ANAND – 388 001.
MAJOR ADVISOR
DR. J. B. NAYAK
Associate Professor
Dept. of Veterinary Public
Health
MINOR ADVISOR
DR. ASHISH ROY
Professor
Dept. of Veterinary
Microbiology
KIRIT BHEDI
REG. NO.:- O4-2458-2014
VPH-691
1

2. Contents
Introduction History Etiology Epidemiology Life cycle
Transmission Outbreak Pathogenesis Symptoms Diagnosis
Treatment Prevention
and control
Public
Health
Significance
Conclusions Future
prospects 2

3. 3

4. Tularemia is a bacterial zoonosis caused by the small,
pleomorphic, gram-negative coccobacillus
Francisella tularensis
It is characterized by fever, localized skin or mucous membrane
ulceration, regional lymphadenopathy and occasionally pneumonia
It occurs naturally in lagomorphs (rabbits and hares)
and rodents
(Feldman et al., 2001)
(Feldman, 2003)

5. Disease of the northern hemisphere
Wide host range and can be spread by the bite of an arthropod, direct
contact with diseased animals, inhalation or ingestion of contaminated
food or water
F. tularensis is listed as a category A bioterrorism agent.
(Hansen et al., 2011)
(Adcock et al., 2013)

6. Deer-fly fever (Utah)
Glandular tick fever (Idaho and Montana)
Market men’s disease (Washington D.C.)
Rabbit fever (Central States)
O’Hara’s disease (Japan)
Synonyms
(Gurcan, 2014)

7. 7

8. In 1911, McCoy and Chapin described a plague-like illness
of rodents in Tulare County, California
Also named the germ bacterium tularensis, after Tulare
County, California
In 1914 The first human cases were reported by Lamb and
Wherry
History
(Levin, 1944)

9. Edward Francis
“Edward Francis was one of the most prominent pioneering scientists
working on Francisella tularensis and the bacterium was given its
present name in his commemoration”

10. In 1919 isolated B. Tularensis from the blood of ill patients
Studied the pathological changes of the disease in guinea
pigs, rabbits and in humans
Recovery of agent from blood and named condition
tularaemia
Developed culture-based and serological diagnostic methods
for tularaemia
Edward Francis
(Tarnvik and berglund, 2003)

11. In 1925, hachiro ohara (Yato-byo) studied hare disease in japan
similar to tularaemia
In USSR 1928, F. tularensis was recognised as the causative
agent of water- rat –trappers disease
In 1930, vaccine research on tularaemia was initiated
In Soviet union, Gaiskii and El’bert attenuated a natural isolate of
F. tularensis into a safe and effective vaccine
In 1946 it was introduced for mass vaccination in the Soviet union.
(Tigertt, 1962)
(Francis, 1937 )

12.  1940s and 1950s F. tularensis considered as a potential biological
weapon
 It was stockpiled by the U.S. military even in the late 1960s.
 In 1969, the WHO calculated that aerosolization of 50 kg of
F. tularensis bacteria in a metropolitan area with a population of 5
million would result in 250,000 incapacitated individuals and
some 19,000 deaths
(Sjostedt, 2007)

13. 1
3

14. Organism
Kingdom Bacteria
Phylum Proteobacteria
Class Gammaproteobacteria
Family Francisellaceae
Genus Francisella
Species F. tularensis
ETIOLOGY
(Sjostedt, 2007)

15. 0.1–1 X 0.1–3mm long
Small pleomorphic gram-negative bacillus.
non-motile
obligately aerobic
does not produce spores
Francisella tularensis
(Foley and Nieto, 2010)
 Bacterium tularense was initially included into the genera
Brucella and Pasteurella,
 In 1947, designated as a new genus for its taxonomy, The
genus, Francisella, was named in honor of Edward Francis

16. Francisella genus
Francisella
tularensis
Francisella
philomiragia
 2 species show a 16S rRNA sequence similarity of ≥98.3%
(Sandstrom & Sjostedt, 1994)

17.  On the basis of virulence testing, biochemical characteristics
and epidemiological features
 four recognised subspecies of F. tularensis
 The 16S rRNA similarity is ≥99.8% among the subspecies
(WHO, 2007)

18. 18
Francisella
genus
Francisella
tularensis
F. tularensis
subspecies
tularensis
F. tularensis
subspecies
holarctica
F. tularensis
subspecies
mediasiatica
F. tularensis
subspecies novicida
Francisella
philomiragia
(Oyston and Quarry, 2005)

19.  Most virulent species
 Prevelent in North America
 Infectious dose of <10 CFU via the respiratory route
19
F. tularensis subspecies tularensis (type A strain, biovar type A)
(Oyston and Quarry, 2005)

20. F. tularensis subspecies holarctica (biovar type B)
 Less virulent strain
 Found through out Northern Hemisphere
 Primary cause of tularemia in Europe
 Infectious dose of 10³ CFU
 Causes a milder form of tularemia in humans
(Morner and Addison, 2001)

21. F. tularensis subspecies mediasiatica
 Is primarily isolated to Central Asian regions of the former
USSR
F. tularensis subspecies novicida
 Found in North America and Australia
 Low virulence in experimental models
 Causes disease in immunocompromised individuals
 Linked to waterborne transmission in Australia, Spain and
USA
(WHO, 2007)
(Whipp et al., 2003)

22. 22
F. philomiragia
 Associated with salty water (Atlantic as well as
Mediterranean)
 low virulence,
 Cause disease in immunocompromised individuals
(Pechous et al., 2009)

23. Sr. No Virulence factor
Activity
1 Surface structures
( A ) Capsule Mediating resistance to various environmental and
host-generated stresses. Serum resistance
( B ) Lps Comprised of lipid a portion that specify antigenicity
due to variations in the O antigen and the NO
response of macrophages due to variation in the lipid
A moiety
( C ) Type IV pili To bind to the exterior of a host cell ,
pili have important functions in adhesion to
host surfaces, biofilm formation and twitching motility
in many bacteria ,oyston 2002
2 Francisella
pathogenesity island
(FPI)
Escape of F. Tularensis from the phagosome and
replication within the host cell cytosol
Virulence factors
(Pechous et al., 2009)

24. 2
4

25. Tularemia has been reported from 250 species of mammals, birds,
reptiles, fish, and invertebrates
Isolates or DNA evidence of F. tularensis have also been recovered
from soil, from infected tick and protozoa
In the United States, lagomorphs are most commonly infected and
transmit F. tularensis to humans
(Morner and Addison, 2001)
(Keim et al., 2007)
(Pechous et al., 2009)

26. Rodents, hares, and rabbits these are unlikely reservoirs for
F. tularensis
Arthropods, including ticks, biting flies, and possibly mosquitoes,
serve as vectors and potentially long-term reservoirs
Among domestic species, cats and dogs can acquire infection,
although clinical illness is more common in cats.
(Eliasson et al., 2002)
(Peterson and Schriefer, 2005)

27. Dogs may serve as reservoirs for the organism or maintenance
hosts for the tick vector
Among livestock, sheep are most commonly affected
Infection also occur in nonhuman primates (pet monkey)
Animals housed in zoo and laboratory facilities are at risk of
infection
(Feldman, 2003)

28. 2
8

29. Incidence of tularemia is related to the socio-economic conditions
It is more frequent in rural areas because of water stagnation, hay and
mud for weeks
It occurs in all age groups.
Transmitted to laboratory staff during bacteriological procedures
29(Karabay and ogutlu, 2014)

30. Diseases have a complex host distribution and Epizootiology
Human cases of tularaemia predominate in late summer and fall,
associated with arthropod inoculation
Outbreaks of disease in humans often parallel outbreaks of
tularemia in wild animals.
(Foley and Nieto, 2010)
(WHO, 2007)

31. Geogrophical distribution
Endemically in most countries of the Northern hemisphere, within a
range of 30 º to 71º latitude
 North America
 Europe
 Russia
 Japan
 Canada
 Rarely found in southern hemisphere
(Oyeston et al., 2004)

32. 32

33. Risk factors
associated with
human disease
Vector
population
Contaminated
Water
Increased
rodent
population
Occupational
exposure
Animal
exposure
(Cross et al., 2000)

34. 1) Ticks (Amblyomma, Dermacentor, Haemaphysalis,
and Ixodes)
The most important vectors in the USA
F. tularensis is maintained in tick populations by
transovarial passage
2) Flies (Chrysops spp.)
In Utah Outbreaks of human tularaemia have been
linked to transmission by Chrysops discalis (Deer
fly)
3) Mosquitoes (Aedes spp., Culex spp., Anopheles
spp.)
In the former Soviet union
(Hopla, 1974)

35. Mammals
• various terrestrial and aquatic mammals
such as ground squirrels, rabbits, hares,
beavers, muskrats and voles.
Reservoirs in the environment
• Faeces of the infected animal
• Contaminated feed
(WHO, 2007)

36. Life cycle of F. tularensis in nature

37. 3
7

38. I) Bites by infected arthropods (United States)
II) Direct contact
Handling of infected animal tissues
Carcass of rabbit or hare
Mode of transmission
(Arav, 2000)

39. iii)Ingestion
contaminated Water, Food & Soil
iv) Inhalation of aerosols
laboratory exposure
shearing of Dog and Sheep
v) Person-to-person transmission is rare or nonexistent
(Feldman, 2001)

40. 40
WHO ARE AT THE RISK ?
farmer Veterinarian Cook or Meat
handler
Laboratory
worker
Hunter landscaper
(CDC, 2012)

41. 4
1

42. Cutaneous
inoculation
Regional
lymphnode
Dissemination and
bacteraemia
liver
spleenIntense inflammatory
response
Granuloma formation
(Achtman et al., 2004) 42
lung
PMN
cells
Varying
Degree of
necrosis
Mononuclear
cell
(Santic et al., 2005)

43. 4
3

44. In human, characterized by acute febrile illness
Incubation period of 3 to 5 days
Infected people develop 1 of 6 clinical syndromes that depend on the
portal of entry.

45. 4
5
Fever Headache
CoughVomiting
Myalgia
Abdominal
pain
Non
Specific
Symptoms
(Saah, 2000)

46. 46
Clinical forms of tularemia

47. On the Basis of
Route of
Entrance.
Ulceroglandular
tularaemia
Oculoglandular
tularaemia
Respiratory
tularaemia
Typhoidal
Oropharyngeal
Glandular
tularemia
(Harik , 2013)

48. 4
8
Ulceroglandular tularaemia
 Most prevalent form of the
disease
 Caused by F. Tularensis subsp.
Holarctica
Source
 Direct contact with flesh of
infected animals
(Tarnvik and Berglund, 2003)

49. Lesions
Hunters may acquire disease by dressing a hare
and touching the infected animal
(WHO, 2007)
papule pustular
ulcerate to
form scar

50. (Kilic and Doganay, 2013)
Oropharyngeal tularaemia (gastrointestinal form)
Source
Ingestion of contaminated food or water
Symptoms
 primary ulcer is localised in the mouth (stomatitis) and
pharynx (pharyngitis)
 Enlargement of regional neck lymph nodes
 a fever, painful sore throat and swelling on the neck a

51. (Kilic and Doganay, 2013)
 Clinical presentation
 Enlargement of tonsils
 Formation of yellow-
white pseudo membrane in
Pharynx

52. Oculoglandular tularemia
(Ellis et al., 2002)
Bacteria enter through the conjunctival sac
Contaminated fingers with infective tissue, water and
aerosols

53. Symptoms
Unilateral Conjuctivitis
Swelling of the eyelids
Enlarged Preauricular gland
(Ellis et al., 2002)

54. (Kilic, 2010)
Glandular form
 Entery through an inapparent abrasion and then to
spread lymphatically
 Same signs and symptoms of ulceroglandular
tularemia with no visible skin ulcers

55.  Affects the bloodstream and body organs
 Patients usually present with fever, chills,
myalgias, malaise and weight loss
 No localizing signs and can be a diagnostic
challenge
 Ulcers and lymphadenopathy are usually absent
(Kilic and Doganay, 2013)
Typhoidal

56. (Karabay and Ogutlu, 2014)
Pneumonic form
 Uncommon
 Occurs after inhalation of the F. tularensis
 Mainly laboratory workers affected
 Farmers appear to be at risk
 By contaminated hay and other activities
such as lawn-mowing

57. Symptoms
Sputum may be purulent or there may be hemoptysis
There can be hilar lymphadenitis, pleuritis and bronchiolitis
(Foley and Nieto, 2010)

58. 5
8

59. Cultural isolation
Serology
Molecular detection
DIAGNOSTIC TECHNIQUES
(Hepburn and Simpson 2008)

60. 60
Sample to be collected
(Penn, 2010)
 Whole blood
 Serum
 Respiratory secretions
 Swabs of visible lesions
 Aspirates from lymph nodes or lesions
 Tissue biopsies
Dependent on the form of clinical illness

61. F. tularensis is a fastidious bacteria that rarely seen on Gram’s
staining
Cultures of F. tularensis should be done only in a biosafety level 3
(BSL-3) laboratory
(Harik, 2013)

62. Cultural Isolation
“Gold standard” for laboratory confirmation of tularemia infection
Selective media
Enriched chocolate agar (CA)
Cysteine heart agar with 9% chocolatized blood
(CHAB)
Buffered charcoal yeast extract (BYCE)
(Ellis et al., 2002)

63. 63
(Versage et al., 2003)
Chocolate agar (CA)
Cysteine heart agar with 9%
chocolatized blood (CHAB)

64. F. Tularensis can be isolated from sheep blood agar (SBA), but
CHAB is strongly recommended for subculture
CHAB agar
Characteristic growth on this media (green, opalescent,
raised, shiny colonies at 24– 48 h)
(Ellis et al., 2002)

65.  Glycerol fermentation test to differentiate type A and type B
 F. Tularensis grows slowly, therefore, 2–4 days are often
required for growth
(Hepburn and Simpson, 2008)

66. Serological
Antibodies to F. Tularensis may be demonstrated by
 Tube agglutination,
 Microagglutination,
 Hemagglutination
 Enzyme-linked immunosorbent assay (ELISA)
(Cross and Penn, 2000)

67. Molecular detection
PCR
Conventional PCR assays targeted at the genes which
are encoding the outer membrane proteins
A multitargeting real-time PCR assay for F. Tularensis
has also been developed
(Versage et al., 2007)

68. 6
8

69. Drug of choice
 Streptomycin
 Gentamicin
(WHO, 2007)
Alternative treatment
 Fluoroquinolones
 Ciprofloxacin
(Boisset et al., 2014)
TREATMENT

70. Antibiotic Dose in adult
Dose in
childern
Duration
Gentamicin
5 mg/kg/day, iv,
divided into two
doses
5-6 mg/kg/day,
divided into
two dose
10
Streptomycin 2x1 gr, im
15 mg/kg/day,
divided into
two doses
10
Ciprofloxaci
n
800 mg/day, iv
1000 mg/da oral,
divided into two
doses
15 mg/kg/day,
(maximum
daily dose up to
1 gr/day)
10-14
Doxycycline
200 mg/day,
divided into two
doses
Not suggested ≥ 15

71. 7
1

72. When hiking, camping or working outdoors:
 Use insect repellants containing 20% to 30% DEET
(n,n-diethyl-meta-toluamide), picaridin or IR3535
 Wear long pants, long sleeves, and long socks to keep
tick and deer flies off your skin.
 Remove attached ticks promptly with fine-tipped
tweezers
 Don’t drink untreated surface water
(Hepburn and Simpson, 2008)

73. When mowing or landscaping
 Don’t mow over sick or dead animals.
 Consider using dust masks to reduce your risk of
inhaling the bacteria.
(Ellis et al., 2002)

74. If you hunt, trap or skin animals
 Use gloves when handling animals, especially
rabbits, muskrats, prairie dogs, and other rodents
 Cook game meat thoroughly before eating.
 BSL 3 level
(Kilic and Yesilyurt, 2011)

75. 7
5
Health education
Education to villagers and forest workers
What is Tularemia???? Why this
Tularemia?
????

76. Beginning in the 1930s, the Soviet union used a live attenuated
vaccine to immunize tens of millions of persons living in tularemia-
endemic areas
In the United States, a live attenuated vaccine derived from the
avirulent live vaccine strain has been used to protect laboratorians
It is currently under review by the US Food and Drug
Administration (FDA), and its future availability is undetermined
Vaccination
(Harik, 2013)

77. Public health
significance
77

78. Veterinarians should consider a diagnosis of tularaemia in animals that have
a febrile illness with or without lymphadenopathy in an endemic area
Standard precautions should used for post-mortem examination to reduce the
risk of transmission from animal to man
Local or state health departments may be useful resources regarding
management of exposures to animals suspected of having tularaemia.
(Feldman, 2003)

79. Pet owners should be educated about the value of a good tick
control programme in the prevention of tularemia and other tick-
borne diseases
Increased risk of tularemia infection are veterinarian, laboratory
worker, farmer, sheep worker, hunter or trapper, cook or meat
handler and landscaper
Medical advice should be sought promptly if fever or other signs
compatible with tularaemia develop in a person exposed to an
animal with tularaemia
79
(Foley and Nieto, 2010)

80. 80
Laboratories processing clinical specimens should at a minimum be
BSL-2 and practice BSL-3 safety procedures
Hunters and those who come in contact with wild game and rabbits
should wear gloves when handling carcasses
(Feldman, 2003)

81. 8
1

82. Tularemia is an important vector borne zoonotic disease having ability
to cause death in human beings.
Caused by the small, pleomorphic, gram-negative , coccobacillus
francisella tularensis.
It occurs naturally in lagomorphs (rabbits and hares) and rodents and
accidently human get infected.
82

83. Can be spread by the bite of an arthropod, direct contact with diseased
animals, inhalation, or ingestion of contaminated food or water.
Six form of disease on the basis of route of entrance.
The persons at a high risk are veterinarian, laboratory worker, farmer,
sheep worker, hunter or trapper, cook or meat handler and landscaper.
Streptomycin is drug of choice.
83

84. Local or state health departments may be useful resources regarding
management of exposures to animals suspected of having tularaemia.
Tularemia can be diagnosed by clinical findings, supported by cultural
isolation , serology, molecular test.
Vaccine is currently under development
84

85. Future Prospects
85

86. In a future subcellular tularemia vaccine may available for public
Trials to use conventional adjuvants in order to obtain a protective T-
cell response to defined immunogens of F. tularensis have been
unsuccessful. The next step should be to introduce cytokines as
natural adjuvants.
Its relationship to Northern Hemisphere strains and its epidemiology
remain avenues for further study
86