zoonosis

1. ZOONOSIS
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2. INTRODUCTION
• Zoonoses :- derived from the Greek words
• Zoon- Animal & Noson – Disease
• Zoonoses was coined and first used by Rudolf
Virchow who defined it for communicable
diseases
• Diseases and infections which are naturally
transmitted between vertebrate animals and
humans - WHO 1959
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3. • Of the 1415 microbial diseases affecting humans, 61% are zoonotic with
13% species regarded as emerging or reemerging.
• Link b/w human & animals with their surrounding are very close especially
in developing countries.
• Emerging zoonosis as “a zoonosis that is newly recognized or newly
evolved, or that has occurred previously but shows an increase in
incidence or expansion in geographical, host or vector range”-
WHO/FAO/OIE joint consultation, May 2004
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4. • Emerging infectious disease-
 Hanta virus in USA
 Avian influenza
 Bovine Spongiform Encephalitis (BSE)
 Nipah virus.
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5. Factors Influencing The Emergence of Zoonotic
Diseases
 Etiological changes in mans environment and agricultural operations e.g.
Leptospirosis, plague, Rift Valley fever, Kyasanur Forest Disease etc.
 Increased movement or traveling of man e.g. amoebiasis, giardiasis,
colibacillosis, salmonellosis, SAARS, Yellow fever etc.
 Handling animal byproducts and waste e.g. anthrax, chlamydiosis,
dermatophytosis, tularaemia
 Increased in density of animal population e.g. dermatophytosis,
tuberculosis etc.
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6.  Increased trade in animal products e.g. anthrax, brucellosis,
salmonellosis, Hantaan virus, Bird flu etc.
 Drug resistant organisms e.g. E.coli, Staphylococcus aureus etc.
 Changing livestock farming practices e.g. E.coli O157:H7, Salmonellosis,
Listeriosis etc.
 Changing environmental conditions including climate and disaster e.g.
plague, Leptospirosis etc.
 Pathogen changes like genetic shift and drift e.g. Influenza, E.coli,
Staphylococcus
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7. Classification Of Zoonoses
According to the Etiological agents
 Bacterial zoonoses e.g. anthrax, brucellosis, plague, leptospirosis,
salmonellosis, lyme disease
 Viral zoonoses  e.g. rabies, arbovirus infections, KFD, yellow fever,
influenza
 Rickettsial zoonoses  e.g. murine typhus, tick typhus, scrub typhus, Q-
fever
 Protozoal zoonoses  e.g. toxoplasmosis, trypanosomiasis, leishmaniasis
 Helminthic zoonoses  e.g. echinococcosis (hydatid disease), taeniasis,
schistosomiasis,dracunculiasis
 Fungal zoonoses  e.g. deep mycosis - histoplasmosis, cryptococcosis,
superficial dermatophytes.
 Ectoparasites  e.g. scabies, myiasis
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8. According to the Mode of transmission
• Direct zoonoses- From an infected vertebrate host to a susceptible host
(man) by direct contact, by contact or thru fomite e.g. rabies, anthrax,
brucellosis, leptospirosis, toxoplasmosis.
• Cyclozoonoses - Require more than one vertebrate host species, but no
invertebrate host for the completion of the life cycle of the agent, e.g.
echinococcosis, taeniasis.
• Metazoonoses - Transmitted biologically by invertebrate vectors, in which
the agent multiplies and/or develops & there is always an extrinsic
incubation (prepatent) period before transmission to another vertebrate
host e.g., plague, arbovirus infections, schistosomiasis, leishmaniasis.
• Saprozoonoses -Require a vertebrate host & a non-animal developmental
site like soil, plant material, pigeon dropping etc. for the development of
the infectious agent e.g. aspergillosis, coccidioidomycosis, cryptococosis,
histoplasmosis, zygomycosis
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9. According to the reservoir host
• Anthropozoonoses - Infections transmitted to man from lower vertebrate
animals e.g. rabies, leptospirosis, plague, arboviral Infcn , brucellosis and
Q-fever.
• Zooanthroponoses - Infections transmitted from man to lower vertebrate
animals e.g. streptococci, staphylococci, diphtheria, enterobacteriaceae,
human tuberculosis in cattle and parrots.
• Amphixenoses - Infections maintained in both man and lower vertebrate
animals and transmitted in either direction e.g. salmonellosis,
staphylococcosis
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10. RABIES
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11. RABIES
• Acute, highly fatal viral disease of the central nervous system
caused by Rabies virus
• In India , rabies account to about 20,000 deaths annually. 1
• Most animal bites in India (91.5%) are by dogs, of which about
60% are strays and 40% pets.
• Rabies is present throughout the country, except in the islands
of Lakshadweep & Andaman and Nicobar.
• Incubation Period:- 3-8 weeks
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1. Sudharshan et al. A community survey of dog bites, anti-rabies treatment, rabies and dog
population management in Bangalore city. J. Commun. Dis. 38 (1) 2006 :32-39

12. • C/f pain and tingling at site of the bite. This is followed by intolerence
to noise and bright light. Aerophobia is present.
• Increased reflexes, muscle spasms, dilation of pupils and increased
perspiration, salivation & lacrimation are present.
• Hydrophobia is pathognomonic of rabies. Paralysis, coma or sudden death
may ensue.
• Prognosis:- Untreated, the fatality rate is 100%. Postexposure treatment is
effective until day 6 post-infection
• Antirabies vaccine before clinical onset of symptoms. Postexposure
treatment with rabies immune globulin & vaccine
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13. BRUCELLOSIS
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14. Brucellosis
• Also called Bang's disease, Crimean fever, Gibraltar fever, Malta fever, Maltese
fever, Mediterranean fever, rock fever, or undulant fever.
• Caused by bacterium Brucella (B. melitensis, B. abortus, B. suis, B.canis)
• Most human infections are caused by Brucella melitensis species in India.
• It is highly contagious zoonosis caused by ingestion of unsterilized milk or
meat from infected animals or close contact with secretions.
• C/F – Acute brucellosis  prolonged bacteraemia, irregular fever, chills,
muscular & articular pains, nocturnal drenching sweats, exhaustion, anorexia,
constipation, nervous irritability.
• Chronic brucellosis Sweating, lassitude, joint pains with minimal or no
pyrexia
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15. • Blood cultures should be done which yields 40-70% positivity.
• PCR – ELISA has superior specificity and sensitivity
• Prevention of human brucellosis  eradication of disease in
animals by vaccination, boiling milk before consumption &
pasteurization of milk.
• Treatment:- Antibiotic combination: streptomycin, tetracycline, and
sulfonamides
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16. PLAGUE
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17. PLAGUE
• Deadly infectious disease that is caused by the enterobacteria Yersinia
pestis
• Ancient disease and has caused 3 pandemics since 6th century.
• India fatal outbreaks in 1994 and 2002 in Maharashtra and Simla
respectively.
• Transmitted by black rat (Rattus rattus) and oriental rat flea (Xenopsylla
cheopis).
• Transmission by droplet contact, direct physical contact, by soil
contamination, airborne transmission, fecal-oral transmission and vector
borne transmission carried by insects or other animals.
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18. • C/f- Fever, chills, weakness, headache, and
swollen, tender lymph nodes (buboes) of
inguinal and femoral regions. Marked edema,
swelling, & inflammation of tissues overlying the
buboes are frequently seen.
• Symptoms begin approximately 2 to 8 days after
exposure
• Complications DIC, meningitis, & multi organ
failure .
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19. DIAGNOSIS
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20. • Hand-held immunochromatographic test are being used  rapid bedside
test even in remote areas.
• Prevention:- Aggressive rodent population control
• Treatment :-Gentamicin 5 mg/kg iv OD, Streptomycin 2 gm im BD,
Doxycycline 200mg PO OD, Tetracycline 2gm iv/PO q6th hrly,
Chloramphenicol 50mg/kg PO/ iv Q 6th hrly.
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22. LEPTOSPIROSIS
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23. Leptospirosis
• Emerging global public health problem
• Caused by Leptospira interrogans naturally seen in rodents
• Endemic in Andaman Islands & southern states of India (Kerala TN,
Gujarat, Karnataka, and Maharashtra)
• Rodents, domestic & wild animals form the reservoir of infection
• Domestic animals such as cattle, dogs, and pigs may act temporary carrier
• Rodents permanent carrier
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24. • Transmission- excreted in the urine of the animals- humans through direct
contact
• C/fconjunctival suffusion, pharyngeal erythema without
exudate,muscle tenderness, rales on lung auscultation or dullness on
chest percussion over areas of pleural hemorrhage
• Weil’s syndrome jaundice, renal failure and myocarditis with cardiac
arrhythmias, pulmonary haemorrhage with respiratory failure
• Diagnosis- Weil's disease  sed RFT values levels ,mixed conjugated and
unconjugated hyperbilirubinemia with aminotransferase elevation to less
than five times the upper limit of normal.
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25. • Isolation of leptospirosis by culture of blood, CSF and urine -media used is
EMJH medium.
• Gold standard- Microscopic Agglutination Test (MAT)- serovar specific test
• Other genus specific tests are the ELISA, Macroscopic slide agglutination
test(MSAT), latex agglutination test, Dipstick tests (Lepto dipstick, Lepto
Tek lateral flow) and Lepto Tek Dri-Dot test.
• Treatment Mild leptospirosis- Doxycycline 100mg PO BD or Amoxicillin
500mg PO TDS, Moderate/ severe leptospirosis- Ceftriaxone 1gm/ day iv
or penicillin (1.5 million units IV or IM q6h) or Cefotaxime (1 g IV q6h),
Chemoprophylaxis- Doxycycline (200 mg PO once a week) or
Azithromycin (250 mg PO once or twice a week)
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26. RICKETTSIAL INFECTIONS
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27. RICKETTSIAL INFECTIONS
• They cause irreversible damage to the human host  associated with high
morbidity & mortality.
• Mortality rate can be as high as 20 – 50 %.
• Prevalent in J&K, Himachal Pradesh, Uttaranchal, Rajasthan, Assam, WB,
Maharashtra, Kerala and TN
• The zoonotic diseases considered important in India are Epidemic typhus,
Murine typhus, Scrub typhus, Indian tick typhus and Q fever
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28. Scrub Typhus
• Causative agent- O. tsutsugamushi
• Transmission- Bite of infected larval
mites
• C/f - High Fever, chills, headache,
malaise, macular rash, generalized
lymphadenopathy, Eschar
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29. • Diagnosis- Immuno Fluorescent Assay, indirect immunoperoxidase &
enzyme immunoassays. PCR amplification of Orientia genes from eschars
and blood is also effective
• Treatment:- Doxycycline (100 mg bid orally for 7–15 days), Azithromycin
(500 mg orally for 3 days), or Chloramphenicol (500 mg qid orally for 7–15
days).
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32. ARBOVIRAL DISEASE
• Arboviruses in India Japanese encephalitis virus, Dengue virus &
Chikungunya fever
• Globally- Approx 2.5 billion people live in dengue-risk regions with about
100 million new cases each year.
• India accounts for nearly one-third of all dengue cases reported globally
• In 2006 more than 1.3 million people were affected by Chikungunya virus
which prevailed across 150 districts of 8 states in India.
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33. DENGUE FEVER
• Also known as break bone fever
• TransmissionBite of Aedes aegyptii bite during
day esp early morning & in the evening.
• C/f- Saddle back fever, headache, retrobulbar pain,
morbiliform rash appears on trunk & spreads
centripetally to face, trunk & limbs. Fever lasts for 5-
7 days
• Lab:- Leucopaenia & neutropaenia.
Thrombocytopenia occurs b/w 3rd and 8th day.
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34. • Complications- Dengue Haemorrhagic
Fever & Dengue Shock syndrome, ARDS
• Diagnosis- Dengue NS1 antigen (+ve in
the first week of illness),IgM antibody
detection (ELISA within 2-5 days of illness
till 1-3 months)
• Treatment- Symptomatic management
• Anti- Dengue day observed every year on
June 15th
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35. Japanese Encephalitis
• Caused by Japanese encephalitis virus
• JE was first recorded in Vellore and Pondicherry in mid 1950s.
• Transmitted through zoonotic cycle b/w mosquito, pigs and water birds
• Vector- Bite of Culex tritaenniorhynchus
• Incubation Period- 6-16 days
• C/f- Fever, rigors, headache & vomiting
• Encephalitis syndrome- Difficulty of speech, ocular palsies, hemiplegia,
quadriplegia, tremors, altered sensorium,convulsions, coma
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36. • Diagnosis- IgM – capture ELISA to detect specific
IgM in the CSF or blood within 7 days of disease.
• Treatment- symptomatic & supportive
• Prevention:- Vector control by aerial or ground
fogging with ultralow – volume insecticides, use
of mosquito nets, locating piggeries away from
human dwellings.
• JENVAC vaccine single dose for mass
vaccination campaigns and also as a two-dose
schedule during routine immunisation.
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Sensitivity & Specificity of the rapid IgM capture ELISA
(JEV-Chex) is 100%

38. Chikungunya fever
• Caused by Chikungunya virus
• Transmitted by Bite of Aedes aegyptii
• C/f- Fever, chills, anorexia, conjunctivitis ,morbilliform rash on trunk and
limbs, coffee colour vomiting, epistaxis, petechiae
• Prominent symptom in adults is arthropathy pain, swelling, stiffness of the
metacarpophalangeal, wrist, elbow, shoulder, knee, ankle and metatarsal
joints.
• Diagnosis- Detected in serum in the first 3-4 days with PCR. RT PCR to detect
viral DNA.
• Treatment- Symptomatic
• Prevention- Mosquito control measures. No vaccine is available.
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39. LEISHMANIASIS
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40. Leishmaniasis
• Complex disease caused by the protozoan
Leishmania
• In Indiaendemic in Bihar, Jharkhand, West
Bengal and UP
• Manifests in two forms  cutaneous &
visceral (kala-azar) variety
• Transmitted by the bite of female
phlebotomine sandfly
• C/f Fever, splenomegaly & hepatomegaly,
anaemia, weight loss, darkening of skin of the
face, hands, feet, abdomen and
lymphadenopathy.
• Post kala-azar dermal leishmaniasis lesions
develop consisting of multiple nodular
infiltrations of the skin, usually without
ulceration.
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41. • Cutaneous leishmaniasis Painful ulcers in
the parts of the body exposed to sandfly bites
–legs, arms or face.
• Diagnosis- Bone marrow & spleen aspirations
• Staining method most appropriate for
leishmania detection is one employing
panoptic May Grunwald–Giemsa stain.
• Classical blood agar NNN medium (consists of
0.6% NaCl added to a simple blood
agar slope) is the most currently used media
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42. • Visceral leishmaniasis PCR assay is found to be almost 100% sensitive
using peripheral blood
• Ultrasensitive PCR asay for visceral leishmaniasis asymptomatic carriage
in man even in immunosuppressed patients.
• Other serological tests- IFAT, Immuno- enzymatic techniques, counter
current immune-electrophoresis, IHA and immune blot
• Easy tests Direct Agglutination Test, rK39 immunochromatography
dipstick, latex particle agglutination, dot – ELISA and fast – ELISA.
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43. • Treatment sodium stibogluconate (100mg/ml). Daily dose 20mg/kg iv
or im for 28-30 days. Amphotericin B deoxycholate – 15 iv infusions ( dose
0.75- 1mg/kg body wt) daily or on alternate days.
• Orally administrable alkyl phospholipid, miltefosine is used. Dose 50mg BD
for adults weighing  25kgand once daily for those < 25 kg, after meals for
28 days.
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46. TAENIASIS & CYSTICERCOSIS
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47. Taeniasis & Cysticercosis
• Caused by 2 parasites- Taenia saginata and Taenia solium
• Taenia solium is endemic in India & widely reported, Taenia Saginata is
moderately reported.
• Transmission- Through ingestion of infective cysticerci in undercooked
pork (Taenia solium ) or beef (Taenia saginata), through ingestion of food,
water of vegetables contaminated with eggs.
• Cysticercosis refers to tissue infection after exposure to eggs of Taenia
solium, the pork tapeworm.
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48. Clinical features
• Cysts are formed in the brain and muscles
• Generalised muscle pain, painful nodules in the muscles and seizures 
cysts in the brain
• Cysts block outflow of CSF with symptoms of sed intracranial pressure
• Cysticerci in the globe, extraocular muscles, and subconjunctiva visual
difficulties that fluctuate with eye position, retinal edema, hemorrhage, a
decreased vision or even a visual loss
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49. • Diagnosis:- Antibodies to cysticerci can be
demonstrated in serum by Enzyme Linked
Immunotransfer Blot assay and in CSF by ELISA
• Neuroimaging with CT or MRI is the most useful
method of diagnosis.
• CT scan shows both calcified and uncalcified cysts
• Cystic lesions can show ring enhancement and focal
enhancing lesions.
• MRI is more sensitive in detection of intraventricular
cysts
• CSF findings include pleocytosis, elevated protein
levels and depressed glucose levels
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50. • Prevention- Massive chemotherapy of infected individuals, improving
sanitation, and educating people, cooking of pork or freezing it and
inspecting meat & by treating or vaccinating pigs.
• TreatmentAlbendazole 15mg/kg body weight/ day divided in 3 oral
doses for 7-28 days along with dexamtheasone.
• Praziquantel in 3 oral doses for 25 mg/kg body weight at 2 hour intervals
followed by 5 hrs later by dexamthasone
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51. TOXOPLASMOSIS
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52. Toxoplasmosis
• Caused by a parasite called Toxoplasma gondii
• Transmitted by infection by ingestion of tissue cysts present in raw or
undercooked beef, lamb or pork and ingestion of oocysts from soil, water,
milk or vegetables.
• Toxoplasmosis present worldwide with seropositivity ranging from less
than 10% to over 90%.
• Seroprevalence in India is about 22% approximately
• Can be transmitted congenitally in pregnant mothers
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53. • Acute toxoplasmosis Swollen lymph nodes,
or muscle aches and pains that last for a month
or more
• Swollen lymph nodes are commonly found in
the neck or under the chin, followed by the
axillae (armpits) and the groin.
• Enlarged lymph nodes will resolve within one to
two months in 60% of cases.
• Young children & immunocompromised
peoplesevere toxoplasmosis leading to
encephalitis or necrotizing retinochoroiditis
• Skin lesions roseola and erythema
multiforme-like eruptions, urticaria, and
maculopapular lesions
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54. • Laboratory diagnosis -detection of Toxoplasmaspecific antibodies done by
serologic tests to detect T. gondii specific IgG, IgM, IgA or IgE antibodies.
• IFAT, LAT, DAT and ELISA are used more commonly.
• Prevention- Avoid eating raw or undercooked meat, avoid handling or
adopting stray cats. Routine antenatal screening for toxoplasmosis and
treatment of infected mothers
• Treatment:-
 In immunocompromised pts- Pyrimethamine 200mg loading dose + 75
mg/dl+ sulphadiazine 1gm QUID or Clindamycin 600mg-1200mgQID or
TMP+SMX 20mg/kg/dlin 4 divided doses+ folinic acid
 In pregnancy- Spiramycin 1gm TDS
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55. ANTHRAX
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56. Anthrax
• Caused by the bacterium Bacillus anthracis
• Oldest recorded disease of animals
• Humans acquire infection from cattle, sheep, goats, horses and swine.
• Anthrax is enzootic in southern India but is less frequent to absent in the
northern Indian states.
• Anthrax in sheep is prevalent in sheep in Andhra – TN border causing
cutaneous & meningoencephalitic human infections with a high mortality
rate.
• Outbreaks of Anthrax have been reported from Mysore 1999, Orissa 2004,
2005, West Bengal 2000
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57. • 3 clinical types of disease based on the
route of infection
 Cutaneous anthrax follows entry of spores
through abraded skin -the typical lesions are
pustules which are more commonly seen on
face, neck, hands and back.
 Pulmonary anthrax occurs due to inhalation
of dust of wool characterized by haemorrhagic
bronchopneumonia.
 Intestinal anthrax is transmitted by ingestion
of improperly cooked infected meat causes
violent enteritis with bloody diarrhea
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58. • Diagnosis- Swabs, fluid or pus from pustules in
cutaneous anthrax, sputum from pulmonary &
blood from septicaemic anthrax patients are
collected.
• Gram staining shows large gram positive bacilli.
• Direct Fluorescent Antibody test for
polysaccharide cell wall antigen confirms the
identification of Anthrax bacilli.
• Culture  Medusa head colonies on nutrient agar
and non hemolytic colonies on blood agar are
seen.
• Gelatin stab culture shows inverted fir tree
appearance
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59. • Treatment:-
 Postexposure Ciprofloxacin 500 mg PO bid x 60 d or Doxycycline, 100 mg
PO bid x 60 d or Amoxicillin, 500 mg PO q8h, likely to be effective if strain
penicillin sensitive
 Active disease  Ciprofloxacin, 400 mg IV q12h or Doxycycline, 100 mg IV
q12h plus Clindamycin, 900 mg IV q8h and/or rifampin, 300 mg IV q12h;
switch to PO when stable. x 60 d total
 Vaccines:-Licensed to prevent anthrax, it is not typically available for the
general public. Anthrax Vaccine Adsorbed (AVA) protects against
cutaneous and inhalation anthrax. Vaccine is approved by the Food and
Drug Administration (FDA) for at-risk adults before exposure to anthrax.
FDA has not approved the vaccine for use after exposure for anyone.
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60. THANK YOU
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