156. Glanders and melioidosis (Zoon.). Flashcards

1
Q

Glanders Occurence aetiology and epidemiology?

A

_1) Glanders (Malleus, Farcy, Rotzkrankheit) ʹ *NOTIFIABLE* - Zoonotic!_

Occurrence:

  • Susceptible: Equidae, Felidae, dog, camel (donkeys, mules more susceptible than horses)
  • Asia, Africa, South America, Hungary is free from 1956

Aetiology:

  • Burkholderia mallei (used to be Pseudomonas mallei)
  • Close relationship to B. pseudomallei
  • Low resistance (lower than Pseudomonas) ʹ kill with disinfectants & heattreatment
  • Discharges contain lots of water: prevents dehydration of the bacterium ʹ survive in environment for long time

Epidemiology

  • Introduced by carrier animals
  • Infection: discharge (nasal, ruptured nodules), feed, water, contact, shared trough, utensils, poorhygiene
  • Discharge drops into the water : consumed by other animals
  • High animal density helps spreading
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2
Q

Pathogenesis of glanders?

A

Pathogenesis

  • Mainly PO (aerogenic) infection
  • -> colonise and replicate in the pharynx
  • -> lymph vessels
  • -> Lns-> blood
  • Spread to organs: lung, nose, skin (lymphatic vessels, LNs)
  • Granulomas: necrosis, suppuration, demarcation with CT, ulceration, star-shaped cicatrices
  • (CT fibres contracted -scar)
  • Remain carriers
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3
Q

Clinical signs of Glanders?

A

Clinical signs

  • Horse (least susceptible species)
  • Chronic disease (can be asymptomatic),
  • incubation at least 2 weeks- several months
  • Sometimes general CS: Anorexia, fever, weakness
  • Nose:
  • Serous, sticky mucous-purulent discharge, blood
  • Nodules, ulcers (like crater), star-shaped cicatrices
  • Lung: cough, nasal discharge
  • Skin:
  • Nodules, ulcers, mucoid nasal discharge
  • Enlarged lymph nodes (cannot be moved ʹ due to prolif of CT)
  • Donkey, mule (more susceptible):
  • acute disease - septicaemia, Pneumonia -> death
  • Camel: mucous nasal discharge, ulcer (not as fast as donkey/mule, faster than horse)
  • Cats: Infected when eat meat of horses that died of glanders
  • Acute septicaemia
  • Pneumonia, enteritis, conjunctivitis
  • Purulent-haemorrhagic nasal discharge
  • Nose: granulomas, ulcers
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4
Q

Pathology of Glanders?

A

Pathology

  • Nose: granuloma, ulcer, cicatrices
  • Pneumonia:
  • Proliferative: granulomas isolated by CT surrounding (less susceptible animals e.g. horse, cat)
  • Exsudative: necrosis, cavern (more aggressive ʹ more susceptible sp. e.g. donkey)
  • Generalised malleus: Parenchymal organs, LNs - focal inflammation, necrosis, purulent granulomas
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5
Q

Diagnosis of Glanders?

A

Diagnosis

ͻ Diagnosis of the disease

  • Epidemiology ʹ clinical signs - pathology
  • Detection of the agent: bacterium isolation (no special demands),
  • PCR, IF, Western Blot, (animaltrial now replaced by PCR)
  • confirm diagnosis using 2 methods e.g. isolation + PCR
  • Detection of antibodies (in case of horse ʹ chronic disease) - serology: complement fixation test, ELISA,
  • immunoblot
  • Diagnosis of infection ʹ cross reaction with B pseudomallei
  • Allergic tests: mallein tests (PPD) ʹ extract from bacterium
  • A) Eye: 0.2 ml drop on conjunctiva of 1 eye (compare with other), 8-12h, 16-24h(repeating!)
  • x +ve case = purulent conjunctivitis
  • B) Skin (intradermal): 0.1 ml: neck/lower eyelid, 24h- 48hr 5mm > increase of thickness
  • Serology: CFT, ELISA, immunoblot
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6
Q

Differential diagnosis, treatment , Prevention , Control eradication public health aspects of glanders?

A

Differential diagnosis:

  1. strangles (enlarged LNs can be moved),
  2. ulcerative lymphangitis (C. pseudotuberculosis no resp CS/lesions in nose),
  3. epizootic lymphangitis (Histoplasma farciminosum ʹ tropical areas, recognise fungi in smear)

Treatment

  • Glanders free area: stamping out (no treatment!)
  • Endemic area
  • Wide spectrum antibiotics: doxycycline, gentamicin, ceftazidime (thick cell wall)
  • long and high dose
  • Remain carriers

Prevention

  • Control of animal import from infected countries
  • Import of animals from infected countries (horse race, exhibition):
  • quarantine, laboratory diagnostics
  • There are no vaccines

Control

  • Killing ill and infected animals
  • Regular serological examinations (moving animals ʹ yearly; non-moving animals ʹ every 3rd year)

Eradication: selection (test and slaughter)

Public health aspects

  • Humans are moderately susceptible
  • Occupational disease: veterinarian, farmer, slaughter house worker
  • Infection: aerogen, PO (raw horse meat), conjunctiva, wound
  • Local suppuration
  • Generalisation: fever, depression, pneumonia, dyspnoea
  • Antibiotics are effective: doxycycline, fluoroquinolones (if diagnosed at right time)
  • Personal protective methods ʹ use a mask to examine animals
  • Biological weapon, bioterrorism
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7
Q

Melioidosis Occurence

A

Melioidosis - Zoonosis

Occurrence:

  • tropical/warm areas - diagnosed in S.E Asia, sporadic importation to Europe

Aetiology: B. pseudomallei

  • Habitat: wet soli (mud), water
  • Susceptible: swine, cattle, sheep, goat, horse, camel (pigs carry infection frequently), human
  • Facultative pathogen
  • Epidemiology
  • Predisposing factors:
  • stress, rainy season, warm weather
  • Doesn’t spread from animal to animals
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8
Q

Pathogenesis, clinical signs and diagnosis?

A

Pathogenesis

Infection:

  • soil
  • aerogenic, PO, skin
  • Septicaemia
  • Abscesses: parenchymal organs, brain

Clinical signs:

  • Acute: variable, fever, depression, purulent nasal discharge, cough, dyspnoea
  • Chronic: variable, respiratory signs, dyspnoea, diarrhoea, CNS: ataxia, circling
  • Pathology:
  • abscesses (lung, spleen, liver, kidney, brain, nose), purulent inflammation

Diagnosis

  • Epidemiology ʹ clinical signs ʹ PM lesions
  • Detection of the agent: isolation of the bacterium, PCR
  • Detection of antibodies: CFT, ELISA ʹ cross with B. mallei
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9
Q

treatment prevention and public health aspects of meloidiosis?

A

Treatment:

  • antibiotics - wide spectrum (thick cell wall of bacteria),
  • large doses,
  • long lasting treatment (need time for
  • the AB to diffuse into the lesions)

Prevention

  • Endemic area: prevention of soil infection
  • Disease-free area: stamping out

Public health aspects

  • zoonosis (diagnosed in the Vietnam war)
  • Infection from: soil, water, infected animals, wound, PO, aerogen, skin
  • Subclinical infection can occur (asymptomatic carriage)
  • Predisposing factors: exhausting work, stress, chronic diseases
  • Acute septicaemia: fever, depression, anorexia
  • Different clinical signs: fever, pneumonia, dyspnoea, diarrhoea
  • Antibiotic treatment: large doses, long treatment
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