PSITTACOSIS

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PSITTACOSIS

• Causative agent Chlamydia psittaci
• Other names parrot fever, ornithosis, Avian
  chlamydiosis
• Primarily a disease of birds

2
PSITTACOSIS

• Background
• first identified in 1879, thought to be primarily
  in parrots (parrot fever)
• in 1929-1930, shipment of amazon parrots from
  Argentina caused world-wide epidemic
• caused outbreaks in many non-psittacine birds

3
PSITTACOSIS

• Background
• because of this pandemic, US (and many other
  countries) imposed a total ban on importation of
  birds
• US finally lifted ban in 1973
• changes in import regulations in 1993 has greatly
  reduced the number of imported birds

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PSITTACOSIS

• Regulations for importation of birds
• permit required in advance of shipping
• health certificate from full-time government
  salaried veterinarian from exporting country
• quarantine
• minimum of 30 days
• USDA approved facility at port of entry
• psittacine birds receive medicated feed (1
  tetracycline)

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PSITTACOSIS

• Background
• correctly called avian chlamydiosis
• ornithosis is name given to disease when
  present in non-psittacine species
• identified in over 140 avian species
• one-eyed roup - conjunctivitis or pink-eye
  associated with infection
• ban on importation of birds
• US finally lifted ban in 1973

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PSITTACOSIS

• Features of organism
• an obligate intracellular bacteria
• non-motile coccoid bacteria entirely dependent on
  host cell for energy metabolism and biosynthesis
• originally thought to be viruses, but have a cell
  wall and contain DNA, RNA and ribosomes, hence
  classified as bacteria

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PSITTACOSIS

• Intracellular inclusion body of Chlamydia

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PSITTACOSIS

• Features of organism
• distinguished from other bacteria, viruses, and
  rickettsia by unique reproduction, existing as
  two stages
• elementary body - infectious form
• reticulate body - intracytoplasmic, reproductive
  form
• closely related to C. trachomatis, C. pneumoniae

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PSITTACOSIS

• Infectious life cycle of Chlamydia

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PSITTACOSIS

• Epidemiology
• occurrence worldwide
• prevalence
• birds
• occurs with high frequency among birds in crowded
  conditions (aviaries, zoos, pet shops
• 20 of all pet birds tested at autopsy in study
  in Florida (1982)
• incidence in wild parrots 100 after capture

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PSITTACOSIS

• Epidemiology
• prevalence
• humans
• sporadic outbreaks
• infrequent in humans, usually sporadic, many mild
  infections not reported
• CDC (1982-1991) - 1,344 cases, 6 deaths (0.4 CFR)

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PSITTACOSIS

• Epidemiology
• reservoir avian species, especially budgerigars
  and parrots
• clinically inapparent (healthy) carriers
• shed organisms during crowding, stress (shipping,
  quarantine, when newly introduced into aviary)

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PSITTACOSIS

• Epidemiology
• source of exposure
• most commonly imported birds
• domestic poultry (turkey, duck) and squab farms
• geese and pigeons
• occasionally laboratory material
• feline psittacosis if conjunctivitis

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PSITTACOSIS

• Epidemiology
• transmission
• inhalation of agent form desiccated droppings,
  excretions
• laboratory exposure has occurred
• person-person transmission can occur but
  considered rare

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PSITTACOSIS

• Clinical features (human infection)
• Incubation period 5-14 days
• Symptoms asymptomatic to severe
• flu-like symptoms with acute fever
• rash
• upper and lower respiratory signs generally mild
  although extensive pneumonia present
• relapse may occur

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PSITTACOSIS

• Clinical features (avian infection)
• Incubation period 7-28 days, but can be up to
  96 days
• Symptoms asymptomatic to severe
• asymptomatic infections
• high number of infertile eggs
• high mortality in nestlings
• severe infections with death within 1 week not
  uncommon

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PSITTACOSIS

• Clinical features (avian infection)
• Symptoms
• strong affinity for mucous membranes
• conjunctivitis, sneezing, diarrhea, pneumonitis
• anorexia, lethargy, ruffled feathers
• if untreated, death due to malnutrition or
  pneumonia

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PSITTACOSIS

• Clinical features (other animal infection)
• Symptoms
• respiratory disease
• feline pneumonitis (once common)
• conjunctivitis pink eye
• enteritis
• abortion (sheep, cattle, goats)
• polyarthritis (sheep, cattle, goats)
• infertility/sterility

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PSITTACOSIS

• Diagnosis
• difficult due to ability to hide in host cells
  and because of variable clinical presentation
• Human infection
• history of exposure
• culture of sputum or serum
• ELISA but may yield false positive if
  post-infection
• chest x-ray

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PSITTACOSIS

• Diagnosis
• Avian species
• CF of paired sera commonly used in avian dx, most
  diagnostic
• Antigen tests (ELISA, Indirect FA) may be helpful
  if shedding organism, but negative test with
  clinical signs cannot rule out infection without
  further testing

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PSITTACOSIS

• Treatment
• readily treated if initiated prior to extensive
  tissue and organ involvement
• humans
• tetracycline - 10-14 days after fever subsides,
  and after relapse if occurs
• erythromycin if ttc contraindicated
• psittacine birds
• doxycycline for 30-45 days

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PSITTACOSIS

• Prevention and control
• difficult to kill, capable of lying dormant in
  environment for many months
• disinfectants
• quaternary ammonia compounds (Roccal-D or
  Zepharin) at 11000
• bleach (Chlorox) at 1100
• Lysol at 1100
• education

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PSITTACOSIS

• Prevention and control
• reportable zoonotic disease
• CDC case definition
• confirmed
• clinical specimens are culture positive
• or
• clinical signs with fourfold or greater rise in
  CF antibody titer in paired sera at least 2 weeks
  apart
• probable
• if signs with single titer of ? 32

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PSITTACOSIS

• Prevention and control
• regulation of importation
• ban importation of wild psittacine birds
• Compendium of Psittacosis (Chlamydiosis) Control,
  1995 - adopted by the National Association of
  State Public Health Veterinarians