PSITTACOSIS

1. 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

4. 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)

5. 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

6. 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

7. PSITTACOSIS Intracellular inclusion body of Chlamydia

8. 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

9. PSITTACOSIS Infectious life cycle of Chlamydia

10. 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 <5%, but may approach 100% after capture

11. 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)

12. 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)

13. 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

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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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 1:1000 • bleach (Chlorox®) at 1:100 • Lysol® at 1:100 • education

23. 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

24. 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