Ornithosis - Causes, Symptoms and Treatments

Ornithosis (also called psittacosis or parrot fever) is caused by the gram-negative intracellular parasite Chlamydia psittaci and is transmitted by infected birds. This disease occurs worldwide and is mainly associated with occupational exposure to birds (such as poultry farming). Incidence is higher in women and in people ages 20 to 50. With adequate antimicrobial therapy, ornithosis is fatal in fewer than 4% of patients.

Causes of ornithosis:

Psittacine birds (parrots, parakeets, cockatoos), pigeons, and turkeys may harbor C. psittaci in their blood, feathers, tissues, nasal secretions, liver, spleen, and feces. Transmission to humans occurs primarily through inhalation of dust containing C. psittaci from bird droppings; less often, transmission occurs through direct contact with infected secretions or body tissues, as in laboratory personnel who work with birds. Person-to-person trans­mission seldom occurs but usually causes severe ornithosis.

Signs and symptoms of Ornithosis:

After an incubation period of 4 to 15 days, onset of symptoms may be insidious or sudden. Clinical effects include chills and a low-grade fever that increases to 103 to 105° F (39.4° to 40.6° C) for 7 to 10 days, then, with treatment, declines during the 2nd or 3rd week. Other signs and symptoms include headache, myalgia, sore throat, cough (may be dry, hacking, and nonproductive, or may produce bloodtinged sputum), abdominal distention and tenderness, nausea, vomiting, photophobia, decreased pulse rate, slightly increased respiratory rate, secondary purulent lung infection, and a faint macular rash. Severe infection also produces delirium, stupor and, in extensive pulmonary infiltration, cyanosis. Ornithosis may recur, but is usually milder.

Diagnosis for Ornithosis:

Characteristic symptoms and a recent history of exposure to birds suggest ornithosis. Firm diagnosis requires recovery of C. psittaci from mice, eggs, or tissue culture that has been inoculated with the patient's blood or sputum.

Comparison of acute and convalesccnt serum shows a fourfold rise in Chlamydia antibody titers. In addition, a patchy lobar infiltrate appears on chest X-rays during the 1 st week of illness.

Treatment of Ornithosis:

Ornithosis calls for treatment with tetracycline. The infection is severe, tetracycline may be given I.V. until the fever subsides. Fever and other symptoms should begin to subside 48 to 72 hours after antibiotic treatment begins, but treatment must continue for 2 weeks after temperature returns to normal.If the patient can't tolerate tetracycline, penicillin G procaine or chloramphenicol is an alternative.

Special considerations and prevention tips for Ornithosis:

1. Monitor fluid and electrolyte balance. Give I.V. fluids as needed.

2. Carefully monitor vital signs. Watch for signs of overwhelming infection.

3. Reduce fever with tepid alcohol or sponge baths and a hypothermia blanket.

4. Reposition the patient often.

5. Observe secretion precautions. During the acute, febrile stage, if the patient has a cough, wear a face mask and wash your hands carefully. Instruct him to use tissues when he coughs and to dispose of them in a closed plastic bag.

6. Report all cases of ornithosis to public health authorities.

To prevent ornithosis, those who raise birds for sale should feed them tetracycline-treated birdseed and follow regulations on bird importation. They should also segregate infected or possibly infected birds from healthy birds, and disinfect structures that housed infected ones.