chlamydia parrot disease


In an otherwise healthy individual with flu-like symptoms, pounding headaches, and a history of working in close contact with parrots or other exotic birds, having co-workers with similar symptoms, and exposure to ill birds, the diagnosis of psittacosis should be considered. Psittacosis (also known as "parrot disease," "parrot fever," or "ornithosis") is a zoonotic disease caused by an obligate intracellular bacterium Chlamydophila psittaci. Treatment for psittacosis should be with tetracycline hydrochloride 500 mg orally four times daily, or doxycycline 100 mg twice daily orally or may be delivered intravenously (choice C is correct). Duration of therapy is usually 10 to 14 days, although some reports suggest extending the therapy to 21 days to prevent relapse.

Patients may develop one of several syndromes: a mononucleosis-like illness, a typhoidal form, a nonspecific febrile illness, or atypical pneumonia. The most common signs and symptoms are fever, cough, headache, pharyngeal erythema, and crackles. Particularly helpful clinical clues are hepatosplenomegaly, hemoptysis, epistaxis, rash, and relative bradycardia (i.e., low pulse rate with fever). Chest radiography may show ground-glass opacities or an interstitial process but is nonspecific. Diagnosis is usually made serologically, by complement fixation (CF) or microimmunofluorescence (MIF). Polymerase chain reaction (PCR) is species-specific but is not generally available.

Although the patient in this case presented with inflammatory changes such as myalgias and flu-like symptoms, empiric treatment with oral corticosteroids would not be indicated (choice A is incorrect).

Oseltamivir is indicated for the treatment of acute, uncomplicated illness due to influenza A and B infection in patients 2 weeks of age and older, and who have been symptomatic for no more than 48 hours. In this case, splenomegaly on examination combined with the occupational exposure and the fact that the symptoms occurred in the spring of the year (not during prime influenza season) with already several days of symptoms that would limit the potential benefits of an antiviral agent (choice B is incorrect).

Itraconazole is indicated for the treatment of mild to moderate severity histoplasmosis, an infection caused by the fungus Histoplasma capsulatum. The fungus is contracted from inhaled spores, particularly in soil that contains large amounts of bird or bat droppings. In the United States, Histoplasma is found mainly in the central and eastern states, especially areas around the Ohio and Mississippi River valleys. The fungus also has been identified in parts of Central and South America, Africa, Asia, and Australia. Although most people who breathe in the spores don’t get sick, those who do may develop acute histoplasmosis, a condition characterized by fever, cough, and fatigue. Many people with acute histoplasmosis will improve without medication, but in some immunocompromised individuals, the infection can become severe. In this particular case, although the patient presented with exposure to bird droppings and experiencing flu-like symptoms, the presence of acute splenomegaly, severe headaches, relative bradycardia, and lack of lymphadenopathy make it less likely (choice D is incorrect).1

Footnotes

  1. SEEK Questionnaires