**4.** *Chlamydia psittachi* **infections**

*Chlamydophila psittaci* can cause systemic infection and pneumonia, often called psittacosis or ornithosis The pathogen *Chlamydophila psittaci* can cause systemic infections and pneumonia, often called psittacosis or ornithosis. Previously, it was classified under the genus of Chlamydia but now it is grouped *with C. pneumoniae* and some other veterinary species in the genus Chlamydophila of the family Chlamydiaceae [4].

## **4.1 Epidemiology**

Psittacosis is responsible for 1% of incident cases of CAP, according to a recent meta-analysis [104]. From 1990 to 2008, the Centers for Disease Control and Prevention (CDC) received 756 reports of psittacosis, of which 9% involved individuals younger than 20 years old [105]. It is not a well-recognized disease by clinicians, there are difficulties in the diagnosis of infection and may be due to underreporting, it is thought that this may not be reflecting the actual number of cases. It is not a well-recognized disease by clinicians, there are difficulties in diagnosing infection, and because of underreporting, this may not reflect the actual number of cases.

*C. psittaci* is transmitted through the inhalation of aerosols containing respiratory tract secretions, eye secretions, urine, or feces from infected birds. Even limited exposure to infected birds or their droppings can cause illness. Most reported cases of psittacosis have been linked to exposure to domestic birds. Since *C. psittaci* is resistant to drying and can remain infectious for months in the environment, avian exposure may not be reported in some cases.

#### **4.2 Clinical manifestations**

Psittacosis classically causes "atypical" pneumonia. Disease presentations can range from minor influenza-like symptoms to severe systemic diseases. The incubation period is typically between 5 and 14 days, but symptoms can appear up to one month after exposure. It is impossible to make a differential diagnosis according to clinical features compared to other pathogens of community-acquired pneumonia [106]. Psittacosis should be considered in any child with pneumonia who has had close contact with birds.

#### **4.3 Diagnosis**

Historically, the diagnosis of *C. psittaci* disease was based on clinical presentation and a positive microimmunofluorescence (MIF) with paired sera serologic test results. Despite the fact that the MIF test is generally more sensitive and specific than complement fixation (CF) assays, MIF still exhibits cross-reactivity with other Chlamydia species in some cases. NAATs and PCR tests are currently accessible only in specialized laboratories [107].

#### **4.4 Treatment**

Doxycycline, erythromycin, and azithromycin are the drugs recommended for treatment.

*Childhood Chlamydia Infections DOI: http://dx.doi.org/10.5772/intechopen.111712*
