1. Prepared by : Group 8
Submitted to : Dr- Ahmad Al Sagarat
EPIDEMIOLOGY AND
BIOSTATISTICS ASSIGNMENT
2. Psittacosis (or ornithosis) is a potentially fatal
systemic disease caused by Chlamydia (or
Chlamydophila) psittaci , It is a zoonotic infection
particularly associated with birds .
3. Much of the reported epidemiology of psittacosis is
based on a combination of respiratory symptoms and
demonstration of Chlamydia group antigen on serology ,
It therefore requires re-examination in the light of the
discovery of the more common C. pneumoniae which
also causes disease fitting such a case definition ,
Around 100 cases of psittacosis are reported a year in
England and Wales , Cases occur worldwide and are
more common in those exposed to birds occupationally
or as pet owners , Cases occur mostly in adults and more
often in males .
There is no distinct seasonal pattern .
4. Onset may be insidious or non-specific with fever and
malaise , followed by an atypical pneumonia with
unproductive cough , fever and headache , with 20%
mortality if untreated .
Other syndromes resemble infectious mononucleosis
and typhoid , Asymptomatic infection may occur ,
Most cases report fever and most (eventually) develop
a cough, Headache , myalgia and chills are each
reported in about half of cases , Relapses may occur.
Ovine strains may cause serious infection in pregnant
women, resulting in late abortion , neonatal death
and disseminated intravascular coagulation( DIC) in
the mother .
5. Culture is rarely used because of the risk of laboratory-
acquired illness and diagnosis is usually based on
serology .
As routine Complement Fixation Tests (CFTs) cross
react with C. pneumoniae , further testing may be
necessary to confirm which species is responsible .
Acute and convalescent samples of serum are usually
collected about 3 weeks apart , Micro
immunofluorescence (MIF) tests are now available and
are specific for C psittaci Antigen or genome detection
may also be possible in some laboratories if rapid
results are required.
6. Quarantine and other controls on imported birds .
Masks , good ventilation and measures to avoid
contamination in poultry plants and other areas
where workers might be exposed .
Pregnant women to avoid exposure to sheep ,
especially during lambing .
7. Although not statutorily notifiable in most of the
UK (local exceptions exist) , all cases of psittacosis
should be reported promptly to local public health
authorities , Psittacosis is notifiable in many
European countries , including Germany , Sweden ,
Denmark and Norway .
Laboratories should report all clinically significant
infections to national surveillance systems .
