Prof. Dr./ Wafaa Abd El-ghany Professor of Poultry Dis ...scholar.cu.edu.eg/?q=wafaaabdelghany/files/chlamydiosis_1.pdfFancy and caged birds, turkeys, ducks, geese, pigeons, and ostriches

Prof. Dr./ Wafaa Abd El-ghany

Professor of Poultry Dis.,

Fac. Vet. Med., Cairo Univ.

Definition Avian chlamydiosis is an acute fatal

or chronic infectious zonootic

respiratory disease of domestic, wild

and migratory birds.

The disease is characterized by nasal

and ocular discharge, diarrhea, loss

of weight, drop in egg production and

the mortality rate reached to 5-30%.

Presence of intracytoplasmic

elementary bodies (LCL) is

characteristic to the organism.

Psittacosis:

This term is given to the infection of

Psittacin or fancy (caged) birds like

parrots, parakeets, and also infection

of human.

Ornithosis:

This term is given to the infection of

non psittacin birds (Domestic birds).

Parrot Fever:

Referred to infection of parrots.

Economic Importance

1. Mortalities 5-30%.

2. Low feed conversion rate

and loss of body weight.

3. Drop in egg production.

4. Medication costs.

5. Zoonotic importance.

The causative agent

Chlamydophila psittaci (previouslyChlamydia Psittaci) (C.Psittaci).

It is a Gram negative, obligatoryintracellular organism.

This organism has different forms thatcould be detected in the impressionsmear stained by Giemsa, Gimenz,Castaneda, Macchiavello or stamp stainas:

1.Elementary body: Intracytoplasmic(LCL)bodies

2.Reticulate body: Intranuclear

Giemsa stain: intracellular chlamydial inclusion

(reddish-purple).

It is sensitive to tetracyclines,

chloraphenicol and erythromycin, resistant

to bacitracin, gentamycin and neomycin.

Disinfectant which affect lipids and cell

wall are effective (Quaternary ammonium

compound and lipid solvent).

It could be cultured in mice, embryonated

chicken eggs via Ys or CAM or on the tissue

culture.

There are 6 serotypes (A, B, C, D, E & F) as

typed by monoclonal antibodies or PCR.

Members of this serotype are differ in

virulence from low to high.

The causative agent

Susceptibility C.Psittaci infects all domestic and400 cages and wild birds (psittacinand non-psittacin).

Fancy and caged birds, turkeys,ducks, geese, pigeons, and ostrichesare highly susceptible.

Chickens are less susceptible.

C.Psittaci can infect human (due todirect contact with infected birds orinhalation of infected dropletscausing fatal pneumonia, heartthrombosis and even sterility).

All ages are susceptible but the

young are more susceptible.

The infection is usually in-apparent

or chronic latent asymptomatic.

Under stress factors, the latent

infection is changed into acute form

and the signs appear.

Concurrent infection with E.coli or

Salmonellae enhance the organism

pathogenicity.

Susceptibility

Mode of infection

C.Psittaci infection occur

horizontally either by inhalation

of infected dust or droplet or by

ingestion of contaminated feed and

water with infected droppings.

There is an evidence of low

percentage of vertical infection

through eggs (transoverian) in

ducks and sea gulls can occur.

Chronic carriers transmit the organism

without signs.

Biting of insects as ticks, lice and

mites.

Direct contact between the parents and

the young's in the nests (pigeons).

Wild birds are important in

transmission.

Incubation period:

5-60 days (age, virulence, health

conditions, management and dose)

Mode of transmission

Pathogenicity

Based on natural pathogenicity for

domestic fowl:

1. Highly virulent strains: acute

epidemics with 5-30% mortality.

2. Less virulent strains: slowly

progressive epidemics.

All strains have equal ability to

spread rapidly

Highly virulent strains Isolated from turkeys & occasionally

wild birds.

Most outbreaks serotypes: D

It is called “Toxigenic” → rapidly

fatal disease.

Causes extensive vascular congestion &

inflammation of internal organs.

Broad spectrum pathogenicity for Lab.

animal.

Serious infection (some fatal) in

humans.

Low Virulent Strains Slowly progressive epidemics.

Mortality less than 5% in

uncomplicated cases.

Isolated from pigeons & ducks and

occasionally from turkeys, sparrows

etc…. often accompanied by Salmonella

infection causes high mortality &

shedding.

Mostly serotype B & E.

Clinical signsTurkeys:

I Acute epidemic form (Highly virulent toxigenic strain)

Systemic fatal infection with:

Sudden death of 5-30% & morbidity rate 50-80%.

Nasal and ocular discharge, swollen eye lids, conjunctivitis and sinusitis.

Fever, off food and loss of weight (emaciation).

Yellow green gelatinous diarrhea.

Rapid drop in egg production (40-50%).

Turkeys:

II Infection with less virulent strain:

Inappetance.

Greenish diarrhea.

Slight drop in egg production.

Morbidity ranges from 5-20%.

Mortality ranges from 1-5%.

Complicated secondary infection with

bacteria, virus and protozoon induced

prolonged severe course and higher

mortalities.

Ducks and geese(water fowl):

In duckling, there are tremors,

trembling and staggered gait (in-

coordination).

Ocular and nasal discharge.

Greenish watery Diarrhea.

Emaciation, convulsion and death.

Morbidity rate 10-80%.

Mortality rate 1-30% (depending on

the age, health status and secondary

infection with Salmonella species).

Pigeons and pet birds:

Uncomplicated (acute disease):

Inappetance and emaciation.

Diarrhea.

swollen eye lids and conjunctivitis.

Rhinitis and sinusitis (dirty nostrils).

Respiratory distress and abnormal

respiratory signs (rattling signs).

Morbidity rate about 20%.

Complicated form:

Trichomoniasis, salmonallosis or paramyxo-

virus increase the severity of the disease.

Chickens:

They are relatively resistant.

Young birds acquired acute infection

and deaths.

The signs may be silent or temporary

(In-apparent infection).

Mortalities not exceeding 5%.

Nasal discharge, conjunctivitis and lacrimation

Parakeet: respiratory distress Chronic chlamydiosis (cachexia)

Post-mortem lesions Congestion of lungs and pneumonia.

All the body cavities are filed with

fibrinous exudates (Fibrinous pericarditis,

perihepatitis, and airsacculitis and

peritonitis).

Pancreas of pigeon enlarged and overlapped

the two duodenal loops with gray foci.

Catarrhal enteritis.

Liver and spleen are enlarged, dark and

covered with gray white foci.

Congestion of the visceral organs.

Fibrinous air sacculitisFibrinous perihepatitis

fibrinous pericarditis.

Pneumonia

Liver necrosis Enlarged and congested liver

congestion of spleen

Diagnosis Signs and lesions are suggestive.

Sections or impression smears of the

affected tissues or exudates or monolayer

of the infected cell culture could be

stained with Giemsa (purple), Giemenz

(red), Macciavello or Castanda and stamp

stains to detect intracellular cytoplasmic

or elementary bodies (LCL) (Levanthi, Cole

and Lelli). or reticulate (intranuclear)

bodies. Bodies etected under phase contrast

or dark field illumination microscope.

C.Psittaci can’t be propagated on

conventional cultural media but could be

isolated and propagated in:

Embryonated chicken eggs:

The eggs are inoculated via YS or CAM

and inocubated at 39 C for acceleration

of chlamydial growth for 6-7 days.

Death of the embryos with vascular

congestion after 3-10 days of

incubation. Sometimes 3 blind passage

in ECE is needed to obtain lesions in

embryos.

Touch impression smear for staining and

microscopic examination.

Diagnosis

Laboratory animal inoculation:

Intra peritoneal, intra cranial or intra

nasal inoculation of 3-4 weeks old mice (3-6

mice), death of mice after 5-7 days post

inoculation.

Intra peritoneal inoculation resulted in

peritonitis with splenomegaly.

Intra cranial inoculation resulted in

meningitis.

Intra nasal inoculation resulted in

pneumonia.

Diagnosis

Laboratory animal inoculation:

You can’t consider mice is negative except

after 3 blind passages.

Examination of the affected tissues by

cytochemical or immuno-flurescent method can

detect the organism in these tissues, also

impression smears of the affected tissues are

valuable.

Diagnosis

Tissue culture inoculation:

McCoy, Vero, Hela, mouse L cells, BHK21 and

BGM media are inoculated with the organism

then stained and examined microscopically.

Detection of bacterial antigen by PCR.

Serological tests like CFT, IF, IP, AGPT,

ELISA or latex agglutination test.

Diagnosis

Vascular congestion

Enlargement and congestion of the liver

and spleen, collected from chicken

embryos inoculated with C. psittaci. A

normal liver and spleen are shown in the

middle of the photo.

Enlarged and congested liver and

spleen collected from chicken embryos

inoculated with C. psittaci. A normal

liver and spleen are shown in the

middle.

Differential diagnosis

Colibacillosis.

Mycoplasmosis.

Fowl cholera.

Control1. Oxytetracyclin (15mg/kg bwt) in the

drinking water for a period for 5 days.

2. Chlorotetracyclin.

(treatment may be extended to 15-45 days)

in severe infection).

3. Usage of combined antibiotics to control

other associated infections as Salmonellae

and E.coli (quinolones like cipro, enro,

and danofloxacin) for 3-5 days in the

drinking water.

Prevention Sanitary measures must be adopted.

Different avian species and ages must

be reared away from each other.

Newly purchased (imported) birds,

especially pets must be quarantined

for 35 days (if positive discarded or

treated with tetracyclines till

recovery).

Prevent the introduction of birds from

the enzootic areas.

Avoid the contact with the free living

wild birds.

Thorough cleaning and disinfection

(iodophors or formaldhydes).

Prophylactic doses of antibiotics.

Regular testing of the birds using

serological tests.

Restrict the movement of people and

visitors.

Trials for vaccine preparation.

Prevention