DR. drh. Hapsari Mahatmi, MP

Chlamydiosis, Psittacosis, Ornithosis Introduction

An infection of turkeys, ducks, psittacines, pigeons, man, rarely chickens, caused by Chlamydia psittaci, a bacterium of highly

variable pathogenicity. It is a 'Scheduled Disease' rarely diagnosed in UK, but occurring probably worldwide. Morbidity is 50-80%,

mortality 5-40%.

It is transmitted by contact, faecal dust and wild bird carriers, especially pigeons and robins. Egg transmission does not occur.

Elementary bodies are highly resistant and can survive in dried faeces for many months.

Iodophores and formaldehyde are effective disinfecting agents, phenolics are less so. Intercurrent salmonellosis and, perhaps,

other infections may be predisposing factors.

DR. drh. Hapsari Mahatmi, MP.Staff Laboratorium Mikrobiologi

I. Penyakit Infeksius I

Signs

Respiratory signs. Greenish-yellow diarrhoea. Depression. Weakness. Inappetance. Weight loss. Nasal discharge. Conjunctivitis. Occasional transient ataxia in pigeons. Production drops in naive laying flocks

Post-mortem lesions

Vascular congestion. Wasting. Fibrinous pericarditis. Airsacculitis. Perihepatitis. Spleen enlarged and congested, may rupture in pigeons. Necrotic foci in liver. Fibrinous pneumonia. Congested lungs and air sacs in the turkey.

Diagnosis

History, signs, lesions. Intracytoplasmic inclusions are helpful but confirmation requires demonstration of causal organisms (Giemsa stain, IFA).

Serology: complement fixation, Elisa and gel diffusion.

Differentiate from Duck viral hepatitis, Duck septicaemia.

Treatment

Tetracycline (200-800 ppm in feed for 3-4 weeks) and/or quinolone medication and supervised slaughter.

PreventionBiosecurity, exclusion of wild birds.

Live and inactivated vaccines are protective although the former result in carriers and the latter require several applications

Infectious coryza

Etiologic agent: Hemophilus paragallinarum bacteria

- Qualitative detection of Infectious coryza (Hemophilus paragallinarum bacteria) by polymerase chain reaction

Infectious coryza (IC) is an infectious respiratory disease found in many avian species worldwide. The causative agent of IC is Hemophilus paragallinarum. The disease can be acute to subacute at onset but typically progresses to a chronic state, with infected birds becoming carriers of the bacteria. Common names for the disease include roup, cold and coryza. In the United States, it is predominantly found in small noncommercial, or hobby flocks. While chickens are the primary host of infectious coryza, pheasants, guinea fowl and turkeys are also susceptible.

Chronically ill or inapparent healthy carrier birds : reservoir

The source of the disease : carrier birds to the flock.Recovered birds remain carriers and shedders for life. Transmission occurs by direct bird to bird contact, inhalation of infectious aerosols coughed into the air, or by ingestion of contaminated feed and water.

The organism can be transferred on contaminated clothing, equipment and other fomites.

Coryza usually occurs in juvenile and mature birds 14 weeks of age or older. Incubation period is 1 to 3 days and the course of the acute disease stage is 4 to 12 weeks.

Symptoms include nasal discharge, facial swelling, sneezing, labored breathing and fetid odor of the exudates. The infection mainly involves the upper respiratory tract--trachea, sinuses and air passages of the head.

Morphology :

H. paragallinarum bacteria have a polar staining and pleomorphic rod morphology. The bacterium is non-motile and gram negative. There are three antigenic types (A, B, and C) which all share certain antigens. H. paragallinarum requires both “X” and “V” factors in the media to grow.

Culture identification has traditionally been used to identify this bacterium. However, the stringent requirements for sample handling for culture for this bacterium, long incubation time and the occurrence of numerous variants of the bacteria have made culture difficult to perform and not optimally sensitive. Serological detection of H. paragallinarum is limited by availability of good monoclonal antibodies and the sensitivity of the individual assay protocol. Molecular detection by PCR has been confirmed to be the most sensitive, specific and rapid way of identifying this bacterium (Blackall, 1999).

Mycoplasmosis (CRD, Air sac, Sinusitis)

Genus Mycoplasma are a significant cause of respiratory disease in poultry. Of the numerous species of Mycoplasma that have been isolated from domestic poultry, three are of known significance. Mycoplasma gallisepticum is associated with chronic respiratory disease (CRD)/air sac syndrome in chickens and turkeys and infectious sinusitis of turkeys; Mycoplasma meleagridis is associated with airsacculitis in turkeys; and Mycoplasma synoviae is the cause of infectious synovitis in chickens and turkeys. Chronic respiratory disease (CRD), air sac syndrome and infectious sinusitis of turkeys have a common cause. CRD was first recognized as a chronic but mild respiratory disease of adult chickens. It reduced egg production but caused little or no mortality. Afterward, a condition known as "air sac disease" became a problem in young birds. It caused high mortality in some flocks. Many birds became stunted, feed efficiency was reduced, and many fowl were rejected as unfit for human consumption when processed.

Mycoplasma gallisepticum is widespread and affects many species of birds. Eradication programs have reduced the incidence in recent years. It is primarily spread through the egg. Infected hens transmit organisms and the chick or poult is infected when it hatches. Organisms may also be transmitted by direct contact with infected or carrier birds.

Signs

Respiratory symptoms such as coughing, sneezing and a nasal discharge. In the air sac syndrome there is an extensive involvement of the entire respiratory system. The air sacs are often cloudy and contain large amounts of exudate. Affected birds become droopy, feed consumption decreases and there is a rapid loss of body weight.

Infectious sinusitis in turkeys occurs in two forms. When

the "upper" form is present, there is only a swelling of the

sinus under the eye. In the "lower" form, the lungs and air sacs are involved. The air sacs become cloudy and may contain large amounts of exudate. Both forms of the disease are usually present in the flock and frequently are present in the same bird.

Diagnosis of either condition must be based on flock history, symptoms and lesions. Blood tests are useful in determining whether a flock is infected.

Therapy :

high levels of one of the broad spectrum antibiotics (Tylosin, aureomycin, terramycin, gallimycin) either in feed, drinking water or by injections. The "upper"; form of infectious sinusitis can be treated with success by injecting antibiotics into the swollen sinus cavity.