Ifectious coryza
acute respiratory disease of chickens caused by bacterium Avibacterium paragallinarum (once known as Haemophilus paraganarum). The genus Avibacterium also contains a number of other species: Av avium (once known as Pasteurella avium), Av. endocardi- ads, Ax gallinarum (once known as P gallina- ram) and Av. volantium (once known as P. volan- m) of these additional members of the genus, here are reports of both acute and chronic disease conditions (fowl cholera-like in nature) in chickens and turkeys that have been associated with Av. gal- narum while Av. endocarditidis has been isolated from valvular endocarditis conditions in adult broi- le parents. Little is known about Av. Endocarditidis as there has been only one publica- Bon to date, and the organism will not be discussed any further
The rest of this text will provide information on Asparagallinarum and, where available, Av. gallinarum.
acute respiratory disease of chickens caused by bacterium Avibacterium paragallinarum (once known as Haemophilus paraganarum). The genus Avibacterium also contains a number of other species: Av avium (once known as Pasteurella avium), Av. endocardi- ads, Ax gallinarum (once known as P gallina- ram) and Av. volantium (once known as P. volan- m) of these additional members of the genus, here are reports of both acute and chronic disease conditions (fowl cholera-like in nature) in chickens and turkeys that have been associated with Av. gal- narum while Av. endocarditidis has been isolated from valvular endocarditis conditions in adult broi- le parents. Little is known about Av. Endocarditidis as there has been only one publica- Bon to date, and the organism will not be discussed any further
The rest of this text will provide information on Asparagallinarum and, where available, Av. gallinarum.
ETIOLOGY & EPIDEMIOLOGY
The causative bacterium of infectious coryza, Avibacterium paragallinarum (once known as Haemophilus paragallinarum) is a Gram-negative, pleomorphic, nonmotile, catalase-negative, microaerophilic rod that requires nicotinamide adenine dinucleotide (V-factor) for in vitro growth. When grown on blood agar with a staphylococcal nurse colony that excretes the V-factor, the satellite elling of the rat colonies appear as dewdrops, growing adjacent to the nurse colony.
Recently, V-factor-independent A paragallinarum has been recovered in Mexico and South Africa. These V-factor-independent Av. Paragallinarum are grown like Pasteurella spp. on blood agar - with no need for a nurse colony.
The most commonly used serotyping scheme is the Page scheme which groups Av. paragallinarum isolates into three serovars (A, B and C) that are correlated with immunotype specificity, i.c., a kil- led vaccine containing serovar A protects against serovar A and not serovars B or C.
Chronically ill or healthy carrier birds are the reservoir of infection. While chickens of all ages are susceptible, the susceptibility increases with age. Typically, the incubation period is one to three days and the duration of the disease is usually two to three weeks for a simple infection. The disease may run up for longer periods in the presence of other diseases such as mycoplasmosis.
Once a flock has been infected, it is a constant threat to any nearby uninfected flocks. Transmission is typically by direct contact, air- borne droplets and contamination of drinking water. "All-in/all-out" production can be a very effective management tool. Commercial farms that have multiple-age flocks tend to perpetuate the disease. Egg transmission does not occur.
Molecular techniques such as restriction endonu- clease analysis and ribotyping have been used to trace outbreaks of infectious coryza. These mole- cular methods have provided the confirmatory evi- dence that the main means of entry of coryza to a property is replacement stock. At the same time, these molecular methods have shown that some farms can be chronically infected - the disease may seem to disappear for a flock or two but will reappear in subsequent flocks.
Traditionally, Av. gallinarum (once known as Pasteurella gallinarum) was regarded as an oppor- tunistic pathogen of chickens. The organism is widely regarded as one that is a secondary agent that is associated with other primary pathogens such as viruses or mycoplasmas. A critical reading of the literature does suggest that the bacterium can play a significant role in infection. While there are reports of infections in chickens, turkeys and gui- nea fowl, only the chicken and turkey isolates have been definitely identified by both phenotypic and genotypic methods. There are no accepted seroty- ping schemes, although genotyping methods such as restriction endonuclease analysis and ribotyping have proven useful in a study of respiratory disease in turkeys.
The causative bacterium of infectious coryza, Avibacterium paragallinarum (once known as Haemophilus paragallinarum) is a Gram-negative, pleomorphic, nonmotile, catalase-negative, microaerophilic rod that requires nicotinamide adenine dinucleotide (V-factor) for in vitro growth. When grown on blood agar with a staphylococcal nurse colony that excretes the V-factor, the satellite elling of the rat colonies appear as dewdrops, growing adjacent to the nurse colony.
Recently, V-factor-independent A paragallinarum has been recovered in Mexico and South Africa. These V-factor-independent Av. Paragallinarum are grown like Pasteurella spp. on blood agar - with no need for a nurse colony.
The most commonly used serotyping scheme is the Page scheme which groups Av. paragallinarum isolates into three serovars (A, B and C) that are correlated with immunotype specificity, i.c., a kil- led vaccine containing serovar A protects against serovar A and not serovars B or C.
Chronically ill or healthy carrier birds are the reservoir of infection. While chickens of all ages are susceptible, the susceptibility increases with age. Typically, the incubation period is one to three days and the duration of the disease is usually two to three weeks for a simple infection. The disease may run up for longer periods in the presence of other diseases such as mycoplasmosis.
Once a flock has been infected, it is a constant threat to any nearby uninfected flocks. Transmission is typically by direct contact, air- borne droplets and contamination of drinking water. "All-in/all-out" production can be a very effective management tool. Commercial farms that have multiple-age flocks tend to perpetuate the disease. Egg transmission does not occur.
Molecular techniques such as restriction endonu- clease analysis and ribotyping have been used to trace outbreaks of infectious coryza. These mole- cular methods have provided the confirmatory evi- dence that the main means of entry of coryza to a property is replacement stock. At the same time, these molecular methods have shown that some farms can be chronically infected - the disease may seem to disappear for a flock or two but will reappear in subsequent flocks.
Traditionally, Av. gallinarum (once known as Pasteurella gallinarum) was regarded as an oppor- tunistic pathogen of chickens. The organism is widely regarded as one that is a secondary agent that is associated with other primary pathogens such as viruses or mycoplasmas. A critical reading of the literature does suggest that the bacterium can play a significant role in infection. While there are reports of infections in chickens, turkeys and gui- nea fowl, only the chicken and turkey isolates have been definitely identified by both phenotypic and genotypic methods. There are no accepted seroty- ping schemes, although genotyping methods such as restriction endonuclease analysis and ribotyping have proven useful in a study of respiratory disease in turkeys.
CLINICAL SIGNS & LESIONS
Infectious coryza is characterized by nasal dis- charge, sneezing, and swelling of the face under the eyes. The disease occurs wherever chickens are raised. The disease occurs only in chickens. Early reports of the disease in quail and pheasants most probably describe a similar disease that is caused by a different etiological agent.
In the developed countries such as Australia and the USA, infectious coryza occurs primarily in pul- lets and layers and only occasionally in broilers. In the developed poultry industries, the impact of the disease is primarily due to a drop in egg production 10 to 40%. The impact is greatest in multi-age flocks.
In other countries, infectious coryza often occurs in very young chicks, even as young as three weeks of age. Poor biosecurity, poor environment and the stress of other diseases are probably the main reasons why infectious coryza is more of a problem in such countries. The disease is often associated with significant mortalities under these conditions.
While the disease is typically thought of as a disease of intensively raised chickens, it can also occur in village chickens. Reports from Indonesia and Thailand are suggesting that the disease can be significant in these types of chickens.
In the mildest form of coryza, the only signs may be depression, a serous nasal discharge and slight facial swelling. In the more severe form of the disease, there is severe swelling of one or both infra-orbital sinuses with edema of the surrounding tissue, which may close one or both eyes. The swelling usually abates in 10-14 days; however, if secondary infection occurs, the swelling can per- sist for months.
Egg production may be delayed in young pullets and severely reduced in laying hens. Egg drops of 10-40% are typical in simple outbreaks in other- wise healthy layers. In layers that are also suffering concurrent diseases, egg drops of up to 87% and lasting for four weeks have been reported in some countries. Birds may have diarrhea and feed and water consumption usually is decreased during the acute stage of the disease.
In Argentina, a septicemic form of the disease has been reported, probably due to concurrent infec tions.
In acute cases, lesions may be limited to the infra- orbital sinuses. There is a copious semifluid exu- date from the nostril. As the disease becomes chro- nic or other pathogens become involved, the sinus exudate may become consolidated and turn yello- wish. Other lesions may include conjunctivitis, tra- cheitis, bronchitis, and airsacculitis, particularly if other pathogens are involved. The histopathologi- cal response of respiratory organs consists of disin- tegration and hyperplasia of mucosal and glandular
epithelia and edema with infiltration of hetero- phils, macrophages, and mast cells.
The pathology associated with infections due to y gallinarum is quite diverse, including reports of conjunctivitis, abscesses in the head and wattles, sinusitis, tracheitis, airsacculitis, hepatitis, endo- carditis, salpingitis, oophoritis, peritonitis and synovitis. Further careful evaluations of the role of Av gallinarum are required and the organism should not be simply dismissed as non-pathogenic
Infectious coryza is characterized by nasal dis- charge, sneezing, and swelling of the face under the eyes. The disease occurs wherever chickens are raised. The disease occurs only in chickens. Early reports of the disease in quail and pheasants most probably describe a similar disease that is caused by a different etiological agent.
In the developed countries such as Australia and the USA, infectious coryza occurs primarily in pul- lets and layers and only occasionally in broilers. In the developed poultry industries, the impact of the disease is primarily due to a drop in egg production 10 to 40%. The impact is greatest in multi-age flocks.
In other countries, infectious coryza often occurs in very young chicks, even as young as three weeks of age. Poor biosecurity, poor environment and the stress of other diseases are probably the main reasons why infectious coryza is more of a problem in such countries. The disease is often associated with significant mortalities under these conditions.
While the disease is typically thought of as a disease of intensively raised chickens, it can also occur in village chickens. Reports from Indonesia and Thailand are suggesting that the disease can be significant in these types of chickens.
In the mildest form of coryza, the only signs may be depression, a serous nasal discharge and slight facial swelling. In the more severe form of the disease, there is severe swelling of one or both infra-orbital sinuses with edema of the surrounding tissue, which may close one or both eyes. The swelling usually abates in 10-14 days; however, if secondary infection occurs, the swelling can per- sist for months.
Egg production may be delayed in young pullets and severely reduced in laying hens. Egg drops of 10-40% are typical in simple outbreaks in other- wise healthy layers. In layers that are also suffering concurrent diseases, egg drops of up to 87% and lasting for four weeks have been reported in some countries. Birds may have diarrhea and feed and water consumption usually is decreased during the acute stage of the disease.
In Argentina, a septicemic form of the disease has been reported, probably due to concurrent infec tions.
In acute cases, lesions may be limited to the infra- orbital sinuses. There is a copious semifluid exu- date from the nostril. As the disease becomes chro- nic or other pathogens become involved, the sinus exudate may become consolidated and turn yello- wish. Other lesions may include conjunctivitis, tra- cheitis, bronchitis, and airsacculitis, particularly if other pathogens are involved. The histopathologi- cal response of respiratory organs consists of disin- tegration and hyperplasia of mucosal and glandular
epithelia and edema with infiltration of hetero- phils, macrophages, and mast cells.
The pathology associated with infections due to y gallinarum is quite diverse, including reports of conjunctivitis, abscesses in the head and wattles, sinusitis, tracheitis, airsacculitis, hepatitis, endo- carditis, salpingitis, oophoritis, peritonitis and synovitis. Further careful evaluations of the role of Av gallinarum are required and the organism should not be simply dismissed as non-pathogenic
DIAGNOSIS
Isolation of a Gram-negative, catalase-negative, satellitic organism from chickens in a flock with a history of a rapidly spreading coryza is diagnostic for infectious coryza. The catalase test must be performed as satellitic non-pathogenic species such as Av avium and Av. volantium, that are cata- lase positive, are present in both healthy and diseased chickens. For those laboratories with more extensive facilities, biochemical tests can be performed to confirm the identity of any isolate Av paragallinarum is characterised by an ability to ferment glucose, sucrose and mannitol and an inability to ferment galactose and trehalose. Care must be taken with the galactose test as some poor quality galactose preparations contain enough contaminating glucose to give a false positive reaction.
Care must be taken in those regions where V-fac- tor-independent Av paragallinarum occur. These V-factor-independent Av paragallinarum can only be confidently identified by biochemical testing or PCR (see below).
Undoubtedly, the definitive diagnostic test for
infectious coryza is a PCR test that specifically detects Av paragallinarum. The Av paragallina- rum can be used directly on the live chicken by squeezing mucus from the sinus. The mucus is collected by swab and submitted for examination - there is no need for aseptic techniques. The PCR can also be agar cultures (pure or mixed). When sinus swabs contain blood, they can be treated by low speed spin to get rid of RBC before extracting crude DNA by boiling method or extract DNA with commercial blood/tissue genomic DNA extraction kits (such as DNeasy blood & Tissue kit, Quiagen cat.69504). For the PCR test, swabs are proces- sed as follows. The swab is soaked in 1 mi of phosphate-buffered saline in a 1.5-ml microfuge tube. The tube is centrifuged at 2000 rpm for 3-5 min to settle the blood. The Av. paragallinarum
PCR has proven superior to culture, even in developing countries.
No suitable serological test exists, although a hemagglutination-inhibition test is the best of the available tests. Hence, serology is not a widely used diagnostic tool. Other diseases that must be considered in a differential diagnosis are fowl cholera, mycoplasmosis, ornithobacterosis, laryn- gotracheitis, Newcastle disease, infectious bron- chitis, avian influenza, swollen head syndrome and vitamin A deficiency.
Bacterial culture and identification is the only means of investigating infections associated with Av. gallinarum. Culture for Av. gallinarum is best done using sheep blood agar plates at 37°C with a 5-10% carbon dioxide atmosphere. Standard texts contain suitable identification tables. To date, no DNA based identification method, other than DNA sequencing, has been established for Av. gallinarum.
Isolation of a Gram-negative, catalase-negative, satellitic organism from chickens in a flock with a history of a rapidly spreading coryza is diagnostic for infectious coryza. The catalase test must be performed as satellitic non-pathogenic species such as Av avium and Av. volantium, that are cata- lase positive, are present in both healthy and diseased chickens. For those laboratories with more extensive facilities, biochemical tests can be performed to confirm the identity of any isolate Av paragallinarum is characterised by an ability to ferment glucose, sucrose and mannitol and an inability to ferment galactose and trehalose. Care must be taken with the galactose test as some poor quality galactose preparations contain enough contaminating glucose to give a false positive reaction.
Care must be taken in those regions where V-fac- tor-independent Av paragallinarum occur. These V-factor-independent Av paragallinarum can only be confidently identified by biochemical testing or PCR (see below).
Undoubtedly, the definitive diagnostic test for
infectious coryza is a PCR test that specifically detects Av paragallinarum. The Av paragallina- rum can be used directly on the live chicken by squeezing mucus from the sinus. The mucus is collected by swab and submitted for examination - there is no need for aseptic techniques. The PCR can also be agar cultures (pure or mixed). When sinus swabs contain blood, they can be treated by low speed spin to get rid of RBC before extracting crude DNA by boiling method or extract DNA with commercial blood/tissue genomic DNA extraction kits (such as DNeasy blood & Tissue kit, Quiagen cat.69504). For the PCR test, swabs are proces- sed as follows. The swab is soaked in 1 mi of phosphate-buffered saline in a 1.5-ml microfuge tube. The tube is centrifuged at 2000 rpm for 3-5 min to settle the blood. The Av. paragallinarum
PCR has proven superior to culture, even in developing countries.
No suitable serological test exists, although a hemagglutination-inhibition test is the best of the available tests. Hence, serology is not a widely used diagnostic tool. Other diseases that must be considered in a differential diagnosis are fowl cholera, mycoplasmosis, ornithobacterosis, laryn- gotracheitis, Newcastle disease, infectious bron- chitis, avian influenza, swollen head syndrome and vitamin A deficiency.
Bacterial culture and identification is the only means of investigating infections associated with Av. gallinarum. Culture for Av. gallinarum is best done using sheep blood agar plates at 37°C with a 5-10% carbon dioxide atmosphere. Standard texts contain suitable identification tables. To date, no DNA based identification method, other than DNA sequencing, has been established for Av. gallinarum.
TREATMENT & CONTROL
Prevention of infectious coryza is the best method of control. "All-in/all-out" farm programs with sound management and good biosecurity are the best to avoid the disease. Replacements should be raised on the same farm or obtained from flocks known to be free of coryza. If replacement pullets are to be placed on a farm that has a history of infectious coryza, vaccines should be used.
Infectious coryza vaccines are widely available. As Page serovars A, B and C are not cross-protective, it is essential that vaccines contain the serovars present in the target population. The immunization should be completed three to four weeks before infectious Coryza usually breaks out on the individual farm. Antibodies detected by the hemagglutination-inhibi- tion test after vaccination correlate with protective
immunity (titers of >1/5 indicate protection).
Controlled exposure to live Av. paragallinarum has also been used to immunize layers in endemic areas. This is a dangerous procedure and should only be used as a method of last resort.
Early treatment of infectious coryza is important Water medication is recommended immediately until medicated feed is available. Erythromycin and oxytetracycline are usually beneficial. Antibiotics should only be used with due care and attention to the local regulatory environment. In more severe outbreaks, although treatment may result in improvement, the disease may recur when medication is discontinued. Preventive medication may be combined with a vaccination program in which started pullets are to be reared or housed on infected premises.
There appears to be no widespread use of Av. gal- linarum vaccines.
Prevention of infectious coryza is the best method of control. "All-in/all-out" farm programs with sound management and good biosecurity are the best to avoid the disease. Replacements should be raised on the same farm or obtained from flocks known to be free of coryza. If replacement pullets are to be placed on a farm that has a history of infectious coryza, vaccines should be used.
Infectious coryza vaccines are widely available. As Page serovars A, B and C are not cross-protective, it is essential that vaccines contain the serovars present in the target population. The immunization should be completed three to four weeks before infectious Coryza usually breaks out on the individual farm. Antibodies detected by the hemagglutination-inhibi- tion test after vaccination correlate with protective
immunity (titers of >1/5 indicate protection).
Controlled exposure to live Av. paragallinarum has also been used to immunize layers in endemic areas. This is a dangerous procedure and should only be used as a method of last resort.
Early treatment of infectious coryza is important Water medication is recommended immediately until medicated feed is available. Erythromycin and oxytetracycline are usually beneficial. Antibiotics should only be used with due care and attention to the local regulatory environment. In more severe outbreaks, although treatment may result in improvement, the disease may recur when medication is discontinued. Preventive medication may be combined with a vaccination program in which started pullets are to be reared or housed on infected premises.
There appears to be no widespread use of Av. gal- linarum vaccines.
should only be used with due care and attention to the local regulatory environment. In more severe outbreaks, although treatment may result in improvement, the disease may recur when medication is discontinued. Preventive medication may be combined with a vaccination program in which started pullets are to be reared or housed on infected premises.
Ifectious coryza
مرض تنفسي حاد
سببه بكتيريا Avibacterium paragallinarum
Which is Gram -ve &non motile
All ages are susceptible
↑age→↑ susceptibility
incubation period is 1-3 days
Duration of the disease is usually 2 to 3 weeks for a simple infection.
قد يستمر المرض لفترات أطول في وجود أمراض أخرى مثل الميكوبلازما
الانتقال افقيا عن طريق
الاتصال المباشر
والقطرات المحمولة جواً
وتلوث مياه الشرب
لا ينتقل عن طريق البيض.
The disease occurs wherever chickens are raised. The disease occurs only in chickens. Early reports of the disease in quail and pheasants most probably describe a similar disease that is caused by a different etiological agent.
اسبابه
Poor biosecurity,
poor environment and
stress is the main reasons why infectious coryza is more of a problem in such countries.
under these conditions.
The disease is often associated with ↑ mortalities
CLINICAL SIGNS & LESIONS
characterized by
nasal discharge
sneezing
swelling of the face under the eyes.
يصيب pullets & layers و احيانا broilers.
تأثيرة ع قطعان البياض
↓ egg production 10 to 40%.
في دجاج البياض التي تعاني من أمراض متزامنة ، قد ينخفض ويصل إلى 87 ٪ وتستمر لمدة أربعة أسابيع
SIGNS
In the mildest form of coryza
depression او كششان
a serous nasal discharge
slight facial swelling.
In the more severe form of the disease,
severe swelling of one or both infra-orbital sinuses with edema of the surrounding tissue which may close one or both eyes.
The swelling usually abates in 10-14 days; however, if secondary infection occurs, the swelling can per- sist for months.
diarrhea
↓ feed and water consumption
lesions
infra- orbital sinuses have a caseous exudate from the nostril & may consolidated and turn yellowish.
conjunctivitis
tracheitis
bronchitis
and airsacculitis,
particularly if other pathogens are involved The histopathological response of respiratory organs consists of
disintegration & hyperplasia of mucosal and glandular epithelia
edema with infiltration of heterophils, macrophages, and mast cells.
TREATMENT & CONTROL:
لانه مرض بكتيري تنفسي يفضل استخدام مضاد حيوي من عائلة الMacrolides
مضادات حيوية اخرى:
Deoxycycline
oxytetracycline
Sulpha + Trimethobrime
مرض تنفسي حاد
سببه بكتيريا Avibacterium paragallinarum
Which is Gram -ve &non motile
All ages are susceptible
↑age→↑ susceptibility
incubation period is 1-3 days
Duration of the disease is usually 2 to 3 weeks for a simple infection.
قد يستمر المرض لفترات أطول في وجود أمراض أخرى مثل الميكوبلازما
الانتقال افقيا عن طريق
الاتصال المباشر
والقطرات المحمولة جواً
وتلوث مياه الشرب
لا ينتقل عن طريق البيض.
The disease occurs wherever chickens are raised. The disease occurs only in chickens. Early reports of the disease in quail and pheasants most probably describe a similar disease that is caused by a different etiological agent.
اسبابه
Poor biosecurity,
poor environment and
stress is the main reasons why infectious coryza is more of a problem in such countries.
under these conditions.
The disease is often associated with ↑ mortalities
CLINICAL SIGNS & LESIONS
characterized by
nasal discharge
sneezing
swelling of the face under the eyes.
يصيب pullets & layers و احيانا broilers.
تأثيرة ع قطعان البياض
↓ egg production 10 to 40%.
في دجاج البياض التي تعاني من أمراض متزامنة ، قد ينخفض ويصل إلى 87 ٪ وتستمر لمدة أربعة أسابيع
SIGNS
In the mildest form of coryza
depression او كششان
a serous nasal discharge
slight facial swelling.
In the more severe form of the disease,
severe swelling of one or both infra-orbital sinuses with edema of the surrounding tissue which may close one or both eyes.
The swelling usually abates in 10-14 days; however, if secondary infection occurs, the swelling can per- sist for months.
diarrhea
↓ feed and water consumption
lesions
infra- orbital sinuses have a caseous exudate from the nostril & may consolidated and turn yellowish.
conjunctivitis
tracheitis
bronchitis
and airsacculitis,
particularly if other pathogens are involved The histopathological response of respiratory organs consists of
disintegration & hyperplasia of mucosal and glandular epithelia
edema with infiltration of heterophils, macrophages, and mast cells.
TREATMENT & CONTROL:
لانه مرض بكتيري تنفسي يفضل استخدام مضاد حيوي من عائلة الMacrolides
مضادات حيوية اخرى:
Deoxycycline
oxytetracycline
Sulpha + Trimethobrime