Review on Diagnostic Methods of Infectious Coryza in Chickens

Review Article

Austin J Infect Dis. 2023; 10(4): 1091.

Review on Diagnostic Methods of Infectious Coryza in Chickens

Adugna Girma Lema¹*; Gemechu Tuli²

¹Yemelogi Welel Woreda Agriculture Office, Livestock development department. Kellem Wollega Zone, Oromia, Ethiopia

²Addis Ababa City Administration, Urban Agriculture office, Addis Ababa, Ethiopia

*Corresponding author: Adugna Girma Lema Yemalogi welel Woreda Agriculture Office, Kellem Wollega, Oromia, Ethiopia. Tel: + 251 0911925885 Email: abdiadugna4@gmail.com

Received: September 21, 2023 Accepted: November 04, 2023 Published: November 11, 2023

Summary

The total poultry population in Ethiopia is estimated to be 51.35 million. The Poultry sector is a fastest growing among the animal production activities offers an opportunity to feed the fastest growing human population and provide income resources for poor farmers. There are different diseases which can affect chicken. Among the bacterial diseases, Infectious Coryza (IC) is an acute and contagious respiratory disease of chickens caused by the bacteria, Avibacterium paragallinarum. IC is distributed worldwide and typically transmitted by direct contact, airborne droplets and contamination of drinking water. But Egg transmission does not occur. The initial step in the pathogenesis of infectious coryza is adherence to and colonization of the nasal mucosa. The diagnosis can be based on a history of rapid disease spread, clinical symptoms, and pathological changes caused by IC. Diagnostic methods for IC include direct isolation, the HI test for serovar A and Polymerase Chain Reaction (PCR). Diagnosis of Avibacterium paragallinarum have been proposed as alternatives to conventional serotyping by the Page scheme. The HI test, which is one of the most widely used serological test, is often utilized to detect changes in antibody titers in cases of field infection or vaccination, and is useful for evaluating the prevalence of IC in certain areas. Rapid and accurate detection of respiratory IC has become a challenge because of the involvement of more than one agent with similar clinical signs and lesions, which complicates diagnostic decisions, as well as treatment and control strategies.

Keywords: Avibacterium paragallinarum; Chickens; Diagnostic; Infectious coryza

Introduction

The total poultry population in Ethiopia is estimated to be 51.35 million (CSA, 2013/14) The Poultry sector is a fastest growing among the animal production activities offers an opportunity to feed the fastest growing human population and provide income resources for poor farmers [23]. Commercial poultry production system is highly intensive production system that involves greater than 10,000 birds kept under in door and heavily depends on imported breeds [3,6,26].

Generally, poultry diseases are responsible for a number of adverse economic effects due to mortality and morbidity of chickens, cost of medication, miscarriage in production and international trade ban and public health significance [24]. Poultry disease such as Infectious coryza, Newcastle disease, Coccidiosis, Infectious Bursal disease, Avian Salmonellosis, Avian Colibacillosis and nutritional deficiency are considered to be the most endemic and the one to incur huge economic losses [2].

Respiratory pathogens of chickens continue to cause heavy economic losses to the poultry industry worldwide. Respiratory infections are multifactorial, involving environmental factors and various viral and bacterial agents, either alone or in combination, leading to “respiratory disease complex” [11,20,25,55,59,63].

Among the bacterial Respiratory diseases, Infectious Coryza (IC) is one of the major threats to the poultry industry and the causal agent is a bacterium, Avibacterium paragallinarum new nomenclature of Haemophillus paragallinarum [36] belonging to genus Haemophilus and Pasteurellaceae family. IC is a respiratory disease of chickens primarily affecting upper respiratory tract, including the involvement of nasal passages, serous nasal discharge, sneezing, and depression and slight facial edema, infra orbital and paranasal sinuses. Chicken (Gallus gallus) is the natural host for Av. paragallinarum and birds of all ages are susceptible [49]. Even though the disease is not associated with heavy mortality losses it possesses significant financial liability to chicken farmers [7]. Infectious Coryza is a cosmopolitan disease and the greatest economic losses associated with infectious coryza are attributed to poor growth performance in growing birds and marked reduction (10%–40%) in egg production in layers and breeding fowls [16,40]. This highly contagious disease, which can turn into a chronic respiratory disease when complicated by other pathogens, [9,48]. There are 2 schemes for Av. paragallinarum serotyping, the Page scheme (which recognizes serogroups A–C) and the Kume scheme (which recognizes serogroups A–C and then serovars A-1, A-2, A-3, A-4, B-1, C-1, C-2, C-3, and C-4), and both schemes use the Hemagglutination Inhibition (HI) test [14].

The diagnosis can be based on a history of rapid disease spread, clinical symptoms, and pathological changes caused by IC. Diagnostic methods for IC include direct isolation, the HI test for serovar A and Polymerase Chain Reaction (PCR). Also use polyclonal antisera for immune localization studies of Av. paragallinarum across the upper respiratory tract of birds by immune histochemistry and obtained some novel information about the migration pattern of the pathogen through nasal passages [10]. For direct isolation, the pathogen can be isolated from sterile cotton swabs obtained from the infra orbital sinus, trachea, and air sac. However, the pathogen must be isolated during the acute stage of infection after 1 to 7 days of incubation, which complicates direct isolation [13]. The HI test, which is one of the most widely used serological test, is often utilized to detect changes in antibody titers in cases of field infection or vaccination, and is useful for evaluating the prevalence of IC in certain areas or conducting retrospective/epidemiological studies [32].

• Therefore, the objectives of this review To assess the currently available diagnostic methods of infectious coryza in the poultry industry.

• To assess the advantages and drawbacks of each method.

• To identify the gaps in the diagnostic techniques of infectious coryza in chicken.

• To recommend on further development activities regarding the diagnostic techniques of infectious coryza.

Infectious Coryza

Infectious Coryza (IC) is an acute and contagious respiratory disease of chickens caused by the bacteria, Avibacterium paragallinarum (formerly called Haemophilus paragallinarum) primarily affecting upper respiratory tract, including the involvement of nasal passages, infra orbital and paranasal sinuses [8]. IC is a cosmopolitan disease, which has been reported from all around the world where chickens are raised and the disease has also been reported to affect other avian species than chicken [49,57] with an initial settlement across the nasal passages during naturally acquired infection. Chickens are the natural hosts for the agent Avibacterium paragallinarum [56].

Chickens of all ages are susceptible and the susceptibility increases with age. The organism is widely regarded as one that is a secondary agent which is associated with other primary pathogens such as viruses or mycoplasmas [5,7]. The clinical signs of this disease include nasal discharge, facial swelling, and lacrimation [9,47]. IC is very important and results in poultry economic losses. The economic effect is associated with both a decrease in egg production (10%-40%) and an increase in the culling rate of laying hens [14].

Etiology

Avibacterium paragallinarum is a fastidious gram-negative bacterium in the Pasteurellaceae family, a causative agent of Infectious coryza (IC) in laying and broiler chickens [50]. It was previously known as Haemophilus paragallinarum. The family is known for its pleomorphic, gram negative, non-motile, bacilli and coccobacilli organisms that are able to reduce nitrates and utilize carbohydrates. As many species in the genus, Av. paragallinarum is catalase negative microaerophilic rod [8,37].

Epidemiology

Distribution of the disease : Infectious Coryza is distributed worldwide. Both commercial chickens as well as village chickens appear to be equally at risk. Chickens of all age group are susceptible, yet susceptibility increases with age [15].

Transmission: Infectious Coryza is typically transmitted by direct contact, airborne droplets and contamination of drinking water. But Egg transmission does not occur [14]. The disease can also be introduced when infected birds are brought into the flock. Birds that have recovered from the disease remain carriers of the organism and be a reservoir for transmission via direct contact, airborne droplets, or fomites [9,51]. Transmission can also occur through the exchange of equipment between farms, and also by personnel [41]. Bird to bird transmission is via respiratory rout or by contact with contaminated drinking water [1].