Seroprevalence of Infectious Bronchitis Virus in Birds of Grenada

Molecular and Serological Investigation of Infectious Bronchitis Virus in the East Shewa, Central Ethiopia

Background

Infectious bronchitis (IB) is an economically important disease in poultry with worldwide distribution. The occurrence of IB has been reported both in commercial and backyard poultry in Ethiopia, although comprehensive information lacks available prevalence of the disease and the circulating serotypes.

Methods

A cross-sectional study was conducted from November 2021 to June 2022 in seven commercial farms found in East Shewa, Central Ethiopia. Serological assay using indirect ELISA, virus isolation techniques in embryonated eggs, and molecular techniques such as one-step reverse transcriptase polymerase chain reaction (RT-PCR) and nested polymerase chain reaction (PCR) targeting a 466 bp S1 gene were employed.

Results

A total of 196 blood samples, 7 pools (35) of swab samples, and 5 pools of tracheal samples were investigated. The results of serological analysis revealed that 97.96% (192/196; 95% CI: 94.86-99.44) of the sera samples were found to be positive for antibodies against IBV. Out of the 7 pools of swab and 5 pools of tracheal tissue samples analyzed using RT-PCR 33.3% (4/12) of them gave positive results all from swab samples. The RT-PCR-positive samples were subjected to a nested PCR yielding 295bp and 154bp indicating the circulation of Mass and 793/B (4/91) strains of IBV, respectively. The 12 pools of samples inoculated into embryonated egg showed cytopathic changes such as congestion, bleeding, and deformation only after three passages.

Conclusion

Two serotypes of IBV are circulating in Ethiopian chickens, and molecular identification of the Massachusetts serotype is the first report in Ethiopia. Further epidemiological investigation is needed in order to devise effective control measures.

Shaarani S, Siddiquee S. Seroprevalence and molecular characterisation of infectious bronchitis virus (IBV) in broiler farms in Sabah, Malaysia

BACKGROUND

Infectious bronchitis virus (IBV) is classified as a highly contagious viral agent that causes acute respiratory, reproductive and renal system pathology in affected poultry farms. Molecular and serological investigations are crucial for the accurate diagnosis and management of IBV.

OBJECTIVES

The purpose of this study was to determine the seroprevalence of IBV and to characterise the circulating IBV in poultry farms in Sabah Province, Malaysia.

METHODS

To determine IBV antibodies, a total of 138 blood samples and 50 organ samples were collected from 10 commercial broiler flocks in 3 different farms by using the enzyme-linked immunosorbent assay (ELISA) (IDEXX Kit) and reverse transcription-polymerase chain reaction (RT-PCR) followed by sequencing.

RESULTS

A total of 94.2% (130/138) of the samples were seropositive for IBV in the vaccinated flock, and 38% (52/138) of the birds was the IBV titre for infection. The selected seropositive samples for IBV were confirmed by RT-PCR, with 22% (11/50) being IBV positive amplified and sequenced by targeted highly conserved partial nucleocapsid (N) genes. Subsequently, phylogenetic analysis constructed using amplified sequences again exposed the presence of Connecticut, Massachusetts, and Chinese QX variants circulating in poultry farms in Sabah, Malaysia.

CONCLUSIONS

The unexpectedly increasing mean titres in serology indicated that post infection of IBV and highly prevalent IBV in selected farms in this study. The sequencing and phylogenetic analysis revealed the presence of multiple IBV variants circulating in Malaysian chicken farms in Sabah, which further monitoring of genetic variation are needed to better understand the genetic diversity.

A comprehensive review of viruses in terrestrial animals from the Caribbean islands of Greater and Lesser Antilles

Viruses pose a major threat to animal health worldwide, causing significant mortalities and morbidities in livestock, companion animals and wildlife, with adverse implications on human health, livelihoods, food safety and security, regional/national economies, and biodiversity. The Greater and Lesser Antilles consist of a cluster of islands between the North and South Americas and is habitat to a wide variety of animal species. This review is the first to put together decades of information on different viruses circulating in companion animals, livestock, and wildlife from the Caribbean islands of Greater and Lesser Antilles. Although animal viral diseases have been documented in the Caribbean region since the 1940s, we found that studies on different animal viruses are limited, inconsistent, and scattered. Furthermore, a significant number of the reports were based on serological assays, yielding preliminary data. The available information was assessed to identify knowledge gaps and limitations, and accordingly, recommendations were made, with the overall goal to improve animal health and production, and combat zoonoses in the region. This article is protected by copyright. All rights reserved.

Seroprevalence of Infectious Bronchitis Virus in Broiler and Layer Farms of Central Ethiopia

Background

Infectious bronchitis virus (IBV) is a highly contagious viral disease of chicken typically affecting the reproductive and respiratory tract and results in possible economic causes from its serious infectious and transmission characteristics.

Methods

A cross-sectional study was carried on serum samples of chickens selected from six (two commercial and four small holder) farms and two types of production (broiler and layer) to detect seroprevalence of IBV and its associated risk factors in Bishoftu and Holeta areas of central Ethiopia from June 2021 to September 2021. A total of 354 blood samples were collected and subjected to indirect ELISA test by IBV antibody test kit ((ProFLOK IBV), from ProFLOK Laboratories Inc., (USA)) to detect specific antibodies against IBV.

Results

Overall, 97.46% seroprevalence was identified. From 230 and 124 samples collected from commercial and smallholder poultry farms, 226 (98.26%) and 119 (95.98%) positive results were obtained, respectively. Among the production types of chickens, high seroprevalence (99.31%) was found in layer poultry, and lower seroprevalence (96.17%) was found in the case of broiler chicken. Significant association was observed among different associated risk factors particularly age, sex, breed, and production types of chickens. From the tested chickens, all age groups, species, and farm types have high seroprevalence of IBV. The prevalence of IBV was highly significant (p ≤ 0.01) in the study site. The risk factors indicated could have increased infection prevalence, pathogens' economic impact, and disease occurrence.

Conclusion

IBD is complicating factor affecting poultry production systems in the area. Vaccine and biosecurity measures are recommended for the control of IBV. Furtherly, identification and characterization (by using RT-PCR) of persistent serotype of IBV circulating in the field are recommended.

Seroprevalence and Associated Risk Factors of Infectious Bronchitis Virus in Chicken in Northwest Ethiopia

Avian infectious bronchitis virus is a highly contagious disease occurring in respiratory, urogenital, and reproductive tissues of chicken causing considerable losses due to death, egg drop, and reduced production. This preliminary study was conducted to investigate the prevalence of antibodies against infectious bronchitis virus (IBV) and to assess the potential risk factors in chickens of northwest Ethiopia. A cross-sectional study was conducted from November 2020 to June 2021. A total of 768 serum samples from three zones were collected. To investigate the presence of antibodies against IBV, the indirect ELISA serological test was applied. Positivity for anti-IBV antibodies was observed in 23.96% (95% CI: 20.98–27.14) of the samples. The mixed-effect logistic regression analysis of potential risk factors showed that IBV prevalence was significantly higher in young chickens than adults (p < 0.001) and higher in intensive farm type than in extensive type (p < 0.001). Based on the production purposes of the chickens, the odds of seropositivity for IB was significantly higher in layers than in broilers (p < 0.001) and dual purposes (p < 0.001). This study revealed higher seroprevalence in farms which had the “all-in-all-out” rearing method than in farms with different batches in one house with a significant difference (p < 0.001), higher seroprevalence in the poor ventilated type than in good ones (p < 0.001), and higher seroprevalence in the houses that did not remove used litter at all than houses of completely disposed and partially disposed litter (p=0.002). Moreover, disinfection of houses had significant effect on the occurrence of IB. Having personal protective equipment was significantly affecting the occurrence of IB, being higher in the farms that have no wearing clothes and shoe than in those having wearing clothes and shoe (p=0.002). In conclusion, the seroprevalence finding in the present study indicated that the organism is circulating among the population of chickens and high enough to cause significant economic losses Therefore, poultry houses should be cleaned, disinfected, and well ventilated and farm attendants should have separate farm shoe and clothes. Further studies on the virus isolation and molecular characterization of the target gene are needed in the study area.

A Review of Eight High-Priority, Economically Important Viral Pathogens of Poultry within the Caribbean Region

Viral pathogens cause devastating economic losses in poultry industries worldwide. The Caribbean region, which boasts some of the highest rates of poultry consumption in the world, is no exception. This review summarizes evidence for the circulation and spread of eight high-priority, economically important poultry viruses across the Caribbean region. Avian influenza virus (AIV), infectious bronchitis virus (IBV), Newcastle disease virus (NDV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV), infectious bursal disease virus (IBDV), fowl adenovirus group 1 (FADV Gp1), and egg drop syndrome virus (EDSV) were selected for review. This review of serological, molecular, and phylogenetic studies across Caribbean countries reveals evidence for sporadic outbreaks of respiratory disease caused by notifiable viral pathogens (AIV, IBV, NDV, and ILTV), as well as outbreaks of diseases caused by immunosuppressive viral pathogens (IBDV and FADV Gp1). This review highlights the need to strengthen current levels of surveillance and reporting for poultry diseases in domestic and wild bird populations across the Caribbean, as well as the need to strengthen the diagnostic capacity and capability of Caribbean national veterinary diagnostic laboratories.

Serological evidence for eight globally important poultry viruses in Trinidad & Tobago

Viruses affecting poultry cause significant levels of disease leading to severe economic losses among poultry farmers worldwide. The Americas region continues to be vulnerable to the spread of poultry viruses across the continents and Caribbean island chains. In Trinidad and Tobago (T&T) there is limited information on the viruses circulating in poultry. Many flock are vulnerable to infection and there are occasional outbreaks of disease resulting in high levels of morbidity and mortality. This study aims to identify important viruses of poultry circulating in T&T through a broad-based surveillance approach. Serum samples from 29 layer farms in Trinidad and 14 layer farms in Tobago were collected from the eldest laying hens. Samples were tested from unvaccinated birds for antibodies by enzyme-linked immunosorbent assay (ELISA) against Avian influenza virus (AIV), Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Infectious laryngotracheitis virus (ILTV), Avian pneumovirus (APV), Infectious bursal disease virus (IBDV), Fowl adenovirus Gp1 (FADV) and Egg drop syndrome virus (EDSV). In Trinidad, the estimated true seroprevalence levels of antibodies were 0% (CI 95%: 0-0%) for AIV, 100% (CI 95%: 97-100%) for IBV, 79.8% (CI 95%: 70.6-86.9%) for NDV, 1% (CI 95%: 0-2.6%) for ILTV, 67.55% (CI 95%: 62.3-72.4%) for APV, 94.93% (CI 95%: 88.0-98.6%) for IBDV, 100% (CI 95%: 99.7-100%) for FADV and 67.8% (CI 95%: 62.4-72.8%) for EDSV. In Tobago, seroprevalence levels were 0% (CI 95%: 0-0%) for AIV, 100% (CI 95%: 95.6-100%) for IBV, 80.5% (CI 95%: 70.1-88.5%) for NDV, 29.9% (CI 95%: 20.8-40.6%) for ILTV, 100% (CI 95%: 97.7-100%) for APV, 97.1% (CI95%: 89.9-100%) for IBDV, 100% (CI 95%: 97.5-100%) for FADV and 100% (CI 95%: 99-100%) for EDSV. The results reveal strong evidence for the circulation of IBV, NDV, APV, IBDV, FADV and EDSV in layer poultry on both islands, as well as ILTV in Tobago.

Infectious Bronchitis Virus in Captured Free-Living, Free-Range and Intensively Reared Birds in Southwest Nigeria

Infectious bronchitis (IB) is an acute infectious viral disease causing severe economic losses in poultry production. In Nigeria, there has only been monitoring of the disease in chickens with little attention given to other bird species. For this study, blood samples were collected from 184 apparently healthy, unvaccinated birds which comprised of 61 captured free-living pigeons, 60 free range indigenous chickens and 63 intensively reared Japanese quails. Sera from these birds were screened for IB virus antibodies (IBV) using a commercial ELISA kit. The birds were from Oyo and Osun States, in southwest Nigeria. Overall, 63 (34.2 %) sera were positive for IBV with 3.3 % (2/61), 95.0 % (57/60) and 6.3 % (4/63) from pigeons, indigenous chickens and Japanese quails, respectively. These findings suggest that they were subclinically infected with either field or vaccine virus and could thus serve as possible reservoirs of this virus to domestic poultry. Thus, there is need for continuous surveillance of the disease in different bird species and their possible role in the spread of IBV in Nigeria.

Emergence of Avian Infectious Bronchitis Virus and its variants need better diagnosis, prevention and control strategies: a global perspective

Growth in poultry sector is being challenged due to increased incidence and re-emergence of diseases caused due to evolution of several viral pathogens and use of live vaccines. Piles of economic losses are encountered due to these diseases. Avian Infectious Bronchitis (IB), caused by Corona virus, is OIE-listed disease and characterized by respiratory, renal and urogenital involvements, causing high mortality. Economic losses are encountered due to loss of productive performance of both egg and meat-type chickens. Variant viruses evolve due to spontaneous mutations and recombinations, causing disease in vaccinated flocks of all ages. Serotyping and genotyping are the common methods of classification of IBV strains. The virus has 4 clusters, grouped into 7 serotypes and the most important strains are Massachusetts, Connecticut, Arkansas, Gray, Holte and Florida along with numerous others, distributed round the globe. Several conventional and molecular diagnostic methods have been described for the diagnosis of IB in chickens. 'All-in/all-out' operations of rearing along with good biosafety measures forms the basis of prevention, whereas vaccination forms the backbone of IB control programme. Both live and inactivated (oil emulsified) conventional vaccines are available. The new generation vaccines (recombinant and vector-based) developed against locally prevailing IBV strains may be more helpful and avoid the reversion of virulence in live vaccine viruses. The present review deals with all these perspectives of this important emerging poultry pathogen.