Serological evidence of chicken infectious anemia in layer and broiler chickens in Grenada , West Indies

Aim: Chicken infectious anemia virus (CIAV) causes immunosuppression leading to serious losses in chickens. Though CIAV has been reported in commercial chickens from many countries of the world, no information is available on CIAV from Grenada. This paper reports the result of a serological survey of CIAV in layer and broiler chickens in Grenada. Materials and Methods: A total of 226 serum samples from layers and 233 from broiler chickens were tested for CIAV antibodies using CIAV/ELISA (IDEXX, West brook, Maine, USA). Results: The results showed seroprevalence for CIAV in layers at 92.9% (95% confidence interval, 89.55% to 96.25%) with a parish seropositivity in the range 89.28% 100%, whereas in broilers overall seroprevalence was 58.3% (95% confidence interval, 51.97% to 64.63%) with a range of 2.85%-92.85%, according to parish. Conclusion: A high prevalence of antibodies to CIAV in commercial chickens indicates a CIAV contaminated environment in Grenada. This in turn emphasizes the need for vaccination of chickens against CIAV and further research on the impact of this disease in Grenada.


Materials and Methods
Chicken infectious anemia (CIA) which was first Ethical approval: The project was approved by reported in Japan [1], is caused by chicken infectious Institutional Animal care and use committee of the St. George's University, Grenada.anemia virus (CIAV), recently classified as the sole A total of 226 blood samples from layer chickens member of the genus Gyrovirus belonging to family and 233 from broilers were collected in various Circoviridae [2].The disease can be diagnosed by parishes of mainland Grenada.The age of the layers detecting virus specific antibodies, detecting infectious varied between 12 and 16 months and for broilers it virus, virus antigen, and virus DNA.However, reports varied between 6 and 7 weeks of age.Blood from on the prevalence of CIAV are mainly based on layers was collected by brachial venipuncture and in serological tests as reported by affected countries; the case of broilers, blood was collected at the time of namely Sudan [3], Iran [4,5], Jordoan [6], India [7,8,9], their slaughter.A minimum of 25 blood samples were Egypt [10], Croatia [11], Turkey [12] Nigeria [13], and taken separately from layer and broiler flocks in each the USA [14].CIAV infection causes aplastic anemia, parish.Blood was transported in cooler boxes to the generalized lymphoid atrophy and immunosuppression pathology laboratory of the school of veterinary medicine [15,16].Since CIAV leads to immune-suppression, the within 2 hours of collection.Serum was obtained after virus plays a key role in many bacterial, viral and centrifugation of blood samples at 2000g.Sera were fungal infections.The virus is transmitted vertically tested for CIAV antibodies using a commercial and horizontally.Horizontally acquired infections CIAV/ELISA kit (IDEXX West brook, Maine, USA), usually remain subclinical which in turn manifests following the instructions of the manufacturer.itself with its poor performance [16][17][18][19] .The authors of this communication are not aware of any previously Statistical analysis: Confidence intervals were published information on chicken infectious anemia in calculated with the help of the following website, Grenada and other countries in the Caribbean.The (http://www.mccallumlayton.co.UK/states/confidenc objective of this study was to estimate the seroe intervalCalcProportion.aspx) prevalence for CIAV in commercial chickens in

Grenada.
We found overall seroprevalence for CIAV in layers at 92.9% (95% confidence interval, 89.55% to 96.25%) with a parish seropositivity range of 89.28% -100%, whereas in broilers overall seroprevalence was 58.3% (95% confidence interval, 51.97% to 64.63%) in commercial chickens in Grenada was made.with a range of 2.85% -92.85%, according to parish Clinical disease occurs comparatively infrequ-(Figure-1).Our results for higher seroprevalence in ently in vertically transmitted CIAV infection and layer chickens compared to broilers are supported by clinical signs develop from 10-14 days of age [17].the observation of previous researchers (Ballal [3], Affected birds develop anemia-dermatitis syndrome Bhatt et al. flocks are being immunized and the vertical transof 83% -100% in layer and pullets than the broilers mission from immune breeders has been reduced to a (16.7% -89.2%) in Nigeria, Hadimili et al. [12] found very low level.Commercial chickens in Grenada are antibodies in 85.7% in commercial layers in Turkey, not vaccinated against CIAV and absence of any report while Ballal [3] reported antibodies to CIAV in 67.3% on anemia -dermatitis syndrome in chickens at their commercial layer and 44.3% in broiler flocks in Sudan.
young age in Grenada points to the possibility of the High degree of positive detection (87.5% was also virus circulating in the poultry houses and infecting made by ELISA in 21 commercial layer flocks in birds horizontally.This is further exacerbated by the Turkey by Kuyucuoglu et al. [21].Farhoodi et al. [4] existing management system of keeping multiage chicken found 71.8% positive antibody detection among in Grenada which supports the infection between birds.broiler flocks in Iran, Roussan [6] reported 82.6% As far as our knowledge, this is the first report on positive detection for CIAV in broilers in Jordan.In the presence of antibodies for CIAV in commercial India an overall prevalence of 86.88% with a higher chickens in Grenada and countries in the Caribbean region.prevalence in breeders were recorded in poultry flocks

Conclusion
in four Northern states of the country, namely Punjab, Haryana, Uttarakhand and Uttarpradesh [7].Cardona Our findings show that chicken infectious anemia et al. [22] have also indicated higher rate of seroprevavirus is widely distributed in commercial layer and lence in sexually mature flocks.The observation of broiler chickens in Grenada.

Owoade et al. [20] is similar to our observation of age
Recommendation related seroprevalence in broiler flocks.They detected antibodies against CIAV in 86% of broilers comprising Since the virus is immunosuppressive alone or in of juveniles and in 100% of flocks older than 6-8 combination with other viruses, extensive studies are weeks.Similarly in Croatia presence of antibodies warranted to find out the economic impact of CIAV in against CAV in 94.7% broiler breeders against 26.65% chickens of this region.in broilers were found [11].Birds living longer are [7], Owoade et all.[20], Kuyucuoglo et al. [18,26,27].However, for the past 2 decades the breeder [21].Owoade et al. [20] reported high seroprevalence

Figure- 1 .
Figure-1.Seroprevalence of Chicken infectious anaemia antibodies in commercial chickens of Grenada