Outbreak investigation of Newcastle disease virus from vaccinated chickens in Eritrea

Abstract

Newcastle disease (ND) is one of the most important infectious viral diseases of poultry in Eritrea.Diagnosis of ND virus infection in Eritrea has been mainly based on clinical examination and post mortem lesions. This study describes ND diagnosis using reverse transcription polymerase chain reaction PCR (RT-PCR), virus isolation and serological techniques (haemaglutination inhibition test) from two times vaccinated 40 days old chicks in Keren poultry farm. Generally clinical signs and postmortem lesions were characterized by rapid onset, death without visible lesions, ruffled plumage, dyspnea, in appetite, weakness and green colored diarrhea. Clinical samples collected were cloacal swabs. Observed postmortem lesions were tracheal hemorrhage, hemorrhage in proventriculus especially at the junction between esophagus and proventriculus and haemorrhage in caecal tonsils. Samples collected after postmortem include spleen, intestine and caecal tonsils. High titer of specific ND virus (NDV) antibody was detected indicating the occurrence of recent infection. ND virus was isolated from aseptically collected samples using embryonated chicken eggs. RT-PCR assay described was able to detect ND virus from cloacal swabs, spleen, intestine and caecal tonsils. Therefore, the described RT-PCR assay can be adopted for rapid and confirmative detection of NDV in Eritrea. Additionally, prevention of ND should not depend only on vaccination.

Detection and molecular characterization of virulent Newcastle disease virus (subgenotype VII.2) in broiler chickens in Northern Vietnam

“…The current study reported that NDV has distinctive clinical signs such as respiratory difficulties, depression, head twisting, and greenish-white diarrhea. This is consistent with the results of previous studies by Alexander [24], Bereket et al [25], and Khorajiya et al [26]. A previous study by Wise et al [27] reported that NDV-infected chickens also showed enlargement and inflammation of the eyes, diarrhea, and lack of appetite.…”

“…At necropsy, the mucus in the respiratory tract and pin-point hemorrhages in the proventriculus were observed in the suspected chickens. These results strongly agree with those of other studies [25,28]. Based on the clinical signs and the postmortem findings, the chickens obtained in the study were considered to be infected with NDV.…”

Isolation and Molecular Detection of Newcastle Disease Virus from Field Outbreaks in Chickens in Central Ethiopia

“…These results were in line with some other reports. 21 , 24–26 Hemorrhagic laryngotracheitis, congestion and edema of the lungs have been reported 27 ; the reported lesion is different from the present study, and this variation may be due to different strains of NDV that can affect different organs of the chickens. In this study, the observed lesions were indicative of ND depending on the observed gross pathological lesions.…”

“…The overall morbidity, mortality and case fatality rates observed in infected chickens in the study area were 18.7%, 9.5% and 50.5%, respectively. According to one study 21 , 21.21% mortality was reported from chickens exposed to outbreaks of ND. Similarly, Saidu and Abdu 23 reported a 97.7% mortality rate which is higher than the present finding.…”

The global circulation of Marxist perspectives on the national question: Borochovism at the service of the Eritrean cause

“…Also see Pateman (1990, p. 47) and Greenfield (1980, p. 24). Taking this one step further, Bereket (1980b, pp. 34–35) contended that Eritrean nationalism is hardly a new phenomenon.…”