Large-Scale Serological Survey of Caprine Arthritis-Encephalitis Virus (CAEV) in Korean Black Goats (<i>Capra hircus aegagrus</i>)

Abstract

ABSTRACT. A national serological survey of caprine arthritis-encephalitis virus (CAEV) infection was conducted using an enzyme-linked immunosorbent assay (ELISA) and an agar gel immunodiffusion (AGID) test. A total of 658 black goats of various breeds were sampled from 59 farms in three regions of Korea. The CAEV-positive goats were predominantly detected in the Southern region (n=17) as compared with the Northern (n=1) and Central regions (n=0) (χ 2 =6.26, P=0.044). Among 658 goats tested, 18 were positive in both ELISA and AGID, indicating a CAEV prevalence of 2.73% (95% confidence interval: 1. 74-4.28 Caprine arthritis-encephalitis virus (CAEV) belongs to the genus lentivirus, family Retroviridae. CAEV is a persistent disease in goats characterized by polyarthritis, mastitis and pneumonia in adults and leukoencephalomyelitis in kids [4,6]. CAEV has been reported in most goat-rearing countries [1,13]. Live animal trading across national boundaries is considered an important cause of horizontal CAEV transmission, whilst ingestion of colostrums and milk represent important causes of transmission from mother to offspring [3,4]. In 2002, CAEV was identified in Japan [10]. Infected goats develop anti-CAEV antibodies and develop a persistent, lifelong infection. Korea was considered free from CAEV; however, CAEV RNA was detected in Korean dairy goats in 2008 [12], and an outbreak of CAEV was reported on a Korean goat farm in 2010 [14].The period between CAEV infection and the detection of antibodies and onset of clinical signs may vary from months to years [3]. Several diagnostic techniques are used to detect CAEV infections. These are based on the detection of either antibodies or virus [9]. Virus isolation and cell culture detection techniques have been used but cannot be extensively applied, as specific cell types are replicationrestrictive to particular strains [15] and CAEV heterogeneity and low viral loads have hampered the use of the polymerase chain reaction (PCR) as a reference technique. In addition, positive PCR results have been obtained in some seronegative animals [9]. Thus, the diagnosis of infection is typically performed by serological testing [9] including enzyme-linked immunosorbent assays (ELISA), and agar gel immunodiffusion (AGID) tests, with PCR used to complement serological methods. ELISA represents a more sensitive technique than AGID testing for the detection of CAEV antibodies. Western blotting, radioimmunoassay, and radioimmunoprecipitation are also used as supplementary tests to discriminate for indeterminate results obtained from screening assays.In Korea, the black goat population contains approximately 266,000 animals distributed in 21,000 herds [11]. Approximately 55% of the total goat population lives in the Southern region. Relatively low populations have been recorded in the Northern and Central regions. Although regional serological and virological investigations in dairy goats have been performed [12], no large-scale serological survey has been reported in Korean black goats. I...

High prevalence of caprine arthritis encephalitis virus (CAEV) in Taiwan revealed by large-scale serological survey

“…Nearly all the commercial dairy goat farms in Taiwan use incompletely pasteurized bulk milk to feed their lambs, whereas for meat goats, whose lambs are fed right from their mother. The former feeding strategy used in dairy goat farm may accelerate the spreading of diseases [ 13 , 14 ]. Previous studies have suggested that the longer lifespan of dairy goats combined with their close proximity to each other may cause this high CAEV prevalence rate in dairy goat farms [ 1 , 15 ].…”

“…Besides, very high herd seropositivity for CAEV has been reported in the U.S.A. (73%) [ 4 ], Australia (82%) [ 5 ] and Brazil (35%) [ 2 ]. Among the neighboring countries of Taiwan, the seroprevalence of CAEV was 10% in a total of 857 goat serum samples in Japan [ 7 ], compared to only 2.73% of goats in South Korea [ 14 ]. In China, the CAEV seropositive rates varied from 0.2 to 30% [ 16 ].…”

Short communication: Genetic parameter estimates for caprine arthritis encephalitis in dairy goats

“…The caprine arthritis encephalitis virus (CAEV) from the genus Lentivirus, first isolated in 1980 (Crawford et al, 1980), is the agent of the chronic disease defined as caprine arthritis encephalitis (CAE). This disease is a problem around the world, with high CAEV prevalence reported in various goat populations, including 98.5, 80.4, 51.6, 23.2, 28.6, 10.3, 82.0, 73.0, 18, 35.3, 35.4 to 81.1, and 21.9% of herds (or animals) infected in Taiwan, Canada, Lebanon, Jordan, Mexico, the United Kingdom, Australia, the United States, Spain, Egypt, Poland, and Croatia, respectively (Dawson and Wilesmith, 1985;Grewal et al, 1986;Cutlip et al, 1992;Al-Qudah et al, 2006;Vallerand et al, 2007;Ghanem, 2011;Oem et al, 2012;Martínez-Navalón et al, 2013;Stonos et al, 2013;Jones, 2014;Tabet et al, 2015;Tariba et al, 2015;Waseem et al, 2015;Thomann et al, 2017;Yang et al, 2017;Gruszecki et al, 2018). This disease causes major economical and welfare problems for the worldwide goat industry, including reduced production, growth rate, and longevity; greater rate of reproductive failures; premature culling; and increased incidence of disease (Smith and Cutlip, 1988;Peterhans et al, 2004;Reina et al, 2009;Leitner et al, 2010;Murphy et al, 2010;Konishi et al, 2011;Kaba et al, 2012;Tageldin et al, 2012;Martínez-Navalón et al, 2013).…”

Achievements of an eradication programme against caprine arthritis encephalitis virus in South Tyrol, Italy

“…These viruses are widespread worldwide with the exception of New Zealand and Australia, which are considered free of SRLV A, and Iceland, which eradicated SRLV after a devastating epizootic outbreak originating from the import of SRLV-infected karakul sheep in the early 1930s. [12][13][14][15][16][17][18][19][20] Genotype B, and in particular the B1 subtype, is considered the most virulent genotype for goats, whereas in sheep genotype A is the principal cause of clinical manifestations. 2 6 SRLVs are known to be the cause of a chronic multisystemic inlammatory disease characterised by a long incubation period and a lifelong persistent infection.…”

“…Noteworthy are the findings of several authors reporting genomic sequences from sheep with higher identities to CAEV than to MVV, 9–11 indicating a possible common ancestral genotype. These viruses are widespread worldwide with the exception of New Zealand and Australia, which are considered free of SRLV A, and Iceland, which eradicated SRLV after a devastating epizootic outbreak originating from the import of SRLV‐infected karakul sheep in the early 1930s 12–20 . Genotype B, and in particular the B1 subtype, is considered the most virulent genotype for goats, whereas in sheep genotype A is the principal cause of clinical manifestations 2 6 …”