1. CAPRINE ARTHRITIS ENCEPHALITIS KEEPS SPREADING IN SARDINIAN GOAT HERDS
XXII International Congress of Mediterranean Federation for Health and Production
of Ruminant s
Sassari, June 17th-20th, 2015
CAPRINE ARTHRITIS ENCEPHALITIS KEEPS SPREADING IN SARDINIAN GOAT HERDS
Bandino E. , Mulas M. , Tanda B. , Boeddu L. , Cocco M. , Solinas C. , Cabras P. , Murgia M.C. , Soddu M. , Rolesu S. (*)
Istituto Zooprofilattico Sperimentale della Sardegna, SC Diagnostico Territoriale di Nuoro
(*)Istituto Zooprofilattico Sperimentale della Sardegna, Centro di Sorveglienza Epidemiologica- Cagliari
INTRODUCTION
Small ruminant lentiviruses (SLRV) are a group of viruses belonging to the Retroviridae family that affects sheep and goats and are responsible for slow, progressive inflammatory pathology involving joints (Fig.1), mammary glands, lungs and brain, known as Maedi-Visna (MV) in sheep and caprine arthritis-encefalitis (CAE) in goats (Pepin et al.,1998). In Goat breeding Lentivirus infections are a serious health problem and cause huge economic damage (loss of up to 25% of production are estimated) (Peretz.G. et al.1993). The goat farming system in Sardinia consists of head representing around 20% of the italian goat population (National Database 2014,
MATERIAL AND METHODS
A serological survey was carried out on 28 goat farms randomly selected and belonging to the territories of the provinces of Nuoro and Ogliastra (Fig.2) collected among samples from Eradication Plan of ovine and caprine brucellosis. N blood samples were tested with ELISA indirect method (MVV-CAEV Indirect – ID.vet) for the detection of antibodies against Caprine Arthritis Encephalitis. A retrospective survey was conducted on positive tested farms to know the health status of the breeding.
In Sardinia, the first report of Caprine Arthritis Encephalitis (CAE) dates back to 1988 (Pintori G. et al. 1988), in subsequent years, there has been a gradual spread of the disease in herds goats, probably as a result of the purchase without any sanitary control of maltese and saanen breed to improve the milk production of sardinian goat. In 2013 the Regional Government approved a three-year voluntary plan of actions that provides the elimination of seropositive animals for the recovery of goat farms infected by CAE.
The aim of this study was the estimation of CAE current prevalence in the Central-East Sardinia in the provinces of Nuoro and Ogliastra where head (about 1/3 of the island‘s goat population) are mostly extensively reared and distributed in 1091 farms (National Database 2014).
FIG.2
FIG. 1
RESULTS AND DISCUSSION
The 100% of the tested herds was serologically positive for CAE (estimated prevalence in the population 100%, with confidence interval at 99% confidence level to lfi 78.02, lfs) and intra-herd prevalences found ranging from 0,0454 to 0,9866 (Table 1). In detail, n.3 farms have a seropositivity percentage between 4.5 and 30%, n.13 farms between 60 and 80% and n.12 farms between 81 and 98.6%. (Grafic 1). Retrospective survey showed that the turn over in 100% of the herds are internal and its percentage varies from 9% to 36%.
Kids are nursed directly by their mothers without any heat treatment of colostrum or milk in all farms but one that adopts artificial feeding. Only 4 farms bought animals in the last year. In 5 farms the breeders referred the presence of respiratory symptoms in 3 or 4 goats and some animals showed lameness or swollen joints in 8 farms: 1 head in 3 farms; 4 heads in two farms; 6 heads in 1 breeding; 10 heads in two farms. In 9 herds were reported cases of mastitis localized to a single udder, 1 involved both. The breeder reported neurological symptoms, as well as ataxia and tremors, in kids of 4 farms but other pathologies were not excluded. Weight loss was observed in 10 farms in animals that had clinical signs. The milk production in recent years have not changed significantly.
flock N.
Municipality
n. of head in the flock
n. tested head
n. positive sample
estimated prevalence
Confidence interval
(lfi e lfs 95%) 1
Irgoli
133 67 45
67,16
59,40-74,44 2
Desulo
286 77 66
85,71
78,67-90,91 3
Orune
185 69 60
86,95
80,00-91,89 4
Urzulei
330 78 57
0,7307
64,55-80,61 5
Siniscola 75 56
0,7466
67,03-81,08 6
Cardedu 73 20
0,2739
20,54-35,68 7
Villagrande
338 81
0,9506
90,24-97,63 8
140 68 65
0,9558
91,43-97,86 9
Seui 70 50 24
0,48
41,43-55,71 10
108 58
0,9827
96,30-99,07 11
Ovodda
130 41
0,6833
60,00-76,15 12
Baunei
235 48
0,64
55,32-71,91 13
142
0,0454
2,11-9,15 14
125 59 17
0,2881
21,60-37,60 15
250 74
0,9866
95,60-99,60 16
Lanusei
390 86 84
0,9767
94,10-99,23
Tertenia
320 80
0,9625
91,88-98,44 18 55 40 35
0,875
81,82-90,91 19
Aritzo
100
0,8474
78,00-89,00
Talana
446 62
0,775
69,06-84,53 21
103 53 37
0,6981
61,17-77,67 22
155
0,7058
62,58-77,42 23
Orotelli
113 49
80,53-92,04
Jerzu 38
0,7916
68,42-86,84 25
247
0,7808
70,04-84,62 26
Orgosolo 34
0,6764
62,50-72,50 27 39
0,7358
68,66-77,61 28
Oliena
166
106 95
0,8962
85,54-92,17
Tot.
4819
1843
1385
0,751
73,58-76,65
TABLE 1
The Regional Government of Sardinia in 2013 approved a three-year voluntary plan of actions, for recovery and support of goat farms affected by lentiviruses diseases and the most important measure of this plan provides the elimination of seropositive animals. Voluntary joining to the plan so far, were very few for the high cost of management and as the intra-herd prevalence is so high it would lead to the elimination of a large part of the flock.
Recent studies have described in Roccaverano goat breed reared in Piedmont (Italy) a SLRV E genotype characterized by low pathogenicity. (Grego E. et al. 2009; Reina R. et al. 2009a). A further research (Reina R. et al .; 2010) reported the presence in large-scale in goat herds raised in Sardinia a SLRV genotype E, genetically very similar to Roccaverano low pathogenic strain isolated in Piedmont. Its presence should be taken into consideration in the predisposition of reliable CAE programs control.
GRAFIC 1
CONCLUSION
The results confirm a high spread of the disease in sardinian goat herds and the disease seems to be evenly distributed in the investigated area. The number of positive breedings and intra-herd prevalence increased significantly compared to a survey carried out in the same territories in the late '90 (Bandino et al. 1999) and confirm the trend of spreading of other serological surveys carried out in Sardinia (Rolesu S. et al. 2009). The retrospective survey indicates however, that to the high serological prevalence does not correspond a high percentage of animals with evident clinical symptoms. The involvement of farmers to the regional program and the consequent elimination of seropositive goats along with the difficulties in finding healthy animals for the replacement of sick goats could lead to loss of an important genetic heritage. For its preservation, given the presence in the island of a low pathogenic genotypes, further investigation is needed in order to know the distribution of circulating genotypes and for the implementation of the best disease control strategies in a region with high rates of seropositivity.
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