A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in... more A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in swamp buffaloes from five provinces in north-eastern Thailand, and to compare infection status in swamp buffaloes and beef cattle at one area of Thailand. A single serum sample was collected from each of 532 swamp buffaloes and 78 beef cattle during January and July 2009. Antibodies against N. caninum were analyzed by a commercial ELISA test. Chisquare tests were used to compare the seroprevalence between species, gender and age groups in Khon Kaen. Result showed that infection prevalence in swamp buffaloes in northeastern Thailand was 4.5%. At one area in Khon Kaen province, proportions of seropositive swamp buffaloes and beef cattle were 6.4% and 43.6%, respectively, with significant difference (p<0.001). In both species, gender and age had no significant effects on the N. caninum infection status. The present study indicated that seroprevalence of N. caninum infection in swamp buf...
Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the ... more Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the northeastern and northern Thailand, and a subset of 11 herds was selected for individual testing. The samples were tested for presence of antibodies to BVDV and BHV-1 using an indirect ELISA. The results from the bulk milk testing demonstrated a moderate level of exposure to BVDV and BHV-1 (73% and 67%, respectively). However, the low proportion of herds with high BVDV antibody-levels (13%) and the low within-herd seroprevalence of BVDV and BHV-1 in the 11 herds (24% and 5%, respectively), particularly among the young stock (15% and 0%, respectively), demonstrated a low prevalence of active BVDV infection and a low rate of reactivation of latent BHV-1. The presence of a self-clearance process was also indicated by the results from the individual testing. Moreover, a surprisingly low prevalence of BVDV and BHV-1 antibody-positive herds at one of the milk centres was found. This centre was...
A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in... more A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in swamp buffaloes from five provinces in north-eastern Thailand, and to compare infection status in swamp buffaloes and beef cattle at one area of Thailand. A single serum sample was collected from each of 532 swamp buffaloes and 78 beef cattle during January and July 2009. Antibodies against N. caninum were analyzed by a commercial ELISA test. Chi-square tests were used to compare the seroprevalence between species, gender and age groups in Khon Kaen. Result showed that infection prevalence in swamp buffaloes in northeastern Thailand was 4.5%. At one area in Khon Kaen province, proportions of seropositive swamp buffaloes and beef cattle were 6.4% and 43.6%, respectively, with significant difference (p<0.001). In both species, gender and age had no significant effects on the N. caninum infection status. The present study indicated that seroprevalence of N. caninum infection in swamp bu...
Neospora caninum, a parasite that can infect a wide range of animals has been suggested to be one... more Neospora caninum, a parasite that can infect a wide range of animals has been suggested to be one of the most important causes of abortion in cattle. Several techniques have been developed to diagnose N. caninum infection in animals. In this paper, isolation, histologic, molecular and serological techniques for the diagnosis of neosporosis in animals are reviewed. TÓM TẮT Neospora caninum là một ký sinh trùng có thể gây nhiễm cho rất nhiều loài động vật và là một trong những nguyên nhân quan trọng gây xảy thai ở bò. Đã có nhiều phương pháp được xây dựng để chẩn đoán bệnh. Trong bài viết này, chúng tôi trình bày các kỹ thuật phân lập ký sinh trùng, tổ chức học, phân tử và huyết thanh học được áp dụng để chẩn đoán bệnh do N. caninum gây ra.
Tạp chí Khoa học và Phát triển 2012 Tập 10, số 4: ABSTRACT Nespora caninum is a parasite which wa... more Tạp chí Khoa học và Phát triển 2012 Tập 10, số 4: ABSTRACT Nespora caninum is a parasite which was first detected in Norwegian dogs and has been known as an important abortive cause of cattle. A high abortion rate up to 44% occurs in N. caninum positive pregnant cows.. Besides, consequence of infection could be culling of the aborted dams, reduction of milk production and weight gain, and increase of veterinary, diagnosis and replacement purchase costs. Various methods have been studied to prevent and control N. caninum infection in cattle. However, there are no highly effective approaches available in terms of both epidemiological and economic aspects so far.
The relationship between the level of Neospora caninum antibodies in bulk milk and the seropreval... more The relationship between the level of Neospora caninum antibodies in bulk milk and the seroprevalence in lactating cows was investigated. Bulk milk was also used to estimate the prevalence of N. caninum infection in dairy herds in the northeast and north Thailand. Bulk milk and individual serum from all lactating cows in 11 herds as well as 220 bulk milk samples from nine milk collection centres were analysed for presence of N. caninum antibodies using an iscom ELISA. In the 11 herds the bulk milk absorbances ranged between 0.04 and 0.89 and the seroprevalences varied between 0 and 46%. Five herds had milk absorbances below 0.20, among those were the two herds housing only seronegative lactating cows. In the remaining three herds with such low bulk milk absorbances one or two cows (5-14%) were seropositive. Six of the investigated herds had bulk milk absorbances above 0.20. In the two herds with the highest bulk milk absorbances more than 30% of the cows were seropositive. Using an absorbance of 0.20 to discriminate between negative and positive herds, 102 (46%) of 220 bulk milk samples were judged positive. There was no significant difference in mean bulk milk absorbance between the milk collection centres within each region. However, the proportion of herds with bulk milk absorbances &amp;amp;amp;amp;amp;amp;amp;amp;gt; or =0.50 in the north was statistically (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) higher than that in the northeast. It was concluded that bulk milk antibody testing can be used to identify N. caninum-infected herds and that N. caninum is a common infection in dairy herds in Thailand.
The epidemiology of bovine herpesvirus type 1 (BHV-1) and bovine viral diarrhoea virus (BVDV) was... more The epidemiology of bovine herpesvirus type 1 (BHV-1) and bovine viral diarrhoea virus (BVDV) was studied in a population of small dairy herds that had not been vaccinated. Bulk tank milk samples of 186 herds in Thailand were collected four times between 2002 and 2004. Serum samples from individual animals in 11 herds were also taken on three occasions. The prevalence of BHV-1 in the 186 herds was 61% in 2002, decreasing to 48% in 2004 and for BVDV was 91% in 2002, decreasing to 72% in 2004. A BVDV antigen-positive calf was found in one of the 11 herds, and animals in this herd and three other herds seroconverted to a recently described atypical BVDV strain (HoBi). This study showed a significantly decreasing prevalence for both BHV-1 and BVDV due to a self-clearance process. Further studies are needed to find out how the atypical BVDV strain entered the cattle population.
A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in... more A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in swamp buffaloes from five provinces in north-eastern Thailand, and to compare infection status in swamp buffaloes and beef cattle at one area of Thailand. A single serum sample was collected from each of 532 swamp buffaloes and 78 beef cattle during January and July 2009. Antibodies against N. caninum were analyzed by a commercial ELISA test. Chisquare tests were used to compare the seroprevalence between species, gender and age groups in Khon Kaen. Result showed that infection prevalence in swamp buffaloes in northeastern Thailand was 4.5%. At one area in Khon Kaen province, proportions of seropositive swamp buffaloes and beef cattle were 6.4% and 43.6%, respectively, with significant difference (p<0.001). In both species, gender and age had no significant effects on the N. caninum infection status. The present study indicated that seroprevalence of N. caninum infection in swamp buf...
Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the ... more Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the northeastern and northern Thailand, and a subset of 11 herds was selected for individual testing. The samples were tested for presence of antibodies to BVDV and BHV-1 using an indirect ELISA. The results from the bulk milk testing demonstrated a moderate level of exposure to BVDV and BHV-1 (73% and 67%, respectively). However, the low proportion of herds with high BVDV antibody-levels (13%) and the low within-herd seroprevalence of BVDV and BHV-1 in the 11 herds (24% and 5%, respectively), particularly among the young stock (15% and 0%, respectively), demonstrated a low prevalence of active BVDV infection and a low rate of reactivation of latent BHV-1. The presence of a self-clearance process was also indicated by the results from the individual testing. Moreover, a surprisingly low prevalence of BVDV and BHV-1 antibody-positive herds at one of the milk centres was found. This centre was...
A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in... more A seroepidemiological survey was carried out to investigate seroprevalence of Neospora caninum in swamp buffaloes from five provinces in north-eastern Thailand, and to compare infection status in swamp buffaloes and beef cattle at one area of Thailand. A single serum sample was collected from each of 532 swamp buffaloes and 78 beef cattle during January and July 2009. Antibodies against N. caninum were analyzed by a commercial ELISA test. Chi-square tests were used to compare the seroprevalence between species, gender and age groups in Khon Kaen. Result showed that infection prevalence in swamp buffaloes in northeastern Thailand was 4.5%. At one area in Khon Kaen province, proportions of seropositive swamp buffaloes and beef cattle were 6.4% and 43.6%, respectively, with significant difference (p<0.001). In both species, gender and age had no significant effects on the N. caninum infection status. The present study indicated that seroprevalence of N. caninum infection in swamp bu...
Neospora caninum, a parasite that can infect a wide range of animals has been suggested to be one... more Neospora caninum, a parasite that can infect a wide range of animals has been suggested to be one of the most important causes of abortion in cattle. Several techniques have been developed to diagnose N. caninum infection in animals. In this paper, isolation, histologic, molecular and serological techniques for the diagnosis of neosporosis in animals are reviewed. TÓM TẮT Neospora caninum là một ký sinh trùng có thể gây nhiễm cho rất nhiều loài động vật và là một trong những nguyên nhân quan trọng gây xảy thai ở bò. Đã có nhiều phương pháp được xây dựng để chẩn đoán bệnh. Trong bài viết này, chúng tôi trình bày các kỹ thuật phân lập ký sinh trùng, tổ chức học, phân tử và huyết thanh học được áp dụng để chẩn đoán bệnh do N. caninum gây ra.
Tạp chí Khoa học và Phát triển 2012 Tập 10, số 4: ABSTRACT Nespora caninum is a parasite which wa... more Tạp chí Khoa học và Phát triển 2012 Tập 10, số 4: ABSTRACT Nespora caninum is a parasite which was first detected in Norwegian dogs and has been known as an important abortive cause of cattle. A high abortion rate up to 44% occurs in N. caninum positive pregnant cows.. Besides, consequence of infection could be culling of the aborted dams, reduction of milk production and weight gain, and increase of veterinary, diagnosis and replacement purchase costs. Various methods have been studied to prevent and control N. caninum infection in cattle. However, there are no highly effective approaches available in terms of both epidemiological and economic aspects so far.
The relationship between the level of Neospora caninum antibodies in bulk milk and the seropreval... more The relationship between the level of Neospora caninum antibodies in bulk milk and the seroprevalence in lactating cows was investigated. Bulk milk was also used to estimate the prevalence of N. caninum infection in dairy herds in the northeast and north Thailand. Bulk milk and individual serum from all lactating cows in 11 herds as well as 220 bulk milk samples from nine milk collection centres were analysed for presence of N. caninum antibodies using an iscom ELISA. In the 11 herds the bulk milk absorbances ranged between 0.04 and 0.89 and the seroprevalences varied between 0 and 46%. Five herds had milk absorbances below 0.20, among those were the two herds housing only seronegative lactating cows. In the remaining three herds with such low bulk milk absorbances one or two cows (5-14%) were seropositive. Six of the investigated herds had bulk milk absorbances above 0.20. In the two herds with the highest bulk milk absorbances more than 30% of the cows were seropositive. Using an absorbance of 0.20 to discriminate between negative and positive herds, 102 (46%) of 220 bulk milk samples were judged positive. There was no significant difference in mean bulk milk absorbance between the milk collection centres within each region. However, the proportion of herds with bulk milk absorbances &amp;amp;amp;amp;amp;amp;amp;amp;gt; or =0.50 in the north was statistically (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) higher than that in the northeast. It was concluded that bulk milk antibody testing can be used to identify N. caninum-infected herds and that N. caninum is a common infection in dairy herds in Thailand.
The epidemiology of bovine herpesvirus type 1 (BHV-1) and bovine viral diarrhoea virus (BVDV) was... more The epidemiology of bovine herpesvirus type 1 (BHV-1) and bovine viral diarrhoea virus (BVDV) was studied in a population of small dairy herds that had not been vaccinated. Bulk tank milk samples of 186 herds in Thailand were collected four times between 2002 and 2004. Serum samples from individual animals in 11 herds were also taken on three occasions. The prevalence of BHV-1 in the 186 herds was 61% in 2002, decreasing to 48% in 2004 and for BVDV was 91% in 2002, decreasing to 72% in 2004. A BVDV antigen-positive calf was found in one of the 11 herds, and animals in this herd and three other herds seroconverted to a recently described atypical BVDV strain (HoBi). This study showed a significantly decreasing prevalence for both BHV-1 and BVDV due to a self-clearance process. Further studies are needed to find out how the atypical BVDV strain entered the cattle population.
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