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Detection of serum neutralizing antibodies to Simbu sero-group viruses in cattle in Tanzania.

Mathew C, Klevar S, Elbers AR, van der Poel WH, Kirkland PD, Godfroid J, Mdegela RH, Mwamengele G, Stokstad M - BMC Vet. Res. (2015)

Bottom Line: Sera from the same area collected in 2008/2009, before the SBV epidemic in Europe, were also tested and 71 (54.6 %) of 130 were positive.Of 71 sera from 2008/2009, 21 % were positive.However, isolation in cattle is difficult due to short viremic period of 2 to 6 days, and isolation in vectors does not necessarily reflect the situation in cattle.

View Article: PubMed Central - PubMed

Affiliation: Department of Production Animal Clinical Sciences, Norwegian University of Life Science, P.O. Box 8146, Dep 0033, Oslo, Norway. coletha.mathew.mtenga@nmbu.no.

ABSTRACT

Background: Orthobunyaviruses belonging to the Simbu sero-group occur worldwide, including the newly recognized Schmallenberg virus (SBV) in Europe. These viruses cause congenital malformations and reproductive losses in ruminants. Information on the presence of these viruses in Africa is scarce and the origin of SBV is unknown. The aim of this study was to investigate the presence of antibodies against SBV and closely related viruses in cattle in Tanzania, and their possible association with reproductive disorders.

Results: In a cross-sectional study, serum from 659 cattle from 202 herds collected in 2012/2013 were analyzed using a commercial kit for SBV ELISA, and 61 % were positive. Univariable logistic regression revealed significant association between ELISA seropositivity and reproductive disorders (OR = 1.9). Sera from the same area collected in 2008/2009, before the SBV epidemic in Europe, were also tested and 71 (54.6 %) of 130 were positive. To interpret the ELISA results, SBV virus neutralization test (VNT) was performed on 110 sera collected in 2012/2013, of which 51 % were positive. Of 71 sera from 2008/2009, 21 % were positive. To investigate potential cross reactivity with related viruses, 45 sera from 2012/2013 that were positive in SBV ELISA were analyzed in VNTs for Aino, Akabane, Douglas, Peaton, Sabo, SBV, Sathuperi, Shamonda, Simbu and Tinaroo viruses. All 45 sera were positive for one or more of these viruses. Twenty-nine sera (64.4 %) were positive for SBV, and one had the highest titer for this virus.

Conclusions: This is the first indication that Aino, Akabane, Douglas, Peaton, Sabo, SBV, Sathuperi, Shamonda and Tinaroo viruses circulate and cause negative effect on reproductive performance in cattle in Tanzania. SBV or a closely related virus was present before the European epidemic. However, potential cross reactivity complicates the interpretation of serological studies in areas where several related viruses may circulate. Virus isolation and molecular characterization in cattle and/or vectors is recommended to further identify the viruses circulating in this region. However, isolation in cattle is difficult due to short viremic period of 2 to 6 days, and isolation in vectors does not necessarily reflect the situation in cattle.

No MeSH data available.


Related in: MedlinePlus

Overview of samples collected in 2012/2013 and used in different tests
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Fig1: Overview of samples collected in 2012/2013 and used in different tests

Mentions: The SBV VNT was performed on selected serum samples that tested positive in the SBV ELISA. This included 110 of 405 serum samples obtained in 2012/2013 (Fig. 1) and 71 of 130 sera collected in 2008/2009. Samples from 2012/ 2013 were selected to represent the whole study area. The test was performed at the Central Veterinary Institute, Lelystad, The Netherlands. In this test an SBV isolate from brain tissue of a lamb, fourth passage on Vero (African green monkey kidney) cells, was used. The VNT was performed on serum samples according to the method published in Loeffen et al. [22] with some small modifications: dilutions tested started at 1:4 and ended at 1:512. All samples were tested in duplicate. Titers were determined using the Reed-Muench method [23].Fig. 1


Detection of serum neutralizing antibodies to Simbu sero-group viruses in cattle in Tanzania.

Mathew C, Klevar S, Elbers AR, van der Poel WH, Kirkland PD, Godfroid J, Mdegela RH, Mwamengele G, Stokstad M - BMC Vet. Res. (2015)

Overview of samples collected in 2012/2013 and used in different tests
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4536799&req=5

Fig1: Overview of samples collected in 2012/2013 and used in different tests
Mentions: The SBV VNT was performed on selected serum samples that tested positive in the SBV ELISA. This included 110 of 405 serum samples obtained in 2012/2013 (Fig. 1) and 71 of 130 sera collected in 2008/2009. Samples from 2012/ 2013 were selected to represent the whole study area. The test was performed at the Central Veterinary Institute, Lelystad, The Netherlands. In this test an SBV isolate from brain tissue of a lamb, fourth passage on Vero (African green monkey kidney) cells, was used. The VNT was performed on serum samples according to the method published in Loeffen et al. [22] with some small modifications: dilutions tested started at 1:4 and ended at 1:512. All samples were tested in duplicate. Titers were determined using the Reed-Muench method [23].Fig. 1

Bottom Line: Sera from the same area collected in 2008/2009, before the SBV epidemic in Europe, were also tested and 71 (54.6 %) of 130 were positive.Of 71 sera from 2008/2009, 21 % were positive.However, isolation in cattle is difficult due to short viremic period of 2 to 6 days, and isolation in vectors does not necessarily reflect the situation in cattle.

View Article: PubMed Central - PubMed

Affiliation: Department of Production Animal Clinical Sciences, Norwegian University of Life Science, P.O. Box 8146, Dep 0033, Oslo, Norway. coletha.mathew.mtenga@nmbu.no.

ABSTRACT

Background: Orthobunyaviruses belonging to the Simbu sero-group occur worldwide, including the newly recognized Schmallenberg virus (SBV) in Europe. These viruses cause congenital malformations and reproductive losses in ruminants. Information on the presence of these viruses in Africa is scarce and the origin of SBV is unknown. The aim of this study was to investigate the presence of antibodies against SBV and closely related viruses in cattle in Tanzania, and their possible association with reproductive disorders.

Results: In a cross-sectional study, serum from 659 cattle from 202 herds collected in 2012/2013 were analyzed using a commercial kit for SBV ELISA, and 61 % were positive. Univariable logistic regression revealed significant association between ELISA seropositivity and reproductive disorders (OR = 1.9). Sera from the same area collected in 2008/2009, before the SBV epidemic in Europe, were also tested and 71 (54.6 %) of 130 were positive. To interpret the ELISA results, SBV virus neutralization test (VNT) was performed on 110 sera collected in 2012/2013, of which 51 % were positive. Of 71 sera from 2008/2009, 21 % were positive. To investigate potential cross reactivity with related viruses, 45 sera from 2012/2013 that were positive in SBV ELISA were analyzed in VNTs for Aino, Akabane, Douglas, Peaton, Sabo, SBV, Sathuperi, Shamonda, Simbu and Tinaroo viruses. All 45 sera were positive for one or more of these viruses. Twenty-nine sera (64.4 %) were positive for SBV, and one had the highest titer for this virus.

Conclusions: This is the first indication that Aino, Akabane, Douglas, Peaton, Sabo, SBV, Sathuperi, Shamonda and Tinaroo viruses circulate and cause negative effect on reproductive performance in cattle in Tanzania. SBV or a closely related virus was present before the European epidemic. However, potential cross reactivity complicates the interpretation of serological studies in areas where several related viruses may circulate. Virus isolation and molecular characterization in cattle and/or vectors is recommended to further identify the viruses circulating in this region. However, isolation in cattle is difficult due to short viremic period of 2 to 6 days, and isolation in vectors does not necessarily reflect the situation in cattle.

No MeSH data available.


Related in: MedlinePlus