title: Seroconversion to bovine viral diarrhoea virus and infectious bovine rhinotracheitis virus in dairy herds of Michoacan, Mexico.
abstract: Bovine viral diarrhoea virus (BVDV) and infectious bovine rhinotracheitis virus (IBRV) are important viral diseases around the world. The objective of this study was to estimate the incidence of seroconversion to BVDV and IBRV and to identify associated risk factors in dairy herds of Michoacan, Mexico. The longitudinal study included 62 herds and ran from December 2001 to November 2002. The total number of animals enrolled and completing the study were 392 and 342 animals for BVDV and 925 and 899 animals for IBRV. Animals were tested monthly for 12 months, for the presence of antibodies. Risk factors were: herd size (2-9, 10-25 and 26-55 animals), herd serostatus (seropositive or seronegative, only for IBRV), age group of the animal (6 to 12, 13 to 24, 25 to 48 and > 48 months) and animal origin (born in farm, purchased). The cumulative incidences for BVDV and IBRV were 16.4% and 3.4%, respectively; whereas, the incidence density rates for BVDV and IBRV were 15.9 and 2.9 per 1000 animal-months at risk, respectively. Seroconversion curves were statistically different for age group for BVDV and IBRV and for herd status for IBR. The relatively high incidence of seroconversion for BVDV suggests that a successful control programme should be oriented towards the identification and elimination of the PI animals and towards avoiding the introduction of PI cattle to the farm. The scenario of IBRV is favourable to implement a programme directed to reduce the number of new seropositive herds.
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia, UADY, Km. 15.5 carretera Mérida-Xmatkuil, A.P.4-116, Itzimná, Mérida, Yucatán, México. segura52@hotmail.com
authors.forename: José C
authors.initials: JC
authors.lastname: Segura-Correa
authors.forename: José L
authors.initials: JL
authors.lastname: Solorio-Rivera
authors.forename: Laura G
authors.initials: LG
authors.lastname: Sánchez-Gil
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000453:epidemiology / Q000821:virology*; D002353:Carrier State / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D002417:Cattle; D001908:Diarrhea Viruses, Bovine Viral / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007242:Herpesvirus 1, Bovine / Q000302:isolation & purification*; D007241:Infectious Bovine Rhinotracheitis / Q000453:epidemiology / Q000821:virology*; D008137:Longitudinal Studies; D008800:Mexico / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D014329:Tropical Climate
chemical_list: D000914:Antibodies, Viral
references.citation: Prev Vet Med. 2008 Mar 17;83(3-4):285-96
references.pmid: 17904667
references.citation: Prev Vet Med. 2002 Dec 30;56(3):193-202
references.pmid: 12441235
references.citation: Vet Microbiol. 1996 Nov;53(1-2):103-10
references.pmid: 9011002
references.citation: J Am Vet Med Assoc. 2001 Nov 15;219(10):1426-31
references.pmid: 11724183
references.citation: Vet Microbiol. 1996 Nov;53(1-2):169-80
references.pmid: 9011009
references.citation: Prev Vet Med. 2005 Nov 15;72(1-2):55-73; discussion 215-9
references.pmid: 16214248
references.citation: Vet Microbiol. 1999 Jan;64(2-3):197-222
references.pmid: 10028173
references.citation: Prev Vet Med. 2003 Apr 15;57(4):199-208
references.pmid: 12609465
references.citation: Anim Reprod Sci. 2000 Jul 2;60-61:615-27
references.pmid: 10844229
references.citation: Vet Microbiol. 2000 Nov 15;77(1-2):137-43
references.pmid: 11042407
references.citation: Prev Vet Med. 1999 Oct 19;47(1-2):91-105
references.pmid: 11018737
references.citation: Vet Res. 2007 Mar-Apr;38(2):181-209
references.pmid: 17257569
references.citation: Vet J. 2002 May;163(3):226-7
references.pmid: 12090762
references.citation: Biologicals. 2003 Jun;31(2):137-43
references.pmid: 12770546
references.citation: Prev Vet Med. 2008 Jun 15;85(1-2):68-80
references.pmid: 18304663
references.citation: Acta Vet Scand. 2004;45(3-4):181-92
references.pmid: 15663078
references.citation: Prev Vet Med. 2001 Sep 20;51(1-2):17-36
references.pmid: 11530192