Bovine leukemia virus proviral load in naturallyinfected animals

ALVAREZ IRENE; GUTIERREZ GERONIMO; POLITZKI ROMINA; GONZALEZ CINTIA; MARTINEZ CECILIA; GAMMELLA MARIELA; TRONO KARINA

RETROVIROLOGY

BIOMED CENTRAL LTD

Lugar: Londres; Año: 2011 vol. 8

1742-4690

Due to the high prevalence of Bovine Leukemia Virus(BLV) in argentinean dairy herds, classical control basedon the individual level of infection do not constitute afeasible strategy. An approach based on selective segregation of animals according to their peripheral-bloodproviral load (PVL) could be a practical alternative.We conducted this work to get information about thefrequency distribution of PVL under natural conditionswith the purpose to describe the proportion of animalsthat could be selected as potential low transmitters.We analyzed the PVL on 332 cattle from four infectedfarms with different levels of seroprevalence (Farm A:30%, Farm B: 66%, Farm C: 87% and Farm D: 92%)together with the correlation of PVL with BLV antibodylevels.In all farms, more than 50% of the seropositive animals showed a proviral load lower than our internalcalibrator sample which corresponds to 1 infected cellin 100 non-infected cells according to: Farm A: 78%,Farm B: 79%, Farm C: 55% and Farm D: 79%.The analysis of antibodies showed that low p24-ELISAreactivity is associated with low PVL in the vast majorityof animals.Thepresentstudyprovidesbiologicaldatathatcouldcontribute with the design of a management programthat includes a selective segregation policy for BLV control based on the level of proviral load, which representsa measure of integrated viral genome in host cells and asurrogate marker of the level of BLV transmission undernatural conditions