Bovine leukemia virus: current perspectives

Figures & data

Table 1 Classification of BLV-infected cattle in terms of hematological status and proviral load

Infection category	Hematological status	PL^a	Antibody titer
			BLVgp51	BLVp24
HPL	PL	≥100,000	400 to ≥6,400	50 to 800
HPL	Non-PL	≥100,000	400 to ≥6,400	Seronegative to 400
LPL	Non-PL	≤100	2 to 1,600	Seronegative to 50

Notes:

a Proviral copies/μg DNA. Copyright ©2007. American Veterinary Medical Association. Adapted from Juliarena MA, Gutierrez SE, Ceriani C. Determination of proviral load in bovine leukemia virus-infected cattle with and without lymphocytosis. Am J Vet Res. 2007;68(11):1220–1225.²⁸

Abbreviations: BLV, bovine leukemia virus; HPL, high proviral load; LPL, low proviral load; PL, persistent lymphocytosis.

Box 1 Main management measures aimed at minimizing BLV transmission

Use disposable needles and syringes for blood extractions and injections Use individual obstetric gloves for transrectal palpation (or separate gloves for BLV negative and infected herd) Use disposable or adequately disinfected equipment for all procedures carrying a risk of blood contamination such as dehorning, castration, ear-tagging, etc Control of blood-sucking insects Feed calves with milk from BLV-negative cows, milk replacer, or heat-inactivated milk from BLV-positive cows Use artificial insemination or natural breeding with BLV-negative bulls Only introduce BLV-negative animals from negative herds. If coming from infected or unknown status herds, they should be kept isolated until two BLV-negative serological examinations are performed at 2- to 3- month interval

Abbreviation: BLV, bovine leukemia virus.