RESUMEN
Whilst bovine leukemia virus (BLV) causes considerable economic losses to the dairy industry worldwide, information on its molecular epidemiology and economic impact in beef cattle is limited. Here, blood from 880 animals from Zambia's major cattle-rearing provinces was screened for BLV by nested PCR. Positive pools were sequenced and phylogenetically analyzed. The estimated pooled prevalence was 2.1%. All strains belonged to genotype 1 and formed a distinct phylogenetic cluster. The study suggests circulation of genotype 1 BLV in beef cattle in these regions. This is the first report on molecular detection and characterization of BLV from beef cattle in Africa.
Asunto(s)
Leucosis Bovina Enzoótica/epidemiología , Leucosis Bovina Enzoótica/virología , Genotipo , Virus de la Leucemia Bovina/genética , Virus de la Leucemia Bovina/aislamiento & purificación , Animales , Bovinos , Virus de la Leucemia Bovina/clasificación , Epidemiología Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN , Zambia/epidemiologíaRESUMEN
Bovine leukemia virus (BLV) causes enzootic bovine leucosis (EBL) and is responsible for substantial economic losses in cattle globally. However, information in Africa on the disease is limited. Here, based on clinical, hematological, pathological and molecular analyses, two clinical cases of EBL were confirmed in a dairy cattle herd in Zambia. In contrast, proviral DNA was detected by PCR in five apparently healthy cows from the same herd, suggesting subclinical BLV infection. Phylogenetic analysis of the env gene showed that the identified BLV clustered with Eurasian genotype 4 strains. This is the first report of confirmed EBL in Zambia.
Asunto(s)
Leucosis Bovina Enzoótica/virología , Virus de la Leucemia Bovina/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Bovinos , Femenino , Genotipo , Virus de la Leucemia Bovina/química , Virus de la Leucemia Bovina/clasificación , Virus de la Leucemia Bovina/genética , Masculino , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia , Proteínas Virales/química , Proteínas Virales/genética , ZambiaRESUMEN
In early 2015, a highly fatal haemorrhagic disease of domestic pigs resembling African swine fever (ASF) occurred in North Western, Copperbelt, and Lusaka provinces of Zambia. Molecular diagnosis by polymerase chain reaction targeting specific amplification of p72 (B646L) gene of ASF virus (ASFV) was conducted. Fourteen out of 16 domestic pigs from the affected provinces were found to be positive for ASFV. Phylogenetic analyses based on part of the p72 and the complete p54 (E183L) genes revealed that all the ASFVs detected belonged to genotypes I and Id, respectively. Additionally, epidemiological data suggest that the same ASFV spread from Lusaka to other provinces possibly through uncontrolled and/or illegal pig movements. Although the origin of the ASFV that caused outbreaks in domestic pigs in Zambia could not be ascertained, it appears likely that the virus may have emerged from within the country or region, probably from a sylvatic cycle. It is recommended that surveillance of ASF, strict biosecurity, and quarantine measures be imposed in order to prevent further spread and emergence of new ASF outbreaks in Zambia.