Úsuga-Monroy Cristina, Alzate-Pavas Jakeline, Ortiz-González María Alejandra, Marín Villa Julián, Loaiza-Escobar Juliana, Sánchez-Zapata Gloria Y, Gómez-Ruiz Daisy A
Grupo GINVER, Facultad de Medicina Veterinaria, Corporación Universitaria Remington, Medellín, 050010.
Grupo BIOGEM, Facultad de Ciencias, Universidad Nacional de Colombia sede Medellín, 050034.
Vet Ital. 2025 Apr 14;61(2). doi: 10.12834/VetIt.3641.31503.1.
Feline leukemia virus (FeLV) is one of the primary pathogens in domestic felines, causing significant immunosuppression, lymphomas, and even death. Various subtypes of this virus have been described, with FeLV-A being the least pathogenic and the most widely distributed subtype. Conversely, the recombination of FeLV-A with endogenous retroviral sequences has resulted in variant B, which is associated with the development of leukemias and lymphomas. FeLV transmission occurs primarily through grooming between individuals, facilitating its distribution and circulation. The aim of this study was to characterize subtype B and analyze risk factors associated with viral infection in a sample of felines from Colombia. To achieve this, blood samples were taken from the cephalic or jugular veins of 151 felines in four municipalities of Antioquia, and data on age, sex, and area of origin were collected. PCR was performed on a region of the pol gene (306 bp), and only FeLV-positive feline samples underwent a second PCR for the env gene (1400 bp). Only env-positive PCR products were sequenced, and phylogenetic and recombination analyses were performed. Logistic regression was used to calculate the odds ratios (OR) for each variable (age, sex, and area of origin). The overall FeLV positivity rate was 33.77%, with an association found between male sex and FeLV infection (OR = 2.23, p = 0.038), as well as between the area of origin and FeLV infection (OR = 0.22, p = 0.035). Of the total samples, only 11 (7.3%) amplified for FeLV-B, with seven samples from Buriticá and four from Medellín. The recombination analyses confirmed that all sequences belonged to the FeLV-B subtype and were unique recombinants. The molecular presence of the virus in the study area demonstrates that the circulation of this retrovirus remains active. Additionally, the area of origin and male sex are risk factors for FeLV infection. Finally, an increase in FeLV positivity was observed, and while the B variants are generated de novo in each feline, it is crucial to continue health monitoring, especially in regions distant from major urban centers.
猫白血病病毒（FeLV）是家猫的主要病原体之一，可导致严重的免疫抑制、淋巴瘤，甚至死亡。已描述了该病毒的各种亚型，其中FeLV - A致病性最低，分布最广。相反，FeLV - A与内源性逆转录病毒序列的重组产生了B型变体，它与白血病和淋巴瘤的发生有关。FeLV主要通过个体间的梳理行为传播，促进了其传播和循环。本研究的目的是对B型亚型进行特征描述，并分析哥伦比亚猫样本中与病毒感染相关的危险因素。为此，从安蒂奥基亚四个市的151只猫的头静脉或颈静脉采集血样，并收集年龄、性别和来源地的数据。对pol基因区域（306 bp）进行PCR，只有FeLV阳性的猫样本对env基因（1400 bp）进行第二次PCR。仅对env阳性的PCR产物进行测序，并进行系统发育和重组分析。使用逻辑回归计算每个变量（年龄、性别和来源地）的比值比（OR）。FeLV总体阳性率为33.77%，发现雄性与FeLV感染之间存在关联（OR = 2.23，p = 0.038），来源地与FeLV感染之间也存在关联（OR = 0.22，p = 0.035）。在所有样本中，只有11份（7.3%）扩增出FeLV - B，其中7份来自布里蒂卡，4份来自麦德林。重组分析证实所有序列均属于FeLV - B亚型，且为独特的重组体。该病毒在研究区域的分子存在表明这种逆转录病毒的传播仍然活跃。此外，来源地和雄性是FeLV感染的危险因素。最后，观察到FeLV阳性率有所上升，虽然B型变体在每只猫中都是重新产生的，但持续进行健康监测至关重要，尤其是在远离主要城市中心的地区。
