Impact of African swine fever virus genotype II on the porcine female reproductive system.

African swine fever virus (ASFV) genotype II is a highly virulent pathogen; however, its effects on the female reproductive system remain poorly understood. This study investigated the pathogenesis of ASFV genotype II in female pigs, focusing on viral dynamics and reproductive tissue damage. Pigs were intramuscularly inoculated with a highly pathogenic ASFV strain (103 HAD50). Clinical signs developed rapidly, with fever exceeding 41 °C at 3-4 days post-infection (dpi), followed by 100% mortality within 9 dpi. Viraemia was detected at 3 dpi, peaked at 6 dpi, and remained high until death, indicating rapid systemic dissemination. ASFV-specific antibodies were undetectable at 6 dpi, with only limited seroconversion observed at the terminal stage. ASFV DNA was detected in all reproductive organs (real-time PCR Ct values: 21.89-27.9). Severe gross and histopathological lesions were identified, including vascular congestion, haemorrhage, inflammatory infiltration, endometrial desquamation, glandular necrosis, and ovarian follicular degeneration. The co-occurrence of high viral loads and marked tissue damage, particularly in the ovaries and endometrium, indicates direct viral involvement in reproductive pathology. These findings demonstrate that ASFV genotype II causes rapid systemic infection and significant reproductive tissue damage, highlighting its potential impact on reproductive performance in swine.