Evaluation of the pathogenicity of culex flavivirus and quang binh virus in mice

As knowledge of Insect-Specific Viruses (ISVs) remains limited, this study aimed to investigate whether Culex Flavivirus (CxFV) and Quang Binh virus (QBV) which were isolated from mosquitoes collected in an Giang province, affect the health of mice following infection.Six-to eight-week-old BALB/c mice were infected with QBV or CxFV.For each virus, mice were divided into three groups (n=5) receiving different inoculation doses (0.2 mL, 0.15 mL, or 0.1 mL per mouse), along with a control group administered DMEM.Each treatment was replicated three times, and animals were observed for 28 days.Body weight was recorded before inoculation and weekly thereafter (days 7, 14, and 28 post inoculation).One mouse from each group was necropsied weekly to assess gross pathology.Throughout the experiment, all infected mice maintained normal feeding and activity, with no clinical symptoms such as lethargy, anorexia, or coat deterioration.Weight data showed a steady increase in both infected and control groups, with the most rapid gain in the first week and gradual increases until day 28.Necropsy revealed no gross abnormalities in the brain or internal organs of infected mice compared with controls.Significance, and The absence of clinical signs and pathological lesions indicates that QBV and CxFV did not affect mammalian health under the tested conditions.These findings support the classification of ISVs as non-pathogenic to mammals.