African swine fever (ASF) causes a contagious hemorrhagic disease in all ages of pigs without sex predilections. The objective of this study was to determine the age-related viral loads and severity of systemic pathological lesions among three different swine group ages (weaned pigs, fattening pigs, and sows) during a recent outbreak of acute ASF in Vietnam. Age-related viral loads were determined in 5 major organs (lung, liver, spleen, kidney, and lymph node) by immunohistochemistry as well as in the blood by real-time polymerase chain reaction (PCR). Age-related systemic pathological lesions were analyzed in the listed organs among three age groups.

Weaned pigs had significantly (p < 0.05) higher levels of viral loads in their lung, liver, lymph nodes and blood than in those of fattening pigs and sows. Fattening pigs had significantly (p < 0.05) higher scores of macroscopic lung and lymphoid lesions, and microscopic liver lesions compared with those of weaned pigs and sows. The results of this study demonstrated that viral loads were age-related in acute naturally occurring ASF but the severity of pathological lesions was not correlated with the level of viral loads in the five major organs.

非洲猪瘟 (ASF) 在没有性别偏好的所有年龄的猪中引起一种传染性出血性疾病。本研究的目的是确定越南最近爆发的急性 ASF 期间三个不同猪群（断奶猪、育肥猪和母猪）的年龄相关病毒载量和全身病理病变的严重程度。通过免疫组织化学测定了 5 个主要器官（肺、肝、脾、肾和淋巴结）中与年龄相关的病毒载量，并通过实时聚合酶链反应 (PCR) 测定了血液中的病毒载量。分析了三个年龄组列出的器官中与年龄相关的全身病理病变。

断奶猪 的肺、肝、淋巴结和血液中的病毒载量水平显着高于育肥猪和母猪（p < 0.05）。 与断奶猪和母猪相比，育肥猪的宏观肺和淋巴病变以及微观肝脏病变评分显着（p < 0.05）更高。这项研究的结果表明，在急性自然发生的 ASF 中，病毒载量与年龄相关，但病理病变的严重程度与五个主要器官中的病毒载量水平无关。