Pathology of enterovirus 71 infection: an autopsy study of 5 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of fatal enterovirus 71 (EV71) infection.</p><p><b>METHODS</b>Autopsy was performed in 5 neonates died of EV71 infection. Tissue samples from major organs were collected, formalin-fixed and examined under light microscopy. Immunohistochemical study was carried out in selected examples.</p><p><b>RESULTS</b>Four of the 5 cases showed predominant changes in central nervous system, with encephalitis and encephalomyelitis identified mainly in brainstem and upper cervical spinal cord. Histologic findings included neuronal degeneration and necrosis, neuronophagia, perivascular cuffing and diffuse or nodular hyperplasia of macrophages/microglia. Cerebral edema, brain herniation and aseptic meningitis were also noted. The lungs showed mainly pulmonary congestion, neurogenic pulmonary edema and focal hemorrhage. There were minimal changes in the intestinal epithelium. The intestinal lymphoid tissue however was hyperplastic and associated with apoptosis of follicular center cells. The remaining case had cerebral edema and mild meningitis. The lung alveolar septa were thickened with lymphocytic infiltrates. Some alveolar cells were hyperplastic and associated with diffuse hyaline membrane formation. No specific abnormalities were identified in gastrointestinal tract. In all the 5 cases studied, there was enlargement of lung hilar and mesenteric lymph nodes, coupled with apoptosis of follicular center cells. In general, no significant pathologic changes were demonstrated in heart, liver and kidneys.</p><p><b>CONCLUSIONS</b>In fatal EV71 infection, the major pathologic changes lie in the central nervous system. The pulmonary lesions are mainly secondary in nature. The usual cause of death is cerebral edema complicated by brain herniation and pulmonary edema. It is also noteworthy that some cases show only lung damages, without classic neurologic changes.</p>

Molecular confirmation of enterovirus type 71 infection: a post-mortem study of two cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the diagnostic application of molecular detection of enterovirus type 71 (EV71) infection using post-mortem paraffin-embedded tissue.</p><p><b>METHODS</b>Two autopsy cases of EV71 infection were studied by histopathological and immunohistochemical methods. Reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the viral RNA in paraffin-embedded tissue samples.</p><p><b>RESULTS</b>Characteristic features of acute encephalitis were seen in the brain, with most prominent lesions found in the brain stem in both cases. Inflammatory cells were largely CD68-positive microglia with a few CD15-positive neutrophils in the areas of neuronal necrosis. The 5'-untranslated region of EV71 was detected in the medulla by RT-PCR using paraffin-embedded tissues of both cases. Sequencing analysis of the RT-PCR products showed 100% homology to the EV71 strain, recently submitted to the GenBank database from Fuyang, Anhui province.</p><p><b>CONCLUSIONS</b>Molecular detection of EV71 can be performed on formalin-fixed, paraffin-embedded tissue samples from fatally infected patients. Timely and accurate diagnosis of the infection by such molecular approach is crucial for the proper clinical and public health intervention.</p>