Objective To analyze the clinical and laboratory features of patients with mild and severe HFMD to identify early predictive or diagnostic markers for severe cases.
Methods Samples of feces, nasopharyngeal-swab specimens, peripheral blood, serum and cerebral spinal fluid were collected. Postmortem pathological examination was conducted on 2 dead patients with complication due to neurogenic pulmonary edema. Reverse transcription-polymerase chain-reaction (RT-PCR), culture and isolation of enterovirus 71 (EV71) were performed to detect EV71 infection. Both univariate and multivariate logistic analysis were used to identify factors associated with severe cases.
Results EV71 was mainly responsible for HFMD. In this study, 5 isolated EV71 strains belonged to C4 gene subtype. Compared with mild patients, EV71-RNA detection rate was higher and CoxA16 detection rate was lower among severe patients (P < 0.01). Inflammatory cell infiltration in the lung, cardiac and liver tissues were mild by postmortem pathological examination. It was found that body temperature, vomitting, limb tremor, neutrophil, blood glucose and EV71 infection were significantly related to the severe cases by univariate logistic analysis. However, after multivariate logistic regression analysis, only vomiting (OR 16.1, CI 2.3-110.5, P < 0.01) and limb tremor (OR 117.6, CI 13.8-1004.5, P < 0.01) were significantly and independently correlated with the severe cases.
Conclusions EV71 was mainly responsible for HFMD, particularly for severe cases. Vomiting and limb tremor were predictive markers for severe cases.