Post-EV71 vaccination outcomes in meningoencephalitis: no increased clinical severity compared with other enterovirus...

To assess clinical differences and prognosis between pediatric meningoencephalitis caused by EV71 and other enterovirus subtypes in the context of widespread EV71 vaccination, and to evaluate changes in the clinical profile of EV71 infection in the vaccine era.

We enrolled 160 children with enterovirus-associated meningoencephalitis admitted to Kunming Children's Hospital between January 2019 and August 2024. Patients were categorized into an EV71 group and an EV-others group based on etiology. Demographic, clinical, laboratory, and outcome data were collected.

Of the 160 cases, 75 (46.0%) were EV-unclassified, 45 (27.6%) EV-A6, 20 (12.3%) EV71, 14 (8.6%) EV-A16, and 9 (5.5%) EV-A10. No significant between-group differences in sex, age, or weight were found. The EV71 group had a longer duration of fever (median 3.5 days vs 2 days, P = 0.032) and a higher frequency of hand-foot vesicular lesions (20/20, 100% vs 99/140, 71%, P = 0.011). Laboratory results showed higher platelet counts and lymphocyte counts in the EV71 group. In contrast, CRP, ferritin, ALT, and CD16 + 56+ levels were lower in the EV71 group. CSF analysis showed significantly higher cell counts (55.5 vs 12 ×10⁶/L, P < 0.001) in the EV71 group. There were no significant differences in ICU admission, length of hospital stays, or mortality.

In the era of widespread EV71 vaccination, pediatric meningoencephalitis caused by EV71 no longer presents worse overall outcomes than other enterovirus subtypes. EV71 remains associated with a stronger central but weaker systemic inflammatory response, suggesting a distinct inflammatory profile. Continued surveillance and multivalent vaccine development are necessary.