Sato K, Yamashita T, Sakae K, Suzuki Y, Ishikawa N, Nishimura Y
Aichi Prefectural Institute of Public Health, Nagoya, Japan.
J Infect. 1998 Sep;37(2):123-6. doi: 10.1016/s0163-4453(98)80165-5.
In 1994, an outbreak of echovirus type 33 (EV33) infection occurred in a maternity hospital in Japan. Nine new-born babies were infected, some presenting symptoms of encephalitis or disseminated intravascular coagulopathy. EV33 was isolated from the faeces or cerebrospinal fluid of all seven of the patients sampled, and serum antibody titres against EV33 were significantly elevated in the convalescence phase sera in all cases.
To study what public health situations EV33 may become a serious pathogen for new born babies, serum EV33 antibody positivity in the general population was examined. Sera were obtained 649 samples before the outbreak, and 344 samples after the outbreak from aged 7 days to 65 years old.
The average positive rate was 12.0% and the rate increased depending on age. Comparison of positive rates before and after this outbreak showed no increase in any age group. However, the positive rate was found to average only 5.6% in persons aged 16-30 years old, including pregnant women. This low positive rate in young adults would result in a lack or only a low level of antibodies in newborn babies.
In conclusion, our findings suggest that EV33 infection in the new-born baby with no or low level of maternal neutralizing antibody may cause serious symptoms.
1994年，日本一家妇产医院发生了33型肠道病毒（EV33）感染疫情。9名新生儿被感染，部分出现脑炎或弥散性血管内凝血症状。从所有7例采样患者的粪便或脑脊液中分离出了EV33，所有病例恢复期血清中针对EV33的血清抗体滴度均显著升高。
为研究EV33在何种公共卫生情况下可能成为新生儿的严重病原体，对普通人群的血清EV33抗体阳性情况进行了检测。在疫情爆发前采集了649份7天至65岁人群的血清样本，疫情爆发后采集了344份。
平均阳性率为12.0%，且阳性率随年龄增长而升高。此次疫情前后阳性率的比较显示，各年龄组均未升高。然而，在包括孕妇在内的16至30岁人群中，阳性率平均仅为5.6%。年轻人中如此低的阳性率会导致新生儿缺乏抗体或抗体水平较低。
总之，我们的研究结果表明，母体中和抗体水平无或低的新生儿感染EV33可能会导致严重症状。
