Abstract: Objective To understand the characteristics of status thymicolymphaticus cases sudden death after vaccination and provide advice for its prevention and control. Methods Sudden death of cases with status thymicolymphaticus happened in Fengtai 2010 are reported and after searching for all the sudden deaths associated with vaccination from 1986 to 2010 nearly 25 years in China published in journals, all the cases were carefully analyzed for related characteristics. Results Besides this case, there were totally 9 cases reported during 1986~2010, 6 boys and 3 girls. The youngest was 3 months and the oldest was 2 years and 11 months. Three cases were vaccinated with 2 or more vaccines and 5 cases were vaccinated with DPT vaccines. The shortest time between vaccination and death was about 1 hour, the longest was 19 hours. Autopsy results showed different extents of thymus enlargement, lymphoproliferation, many had visceral edema and congestion. Conclusion The diagnosis of status thymicolymphaticus is difficult, and usually confirmed after the death of patients. Pediatricians and radiologists should be careful in reading pediatric vertical chest X-ray taken for the thymus, and use the heart-thymus-thorax ratio to measure the size of the thymus. If there is any abnormality in the ratio, the child should be contraindicated for vaccination in order to reduce deaths possibly associated with vaccination.

Key words: status thymicolymphaticus, immunization, sudden death