Surveillance and Analysis of Plague Epidemic - China, 2010-2024.

INTRODUCTION

Plague, caused by Yersinia pestis, is a class A infectious disease in China. In order to address the practical requirements of plague prevention and control, this study conducted a systematic analysis based on the national surveillance data from 2010 to 2024.

METHODS

Data on human and animal plague epidemics were collected from the National Plague Prevention and Control Management Information System and analyzed using descriptive epidemiological methods.

RESULTS

As of 2024, 12 types of natural plague foci have been identified in China. Between 2010 and 2024, 33 human plague cases and 14 deaths were reported nationwide. Geographically, cases were concentrated in Inner Mongolia (15, 45.5%), Xizang (8, 24.2%), and Gansu (6, 18.2%). By focus type, cases originated primarily from Marmota himalayana (16, 48.5%), Meriones unguiculatus (15, 45.5%), and Rattus flavipectus (2, 6.1%). Pneumonic plague was most common (15, 45.5%), followed by bubonic (10, 30.3%), septicemic (7, 21.2%), and intestinal plague (1, 3.0%). Animal plague epidemics persisted nationwide, with active outbreaks in foci of M. himalayana, Marmota baibacina, Spermophilus undulatus, and Meriones unguiculatus. Bacterial isolation positivity rates in animals and insects were 0.05%-0.13% and 0.04%-0.11%, respectively, while Indirect Hemagglutination Assay (IHA) and Reverse Indirect Hemagglutination Assay (RIHA) positivity rates were 0.08%-0.25% and 0.09%-2.18%, respectively. Currently, Polymerase Chain Reaction (PCR) testing has been implemented in some regions, with positivity rates of 0.80% in animals and 1.59% in insects in 2024.

CONCLUSIONS

The current plague epidemic situation in China is characterized by "sporadic human cases, active animal epidemics in some foci." It is recommended to strengthen targeted surveillance, promote PCR-based screening, and enhance cross-provincial coordination.