Analysis of Himalayan marmot distribution and plague risk in Qinghai province of China using the "3S" technology.

To provide guidance for plague surveillance and a reliable basis for plague prevention and control, we analyzed the habitat characteristics of Himalayan marmots, developed Himalayan marmot information collection system V3.0 based on global navigation satellite system (GNSS), remote sensing, and geographic information system ("3S") technology, and drew a predictive spatial distribution map of Himalayan marmots in Qinghai Province. Field survey data of 352 marmot plague sites in Qinghai Province were collected in 2014, and the data from 80 sample sites were included. The Himalayan marmot habitat characteristics were analyzed based on "3S" technology using five environment variables (elevation, slope, aspect, vegetation cover, and grass type) and the geographical coordinates. Himalayan marmot information collection system V3.0, which has been approved by the National Copyright Administration of the People's Republic of China (No.00764743), was used to draw a predictive spatial distribution map of Himalayan marmots in Qinghai province. Moreover, from 2015 to 2017, positioning data of the plague-foci and plague-free areas in Qinghai Province were collected using GNSS receptor for field validations to verify the accuracy of the marmot predictive spatial distribution map. Elevation, slope, vegetation cover, and grassland type were identified as important environmental factors that determine the spatial distribution of Himalayan marmots. The suitable range of environmental features was 3400-4600 m elevation, 5°-20° slope, 0.60-1.00 vegetation cover, and alpine meadows. The Himalayan marmot predictive spatial distribution map in Qinghai Province based on "3S" technology and marmot information collection system V3.0 had a spatial resolution of 30 m. Field validation in areas of Qinghai Province revealed a prediction accuracy and mean absolute error of 0.8669 and 0.1331, respectively, which indicated excellent prediction accuracy. This study greatly improved the work efficiency of plague surveillance and effectively reduced the work intensity of researchers. Application of "3S" technology and marmot information collection system V3.0 has improved the data collection efficiency, provided new technical means for plague investigation and research, and provided a reference for development of plague surveillance programs. The research results will play a positive role in promoting the improvement and perfection of plague prevention and control strategies in Qinghai province and even in China.

Tackling COVID-19: Insights from the Qinghai Province plague prevention and control (PPC) model.

Plague, caused by Yersinia pestis, is a natural focus infectious disease. In China, plague is classified as category A, with the highest risk and hazard among the infectious diseases. Qinghai used to be considered as one of the most serious areas of plague in China. In recent years, thank to the measures in eight aspects summarized as the "Qinghai model" which were adopted to prevent and control the human plague in Qinghai, Qinghai has not experienced any plague case reported for eight years. In early 2020, coronavirus disease 2019 (COVID-19) outbroke in China. The Qinghai model on plague was employed to deal with the COVID-19 emergency in Qinghai Province. The Qinghai Center for Disease Control and Prevention (Qinghai CDC) and hospitals, along with the departments of public security, animal husbandry and other departments, quickly tracked and treated the patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and started surveillance programs on close contacts timely. At present, the cure rate of patients has reached 100%, and close contacts have been effectively quarantined and tested to avoid the spread of COVID-19. The findings from the study suggest that the prevention and control measures undertaken in Qinghai Province might be effective in dealing with the category A infectious diseases such as COVID-19 and other diseases.

Serum cytokine responses in primary pneumonic plague patients.

The serum levels of interleukin-2 (IL-2), gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), IL-4, IL-6, and IL-10 of pneumonic plague patients were determined by enzyme-linked immunosorbent assay. IL-6 was the only elevated cytokine in the patients, and its level increased with a clear time course, indicating that IL-6 might be a prognostic marker for predicting the progression of plague.