Objective:To study the prevalence and correlations of HIV infection among cross-border couples in the Dehong prefecture.Methods:A cross-sectional mass screening study with questionnaire interview and HIV testing was conducted among 17 594 registered cross-border couples from May 2017 through June 2018.Results:Among 32 400 participants, the overall prevalence of HIV infection was 2.27% (736/32 400), 2.44% (375/15 372) for Chinese citizens, and 2.12% (361/17 028) for foreign spouses. Among all the 13 853 couples with both spouses receiving HIV testing, 13 415(96.84%) were seroconcordant-negative couples, 142(1.03%) were serocondordant-positive couples, and 296(2.13%) were serodiscordant couples, including 167(1.20%) couples with positive husband and negative wife and 129(0.93%) couples with positive wife and negative husband. Multiple logistic regression analyses indicated that HIV infection was associated with drug use and risky sexual behaviors for male spouses. In contrast, HIV infection was associated with risky sexual behaviors for female spouses.Conclusion:The prevalence of HIV among cross-border couples in Dehong prefecture is high, underscoring the urgent need to scale up HIV testing, prevention, and behavioral intervention.

ObjectiveTo investigate a cluster epidemic of coronavirus disease 2019 （COVID-19） infections in a school in Longchuan County， Yunnan Province， and further guide the prevention and control of COVID-19 in the border area. MethodsAccording to the Protocol on Prevention and Control of Novel Coronavirus Pneumonia （8th Edition）， an epidemiological investigation was performed on all COVID-19 cases to collect the information on demographics， onset， diagnosis and treatment， prognosis， and epidemiological history. Close contacts were also tracked to determine the transmission chains. ResultsIn this cluster epidemic， a total of 37 COVID-19 cases were identified， including 32 females and 5 males aged from 13 to 25 years， who were 35 students and 2 teachers. The student cases were found in four classes of two grades. Furthermore， gene sequencing showed that all cases had been infected with delta variants， belonging to the same transmission chain that was not related to the previous epidemics in Dehong Prefecture. In additionally， a total of 2 127 close contacts were found. After 21 days of centralized quarantine for medical observation， all close contacts tested negative for SARS-CoV-2. In the COVID-19 cases， only one case remained positive for SARS-CoV-2， while the other 36 cases were successfully treated and became negative. ConclusionThis school cluster is caused by the border villagers who contacted the water polluted with SARS-CoV-2. It warrants more strict management of students from border villages and their belongings to prevent similar epidemics in school settings.