Chest Radiography in Coronavirus Disease 2019 (COVID-19): Correlation with Clinical Course

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 and was declared a global pandemic by the World Health Organization on 11 March 2020. A definitive diagnosis of COVID-19 is made after a positive result is obtained on reverse transcription-polymerase chain reaction assay. In Singapore, rigorous contact tracing was practised to contain the spread of the virus. Nasal swabs and chest radiographs (CXR) were also taken from individuals who were suspected to be infected by COVID-19 upon their arrival at a centralised screening centre. From our experience, about 40% of patients who tested positive for COVID-19 had initial CXR that appeared "normal". In this case series, we described the temporal evolution of COVID-19 in patients with an initial "normal" CXR. Since CXR has limited sensitivity and specificity in COVID-19, it is not suitable as a first-line diagnostic tool. However, when CXR changes become unequivocally abnormal, close monitoring is recommended to manage potentially severe COVID-19 pneumonia.

Changes of proportion regarding consistent condom use and syphilis infection among low-fee female sex workers aged 35 and above / 中华流行病学杂志

Objective: To investigate the changes of proportion on both consistent condom use and syphilis infection among low-fee female sex workers aged 35 and above (LFSW), in order to provide evidence for targeted intervention strategies. Methods: A total of six cities-Liuzhou city and Pingnan couty of Guigang city of Guangxi Zhuang Autonomous Region, Jinghong city of Xishuangbanna Dai autonomous prefecture and Dali city of Dali Bai autonomous prefecture of Yunnan province, Zhangjiajie city and Jianghua Yao autonomous county of Yongzhou city Hunan province were involved in this study, with 60 eligible participants needed in each city, estimated through a pre-study. The first cross-sectional survey was completed from October 2012 to January 2013. Face-to-face questionnaire interview was carried out to collect information on socio-demography, work-related information and condom use situation. Blood was collected for syphilis testing. The second cross-sectional survey was carried out from June to September, 2015 under the same procedure. Results: A total of 371 and 403 eligible participants were included in the first and second survey, respectively. When comparing the two surveys, we noticed that the average age showed a slight change, from 42.4 years to 43.8 years old (t=3.537, P<0.001) and the average price for every commercial sex exchange increased from 36.8 RMB to 49.5 RMB (t=11.961, P<0.001). In the first survey, 46.9% (174/371) of the participants had more than two years of experience working as LFSW, compared to 61.3% (247/403) in the second survey (χ(2)=16.125, P<0.001). Also, 46.9% (174/371) of the participants consistently used condoms with clients in the past month in the first survey versus 64.3% (259/403) (χ(2)=23.641, P<0.001) in the second one. Rates of syphilis infection were found from 15.9% (59/371) in the first survey reduced to 7.2% (29/403) in the second survey (χ(2)=14.533, P<0.001). Conclusion: Compared with the first survey, the proportion of consistent condoms use showed an increase. Although the proportion of syphilis infection decreased in the second survey, the scope did not meet the criteria on syphilis, set by the government. Targeted intervention strategies on condom promotion and syphilis control should be implemented consistently in this population.

Survey on extramarital sexual behaviors and HIV infection in middle-aged and elderly people aged 50 and above in selected areas of Chongqing / 中华流行病学杂志

Objective: To know the situation of extramarital sexual behaviors and HIV infection in middle-aged and elderly people in Chongqing, and provide reference for AIDS prevention and treatment. Methods: From October to December 2017, a multi-stage sampling method was used to recruit middleaged and elderly people aged ≥50 years who lived in Dazu and Hechuan districts of Chongqing for at least one year, with a sample size of 410. Face-to-face questionnaires survey and HIV antibody test were conducted. Results: A total of 408 people were surveyed, including 313 males and 95 females aged 50-88 (64.93±9.03) years. The HIV infection rate was 1.47% (6/408), with the rate of 1.28% (4/313) in males and 2.11% (2/95) in females. The awareness rate of AIDS related knowledge was 37.50% (153/408). And 18.87% (77/408) of subjects surveyed reported extramarital sexual behaviors, 7.60% (31/408) reported extramarital sexual behaviors in the past half year, the constant condom use rate was 19.35% (6/31). The results of multivariate logistics model analysis on extramarital sexual behaviors showed that the prevalence in males were 39.51 times higher than that in females (OR=39.51, 95%CI: 5.03-310.30), 4.60 times higher in those who were unmarried, divorced or widowed than that in the married or cohabitants (OR=4.60, 95%CI: 1.50-14.05), 2.03 times higher in those with outside activities than those with individual activities (OR=2.03, 95%CI: 1.08-3.81) and 3.94 times higher in those with self-evaluation of emptiness of living state than that in those with engaged life (OR=3.94, 95%CI: 1.86-8.36). Conclusions: The prevalence of extramarital sexual behavior in middle-aged and elderly people in some counties and districts in Chongqing is high. The factors such as gender, marital status, leisure activities, and self-evaluation of living state were related to the prevalence of extramarital sexual behaviors in this population. The condom use rate in extramarital sexual behavior was low. It is necessary to take effective interventions in this population.