HIV/AIDS has posed an increasingly serious issue in China. In recent years, Chinese government has taken further intensified efforts to combat HIV/AIDS with high-level political commitment, supportive policy development, increased financial allocation, large-scale of governmentled initiatives, expanded international cooperation and great involvement of non-governmental organizations. Meanwhile gaps and challenges coexist impacting the implementation and the results of national HIV/AIDS programs. Thus, further government efforts are needed to improve and tailor the actions to meet the requirement of HIV/AIDS control in China.

Social network is a type of structure of social actors by their relations.Human immunodeficiency virus(HIV)transmits among population followed a type of structural and non-random mode,so we use social network concept and socio-metric analysis to conduct HIV related research that may enhance the understanding and prediction of HIV epidemic patterns and intervention measures.

This article reviews studies regarding "sero-sorting" among MSM living with HIV/AIDS,for the purpose of analyzing its positive impact on reducing HIV incidence and promoting HIV testing and sero-status disclosure to sex partners. Contradictive issues in terms of implementing "sero-sorting" are also discussed in this article to provide some information for further conducting MSM related interventions in China.

Sexual behavior of HIV-positive men who have sex with men (MSM) are different from the general MSM. HIV-positive men who know their HIV status are more likely to have sex with positive partner and to engage in receptive anal intercourse as a self harm reduction approach than the general MSM. It is important to strengthen behavioral interventions so as to practice safe sexual behavior to prevent HIV transmission and maintain high life quality among HIV-positive MSM.

In China,compared with other high risk population, drug users have higher rates of HIV infection, HCV infection and co-infection of HIV and HCV. These infections are major factors influencing this population’s health status. By describing and comparing the status of HIV infection, HCV infection, and HIV/HCV co-infection among drug users in China in terms of geographic distribution, demographic distribution, analyzing the interaction of the two viruses and the velocity of transmission and pathogenicity, this article provides recommendation for prevention and control of HIV and HCV.

Over past three decades,many prevention strategies have been proven effective in reducing human immunodeficiency virus (HIV) transmission.However,none of these strategies alone are effective to stop the spread of HIV.This review discusses a few key prevention strategies,including testing,harm reduction,prevention,prophylaxis,and modern communication strategies.We argue that although there are great challenges remaining to stop HIV transmission via sexual contact and injecting drug use routes,the combination of these effective strategies,control HIV epidemic can be achieved.

The asymptomatic carrier state of COVID-19 has become a topic of concern for preventing a possible epidemic rebound. This review describes and defines the COVID-19 asymptomatic carrier state and outlines methods for identifying counting and reporting these cases. The author elaborates that the asymptomatic carrier state can be further divided into asymptomatic infection and pre-symptomatic infection after extended follow-up based on the nature of disease progression. The author presents the limited available data about infectiousness of asymptomatic and pre-symptomatic cases and their possible contributions to the overall epidemic of COVID-19 observed so far in China. Challenges of a possible second epidemic wave of COVID-19 caused by asymptomatic and pre-symptomatic cases are discussed and suggestions for control strategies and scientific research are provided.

We used nationally reported cases (NCAIDS/China CDC,2016) and published literature to summarize up-to the end of 2015 epidemiologic trends in the HIV/AIDS epidemic in China.HIV-positive cases are distributed unevenly with most infections found in southwest China and the most affected population being men who have sex with men.Transmission mode of HIV infection has shifted from drug injection to sexual contact,which accounts for 95％ of total reported cases.Two thirds of cases are from heterosexual transmission.Transmission pattern varies greatly throughout China.Some provinces in China reported heterosexual transmission accounted for over 90％ of cases while other provinces reported homosexual transmission accounted for over 80％ of cases.Patterns of heterosexually acquired HIV also vary widely,with 80％ of cases attributed to commercial sex in some provinces,while in other provinces non-commercial extramarital sex accounted for over 70％ of cases.Significant increase in HIV infection was observed among young students aged 15-24.China has successfully controlled blood transfusion-and injecting drug-related transmissions of HIV.Homosexual and non-commercial extramarital heterosexual transmissions have become new challenges for China's HIV/AIDS program.Urgent adoption of the UNAIDS/WHO 90-90-90 target will help overcome these new challenges.

OBJECTIVETo understand where and how drug-using and sexual behaviors occurred among drug users.

METHODSTwenty-five drug users were recruited from detoxification centers and communities. In-depth interview was used to collect information about drug-using and sexual behaviors. Each subject was interviewed separately and privately for about 2 - 3 hours.

RESULTSMost drug users shifted from oral taking drugs to injecting drugs in order to reduce economic burden and look for "high feeling". Reasons for not injecting among few drug users included 'perceiving information on harm of injection', 'over-dose death' or 'infection with HIV'. Most drug users knew that HIV transmit through sharing needles or having sexual intercourse without using a condom. However, needles were shared at night when drug or needles were scarce. Promiscuous sexual relationship was common among drug users. Most female drug users had engaged in prostitution but few used condoms.

CONCLUSIONHigh-risk drug injecting behaviors and high-risk sexual behaviors were prevalent among drug users despite knowledge on HIV transmission and prevention. Thus, education alone would not work unless specific intervention programs are taken.