Effects of HIV status notification on reducing the risk of sexual transmission of HIV in China

Background The risk of HIV sexual transmission is much higher among people unaware of their HIV status than among those aware. Only a few studies have indicated that the incidence of unsafe sex can be reduced when people know their HIV status. This study was to investigate this effect in China. Methods A cohort study consisting of two surveys was conducted at two different times among a group of people living with HIV/AIDS, whose status was newly diagnosed with HIV via sexual contact, in Shanghai, Chongqing, and Kunming. The first survey was conducted among 823 people tested positive for HIV before notifying them of the HIV status. The second survey was conducted among 650 HIV-positive people at six months following the first survey （after notification of HIV status）. The scope of survey covered unsafe sex practices, number of unsafe sexual partners, and frequency of unsafe sexual behaviors over the prior six months. Unsafe sex is defined as unprotected anal or vaginal sex with partners who are HIV positive or whose HIV status is unknown. Results The proportion of unsafe sex was reduced by about 85% after HIV status notification. The risk of HIV sexual transmission was 15 times higher among persons unaware of their HIV status than among those aware. Approximately 95% of new sexually transmitted HIV infections stemmed from 56% of the infected persons unaware of their HIV status in China. Conclusion Timely HIV status notification has the potential to significantly reduce unsafe sex among HIV-infected persons and reduce the risk for HIV transmission via unsafe sex.

A Simulation Model for Sexual and Vectorial Transmission of Zika Virus(ZIKV)

Nowadays the Zika virus (ZIKV) has been one of the most studied vector-borne diseases due to the considerable outbreaks that have generated around the world as well as due to the new transmission mechanisms and health complications originated. According to statistics of the INS-Colombia for July 2016, 68% of the population infected by ZIKV (confirmed cases) are pregnant women. Furthermore, the Quindío department belongs to the states with more than 50% of the total infected persons being pregnant women. Taking into account those characteristics, a theoretical model is proposed and analyzed to describe the population dynamics considering the sexual and vectorial transmission of ZIKV, with special emphasis in the consequences of the non-vectorial transmission in the population. The obtained results with simulations through the beta parameter indicate that the probability of sexual transmission between susceptible women and infected men points out the importance of campaigns to inculcate prevention measures for the safe sexual relationships between ZIKV infected population.

Infectivity and Risk Factors of Hepatitis C Virus Transmission Through Sexual Contact

HCV infection among heterosexuals with multiple partners and family members of patients with hepatitis C, and FICV RNA in the body fluid of these patients were investigated. The results showed that the HCV infection in heterosexuals with multiple partners, which was related to sexual activity, was much higher than that of healthy pregnant women. The HCV RNA in the saliva, semen or vaginal discharge of patients with hepatitis C was at detectable level. Among the patient's relatives, none of the children but 2 spouses were found to be infected with HCV. We concluded that sexual contact might play some role in HCV transmission.

Health-related attitudes and risk factors for sexually transmitted infections of Chinese women who have sex with women

Background Previous studies have shown evidence of health-related risk behaviors among women who have sex with women （WSW）, such as sex with men, multiple bisexual partners, and drug use. Women who have sex with women have also been known to avoid routine physical examinations and conceal their same-sex history from physicians, which can affect their ability to receive an accurate diagnosis and treatment. No previous research has targeted women who have sex with women in China. We sought to describe women who have sex with women in China and explore risk factors for their reproductive tract infections （RTI）/sexually transmitted infections （STI）. Methods Participants were recruited through outreach in venues and online for a cross-sectional study. Data were collected using interviews and laboratory tests. Results We recruited 224 women who have sex with women. In the year preceding their participation in the study, 92% （206/224） of women reported sexual relations with women. The RTI rates were： gonorrhea （15.8%）, chlamydia （3.5%）, syphilis （0.5%）, bacterial vaginosis （14.4%）, hepatitis B virus （HBV） （0.9%）, hepatitis C virus （HCV） （0.5%）, and candidiasis （6.9%）. No HIV or herpes simplex virus （HSV） positive cases were detected. Factors associated with gonorrhea infection were non-Beijing local residency （odds ratio （OR）=2.1, 95% confidence interval （C/）： 1.2-3.8） and genital-genital contact （OR=3.1, 95% CI： 1.3-7.2）; factors associated with curable STI （excluding bacterial vaginosis, candidiasis, HBV and HCV） were non-Beijing local residency （OR=1.9; 95% CI： 1.2-3.0） and bleeding during or after sex （OR=18.1; 95% CI： 5.2-62.6）; and the factor associated with RTI （including all the infections tested） was bleeding during or after sex （OR=37.8, 95% CI： 11.2-127.4）. Conclusions Behaviors that may cause RTI/STI exist among Chinese women who have sex with women. Researchers should consider these behaviors when planninq correspondin.q prevention and interventions.

Viral infections and implications for male reproductive health

Viral infections have haunted humankind since times immemorial.Overpopulation,globalization,and extensive deforestation have created an ideal environment for a viral spread with unknown and multiple shedding routes.Many viruses can infect the male reproductive tract,with potential adverse consequences to male reproductive health,including infertility and cancer.Moreover,some genital tract viral infections can be sexually transmitted,potentially impacting the resulting offspring's health.We have summarized the evidence concerning the presence and adverse effects of the relevant viruses on the reproductive tract(mumps virus,human immunodeficiency virus,herpes virus,human papillomavirus,hepatitis B and C viruses,Ebola virus,Zika virus,influenza virus,and coronaviruses),their routes of infection,target organs and cells,prevalence and pattern of virus shedding in semen,as well as diagnosis/testing and treatment strategies.The pathophysiological understanding in the male genital tract is essential to assess its clinical impact on male reproductive health and guide future research.

Mathematical model of zika virus dynamics with vector control and sensitivity analysis

In this paper,we have developed and analyzed a deterministic Zika model considering both vector and sexual transmission route with the effect of human awareness and vector control in the absence of disease induce death.To formulate the model,we assume that the Zika virus is being first transmitted to human by mosquito bite,and then it is being transmitted to his or her sexual partner.The system contains at most three equilibrium points among them one is the disease free and other two are endemic equilibrium points,exists under certain conditions.The theoretical analysis shows that the diseases-free equilibrium is locally and globally asymptotically stable if the basic reproduction number is less than one.Theatrically we have established that endemic equilibrium point which is locally asymptotically stable if the basic reproduction number is greater than one.The system exhibits backward bifurcation when the transmission probability per biting of susceptible mosquito with infected humans crosses the critical value.We estimate the model parameters and validate the model by fitting the model with the reported Zika infected human data from 1 to 36 week of 2016 Zika outbreak in Colombia.Furthermore,using the normalised forward sensitivity index method we have established that the model parameter mosquito biting rate,recruitment rate of mosquito,transmission probability per biting of Susceptible(infected)humans with infected(susceptible)mosquito,rate of awareness in host population,recovery rates of infected human are most sensitive parameters of the considered Zika model.Lastly,some conclusions are given to control the spreading of the Zika disease.

Assessment of SARS-CoV-2 RNA shedding in semen of 36 males with symptomatic,asymptomatic,and convalescent infection during the first and second wave of COVID-19 pandemic in Italy

The severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)receptor,angiotensin-converting enzyme 2(ACE2),has been identified in the human testis,but the risk of transmission of SARS-CoV-2 through sexual intercourse still needs to be defined.The goal of our study was to determine if SARS-CoV-2 is detectable in the semen of patients suffering or recovering from coronavirus disease-19(COVID-19),still testing positive at nasopharyngeal swabs but showing mild or no symptoms at the time of sampling.Detection of SARS-CoV-2 RNA in semen was performed by real-time reverse transcriptase-polymerase chain reaction(RT-PCR)and nested PCR targeting open reading frame(ORF)1ab.Medical history of the enrolled patients was taken,including COVID-19-correlated symptoms,both at the time of diagnosis and at the time of interview.Results of real-time RT-PCR and nested PCR in semen showed no evidence of SARS-CoV-2 RNA in the 36 patients suffering or recovering from COVID-19 but still positive in a nasopharyngeal swab,from over 116 patients enrolled in the study.SARS-CoV-2 detection and persistence in semen would have an impact on both clinical practice and public health strategies,but our results would suggest that SARS-CoV-2 is not present in the semen of men recovering from COVID-19.

HIV microbicides： innovation and challenge

According to Joint United Nations Program on HIV/AIDS （UNAIDS） report in 2009, the estimated number of people living with HIV-1 is 33.4 million, and half of the infected adults （aged 15-49 years） are women, who acqluired HIV-1 mainly through heterosexual exposure. In China, HIV-1 transmission through sexual contact has also increased rapidly, and has reached over 70% in overall cases; heterosexual transmission accounted for 40% and men who had sex with man （MSM） for 32.0%.