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Studies have shown that sexual transmission, both heterosexually and homosexually, is one of the main ways of HBV infection. Based on this fact, we propose a mathematical model to study the sexual transmission of HBV among adults by classifying adults into men and women and considering both same-sex and opposite-sex transmissions of HBV in adults. Firstly, we calculate the basic reproduction number $ R_{0} $ and the disease-free equilibrium point $ E_{0} $ . Secondly, by analysing the sensitivity of $ R_{0} $ in terms of model parameters, we find that the infection rate among people who have same-sex partners, the frequency of homosexual contact and the immunity rate of adults play important roles in the transmission of HBV. Moreover, we use our model to fit the reported data in China and forecast the trend of hepatitis B. Our results demonstrate that popularizing the basic knowledge of HBV among residents, advocating healthy and reasonable sexual life style, reducing the number of adult carriers, and increasing the immunization rate of adults are effective measures to prevent and control hepatitis B.

The aim of the study was to explore the common misconceptions about HIV as a determinant of the HIV epidemic growth and as a factor affecting disease outcomes.Materials and methods. The study involved 136 persons (50 persons with blood-borne infection route, 50 persons with heterosexual transmission, 36 persons without HIV). As research methods a special clinical map was used, as well as an author’s questionnaire, which allows to register the characteristics of risky behavior in relation to infection and the characteristics of the life situation of the disease. Statistical data processing included the definition of primary statistics, the Fisher criterion, ANOVA.Study results. A frequent occurrence of distorted representations about HIV was noted in all groups. It has been established that people living with HIV and healthy respondents do not differ in the frequency of HIV testing. The features of the life situation of the disease related to the method of the disease transmission were revealed in the study. It has been established that people living with HIV with different infection route differ in the frequency of late HIV diagnosis, the presence of AIDS, refusal of treatment. The results determine the need to increase public awareness of the disease and correct distorted representations about it.

We report a case of HIV-1 superinfection in a patient with established HIV-2 infection. The patient was not taking antiretroviral therapy, in line with criteria in national guidelines, and reported no risk for infection with HIV-1. This case serves as a reminder that patients infected with HIV-2 remain susceptible to HIV-1 infection. The protective effect of antiretroviral treatment against HIV-1 infection should be a consideration in treatment decisions for individuals with HIV-2 infection.

Injection drug use and heterosexual transmission from male key populations to their female partners have been the dominant modes of HIV transmission in Vietnam. A demonstration project was conducted to offer immediate antiretroviral therapy (ART) (regardless of CD4 cell count) to HIV-seropositive partners in serodiscordant couples. During March–December 2013, couples HIV testing and counselling (HTC) and immediate ART were offered in two drug use-affected provinces. Of 256 couples receiving couples HTC, 146 (57%) were serodiscordant; 134 (92%) seropositive partners initiated ART irrespective of CD4 cell count. Of these, 86% were male; 57% reported ever using illicit drugs; median CD4 cell count before ART initiation was 374 cells/mm3. Consistent condom use was reported by 58, 70 and 71% among HIV-positive partners at months 0, 3 and 12. At 12 months after ART initiation, 119 (89%) HIV-positive partners were retained in care; 96 (95% of those tested) achieved viral suppression (

Background Heterosexual transmission has contributed greatly to the current HIV-1 epidemic in China. However, the HIV-1 genetic characteristics in the heterosexually transmitted population in Jiangsu province remained unclear. Methods A molecular epidemiological investigation on heterosexual transmission of HIV-1 was conducted across Jiangsu province. 301 HIV-1 patients infected through heterosexual transmission were involved in this study. The epidemiological information was investigated by trained staff via face-to-face interviews. Blood samples were taken from each patient, HIV-1 RNA was extracted from the plasma, and used for amplifying the gag and env genes followed by further products sequencing. The genotypes of HIV-1 were determined using phylogenetic tree analyses in the neighbor-joining method. Results A total of 262 samples were successfully taken for genotyping. The main subtypes which accounted for 90.5% of all HIV-1 strains are CRF01_AE (45.4%), CRF07_BC (21.4%), subtype B (12.6%), CRF08_BC (11.1%). Minor subtypes were also detected, such as CRF68_01B, subtype C, CRF55_01B, CRF02_AG and subtype A. Time trend analysis suggested the prevalence of subtype B and CRF08_BC decreased gradually, but the prevalence of CRF01_AE increased over time. A relatively higher prevalence of CRF07_BC in Central Jiangsu and subtype B were detected in South Jiangsu, while a relatively lower prevalence of subtype B and CRF08_BC were detected in Central Jiangsu. Conclusion Complex and unbalanced HIV distribution characteristics suggest that heterosexual transmission of HIV needs to be taken seriously. It is necessary to implement more effective and comprehensive intervention strategies for further control of HIV-1 dissemination.

The global HIV policy environment changed dramatically for same-sex practising men from 2000 to 2020. These changes were especially pronounced in African countries, where research, prevention, and surveillance focused almost exclusively on heterosexual transmission for the previous 20 years. In stark contrast to the beginning of the century, by 2020, nearly all African countries identified same-sex practicing men as key populations in need of targeted HIV prevention and surveillance to control their epidemics. Drawing on a rich collection of archival, qualitative interview, and quantitative data, this chapter illuminates the global policy changes and initiatives that facilitated the recognition of the burden of HIV among same-sex practising men in African contexts, examines whether and when African countries have integrated same-sex practising men into the national HIV responses, and identifies key drivers of both inclusion and resistance to inclusion of same-sex practising men in the national HIV responses of African countries.

Background Although effective, some oral pre-exposure prophylaxis (PrEP) users face barriers to adherence using daily pills, which could be reduced by long-acting formulations. Long-acting cabotegravir (CAB LA) is a potential new injectable formulation for human immunodeficiency virus (HIV) PrEP being tested in phase III trials. Methods We use a mathematical model of the HIV epidemic in South Africa to simulate CAB LA uptake by population groups with different levels of HIV risk. We compare the trajectory of the HIV epidemic until 2050 with and without CAB LA to estimate the impact of the intervention. Results Delivering CAB LA to 10% of the adult population could avert more than 15% of new infections from 2023 to 2050. The impact would be lower but more efficient if delivered to populations at higher HIV risk: 127 person-years of CAB LA use would be required to avert one HIV infection within 5 years if used by all adults and 47 person-years if used only by the highest risk women. Conclusions If efficacious, a CAB LA intervention could have a substantial impact on the course of the HIV epidemic in South Africa. Uptake by those at the highest risk of infection, particularly young women, could improve the efficiency of any intervention., Using injectable cabotegravir for HIV prevention could, if efficacious, be a valuable addition to the portfolio of HIV prevention options in South Africa and could have a substantial impact on the progression of the epidemic.

ObjectivesTrichomoniasis is the most prevalent curable STI globally, with the highest incidence and prevalence in sub-Saharan Africa (sSA). STIs have largely been associated with an increase in HIV acquisition. Our objective was to assess the existing literature available in English regarding the association of Trichomoniasis and HIV-1 acquisition.MethodsThe review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under number CRD42018082702. We searched MEDLINE, Embase and Scopus databases to collect articles measuring the association of Trichomonas vaginalis infection and HIV acquisition and performed a meta-analysis and qualitative synthesis of the literature.ResultsWe identified 1806 unduplicated citations, of which 18 papers and 1 conference abstract were eligible for inclusion in the review after applying our inclusion and exclusion criteria. All the studies included in the systematic review had been carried out in sSA. The articles reported various measures of effects, namely: HRs, rate ratios, risk ratios and ORs. In a meta-analysis restricted to 11 studies reporting HR, individuals infected with T. vaginalis were 1.5 times more likely to acquire HIV compared with individuals not infected with T. vaginalis (95% CI 1.3 to 1.7; pConclusionsT. vaginalis is an important factor in HIV acquisition especially in sSA where the prevalence of both T. vaginalis and HIV-1 are high. This systematic review and meta-analysis confirms the evidence that infection with T. vaginalis augments HIV acquisition with 50%. Diagnosis and treatment of T. vaginalis infection in both high-risk and low-risk individuals may be a potential tool to reduce new HIV infections.Trial registration numberCRD42018082702

A surge in heterosexual transmission of HIV among men in post-Soviet countries prompts the need to understand the determinants of HIV testing in the region. Survey data from Belarus (n = 2,769), Moldova (n = 1,545), and Ukraine (n = 3,620) were used to assess an influence of psychosocial determinants on testing among men. A mediation analysis for binary outcomes was used to assess effects of knowledge and stigma on testing. While knowledge had a positive influence on testing in each country, an indirect influence of knowledge through stigma was unique for each country. Implications for interventions and social work are discussed in the light of findings.

HIV remains a public health concern in Tanzania and other Eastern and Southern African countries. Estimates show that there were about 1.4 million people living with HIV in Tanzania in the year 2013. HIV is a generalized epidemic in Tanzania with heterosexual transmission being the main route of transmission. Recently, however, there has been growing concern on the potential role of the key populations in HIV epidemic in the country. Studies done have shown significantly higher HIV prevalence in these populations compared to the general population. These studies have also reported high risky behaviors among members of these populations. This review aims at discussing the possible role of the key populations in the HIV epidemic in Tanzania.

Guangxi Zhuang Autonomous Region is one of the least economically developed regions in China and has been granted the status of autonomous region due to the high share of Zhuang minority population in the region. HIV was initially spread mainly among drug users, later to be transmitted further to the general population. The epidemic also shows some specific patterns that are not as prevalent in other parts of the country. For instance, the region has the highest rate of heterosexual transmission in China, and the prevalence among senior citizens has become alarmingly high in later years (the share of reported cases age 50 and above, makes up almost 60%). In addition to this, Guangxi faces issues with a large number of late diagnosed cases; around 50% of those diagnosed are already in an advanced clinical stage. Also related to this, the region exhibits the highest HIV-related mortality rates in China. In comparison with other Chinese regions, the HIV epidemic is relatively evenly distributed throughout the region, making it difficult to target the response. In response to these issues, there have been a large number of programs implemented to increase testing and facilitate treatment.

Introduction : Nigeria has the second largest number of people living with HIV (PLWH) (3.1 million) after South Africa (5.6 million) and accounts for 10% of the global HIV burden. Lagos State is one of the priority States in Nigeria with a high population (over 20 million). Sero-discordance applies when one partner of an intimate couple pair’s HIV result is positive and other negative. A discordant status is particularly risky because regular coitus without condoms is more probable in stable long-term partnerships (married or cohabiting). The aim is to study the trends of HIV sero-positivity among antenatal clinic attendees and their discordant partners. Methods : secondary data from the National Health Management Information System (NHMIS) was extracted through the District Health Information System (DHIS) platform, cleaned and analysed with Microsoft excel for frequency and proportion. Results : in 2013 the HIV prevalence amongst ANC attendee in the health facilities of Lagos state was 2.83% with slight increase to 4.77% in 2014 and a decline to 2.77% and 1.88% in 2015 and 2016 respectively. In 2013 only 2.35% of women knew their HIV status at antenatal (ANC), the proportion increased slightly to 4.35% in 2014 with a decline to 2.54% and 1.69% in 2015 and 2016 respectively. There were 2300 (37.6%), 2347 (27.0%), 2314 (32.6%) and 1527(35.6%) sero-discordant partners in 2013, 2014, 2015 and 2016 respectively. Of the sero discordant partners 1780, 1770, 1573 and 1276 were partners of HIV Positive women who tested Negative in 2013, 2014, 2015 and 2016 respectively. Also, of the sero discordant partners 520 (22.6%), 577 (24.6%), 741(32%) and 251(16.4%) were partners of HIV Negative pregnant women who tested HIV Positive for 2013, 2014, 2015 and 2016 respectively. Conclusion : the data revealed a decline in HIV prevalence among pregnant women in Lagos State; however HIV sero-discordant partners may be responsible for new Paediatric infection within heterosexual transmission setting. We therefore recommend that couple counseling should be enforced during ANC.

Heterosexual transmission of HIV and other sexually transmitted diseases (STDs) is increasing in older adult populations around the world. This study compares Hispanic and non-Hispanic men ages 50 years and older currently using prescribed erectile dysfunction medications in relation to their perception of the effect of condoms on sexual experience. A sample of 86 men (40 Hispanic and 46 non-Hispanic men) ages 50-79 years completed the 10-item Effect on Sexual Experience (ESE) subscale. Although there was no difference between the 2 groups on the subscale mean score, t(84) = 1.449, p = .151, analysis of the subscale items found 1 item that was significantly different (p = .005) between the 2 groups, although this difference could have been related to different perceptions of the word disgusting. Hispanic men were also less concerned than non-Hispanic men about condom-related loss of erection. This study adds to the literature on HIV and STD prevention for older Hispanic/Latinos.

Background: Latinos in the USA have been disproportionally affected by HIV and sexually transmitted infection (STI) epidemics and the prevalence of heterosexual transmission of HIV among this population is increasing. Latino day laborers (workers who seek jobs at day labor sites) are especially vulnerable to these risks due to their immigration status, poverty, and social isolation. While day laborers remain marginalized and vulnerable, studies on their HIV-related risks are limited. Methods: A total of 40 male day laborers were recruited from a day labor site in a semi-rural area in central Texas. Semi-structured interviews were conducted in Spanish by male interviewers and subsequently transcribed and translated. Results: Most day laborers were from Mexico, and ranged in age from 21 to 51 (mean = 43, SD = 11.5); about three-quarters of them were undocumented. More than 80% of the men were married, 65.8% of men were married but their wives were in their country of origin. Many participants had short-term...

Background: Heterosexual transmission (HST) has become the current predominant transmission pathways of the HIV-1 epidemic in China. The aim of this study was to explore the geographic and dynamic change of HIV-1 subtypes through HST in China from published studies. Methods: Several electronic databases were searched to identify the studies, and the overall prevalence of HIV-1 subtypes was estimated by a meta-analysis method. Subgroup analysis was conducted by study region and time period. Publication bias was evaluated using Egger’s test. The χ2 test was used to evaluate the proportion differences among subgroups. Sensitivity analysis was carried out to assess the stability of the overall prevalence estimates. Results: 42 studies were included in our final analysis. The overall prevalence of CRF01_AE was 46.34% (95% CI: 40.56–52.17%), CRF07_BC was 19.16% (95% CI: 15.02–23.66%), B/B’ was 13.25% (95% CI: 9.68–17.25%), CRF08_BC was 10.61% (95% CI: 7.08–14.70%), and C was 4.29% (95% CI: 1.85–7.48%). In subgroup analysis, the prevalence of CRF01_AE and CRF07_BC increased, while the prevalence of B/B’ decreased over time, whereby the prevalence of CRF07_BC and CRF08_BC have exceeded that of B/B’ since 2010. A significant higher prevalence of CRF01_AE was found in the South provinces, CRF07_BC in East provinces, CRF08_BC and C in Southwest provinces, and B/B’ in North provinces. Conclusions: The HIV-1 prevalent strains have evolved into complicated and diverse subtypes, and the proportion of HIV-1 subtypes through HST has changed constantly in different regions and periods in China. This highlights the urgent need to vigorously strengthen the prevention and control of the HIV-1 epidemic.

Understanding the factors that promote or prevent HIV transmission remains a critical component of the global battle against HIV/AIDS. Gosmann et al. (2017) reveal a putative role for the vaginal microbiome in modulating heterosexual transmission of HIV, uncovering a potential strategy for protecting women from acquisition of the virus.

The human immunodeficiency virus (HIV) poses a formidable risk to the health of women, who made up almost 20% of new HIV infections in 2014 in the U.S. (the most recent year for which data are available). Women represent 25% of those infected with HIV. Sixty-two percent of infected women are African American; Latina and White women each represent 17% of cases in women. The CDC reports that heterosexual transmission accounts for 87% of HIV cases in women. However, it is not clear why some women in HIV-dense neighborhoods become infected, and others do not.

Indian HIV policy is based on the misguided assumption that most sex in India takes place within monogamous, heterosexual settings. This over-emphasis on the heterosexual transmission of the disease has meant the rise of prevalence in the population vulnerable to non-heterosexual transmission of the disease. This article will place the disavowal of same-sex desire in post-colonial India within a historic context, and go behind the veil of heteronormative silence to tell the stories of sexual minorities, doubly stigmatized by poverty, as they seek sexual gratification in the shadows of Indian society.

We analyzed data on reported mode of transmission in case reports of HIV-infections among men in Ukraine. The number of men who were reported to have acquired HIV through heterosexual transmission increased substantially in 2006-2011. However, we estimate that up to 40 % of reported cases of heterosexual transmission among men may actually represent misclassified men who have sex with men or persons who inject drugs. These findings indicate a need to improve the quality of data on reported mode of HIV transmission. Accurate information has important public health implications in planning prevention and treatment services.

Tenofovir was incorporated in controlled-release polycaprolactone (PCL) matrices designed for production of vaginal inserts for prevention of HIV transmission. Rapid cooling of suspensions of the drug powder in PCL solution resulted in micro-porous matrices with tenofovir loadings up to 12% (w/w) and high incorporation efficiencies in excess of 90%. The release behaviour of tenofovir in simulated vaginal fluid (SVF) demonstrated high delivery efficiency of 85%-99% over 30 days and could be described effectively by a first-order kinetics model giving a mean value of 0.126 day-1 for the release constant (k1 ). Tenofovir released from PCL matrices into SVF exhibited high relative activity ranging from 70 to 90%, against pseudo-typed HIV-1-infected HeLa cells. The inhibitory activity of tenofovir standard solutions in SVF provided an IC50 value of 2.38 μM. Besides confirming high levels of in vitro antiviral activity, the predicted concentrations of tenofovir, which would be released from a PCL intra-vaginal ring in vivo, exceeded the IC50 value for HIV-1 by a factor of 35-200 and clinically protective concentrations by a factor of 50. These findings recommend further investigations of antiviral-loaded PCL matrices for controlling heterosexual transmission of HIV.

INTRODUCTION: Globally the majority of human immunodeficiency virus (HIV) epidemic is through heterosexual transmission; The complex interaction between STD and the HIV has been demonstrated in many epidemiological, in vitro and clinical studies over the last number of years. Classic STD could facilitate HIV 1 transmission by increasing either the infectiousness of the index case, the susceptibility of the partner, or both.

Viver com o VIH pode diferir de forma importante segundo o modo de aquisição do VIH. Considerar esta diferença é essencial para evitar abordagens one-size-fits-all. O objetivo deste estudo consistiu em avaliar os perfis de qualidade de vida (QdV) segundo a categoria de transmissão do VIH e analisar os domínios que contribuem para a QdV geral. A amostra deste estudo transversal foi composta por 1112 doentes infetados com o VIH, recrutados nos serviços de doenças infeciosas de 10 hospitais de Portugal. Todos os participantes preencheram o questionário WHOQOL-HIV-Bref. Os resultados revelaram diferenças significativas nos domínios de independência, ambiente e espiritualidade, e na faceta geral de QdV. O grupo que reportou aquisição do VIH por via de drogas intravenosas (DIV) reportou pior QdV que o grupo de homens que têm sexo com homens (HSH) e o grupo que referiu transmissão heterossexual. Este último apresentou significativamente pior QdV no domínio ambiente e na faceta geral que o grupo HSH. Os domínios psicológico e independência contribuíram para a QdV geral de todos os grupos, porém, os domínios físico e ambiente só contribuíram para a QdV geral dos grupos de transmissão por DIV e heterossexual. Os resultados sugerem importantes diferenças segundo o modo de transmissão do VIH e reforçam a importância de intervenções de promoção da QdV adaptadas às características e necessidades destes diferentes subgrupos da população com VIH. Living with HIV may differ significantly in function of the acquisition mode of HIV. Considering this difference is crucial to avoid one-size-fits-all approaches. The aim of this study was to assess the profiles of quality of life (QoL) according to the mode of HIV transmission and to analyze the domains that contribute to the overall QoL. The sample of this cross-sectional study comprised 1112 HIV-infected patients, recruited at the departments of infectious diseases of 10 Portuguese hospitals. All participants completed the WHOQOL-HIV-Bref questionnaire. The results revealed significant differences in the independence, environment, and spirituality domains, and in the overall facet of QoL. The group that reported HIV acquisition through intravenous drug use (IDU) reported poorer QoL than group of men who have sex with men (MSM) and the group that reported heterosexual transmission. This last group also presented significantly worse QoL in the environment domain and in the overall facet than the MSM group. The psychological and independence domains contributed significantly to the overall QoL of all groups; however, the physical and environment domains were only significant contributors to the overall QoL of IDU and heterosexual transmission groups. The results suggest important differences in function of the category of HIV transmission and reinforce the importance interventions for promoting QoL tailored to the characteristics and needs of these different subgroups of the HIV population.

Increased heterosexual transmission of HIV among young women and their difficulties with safer sex communication calls for women-focused research. This qualitative phenomenological study explored the meaning and lived experiences of women, as part of larger pre-dissertation pilot on health protective sexual communication among young women in Gaborone, Botswana. This was a study conducted in two Gaborone City Council MCH clinics. Twenty women participated in individual in-depth interviews conducted in Setswana, tape-recorded, transcribed verbatim, translated into English for line by line analysis to extract themes and subthemes. Six main themes and nine subthemes emerged from the data. The main themes were: the meaning of HPSC, responsibility for HPSC, HPSC content, facilitating factors, partner’s response. Batswana women communicate with their male sexual partners about safer sex but face some difficulties. Further quantitative research can further explore women’s experiences with safer sex communication.

A sex-structured staged progression model for heterosexual transmission dynamics of HIV/AIDS in a community to theoretically assess the effects of gender parameter accounting for population heterogeneity is formulated and analyzed. The basic model without this parameter is analyzed, and then extended to include gender heterogeneity in order to explore its role on the transmission dynamics of the disease. Mathematical properties including epidemic thresholds known as reproductive numbers are derived. The models are numerically analysed using some demographic and epidemiological parameters for Zimbabwe. These simulations suggest that the use of identical gender attributes simplifies computation at the expense of reality as it underestimates the size of the epidemic by 5%. This study demonstrates that the use of gender related parameter in the transmission dynamics of HIV gives a better estimate of the prevalence of the epidemic and should be given prominence.

Objective: To ascertain the role of HIV-1 gp120 env PNGs variations and sequence length polymorphism following transmission events as possible supporting forensic evidence to determine directionality of HIV transmission. Method: An observational study of HIV-1 infected family members, where median and range values of the amino acid lengths and PNGs for the genotyped C2V5 region were calculated. Wilcoxon rank-sum test was used to determine differences in these parameters between different family members. Results: For heterosexual transmission, two mothers had longer C3 sequences relative to that of their spouses; p=0.006 and=0.025 whilst the opposite was observed for one mother, p = 0.028. No clear trends were observed for PNGs. Index children had longer C2V5 amino acid sequences compared to their mothers p = 0.013, 0.040, 0.043 for families 205, 375, 567 respectively. Second siblings “V4 and V5 sequences were generally shorter relative to the maternal ones p = 0.039 and 0.028, respectively. Adults had longer V3 amino acid sequences compared to children; p = 0.018. Similar trends were also observed regarding PNGs within the entire C2V5 region, C3 and V4 sub-regions; p= 0.0025, 0.005 and 0.008, respectively. First siblings’ C2V5 and C3 sequence lengths were significantly longer relative to those of the second siblings; p = 0.005 and 0.007, respectively. Conclusion: Our results are suggestive that HIV-1 env C2V5 amino acid length polymorphism and PNGs tend to increase with age and HIV disease progression. Though sensitive and should be cautiously handled, it is tempting to propose the direc-tionality of the HIV transmission events with respect to C3 sequence length polymorphisms. Correlating HIV-1 env C2V5 amino acid length polymorphism and age of infection may be the first step towards a possible valuable piece of forensic evidence which may be useful in criminalisation of willful HIV infections. However, bigger studies are war-ranted to substantiate the authenticity of this potentially useful application.

Sexual transmission of HIV is the most common mode of infection in the global HIV epidemic. In the absence of an effective vaccine, there is an urgent need for additional strategies to prevent new HIV infections. An emerging body of evidence now indicates that Langerhans cells (LC) are initial cellular targets in the sexual transmission of HIV, and CD4- and CCR5-mediated infection of LC plays a crucial role in virus dissemination. I focus on the recent advances regarding the cellular events that may occur during heterosexual transmission of HIV.

A sex-structured model for heterosexual transmission of HIV/AIDS for addressing the epidemic as a gender-based issue in African heterosexual settings is presented. The epidemic threshold and equilibria for the model are determined and stabilities are investigated. Comprehensive qualitative analysis of the model including positivity and boundedness of solutions, as well as persistence are carried out. The epidemic threshold for the model is computed and used to assess the effects of gender-inequality affecting women in heterosexual settings. The obtained gender-inequality-induced reproductive number [Formula: see text] is greater than the reproductive number in the absence of gender-inequality [Formula: see text] suggesting that gender-inequality affecting women in heterosexual settings enlarges the HIV/AIDS epidemic. Numerical simulations are carried out using demographic and epidemiological parameters for Zimbabwe and the obtained results confirm that gender-inequality increases HIV/AIDS prevalence in heterosexual settings. We conclude from the study that gender-inequality affecting women among heterosexuals should be properly addressed for the effective control of the HIV/AIDS epidemic.

Several strategies are being investigated for the prevention of heterosexual transmission of HIV. Of these, topical vaginal drug delivery systems, microbicides, are being actively pursued. HIV prevention by means of a topical microbicide has several drug delivery challenges. These challenges include the vaginal mucosal barriers and potential degradation of the drugs in the vaginal lumen due to pH and enzymes present. Also, new drugs being evaluated as microbicides have specific mechanisms of action, which in some cases require drug targeting to a specific site of action. Nanoparticles provide a delivery strategy for targeted or controlled delivery to the vagina which can be applied in the field of HIV prevention.This review summarizes nanoparticulate systems and their use in mucosal delivery to date. The sexual transmission of HIV along with the various targets to prevent transmission are discussed as well as the potential opportunities, challenges and advantages in using a nanoparticle-based approach for microbicidal drug delivery.This review provides a general understanding of vaginal drug delivery, its challenges, and nanoparticulate delivery systems. Additionally, insight will be gained as to the limited existing application of this technology to the field of HIV prevention.To date, few studies have been published that exploit nanoparticle-based microbicidal delivery to the vagina. The use of nanoparticles for vaginal drug delivery provides an approach to overcome the existing barriers to success.

Resume Introduction et methodologie Le retard au diagnostic de l’infection a VIH constitue un obstacle majeur a la prise en charge optimale de cette affection a l’ere de la tritherapie. Nous avons realise chez les patients infectes par le VIH nouvellement depistes a la clinique des maladies infectieuses de Fann : une etude descriptive des aspects epidemiocliniques, evolutifs et des antecedents pathologiques recents ; et une enquete socio-anthropologique pour comprendre et decrire la logique des processus decisionnels dans la quete therapeutique des patients. Resultats Cent patients ont ete inclus, avec une moyenne d’âge de 39,5 ± 11,1 ans et un sex-ratio de 1,08. La diarrhee chronique (64 %) et/ou la toux chronique (66 %) ont ete les principales circonstances de decouverte. Le retard diagnostic etait de 5 ± 4,27 mois en moyenne. Les principaux diagnostics retenus etaient la tuberculose (44 cas) et les enterocolites infectieuses (23 cas). La majorite des patients (97 %) etaient au stade de sida et 30 % sont decedes en cours d’hospitalisation. Dans les antecedents, 68 % des patients avaient consulte au moins trois fois, le plus souvent un « tradipraticien » la premiere fois et 43 % des patients avaient ete hospitalises au moins une fois. L’enquete qualitative a revele que la « representation » et le « sentiment de gravite » de la maladie sont les principaux elements qui ont motive la consultation du « tradipraticien » et du medecin, respectivement. Conclusion Une sensibilisation des praticiens et une education des populations sont necessaires pour un depistage plus precoce du VIH.

We use a simple mathematical model to estimate the probability and its time dependence that one or more HIV virions successfully infect target cells. For the transfer of a given number of virions to target cells we derive expressions for the probability P(inf), of infection. Thus, in the case of needlestick transfer we determine P(inf) and an approximate time window for post-exposure prophylaxis (PEP). For heterosexual transmission, where the transfer process is more complicated, a parameter gamma is employed which measures the strength of the infection process. For the smaller value of gamma, P(inf) is from 6 x 10(-5) to 0.93 or from 7.82 x 10(-6) to 0.29, where the lower figures are for the transfer of 100 virions and the upper figures are for the transfer of 4.4 million virions. We estimate the reductions in P(inf) which occur with a microbicide of a given efficacy. It is found that reductions may be approximately as stated when the number of virions transferred is less than about 10(5), but declines to zero for viral loads above that number. It is concluded that PEP should always be applied immediately after a needlestick incident. Further, manufacturers of microbicides should be encouraged to investigate and report their effectiveness at various transferred viral burdens.

Background : The male-to-female ratio of infection for HIV/AIDS has rarely been reported since the 1990s. We previously calculated the country-specific male-to-female ratio of people living with HIV/AIDS, in 1999, 2001, and 2003. Methods : The data of people living with HIV/AIDS and the HIV adult rate were obtained from the table of country-specific HIV/AIDS estimates in the Report on the global HIV/AIDS epidemic, UNAIDS. Results : The male-to-female ratios of the countries in Africa region were reported to be below 1.00 in 1999, 2001, and 2003. The ratios of the countries in other regions were all over 1.00, except for the Bahamas in 2001, Haiti in 2001 and 2003, Jamaica in 2001, Guyana in 2001 and 2003, and Honduras in 2001 and 2003. The male-to-female ratios significantly decreased in Africa and Latin America region between 1999 and 2003 according to the Wilcoxon signed rank test (p< 0.0005). The countries with a high HIV adult rate tended to have lower male-to-female ratios and vice versa in 1999, 2001, and 2003 according to the Wilcoxon rank sum test (p< 0.005). In the 1980s homosexual or bisexual transmission and transmission through drug-injecting behavior were the major modes of spreading HIV in North America, Australia, and Europe where the male-to-female ratios were 10-15. In contrast, heterosexual transmission predominated in Africa, the Caribbean and Latin America where the male-to-female ratios were 1-5. Conclusions : These results indicate that the ratios have therefore been declining in most countries recently, and even within the four-year period between 1999 and 2003, a decreasing tendency was observed in Africa and Latin America.

Objective: This systematic review and meta-analysis aimed to reassess the effectiveness of condoms in reducing heterosexual transmission of HIV. Methods: Medline, Scopus, and the ISI Web of Science databases were searched up to June 2014. Eligible studies were synthesized using random-effects models. Results: Twenty-five studies with 10,676 HIV serodiscordant heterosexual couples were analyzed. The risk of HIV transmission was considerably lower among couples that were always using condoms compared to never-users (RR: 0.29, 95% CI: 0.20–0.43) or inconsistent users (RR: 0.23, 0.13–0.40). The protective effect was slightly higher when the male rather than the female partner was infected (RR: 0.31, 0.20–0.48; vs. RR: 0.44, 0.24–0.80), and very high in Asian settings (RR: 0.06, 0.01–0.46). Conclusions: Though imperfect, condoms reduce HIV transmission by more than 70% when used consistently by HIV serodiscordant heterosexual couples. Social, cultural and biological differences need to be studied further to inform projection modelers and policy makers. © 2015 Informa UK Limited, trading as Taylor & Francis Group. 16 4 489 499

Background Studies performed in high-HIV prevalence countries showed a strong epidemiological association between male circumcision (MC) and the prevention of HIV transmission. We estimated the potential impact of MC on the general heterosexual population in low-HIV prevalence countries. Methods Cross-national comparisons, including data on newly diagnosed HIV cases among heterosexuals living in Israel (where almost all males undergo MC), to similar data from the Netherlands and France (where

Sexual transmission of HIV is the most common mode of infection in the global HIV epidemic. In the absence of an effective vaccine, there is an urgent need for additional strategies to prevent new HIV infections. An emerging body of evidence now indicates that Langerhans cells (LC) are initial cellular targets in the sexual transmission of HIV, and CD4- and CCR5-mediated infection of LC plays a crucial role in virus dissemination. However, interactions between HIV and LC are complex. For example, it is evident that HIV can interact concomitantly with non-LC dendritic cells in two separate and distinct ways: a CD4- and CCR5-dependent infection pathway and a CD4- and CCR5-independent capture pathway mediated by DC-SIGN, a C-type lectin molecule. Thus, there may be multiple ways by which HIV interacts with target cells in the genital mucosa. This review focuses on the recent advances regarding the cellular events that may occur during heterosexual transmission of HIV.

We used a previously described simple compartment model to simulate the conditions required for heterosexual (penile-vaginal) contact to be responsible for 80% or more of transmission of HIV in Africa. In general, the configurations required substantially exceed reported survey and other data for the number of sexual partners, the transmission probabilities, and the distribution of HIV prevalence in population segments. Though the model does not capture nuances of transmission dynamics, it does offer an approximation of the gap between empirical data and current hypotheses.

ObjetivoDescribir las situaciones de riesgo y la prevalencia del virus de la inmunodeficiencia humana (VIH) en mujeres con pareja heterosexual infectada por el VIH.DiseñoEstudio descriptivo y transversal.EmplazamientoCentro ambulatorio de diagnóstico del VIH de Madrid.PacientesSe incluyó en el estudio a 229 mujeres atendidas por primera vez entre 1993 y 2002 por tener una pareja heterosexual estable diagnosticada de infección por el VIH, sin otra exposición de riesgo.Mediciones principalesInformación sociodemográfica, historial reproductivo, conducta sexual, datos clínicos y analíticos de ambos miembros de la pareja.ResultadosEl 66% de las parejas mantenían relaciones sexuales desde hacía más de un año. Las mujeres tenían menor edad media (29,6 años) que los varones. El 29% de las mujeres tenían hijos y el 5,2% estaban embarazadas. Entre los varones, el 82% se había inyectado drogas, pero sólo el 13% mantenía esta práctica. El 73% estaba diagnosticado de infección por el VIH desde hacía más de 6 meses, el 16% presentaba criterios de sida y el 35% recibía tratamiento antirretroviral. El 60% de los varones que conocían previamente su infección habían evitado sistemáticamente los coitos sin preservativo, frente al 33% de los que no se sabían infectados (p < 0,001). El 19% había tenido accidentes en el uso del preservativo. La seroprevalencia del VIH en las mujeres fue del 6,1% (intervalo de confianza del 95%, 3,5-10,3%).ConclusionesLa atención a las personas con VIH debe incluir la asistencia a la pareja sexual, ofreciendo información, apoyo psicológico, consejo preventivo y reproductivo, además del diagnóstico del VIH y de otras infecciones de transmisión sexual.ObjectiveTo describe the situations of risk and the prevalence of HIV in women with a heterosexual partner infected by HIV.DesignCross-sectional descriptive study.SettingOut-patient HIV diagnosis centre in Madrid.Patients229 women seen for the first time between 1993 and 2002 because they had a stable heterosexual partner diagnosed with HIV, and who were exposed to no other risk.Main measurementsSocial and personal details, reproduction history, sexual conduct, clinical, and analytic data of both partners.Results66% of couples had maintained sexual relations for over a year.Women were on average younger (29.6 years old) than the men. 29% of the women had children and 5.2% were pregnant. 82% of men had injected drugs, but only 13% still did. 73% had been diagnosed with HIV for over 6 months, 16% had AIDS criteria, and 35% were taking retroviral treatment. 60% of the men who knew of their infection had systematically avoided sex without condoms, against 33% of those who did not know they were infected (P

Introduction : An important public health question is the degree to which HIV epidemics among injecting drug users (IDUs) can contribute to more generalised spread of the virus heterosexually among non-IDUs. Mathematical models can be of use in understanding the complexities of such epidemiological problems. Methods: In this paper, the Asian Epidemic Model (AEM) is used to explore different scenarios for potential HIV transmission by IDUs to non-injecting sexual partners and beyond. The model is applied to a ‘general Asian' setting, in which (1) there is the potential for sex work to drive a self-sustaining heterosexual epidemic, and (2) the vast majority of IDUs are male and do not engage in sex work themselves, but a substantial minority of the IDUs do purchase sexual services from sex workers. Within such a setting, three different scenarios are modeled, and within each scenario, the level of HIV prevalence among IDUs is varied, to see the impact of preventing HIV among IDUs at different stages. Results: The number of HIV infections attributable to IDUs over a 15-year period was greatest when the epidemic among IDUs started in advance of a generalised heterosexual epidemic, with a 171% increase in infections if the IDU prevalence was not kept under control. Once a heterosexual epidemic was underway, controlling HIV prevalence among IDUs still resulted in a meaningful reduction in infections (23%), including among non-IDUs. Once the heterosexual epidemic started to decline, the relative proportion of infections attributable to IDUs increased, creating a situation for IDUs to feed into new epidemics. Discussion: In the early stages of a heterosexual epidemic, maintaining HIV prevalence at low levels among IDUs can buy critical time to address the potential for rapid heterosexual transmission. In more advanced heterosexual epidemics, preventing HIV among IDUs can still avert a substantial number of infections.

Transmission of the human immunodeficiency virus (HIV) continues at a staggering rate in many areas of the world. The rate of HIV acquisition in young, healthy adults (mostly women) was 3 to 5 per 100 person-years in two trials studying heterosexual transmission of HIV in sub-Saharan Africa, now reported in the Journal (the Preexposure Prophylaxis Trial for HIV Prevention among African Women [FEM-PrEP]1 and the TDF2 study2). This rate of HIV transmission demands the urgent development of new prevention strategies as well as the deployment of all existing strategies, including the use of condoms, male circumcision, and the treatment . . .

In this work, we propose a model for heterosexual transmission of HIV/AIDS in a population of varying size with an intervention program in which treatment and/or behavior change of the infecteds occur as an increasing function of the density of the infected class in the population. This assumption has socio-economic implications which is important for public health considerations since density-dependent treatment/behavior change may be more cost-saving than a program where treatment/behavior change occurs linearly with respect to the number of infecteds. We will make use of the conservation law of total sexual contacts which enables us to reduce the two-sex model to a simpler one-sex formulation. Analytical results will be given. Unlike a similar model with linear treatment/behavior change in Hsieh (1996) where conditions were obtained for the eradication of disease, we will show that density-dependent treatment/behavior change cannot eradicate the disease if the disease is able to persist without any treatment/behavior change. This work demonstrates the need to further understand how treatment/behavior change occurs in a society with varying population.

Realistic models have a larger number of parameters than simple models do. In such realistic models some of the parameter values will be less realistic because of the availability and the difficulty in estimation. On the contrary, a simple model with a smaller number of parameters of which reliable values are available can make reliable prediction if the simple model has involved the essential structure of phenomena. In this paper we propose a simple pair formation model for HIV spread by heterosexual transmission. By setting the parameters involved in the model as close as the actual situation in Japan, we examined whether the outcome is consistent with the observation. The outcome suggested plausible range for some unknown parameters. How to deal with inevitably ambiguous parameters is discussed. The model is ready to be used for other countries than Japan and the validity of such an analysis is also discussed.

My old patient Nancy phoned me last week. She just wanted to say hello tell me the good news about her latest blood tests see what I thought about a stomachache she’s been having. If anyone had told me a dozen years ago that at the dawn of the new millennium I would still be getting phone calls from Nancy I would have laughed. It would have seemed impossible for our relationship to last this long. Nancy and I first met in a tiny Bronx clinic in 1988 in the very dark days of AIDS. The blood test for HIV had been available for about three years; the first antiretroviral drug AZT was just out. Most of the patients in our waiting room had been diagnosed with AIDS after a catastrophic infection of some sort and lived for only a year or two longer. Implicit in one’s first handshake with a new patient was the understanding that the doctor/patient relationship was going to be very intense—and very brief. Nancy was one of the first identified cases of the heterosexual transmission of HIV in the Bronx. She could date her infection to 1984; by the time we met she had survived for four full years and assumed that her time was running out. Other than the nightmare of her husband’s short illness and death she didn’t know much about AIDS but she did know that her husband’s doctor my boss Jerry Friedland was the only doctor she wanted at her bedside when she died. When she discovered that he had lightened his patient load and bequeathed her to me she was beside herself. She wouldn’t look at me wouldn’t sit in my chair and slammed the door on her way out. I thought I would never see her again. (excerpt)

Transmission rates of human immunodeficiency virus (HIV) during heterosexual intercourse vary dramatically around the world. In Asia and South America, they are extraordinarily high, whereas in the United States and Europe, rates are much lower even after a large number of unprotected contacts. The transmission rates in Africa also probably are high, but the available studies unfortunately are weak. In Thailand, female-to-male transmission rates per contact were estimated at.056 (l in 18) compared to.0002 to.0015 (1/5000-1. 5/1000) for male-to-female transmission in the United States and Europe. Male-to-female transmission in Thailand appears to show, as expected, even greater transmission likelihood compared to female-to-male rates. In general, in the United States and Europe, transmission rates within heterosexual couples range from less than 10% to 22%, whereas in Thailand and Brazil, the rates exceed 40%. The much lower transmission rate per contact in the United States and Europe is based on an assumption that HIV transmitters are a homogeneous group. Wiley and colleagues argue that transmitters are likely to be a heterogeneous group with a large percentage of very low frequency transmitters and a small percentage of high frequency transmitters. That hypothesis is given some support by a cluster of cases in rural New York State in which one man appeared to infect 31% of his many contacts.

A recent report suggests that the human immunodeficiency virus (HIV) was introduced into the human population in West Africa shortly before 1959. 74 The rapid spread of the infection threatens the entire world. It has been estimated that in 1997, there were over 30 million people in the world infected with HIV, and by the year 2000 over 40 million. 59 It is clear from world statistics that there is an equal distribution of new infections between men and women, and that heterosexual transmission accounts for the vast majority of cases. Of considerable poignancy is the fact that there soon will be five million AIDS orphans in the world because of the loss of infected parents, as well as an equal number of children with HIV infection. One thousand children and 15,000 adults become infected with HIV every day. Of special note in the United States is the discovery that women, particularly women of minority race, are experiencing the greatest increases in infection by HIV. 73

The epidemic of HIV infection continues to grow in adolescents and young adults. Unfortunately, because treatment regimens have been developed based on data derived from clinical trials, little data are available on adolescents because they are infrequently included in these trials. In an effort to facilitate the enrollment of more adolescents into AIDS Clinical Trials Group (ACTG) clinical trials, we designed a nontreatment protocol to familiarize adolescents with clinical trials requirements. Two hundred fifty-six adolescents (150 females, 106 males) between the ages of 13 and 21 years were enrolled at 43 different clinical trials sites throughout the United States. The majority of patients (50%) were enrolled at sites that had specific programs for adolescents. Most of the young women (85%) had acquired their infection via heterosexual transmission, whereas the largest transmission categories in men were blood or factor transfusions (43%) or same-sex contact (34%). Admission CD4 counts were lower in males (mean = 396 cells/mm3) than in females (mean = 513 cells/mm3) (p = 0.01). Psychosocial profiles revealed a variety of ongoing risk behaviors in HIV-infected adolescents. Two years into the study, 223 patients are still being observed. We conclude that adolescents can be enrolled in an observational protocol. The success of this trial will be determined by how many ACTG Protocol 220 participants are ultimately enrolled in therapeutic trials.

Study of the heterosexual transmission of HIV has shifted focus from the behavioral and demographic risk factors associated with HIV to the biological and molecular factors. Although factors such as genetic predisposition may be immutable, others such as co-infection with sexually transmitted diseases are modifiable by the use of treatment. The effect of antiretroviral treatment is also promising but deserves more study, as does the use of contraception and microbicides (chemical barriers meant for intravaginal use).