Risk Of Seroconversion Research Articles

Efficacy of HIV Postexposure Prophylaxis: Systematic Review and Meta-analysis of Nonhuman Primate Studies.

The efficacy of antiretrovirals as postexposure prophylaxis (PEP) to prevent viral acquisition was demonstrated in nonhuman primate models of human immunodeficiency virus (HIV) in the early 1990s. To complement the evidence base for efficacy of HIV PEP in humans, we systematically reviewed the published data on PEP efficacy across animal studies. PubMed, Web of Science, and Embase were searched from inception to 31 May 2014 for randomized and nonrandomized studies reporting seroconversions among uninfected animals exposed to HIV or simian immunodeficiency virus, irrespective of route of exposure. Seroconversion risk data were pooled using random-effects models, and associations explored through meta-regression. Twenty-five studies (408 primates) were included for review. The risk of serconversion was 89% lower among animals exposed to PEP compared with those that did not receive PEP (odds ratio, 0.11 [95% confidence interval, .05-.23]). Heterogeneity was low (I(2) = 0.0%). In meta-regression, a significant association was found between timing of PEP and seroconversion and the use of tenofovir compared with other drugs. This review provides further evidence of the protective benefit of PEP in preventing HIV acquisition, and the importance of initiating PEP as early as possible following virus exposure.

Serological investigation to identify risk factors for post-flood infectious diseases: a longitudinal survey among people displaced by Typhoon Morakot in Taiwan

ObjectivesAfter Typhoon Morakot struck Taiwan in 2009, thousands of Taiwanese citizens were displaced to shelters for several weeks. Others were placed in urban communities where they had family members. This...

Treatment to Prevent HIV Transmission in Serodiscordant Couples in Henan, China, 2006 to 2012.

Antiretroviral therapy (ART) administered in clinical trial settings virtually eliminates the sexual transmission of human immunodeficiency virus (HIV) in serodiscordant couples, but effectiveness of treatment as prevention in the community is debated. Conflicting results from previous analyses in a Chinese cohort underscore the importance of determining effectiveness of ART delivered in resource limited settings. All available years of data (2006-2012) from local disease control records of HIV patients and their seronegative spouses in Henan Province, China, were analyzed using marginal structural Cox models to estimate the effect of ART in the initially infected partner his or her partner's HIV seroconversion risk. We observed 157 seroconversion events in 4916 serosdiscordant couples, for an incidence rate of 0.59 cases per 100 person-years (PY) (95% confidence interval [CI], .51-.70). Of these, 84 occurred after the index partner had initiated ART (0.43/100PY; 95% CI, .35-.53) and 73, whereas index partners were untreated (5.87/100 PY; 95% CI, 4.65-7.42). In a marginal structural Cox model weighted for confounding and censoring, the hazard ratio (HR) for HIV transmission was 0.52 (95% CI, .34-.82). ART efficacy varied significantly by time period; least effective in the early phase from 2006 to 2008 (HR, 0.68; 95% CI, .34-1.36) but far more protective from 2009 onward (HR, 0.33; 95% CI, .20-.55). ART can provide HIV-infected persons in resource-limited setting substantial protection against sexual transmission. Effectiveness in the Henan cohort appears to have increased over time, suggesting that quality of care and service infrastructure may be integral to successful use of treatment for prevention.

Voluntary medical male circumcision for HIV prevention and early resumption of sexual activity: a literature review

A number of programs have focused on scale-up and implementation research regarding voluntary medical male circumcision; however, there is limited research with regard to factors and strategies related to abstinence compliance and the effects of resuming sex during the wound healing period (42-day post-circumcision). We searched the literature for peer-reviewed articles examining early resumption of sex during this period. This review identifies factors that may predispose a client to engage in sex during the 42-day postoperative period, examines how early resumption of sex can inhibit wound healing and increase seroconversion, and reviews strategies that may increase adherence to abstinence during the wound healing period. We found that the most common factor that may predispose a client to engage in sex before the end of the postoperative period is marriage or cohabitation with a sexual partner. With regard to the effect of sex during the postoperative period on wound healing and seroconversion, we found that adverse events incurred were mild, and there was an increased risk of seroconversion. The only strategy studied to increase compliance to abstinence during the postoperative period utilized text messaging, and the trial results indicate that text messaging did not increase abstinence compliance.

The effect of psychosocial syndemic production on 4-year HIV incidence and risk behavior in a large cohort of sexually active men who have sex with men.

Cross-sectional studies have suggested that co-occurring epidemics or "syndemics" of psychosocial health problems may accelerate HIV transmission among men who have sex with men (MSM) in the United States. We aimed to assess how 5 syndemic conditions (depressive symptoms, heavy alcohol use, stimulant use, polydrug use, and childhood sexual abuse) affected HIV incidence and sexual risk behavior over time. Eligible men in a large prospective cohort of sexually active HIV-uninfected MSM completed HIV testing and behavioral surveys at baseline and every 6 months for 48 months. We examined interrelationships between psychosocial problems and whether these interactions increased the odds of HIV risk behaviors and risk of seroconversion over study follow-up. Among 4295 men, prevalence of psychosocial conditions was substantial at baseline and was positively associated with each other. We identified a statistically significant positive dose-response relationship between numbers of syndemic conditions and HIV seroconversion for all comparisons (with the greatest hazard among those with 4-5 conditions, adjusted hazard ratio = 8.69; 95% confidence interval: 4.78 to 15.44). The number of syndemic conditions also predicted increased HIV-related risk behaviors over time, which mediated the syndemic-HIV seroconversion association. The accumulation of syndemic psychosocial problems predicted HIV-related sexual risk behaviors and seroconversion in a large sample of US MSM. Given the high prevalence of syndemic conditions among MSM and the moderate effect sizes attained by traditional brief behavioral interventions to date, the HIV prevention agenda requires a shift toward improved assessment of psychosocial comorbidities and stronger integration with mental health and substance abuse treatment services.

HIV transmission and related risk factors among serodiscordant couples in Liuzhou, China.

To evaluate the incidence and risk factors for human immunodeficiency virus (HIV) seroconversion of HIV-negative partners among HIV-discordant couples in Liuzhou, China, 1854 eligible HIV-serodiscordant couples were retrospectively identified through the HIV epidemiology and follow-up database from January 1, 1996 to June 30, 2013. Cox proportional-hazards model was used to examine risk factors related to HIV seroconversion of negative partners. Finally, 125 HIV seroconversion occurred over 4963.5 person-years, resulting in an overall HIV incidence of 2.52/100 person-years. HIV-positive partners with the last CD4 counts of 350 cells/ul or more were significantly protected against HIV seroconversion compared with those CD4 counts of less than 200 cells/ul (aHR = 0.46, 95% CI: 0.27-0.81, P < 0.01). Men with HIV-positive wives (aHR: 1.96, 95% CI: 1.27-3.02, P < 0.01), HIV-positive partners who did not receive ART before their HIV-negative partners' seroconversion (aHR: 2.22, 95% CI, 1.41-3.51, P < 0.01) and patients reported intermittent condom use (aHR: 7.60, 95% CI, 4.37-13.21, P < 0.01) were associated with increased risk of HIV seroconversion. HIV-negative partners remain high risk of HIV infection in Liuzhou city. Comprehensive package of HIV prevention services should contribute to reduction in HIV transmission of discordant couples.

Hepatitis C virus seroconversion among HIV-positive men who have sex with men with no history of injection drug use: Results from a clinical HIV cohort.

Internationally, there is a growing recognition that hepatitis C virus (HCV) may be sexually transmitted among HIV-positive men who have sex with men (MSM). To report the first Canadian estimate of HCV seroincidence in 2000 to 2010 and its risk factors among HIV-positive MSM with no known history of injection drug use. Data from the Ontario HIV Treatment Network Cohort Study, an ongoing cohort of individuals in HIV care in Ontario, were analyzed. Data were obtained from medical charts, interviews and record linkage with the provincial public health laboratories. The analysis was restricted to 1534 MSM who did not report injection drug use and had undergone ≥2 HCV antibody tests, of which the first was negative (median 6.1 person-years [PY] of follow-up; sum 9987 PY). In 2000 to 2010, 51 HCV seroconversions were observed, an overall incidence of 5.1 per 1000 PY (95% CI 3.9 to 6.7). Annual incidence varied from 1.6 to 8.9 per 1000 PY, with no statistical evidence of a temporal trend. Risk for seroconversion was elevated among men who had ever had syphilis (adjusted HR 2.5 [95% CI 1.1 to 5.5) and men who had acute syphilis infection in the previous 18 months (adjusted HR 2.8 [95% CI 1.0 to 7.9]). Risk was lower for men who had initiated antiretroviral treatment (adjusted HR 0.49 [95% CI 0.25 to 0.95]). There were no statistically significant effects of age, ethnicity, region, CD4 cell count or HIV viral load. These findings suggest that periodic HCV rescreening may be appropriate in Ontario among HIV-positive MSM. Future research should seek evidence whether syphilis is simply a marker for high-risk sexual behaviour or networks, or whether it potentiates sexual HCV transmission among individuals with HIV.

Biological impact of recurrent sexually transmitted infections on HIV seroconversion among women in South Africa: results from frailty models.

IntroductionUnderstanding the impact of curable sexually transmitted infections (STIs) on HIV transmissibility is essential for effective HIV prevention programs. Investigating the impact of longitudinally measured recurrent STIs on HIV seroconversion is the interest of the current paper.MethodsIn this prospective study, data from a total of 1456 HIV-negative women who enrolled in a HIV biomedical trial were used. It was hypothesized that women who had recurrent STI diagnoses during the study share a common biological heterogeneity which cannot be quantified. To incorporate this “unobserved” correlation in the analysis, times to HIV seroconversion were jointly modelled with repeated STI diagnoses using Cox regression with random effects.Results and discussionA total of 110 HIV seroconversions were observed (incidence rate of 6.00 per 100 person-years). In a multivariable model, women who were diagnosed at least once were more likely to seroconvert compared to those who had no STI diagnosis [hazard ratio (HR): 1.63, 95% confidence interval (CI): 1.04, 2.57]; women who had recurrent STI diagnoses during the study were 2.5 times more likely to be at increased risk of HIV infection (95% CI: 1.35, 4.01) with an estimated frailty variance of 1.52, with p<0.001, indicating strong evidence that there is a significant correlation (heterogeneity) among women who had recurrent STIs. In addition to this, factors associated with incidence of STIs, namely not being married and having a new sexual partner during the study follow-up, were all significantly associated with increased risk for HIV seroconversion (HR: 2.92, 95% CI: 1.76, 5.01 and HR: 2.25, 95% CI: 1.63, 3.83 respectively).ConclusionsThe results indicated that women who were at risk for STIs were also at risk of HIV infection. In fact, they share the similar risk factors. In addition to this, repeated STI diagnoses also increased women’s susceptibility for HIV infection significantly. Decreasing STIs by increasing uptake of testing and treatment and reducing partner change plays a significant role in the trajectory of the epidemic.

The role of neighboring infected cattle in bovine leukemia virus transmission risk.

A cohort study was conducted to evaluate the risk of bovine leukemia virus (BLV) transmission to uninfected cattle by adjacent infected cattle in 6 dairy farms. Animals were initially tested in 2010–2011 using a commercial ELISA kit. Uninfected cattle were repeatedly tested every 4 to 6 months until fall of 2012. The Cox proportional hazard model with frailty showed that uninfected cattle neighboring to infected cattle (n=53) had a significant higher risk of seroconversion than those without any infected neighbors (n=81) (hazard ratio: 12.4, P=0.001), implying that neighboring infected cattle were a significant risk factor for BLV transmission. This finding provides scientific support for animal health authorities and farmers to segregate infected cattle on farms to prevent spread of BLV.

Cost and safety of assisted reproductive technologies for human immunodeficiency virus-1 discordant couples.

Due to significant advances in the treatment of human immunodeficiency virus type-1 (HIV-1), HIV-1 infection gradually has become a treatable chronic disease. Successfully treated HIV-positive individuals can have a normal life expectancy. Hence, more and more HIV-1 discordant couples in Taiwan and the rest of the world are seeking fertility assistance. Pre-treatment of highly active antiretroviral therapy (HAART) combined with sperm washing and RT-polymerase chain reaction examination for HIV-1 viral load has become the standard procedure to assist them to conceive. However, in order to reduce the transmission risk to the lowest level for the couple and to diminish the cost of health care for the insurance institutes or government, in vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) therapy provides the ideal solution for HIV-1 discordant couples with infected men. Intrauterine insemination (IUI) theoretically introduces more than 10(7) times of sperm counts or semen volume to uninfected women vs IVF-ICSI. However, since some regimens of HAART may significantly decrease the sperm motility, compared to IVF-ICSI, IUI only produces 1/5 to 1/2 pregnancy rates per cycle. Given the risk of seroconversion of HIV infection which actually happens after successful treatment, IVF-ICSI for these HIV-1 seropositive men is more cost-effective and should be the first line treatment for these cases.

Continuous increase in HIV-1 incidence after the year 2000 among men who have sex with men in Rome: insights from a 25-year retrospective cohort study.

To assess trends in HIV-1 incidence and risk factors for seroconversion among men who have sex with men (MSM) resident in Rome, Italy, a retrospective longitudinal cohort study was conducted over 25 years. Incidence rates and trends were modelled using Poisson regression and risk factors were assessed by multivariate Cox models. Of 1,862 HIV-1-negative individuals, 347 seroconverted during follow-up. HIV-1 incidence rates increased from 5.2/100 persons/year (p/y) in 1986 (95% confidence interval (CI): 2.3–11.5) to 9.2/00 p/y in 1992 (95% CI: 6.4–13.0), decreased to 1.3/100 p/y in 2001 and increased until 2009 (11.7/100 p/y; 95% CI: 7.4–18.6). The risk of HIV-1 seroconversion increased during the study period in younger MSM (incidence rate ratio (IRR) = 17.18; 95% CI: 9.74–30.32 in 16–32 year-olds and IRR = 5.09; 95% CI: 2.92–8.87 in 33–41 year-olds) and in those who acquired syphilis (IRR = 7.71; 95% CI: 5.00–11.88). In contrast, the risk of seroconversion decreased among highly educated MSM (IRR = 0.54; 95% CI: 0.35–0.82) and those without Italian citizenship (IRR = 0.45; 95% CI: 0.28–0.71). The HIV epidemic in MSM living in Rome continues to expand. Targeted prevention programmes against sexually transmitted infections to enhance knowledge transfer and behavioural skills are urgently required.

Post-exposure prophylaxis use and recurrent exposure to HIV among men who have sex with men who use crystal methamphetamine

BackgroundMen who have sex with men (MSM) who use crystal methamphetamine (CM) are at increased risk for HIV infection. Post-exposure prophylaxis (PEP) is a useful HIV prevention strategy if individuals are able to identify high-risk exposures and seek timely care, however to date there has been limited data on the use of PEP by CM users. MethodsA: Retrospective cohort study of all PEP prescriptions (N=1130 prescriptions among 788 MSM) at Fenway Community Health in Boston, MA was undertaken. Multivariable models were used to assess the association between CM use during exposure (7.4% used CM during exposure) and chronically (7.4% of MSM were chronic CM users) and individual-level and event-level outcomes among MSM who used PEP at least once. ResultsCompared to those who had not used CM, MSM PEP users who used CM more frequently returned for repeat PEP (aOR 5.13, 95% CI 2.82 to 9.34) and were significantly more likely to seroconvert over the follow-up period (aHR 3.61, 95% CI 1.51 to 8.60). MSM who used CM had increased odds of unprotected anal intercourse as the source of exposure (aOR 2.12, 95% CI 1.16 to 3.87) and knowing that their partner was HIV infected (aOR 2.27, 95% CI 1.42 to 3.64). ConclusionsWhile MSM who use CM may have challenges accessing ART in general, these data highlight the fact that those who were able to access PEP subsequently remained at increased risk of HIV seroconversion. Counseling and/or substance use interventions during the PEP course should be considered for CM-using MSM.

Time to seroconversion in HIV-exposed subjects carrying protective versus non protective KIR3DS1/L1 and HLA-B genotypes.

Natural killer (NK) cells play a role in the clearance of viral infections. Combinations of alleles at the polymorphic HLA-B locus and the NK cell surface killer immunoglobulin-like receptor locus KIR3DL1/S1 have been shown to influence time to AIDS in HIV-infected individuals and risk of seroconversion in HIV exposed seronegative (HESN) subjects. Here, we assessed time to seroconversion or duration of seronegative status in a group of 168 HIV exposed individuals, including 74 seroconverters and 94 HESN based on carriage or not of KIR3DL1/S1/HLA-B genotypes previously shown to be associated with protection from infection and/or slow time to AIDS. KIR3DL1/S1 genotyping was performed by sequence-specific primer polymerase chain reaction using two pairs of specific primers for each locus. The MHC class IB locus was typed to four-position resolution to resolve Bw4 and Bw6 alleles and the amino acid present at position 80. KIR3DL1/S1 heterozygotes became HIV infected significantly faster than KIR3DS1 homozygotes. Individuals who carried both KIR3DS1 and Bw4*80I did not remain HIV seronegative longer than those from a control group who were homozygous for HLA-Bw6 and carried no HLA-A locus Bw4 alleles Subjects who were *h/*y+B*57 showed a trend towards slower time to serconversion than those with other KIR3DL1 homozygous and KIR3DL1/S1 heterozygous genotypes. Thus, KIR3DS1 homozygosity is associated with protection from HIV infection while co-carriage of KIR3DS1 and Bw4*80I is not. The requirements for protection from HIV infection can differ from those that influence time to AIDS in HIV infected individuals.

Prescription opioid injection and risk of hepatitis C in relation to traditional drugs of misuse in a prospective cohort of street youth

ObjectiveDespite dramatic increases in the misuse of prescription opioids, the extent to which their intravenous injection places drug users at risk of acquiring hepatitis C virus (HCV) remains unclear. We...

Seroconversion Risk Perception Among Jail Populations

The prevalence of HIV/AIDS infection among prisoners is 3 to 4 times higher than in the U.S. population. Given that one in seven HIV-positive Americans pass through a correctional facility every year, the criminal justice system is in an ideal position to aggressively implement effective HIV education, treatment, and prevention. This study examines barriers to the effective delivery of these services and evaluates differences in risk perception among nearly 600 female and male inmates. The results underscore gender differences in Perceived Risk of Seroconversion and Exposure to HIV Education, suggesting that jails should implement gender-specific HIV prevention programming.

(118) - Prolonged Ischemia Does Not Affect Survival Following Lung Transplantation

HBcAb+ or non-HBcAb+ donors. At 5 years, mean(SD) survival for the HBcAb+ group was 187(14) weeks as compared to 184(3.8) weeks for the non-HBcAb group (p= 0.2). The HBcAb+ group had similar mean(SD) time to diagnosis of chronic rejection as compared to the non-HBcAb group (1130 +/537 compared to 916 +/451 days, respectively). Conclusion: Lung transplant recipients from HBcAb + donors have low risk (5/32; 16%) of seroconversion to HBcAb positivity without evidence of increased risk of viremia which does not impact short or long term survival. This supports HepB vaccination of recepients pre-transplantation in order for HbcAb+ organs to continue to be utilized safely.

Risk Factors for Visceral Leishmaniasis and Asymptomatic Leishmania donovani Infection in India and Nepal

There is increasing interest in the role of asymptomatic infection in transmission of Visceral Leishmaniasis (VL). We studied the individual, household and environmental factors associated with asymptomatic Leishmania donovani infected individuals and VL. 7,538 individuals living in VL endemic villages in India and Nepal were divided into three mutually exclusive groups based on their VL history and Direct Agglutination Test (DAT) results in yearly serosurveys over a two-year period. The groups were (1) VL cases, (2) asymptomatically infected individuals (seroconverters) and (3) seronegative individuals. VL cases and seroconverters were compared to seronegative individuals in mixed logistic regression models. The risk of seroconversion and disease was significantly increased in individuals aged 14 to 24 years old and by the presence of other DAT-positive, asymptomatically infected individuals and VL cases in the house. The risk of seroconversion was higher in Indian than in Nepalese villages and it increased significantly with age, but not so for VL. This study demonstrates that, when risk factors for leishmanial infection and VL disease are evaluated in the same population, epidemiological determinants for asymptomatic infection and VL are largely similar.

Age, Race/Ethnicity, and Behavioral Risk Factors Associated With Per Contact Risk of HIV Infection Among Men Who Have Sex With Men in the United States

Young men who have sex with men (MSM) and MSM of color have the highest HIV incidence in the United States. To explore possible explanations for these disparities and known individual risk factors, we analyzed the per contact risk (PCR) of HIV seroconversion in the early highly active antiretroviral therapy era. Data from 3 longitudinal studies of MSM (HIV Network for Prevention Trials Vaccine Preparedness Study, EXPLORE behavioral efficacy trial, and VAX004 vaccine efficacy trial) were pooled. The analysis included visits where participants reported unprotected receptive anal intercourse (URA), protected receptive anal intercourse, or unprotected insertive anal intercourse (UIA) with an HIV seropositive, unknown HIV serostatus, or an HIV seronegative partner. We used regression standardization to estimate average PCRs for each type of contact, with bootstrap confidence intervals. The estimated PCR was highest for URA with an HIV seropositive partner (0.73%; 95% bootstrap confidence interval [BCI]: 0.45% to 0.98%) followed by URA with a partner of unknown HIV serostatus (0.49%; 95% BCI: 0.32% to 0.62%). The estimated PCR for protected receptive anal intercourse and UIA with an HIV seropositive partner was 0.08% (95% BCI: 0.0% to 0.19%) and 0.22% (95% BCI: 0.05% to 0.39%), respectively. Average PCRs for URA and UIA with HIV seropositive partners were higher by 0.14%-0.34% among younger participants and higher by 0.08% for UIA among Latino participants compared with white participants. Estimated PCRs increased with the increasing number of sexual partners, use of methamphetamines or poppers, and history of sexually transmitted infection. Susceptibility or partner factors may explain the higher HIV conversion risk for younger MSM, some MSM of color, and those reporting individual risk factors.

Knowledge, Attitude and Practices of HIV Post Exposure Prophylaxis Amongst Health Workers in Lagos University Teaching Hospital

Background: Timely PEP after needle stick exposure to high risk body fluids can reduce the rate of occupational transmission significantly. Ignorance of this may increase the risk of seroconversion to HIV for healthcare workers. This study was conducted with the aim of demonstrating the current level of knowledge of healthcare workers as regards PEP. Methods: This was a cross-sectional study, pretested questionnaire were self-administered to 372 health workers from various clinical specialties. The responses were collated and analysed; results were presented in frequency tables. Result: This study revealed a high level of awareness among the respondents as 83.3% were aware of PEP. Despite the high level of awareness, respondents still have an inadequate knowledge about PEP, only 32% of the respondents could name at least two of the recommended drugs for PEP, only 54.0% of respondents knew when to commence PEP following occupational exposure to HIV. There was a low level of practice of PEP among the respondents as only 6.3% of respondents had PEP despite occurrence of needle stick injury. Conclusion: This study revealed a general low level use of PEP despite the average knowledge of PEP and the favourable attitude towards HIV PEP amongst the respondents.

Knowledge, attitude and practices of HIV post exposure prophylaxis amongst health workers in Lagos University Teaching Hospital.

IntroductionTimely PEP after needle stick exposure to high risk body fluids can reduce the rate of occupational transmission significantly. Ignorance of this may increase the risk of seroconversion to HIV for healthcare workers. This study was conducted with the aim of demonstrating the current level of knowledge and practise of healthcare workers as regards PEP.MethodsThis was a cross-sectional study, pretested questionnaire were self administered to 372 health workers from various clinical specialties. The responses were collated and analyzed; results were presented in frequency tables.ResultsThis study revealed a high level of awareness among the respondents as 83.3% were aware of PEP. Despite the high level of awareness, respondents still have an inadequate knowledge about PEP, only 32% of the respondents could name at least two of the recommended drugs for PEP, only 54.0% of respondents knew when to commence PEP following occupational exposure to HIV. There was a low level of practice of PEP among the respondents as only 6.3% of respondents had PEP despite occurrence of needle stick injury.ConclusionThis study revealed a general low level use of PEP despite the average knowledge of PEP and the favourable attitude towards HIV PEP amongst the respondents.