Detection of human immunodeficiency virus type 1 and type 2 in the female genital tract: implications for the understanding of virus transmission

Evidence of HIV-1 Genital Shedding after One Year of Antiretroviral Therapy in Females Recently Diagnosed in Bamako, Mali

Little is known about the dynamic of HIV-1 shedding and resistance profiles in the female genital reservoir after antiretroviral therapy (ART) initiation in resource-limited countries (RLCs), which is critical for evaluating the residual sexual HIV-1 transmission risk. The present study aimed to evaluate the efficacy of 1 year duration ART at blood and genital levels in females newly diagnosed for HIV-1 from three centers in Bamako, Mali. Seventy-eight consenting females were enrolled at the time of their HIV-1 infection diagnosis. HIV-1 RNA loads (Abbott Real-Time HIV-1 assay) were tested in blood and cervicovaginal fluids (CVF) before and 12 months after ART initiation. Primary and acquired resistances to ART were evaluated by Viroseq^TM HIV-1 genotyping assay. The vaginal microbiota was analyzed using IonTorrent^TM NGS technology (Thermo Fisher Scientific). Proportions of primary drug resistance mutations in blood and CVF were 13.4% and 25%, respectively. Discrepant profiles were observed in 25% of paired blood/CVF samples. The acquired resistance rate was 3.1% in blood. At month 12, undetectable HIV-1 RNA load was reached in 84.6% and 75% of blood and CVF samples, respectively. A vaginal dysbiosis was associated with HIV RNA shedding. Our findings emphasize the need of reinforcing education to improve retention in care system, as well as the necessity of regular virological monitoring before and during ART and of implementing vaginal dysbiosis diagnosis and treatment in RLCs.

Lower levels of HIV-2 than HIV-1 in the female genital tract: correlates and longitudinal assessment of viral shedding

BACKGROUND

The differing magnitude of the HIV-1 and HIV-2 epidemics is likely a consequence of differing transmission rates between the two viruses. Similar to other sexually transmitted pathogens, risk of HIV-1 and HIV-2 transmission is likely associated with the presence and amount of HIV in the genital tract. Thus, understanding patterns of, and risk factors for HIV genital tract shedding is critical to effective control of HIV transmission.

METHODS

We evaluated HIV DNA and RNA detection in cervicovaginal specimens among 168 HIV-1 and 50 HIV-2-infected women in Senegal, West Africa. In a subset of 31 women (20 with HIV-1, 11 with HIV-2), we conducted a prospective study in which cervicovaginal specimens were taken at 3-day intervals over a 6-week period.

RESULTS

We found significantly lower rates and levels of HIV-2 RNA (58% shedding; 13% with >1000 copies/ml) in the female genital tract than HIV-1 RNA (78% shedding; 40% with >1000 copies/ml) (P = 0.005 and 0.005, respectively), and shedding correlated with plasma viral load irrespective of virus type (odds ratio = 1.9, 95% confidence interval = 1.3-2.8 for each log10 increase in HIV viral RNA). Plasma viral load, not HIV type, was the strongest predictor of genital viral load. Over 80% of closely monitored women, regardless of HIV type, had at least intermittent HIV RNA detection during every 3-day sampling over a 6-week time period.

CONCLUSION

These data help in explaining the different transmission rates between HIV-1 and HIV-2 and may provide new insights regarding prevention.

Lower levels of HIV RNA in semen in HIV-2 compared with HIV-1 infection: implications for differences in transmission

BACKGROUND AND OBJECTIVES

HIV-2 infection, in comparison with HIV-1, is characterized by lower plasma viral loads, slower CD4 cell count decline, decreased AIDS-related mortality, and lower rates of mother-to-child and sexual transmission. To gain further insight into why HIV-1 is more readily transmitted as compared with HIV-2, we analyzed semen and plasma HIV RNA levels in HIV-1 and HIV-2-positive men from Senegal.

DESIGN AND METHODS

Twenty-two HIV-1 and 10 HIV-2-infected subjects from the University of Dakar donated semen and blood samples for this analysis. HIV-1 and HIV-2 viral loads in semen and plasma were quantified using type-specific polymerase chain reaction assays.

RESULTS

The mean age of the subjects was 37 and 40 years; mean CD4 cell count was 222 and 276 cells/microl and the mean plasma viral load was 4.7 and 3.0 log10 copies/ml for HIV-1 and HIV-2, respectively (P = 0.002). HIV RNA was detected in semen in 21 of 22 (95%) of HIV-1 and seven of 10 (70%) of HIV-2-infected subjects; P = 0.07). However, the levels of HIV RNA present in semen were markedly different between those with HIV-1 and HIV-2, with a mean of 4.4 log10 copies/ml among those with HIV-1 and a mean of 2.6 log10 copies/ml among those with HIV-2 (P < 0.001). In multivariate analysis, plasma viral load and HIV type, but not CD4 cell count, were independently predictive of semen viral load (P = 0.03, 0.05, 0.48, respectively)

CONCLUSIONS

These data suggest that differences in semen viral load between HIV-1 and HIV-2 may be in part responsible for the markedly different transmission rates of these two viruses. In addition, risk of male genital tract shedding strongly correlates with plasma viral loads. Interventions that decrease viral load may help decrease transmission of both HIV-1 and HIV-2.

Myeloid-related protein (MRP)-8 from cervico-vaginal secretions activates HIV replication

OBJECTIVES

To identify a substance found in female genital tract secretions that enhances HIV expression in infected cells.

DESIGN

Cervico-vaginal lavages (CVL), collected in sterile normal saline, were fractionated and tested for HIV-inducing activity using HIV-infected monocytes.

METHODS

To purify the component(s) of CVL that enhance HIV production, Mono-Q ion exchange chromatography followed by Superose-12 molecular sieve analysis, and SDS--PAGE were performed. The purified protein was identified by amino acid sequence analysis.

RESULTS

SDS--PAGE of bioactive fractions showed a 14 kDa polypeptide band. Amino acid sequence analysis of selected peptides from the 14 kDa band showed 100% homology with the myeloid-related protein (MRP)-8, an inflammatory protein found in mucosal secretions. Western blot analysis revealed that bioactive CVL contained more immunoreactive MRP-8 than samples without bioactivity. The HIV-inducing activity of MRP-8 was further confirmed by showing that human recombinant MRP-8 increased HIV expression by up to 40-fold.

CONCLUSIONS

MRP-8 in cervico-vaginal secretions stimulates HIV production. Strategies aimed at blocking MRP-8 activity in the genital tract could reduce risk of sexual as well as maternal--infant transmission of HIV.

HIV/AIDS among African Americans: progress or progression?

OBJECTIVES

To review data on the extent of HIV infection and associated risk behaviors, the occurrence of AIDS, and HIV-related mortality in African Americans and to suggest what can be done to reduce HIV exposure and infection in this population.

DESIGN/METHODS

Review of epidemiologic, published, multisite data on HIV infection in, and related behaviors of, African Americans.

RESULTS

On every epidemiologic measure in common use, African Americans, compared with the four other federally recognized racial/ethnic groups, have the most severe epidemic. The trend data show continuing growth in the African American epidemic despite the availability of effective behavioral interventions and biomedical treatments. Few published intervention studies with African American populations have been adequately evaluated; nor have they focused proportionately on men who have sex with men, a group in the African American community with continuing high rates of infection.

CONCLUSIONS

Rates of HIV transmission and disease among African Americans are high, disproportionate, and are not declining as significantly in response to effective interventions as they are among whites. Attention is urgently needed to increase our understanding of risk behaviors, social networks, and specific factors in the African American community that can be altered to reduce HIV infection. Macroenvironmental factors--poverty, social class, racism--need to be studied to suggest possible intervention components to reduce rates of HIV transmission and to increase the use of therapies that are more effectively slowing disease progression and lowering death rates among whites.

Human immunodeficiency viruses in the developing world

AIDS has become a major burden in developing countries. At present, more than 90% of new HIV infections are emerging in Asia and Africa. Particularly ominous is the epidemic due to HIV-1 C in southern Africa, where about 25% of adults in several countries are infected. Although most of its spread apparently occurred during the 1990s, HIV-1 C currently accounts for one-half of the infections in the world. Both HIV-2, which is less virulent than HIV-1, and HIV-1 apparently spread to the human population from nonhuman African primates during the twentieth century. HIV-1 infection is usually lethal in the absence of antiretroviral therapy, but clinical disease occurs only after an induction period of several years. Some subtypes of HIV-1, such as C, E, and A, appear to be transmitted more efficiently than HIV-1 B, which is the major subtype in the United States and Europe. Molecular evolutionary changes that include receptor affinity, mediated by the env gene, and increased transcriptional activation, mediated by changes in the LTR and the tat gene, may account for some of the changes in transmission. Current therapies are prohibitively expensive for use in adults in most developing countries, although drugs for maternal-to-infant transmission are becoming accessible. A vaccine for HIV is desperately needed for the developing world.

Effect of intrauterine device use on cervical shedding of HIV-1 DNA

OBJECTIVE

Hormonal contraception has been associated with an increased prevalence of cervical shedding of HIV-1 DNA among infected women. We conducted this study to evaluate the effect of the use of an intrauterine device (IUD) on the detection of HIV-1 DNA in cervical secretions.

DESIGN

A prospective study of HIV-1-seropositive women undergoing IUD insertion at two public family planning clinics in Nairobi, Kenya.

METHODS

Cervical swab samples were collected before IUD insertion and approximately 4 months thereafter for the detection of HIV-1-infected cells using polymerase chain reaction (PCR) amplification of HIV-1 gag DNA sequences.

RESULTS

Ninety-eight women were enrolled and followed after IUD insertion. The prevalence of HIV-1 DNA cervical shedding was 50% at baseline and 43% at follow-up [odds ratio (OR) 0.8, 95% confidence interval (CI) 0.5-1.2]. There was no statistically significant difference between the baseline and follow-up shedding rates in a multivariate model that controlled for previous hormonal contraceptive use, condom use, cervical ectopy, friable cervix, cervical infections at an interim visit, and CD4 lymphocyte levels (OR 0.6, 95% CI 0.3-1.1).

CONCLUSION

The insertion of an IUD did not significantly alter the prevalence of cervical shedding of HIV-1-infected cells. The use of IUDs, in conjunction with condoms, may be an appropriate method of contraception for HIV-1-infected women from the standpoint of potential infectivity to the male partner through exposure to genital HIV-1.