The epidemiology of HIV population viral load in twelve sub-Saharan African countries.

Background: We examined the epidemiology and transmission potential of HIV population viral load (VL) in 12 sub-Saharan African countries.

Methods: We analyzed data from Population-based HIV Impact Assessments (PHIAs), large national household-based surveys conducted between 2015 and 2019 in Cameroon, Cote d'Ivoire, Eswatini, Kenya, Lesotho, Malawi, Namibia, Rwanda, Tanzania, Uganda, Zambia, and Zimbabwe. Blood-based biomarkers included HIV serology, recency of HIV infection, and VL.

HIV Incidence, Recent HIV Infection, and Associated Factors, Kenya, 2007-2018.

Nationally representative surveys provide an opportunity to assess trends in recent human immunodeficiency virus (HIV) infection based on assays for recent HIV infection. We assessed HIV incidence in Kenya in 2018 and trends in recent HIV infection among adolescents and adults in Kenya using nationally representative household surveys conducted in 2007, 2012, and 2018. To assess trends, we defined a recent HIV infection testing algorithm (RITA) that classified as recently infected (<12 months) those HIV-positive participants that were recent on the HIV-1 limiting antigen (LAg)-avidity assay without evidence of antiretroviral use.

Changes in D-dimer after initiation of antiretroviral therapy in adults living with HIV in Kenya.

Background: Increased coagulation biomarkers are associated with poor outcomes among people living with HIV (PLHIV). There are few data available from African cohorts demonstrating the effect of antiretroviral therapy (ART) on coagulation biomarkers.

Methods: From March 2014 to October 2014, ART-naïve PLHIV initiating non-nucleoside reverse transcriptase inhibitor-based ART were recruited from seven clinics in western Kenya and followed for up to 12 months.

Effectiveness of a Lay Counselor-Led Combination Intervention for Retention of Mothers and Infants in HIV Care: A Randomized Trial in Kenya.

Background: Retention of mothers and infants across the prevention of mother-to-child HIV transmission (PMTCT) continuum remains challenging. We assessed the effectiveness of a lay worker administered combination intervention compared with the standard of care (SOC) on mother-infant attrition.

Methods: HIV-positive pregnant women starting antenatal care at 10 facilities in western Kenya were randomized using simple randomization to receive individualized health education, retention/adherence support, appointment reminders, and missed visit tracking vs.

Lay health worker experiences administering a multi-level combination intervention to improve PMTCT retention.

Background: The recent scale-up of prevention of mother-to-child transmission of HIV (PMTCT) services has rapidly accelerated antiretroviral therapy (ART) uptake among pregnant and postpartum women in sub-Saharan Africa. The Mother and Infant Retention for Health (MIR4Health) study evaluates the impact of a combination intervention administered by trained lay health workers to decrease attrition among HIV-positive women initiating PMTCT services and their infants through 6 months postpartum.

Methods: This was a qualitative study nested within the MIR4Health trial.

Mother Infant Retention for Health (MIR4Health): Study Design, Adaptations, and Challenges With PMTCT Implementation Science Research.

Background: Effective retention of HIV-infected mothers and their infants is fraught with multiple challenges, resulting in loss across the continuum of prevention of mother-to-child HIV transmission (PMTCT) care and missed opportunities to offer life-saving HIV prevention and treatment.

Methods: The Mother Infant Retention for Health study is an individual-randomized study evaluating the effectiveness of active patient follow-up compared with standard of care on the combined outcome of attrition of HIV-infected women and their infants at 6 months postpartum. Lay counselors administered the active patient follow-up package of interventions, including individualized health education, use of flip charts during clinic visits, and at home, phone and short message service appointment reminders, active phone and physical tracking of patients immediately after missed clinic visits, and individualized retention and adherence support.

Identifying the Gaps: An Assessment of Nurses' Training, Competency, and Practice in HIV Care and Treatment in Kenya.

Given the burden of HIV and the critical shortage of health workers in Kenya, in 2011 the National AIDS and STI Control Program recommended shifting HIV care and treatment tasks to nurses in settings without physicians and clinical officers in order to decentralize and scale-up HIV services. In September 2013, ICAP at Columbia University conducted a survey with nurses in four health facilities in eastern Kenya to assess preparedness for task shifting. Findings indicated gaps in nurses' training, perceived competency, and practice in HIV care and treatment.

Monitoring quality at scale: implementing quality assurance in a diverse, multicountry HIV program.

The centrality of quality as a strategy to achieve impact within the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) has been widely recognized.

Murine Plasmodium chabaudi malaria increases mucosal immune activation and the expression of putative HIV susceptibility markers in the gut and genital mucosae.

Objective: To evaluate if systemic murine malarial infection enhances HIV susceptibility through parasite-induced mucosal immune alterations at sites of HIV sexual exposure.

Background: Malaria and HIV have a high degree of geographical overlap and interact substantially within coinfected individuals. We used a murine model to test the hypothesis that malaria might also enhance HIV susceptibility at mucosal sites of HIV sexual exposure.

Mucosal Th17 cell function is altered during HIV infection and is an independent predictor of systemic immune activation.

Mucosal Th17 cells maintain the gut epithelial barrier and prevent invasion by luminal bacteria through a delicate balance of immunosuppressive and proinflammatory functions. HIV infection is characterized by mucosal Th17 depletion, microbial translocation, and immune activation. Therefore, we assessed the function of blood and sigmoid Th17 cells during both early and chronic HIV infection, as well as the impact of short- and long-term antiretroviral therapy.

Blunted IL17/IL22 and pro-inflammatory cytokine responses in the genital tract and blood of HIV-exposed, seronegative female sex workers in Kenya.

Background: Identifying the immune correlates of reduced susceptibility to HIV remains a key goal for the HIV vaccine field, and individuals who are HIV-exposed, seronegative (HESN) may offer important clues. Reduced systemic immune activation has been described in HESN individuals. Conversely, pro-inflammatory T cell subsets, particularly CD4+ T cells producing the cytokine IL17 (Th17 cells), may represent a highly susceptible target for HIV infection after sexual exposure.

Does antiretroviral therapy initiation increase sexual risk taking in Kenyan female sex workers? A retrospective case-control study.

Objectives: Although antiretroviral therapy (ART) prolongs life and reduces infectiousness, in some contexts, it has been associated with increased sexual risk taking.

Design: Retrospective case-control study.

Setting: Nairobi-based dedicated female sex worker (FSW) clinic.

Effect of raltegravir intensification on HIV proviral DNA in the blood and gut mucosa of men on long-term therapy: a randomized controlled trial.

Background: Highly active antiretroviral therapy (HAART) dramatically reduces plasma HIV-1 viremia. However, despite completely suppressive HAART, it has been suggested that low-levels of viral replication may persist in the gut mucosa and elsewhere in individuals on long-term HAART.

Objective: We conducted a double-blind randomized, placebo-controlled trial evaluating whether intensification of HAART in long-term virologically suppressed individuals with raltegravir is associated with a reduction in the level of proviral HIV-1 DNA in CD4(+) T cells in blood and the sigmoid colon (gut).

Characterization of a human cervical CD4+ T cell subset coexpressing multiple markers of HIV susceptibility.

The HIV pandemic disproportionately affects women, with most infections acquired through receptive vaginal sex. Although the target cells by which HIV establishes infection in the female genital tract remain poorly defined, it is known that immune activation results in CD4(+) T cells with enhanced susceptibility, as does expression of the mucosal integrin α4β7 and the HIV coreceptor CCR5. Blood and cervical cytobrush specimens were collected from female sex workers (FSWs) in Nairobi, Kenya.

Sigmoid Th17 populations, the HIV latent reservoir, and microbial translocation in men on long-term antiretroviral therapy.

Objective: Th17 cells play an important role in mucosal defence and repair and are highly susceptible to infection by HIV. Antiretroviral therapy (ART) suppresses HIV viremia and can restore CD4(+) numbers in the blood and gastrointestinal mucosa, but the resolution of systemic inflammation and gut microbial translocation is often incomplete. We hypothesized that this might relate to persistent dysregulation of gut CD4(+) Th17 subsets.

Biological factors that may contribute to regional and racial disparities in HIV prevalence.

Despite tremendous regional and subregional disparities in HIV prevalence around the world, epidemiology consistently demonstrates that black communities have been disproportionately affected by the pandemic. There are many reasons for this, and a narrow focus on socio-behavioural causes may be seen as laying blame on affected communities or individuals. HIV sexual transmission is very inefficient, and a number of biological factors are critical in determining whether an unprotected sexual exposure to HIV results in productive infection.

Evaluation of a quantitative real-time PCR assay to measure HIV-specific mucosal CD8+ T cell responses in the cervix.

Several candidate HIV vaccines aim to induce virus-specific cellular immunity particularly in the genital tract, typically the initial site of HIV acquisition. However, standardized and sensitive methods for evaluating HIV-specific immune responses at the genital level are lacking. Therefore we evaluated real-time quantitative PCR (qPCR) as a potential platform to measure these responses.

HIV-specific IL-21 producing CD4+ T cells are induced in acute and chronic progressive HIV infection and are associated with relative viral control.

We examined the role of CD4(+) T cell IL-21 production in viral control of HIV infection. HIV-infected individuals had greater circulating IL-21-producing CD4(+) T cells in blood compared with uninfected volunteers. HIV-specific IL-21-producing CD4(+) T cells were detected in blood during untreated acute and chronic HIV infection, and elevated frequencies of these cells correlated with relative viral control.

Estradiol limits viral replication following intravaginal immunization leading to diminished mucosal IgG response and non-sterile protection against genital herpes challenge.

Problem: Previously we reported that ovariectomized (OVX) mice receiving estradiol (E) prior to immunization with an attenuated strain of HSV-2 (TK-HSV-2) were not protected. Lack of protection in the E group was because of the inability of TK-HSV-2 to penetrate the thick keratinized epithelium. In this study, we determined the outcome of immunization after the thickening of vaginal epithelium following E-treatment waned.

Relative HIV resistance in kenyan sex workers is not due to an altered prevalence or mucosal immune impact of herpes simplex virus type 2 infection.

Chronic infection by herpes simplex virus type 2 (HSV-2) increases HIV susceptibility, perhaps due to HSV-2-associated increases in activated mucosal immune cells. A small number of Kenyan female sex workers (FSWs) exhibit relative HIV resistance. We examined whether relative HIV resistance was related to differences in the prevalence or mucosal immune impact of HSV-2.