The enzyme-linked immunospot (ELISpot) assay is one of the leading technologies used to measure cellular responses in many settings including HIV vaccine clinical trials. HIV-1-specific effector T lymphocyte responses are considered necessary in the control of infection. Accurate measurement and summary of cellular immune responses are critical to HIV research. ELISpot assay readout is often dichotomized into positive/negative responses according to some pre-specified criteria. Given the increase in the number of replicates used for each stimulation with current assay configurations in the HIV Vaccine Trials Network (HVTN) laboratories, a new approach is now possible. We propose an objective criteria based on a hypothesis-driven method that controls the false positive rate while maintaining sensitivity to each of the antigen-specific responses under study. The new approach is compared to other commonly employed criteria using real and simulated data.

Blood and tissue are composed of many functionally distinct cell subsets. In immunological studies, these can be measured accurately only using single-cell assays. The characterization of these small cell subsets is crucial to decipher system-level biological changes. For this reason, an increasing number of studies rely on assays that provide single-cell measurements of multiple genes and proteins from bulk cell samples. A common problem in the analysis of such data is to identify biomarkers (or combinations of biomarkers) that are differentially expressed between two biological conditions (e.g. before/after stimulation), where expression is defined as the proportion of cells expressing that biomarker (or biomarker combination) in the cell subset(s) of interest. Here, we present a Bayesian hierarchical framework based on a beta-binomial mixture model for testing for differential biomarker expression using single-cell assays. Our model allows the inference to be subject specific, as is typically required when assessing vaccine responses, while borrowing strength across subjects through common prior distributions. We propose two approaches for parameter estimation: an empirical-Bayes approach using an Expectation-Maximization algorithm and a fully Bayesian one based on a Markov chain Monte Carlo algorithm. We compare our method against classical approaches for single-cell assays including Fisher's exact test, a likelihood ratio test, and basic log-fold changes. Using several experimental assays measuring proteins or genes at single-cell level and simulations, we show that our method has higher sensitivity and specificity than alternative methods. Additional simulations show that our framework is also robust to model misspecification. Finally, we demonstrate how our approach can be extended to testing multivariate differential expression across multiple biomarker combinations using a Dirichlet-multinomial model and illustrate this approach using single-cell gene expression data and simulations.

Based on previous findings supporting HLA-F as a ligand for KIR3DL2 and KIR2DS4, we investigated the potential for MHC-I open conformers (OCs) as ligands for KIR3DS1 and KIR3DL1 through interactions measured by surface plasmon resonance. These measurements showed physical binding of KIR3DS1 but not KIR3DL1 with HLA-F and other MHC-I OC while also confirming the allotype specific binding of KIR3DL1 with MHC-I peptide complex. Concordant results were obtained with biochemical pull-down from cell lines and biochemical heterodimerization experiments with recombinant proteins. In addition, surface binding of HLA-F and KIR3DS1 to native and activated NK and T cells was coincident with specific expression of the putative ligand or receptor. A functional response of KIR3DS1 was indicated by increased granule exocytosis in activated cells incubated with HLA-F bound to surfaces. The data extend a model for interaction between MHC-I open conformers and activating KIR receptors expressed during an inflammatory response, potentially contributing to communication between the innate and adaptive immune response.

The level of expression of retroviral vector-encoded proteins in T cells, decreasing during periods of quiescence, could be an obstacle to their clinical utility. To identify promoter systems that could increase the strength and persistence of transgene expression in primary human CD8(+) T cells, we designed a panel of Moloney retroviral vectors to express a destabilized enhanced green fluorescent protein (d4EGFP) reporter protein (t(1/2) = 4 hr). We found that the promoters phosphoglycerate kinase (Pgk), beta-actin, and long terminal repeat (LTR) produced the highest levels of d4EGFP expression in proliferating T cells, but that expression dramatically declined in quiescent cells with all promoters. To improve gene expression, we examined the effect of the beta-interferon (IFN) scaffold attachment region (SAR). This SAR augmented expression from mammalian promoters in cycling T cells, but had a small effect on maintenance of expression in resting T cells. However, when the SAR was combined with the LTR promoter, it significantly enhanced expression in resting and cycling cells. These data support use of the IFN-beta SAR with the LTR in Moloney retroviral vectors to help sustain gene expression in resting primary human CD8(+) T cells and to enhance gene expression in activated T cells.

There are few recent data on the rates of AIDS-defining opportunistic infections (OIs) among human immunodeficiency virus (HIV)-infected patients in care in the United States and Canada.

We studied HIV-infected participants in 16 cohorts in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) during 2000-2010. After excluding 16 737 (21%) with any AIDS-defining clinical events documented before NA-ACCORD enrollment, we analyzed incident OIs among the remaining 63 541 persons, most of whom received antiretroviral therapy during the observation. We calculated incidence rates per 100 person-years of observation (hereafter, "person-years") with 95% confidence intervals (CIs) for the first occurrence of any OI and select individual OIs during 2000-2003, 2004-2007, and 2008-2010.

A total of 63 541 persons contributed 261 573 person-years, of whom 5836 (9%) developed at least 1 OI. The incidence rate of any first OI decreased over the 3 observation periods, with 3.0 cases, 2.4 cases, and 1.5 cases per 100 person-years of observation during 2000-2003, 2004-2007, and 2008-2010, respectively (Ptrend<.001); the rates of most individual OIs decreased as well. During 2008-2010, the leading OIs included Pneumocystis jiroveci pneumonia, esophageal candidiasis, and disseminated Mycobacterium avium complex or Mycobacterium kansasii infection.

For HIV-infected persons in care during 2000-2010, rates of first OI were relatively low and generally declined over this time.

BACKGROUND

Human immunodeficiency virus type 2 (HIV-2) is distantly related to the more widespread HIV-1. Although HIV-2 infection is rare in the U.S., cases are concentrated in the Northeast. No FDA-approved HIV-2 viral load assays exist. A clinically validated laboratory-developed assay is currently available in the U.S., however it is not currently approved for use on New York State patients.

OBJECTIVE

To develop a sensitive viral load assay to quantify HIV-2 RNA in plasma and to validate it for clinical use.

METHODS

The real-time RT-PCR assay simultaneously amplifies HIV-2 and a whole virus internal control, added during the lysis step. Two extraction volumes can be used. Results are reported in HIV-2 RNA International Units (IU).

RESULTS

The assay has a limit of detection of 7 IU/mL and a lower limit of quantification of 29 IU/mL. The assay detects multiple strains of HIV-2 group A and B and generates reproducible results. Samples exchanged with a comparator laboratory produced similar viral load results, with 74% of positives differing by <0.5 log10 IU/mL. To date, we have tested 52 clinical specimens from 25 individuals. Twenty-eight (54%) specimens had measurable HIV-2 viral loads (range: 1.63-5.14 log10 IU/mL), 10 (19%) were positive but not quantifiable, and 14 were negative. HIV-2 RNA was detected in at least one specimen from 19 of 25 (76%) individuals tested.

CONCLUSIONS

We developed a sensitive and accurate HIV-2 viral load assay. Validation data indicate the assay is suitable for clinical use and its availability in New York State will improve clinical monitoring of HIV-2 infected patients.

OBJECTIVE

Few routine systems exist to test older, asymptomatic children for HIV. Testing all children in the population has high uptake but is inefficient, whereas testing only symptomatic children increases efficiency but misses opportunities to optimize outcomes. Testing children of HIV-infected adults in care may efficiently identify previously undiagnosed HIV-infected children before symptomatic disease.

METHODS

HIV-infected parents in HIV care in Nairobi, Kenya were systematically asked about their children's HIV status and testing history. Adults with untested children ≤12 years old were actively referred and offered the choice of pediatric HIV testing at home or clinic. Testing uptake and HIV prevalence were determined, as were bottlenecks in pediatric HIV testing cascade.

RESULTS

Of 10,426 HIV-infected adults interviewed, 8,287 reported having children, of whom 3,477 (42%) had children of unknown HIV status, and 611 (7%) had children ≤12 years of unknown HIV status. After implementation of active referral, the rate of pediatric HIV testing increased 3.8-fold from 3.5 to 13.6 children tested per month (Relative risk: 3.8, 95% confidence interval: 2.3 to 6.1). Of 611 eligible adults, 279 (48%) accepted referral and were screened, and 74 (14%) adults completed testing of 1 or more children. HIV prevalence among 108 tested children was 7.4% (95% confidence interval: 3.3 to 14.1%) and median age was 8 years (interquartile range: 2-11); 1 child was symptomatic at testing.

CONCLUSIONS

Referring HIV-infected parents in care to have their children tested revealed many untested children and significantly increased the rate of pediatric testing; prevalence of HIV was high. However, despite increases in pediatric testing, most adults did not complete testing of their children.

Cytomegalovirus (CMV) is acquired by the oral route in children, and primary infection is associated with abundant mucosal replication, as well as the establishment of latency in myeloid cells that results in lifelong infection. The efficiency of primary CMV infection in humans following oral exposure, however, is unknown. We consistently detected self-limited, low-level oral CMV shedding events, which we termed transient CMV infections, in a prospective birth cohort of 30 highly exposed CMV-uninfected infants. We estimated the likelihood of transient oral CMV infections by comparing their observed frequency to that of established primary infections, characterized by persistent high-level shedding, viremia, and seroconversion. We developed mathematical models of viral dynamics upon initial oral CMV infection and validated them using clinical shedding data. Transient infections comprised 76 to 88% of oral CMV shedding events. For this high percentage of transient infections to occur, we identified two mathematical prerequisites: a very small number of initially infected oral cells (1 to 4) and low viral infectivity (<1.5 new cells infected/cell). These observations indicate that oral CMV infection in infants typically begins with a single virus that spreads inefficiently to neighboring cells. Thus, although the incidence of CMV infection is high during infancy, our data provide a mechanistic framework to explain why multiple CMV exposures are typically required before infection is successfully established. These findings imply that a sufficiently primed immune response could prevent CMV from establishing latent infection in humans and support the achievability of a prophylactic CMV vaccine.IMPORTANCE CMV infects the majority of the world's population and is a major cause of birth defects. Developing a vaccine to prevent CMV infection would be extremely valuable but would be facilitated by a better understanding of how natural human CMV infection is acquired. We studied CMV acquisition in infants and found that infections are usually brief and self-limited and are successfully established relatively rarely. Thus, although most people eventually acquire CMV infection, it usually requires numerous exposures. Our analyses indicate that this is because the virus is surprisingly inefficient, barely replicating well enough to spread to neighboring cells in the mouth. Greater knowledge of why CMV infection usually fails may provide insight into how to prevent it from succeeding.

Flow cytometry datasets from clinical trials generate very large datasets and are usually highly standardized, focusing on endpoints that are well defined apriori. Staining variability of individual makers is not uncommon and complicates manual gating, requiring the analyst to adapt gates for each sample, which is unwieldy for large datasets. It can lead to unreliable measurements, especially if a template-gating approach is used without further correction to the gates. In this article, a computational framework is presented for normalizing the fluorescence intensity of multiple markers in specific cell populations across samples that is suitable for high-throughput processing of large clinical trial datasets. Previous approaches to normalization have been global and applied to all cells or data with debris removed. They provided no mechanism to handle specific cell subsets. This approach integrates tightly with the gating process so that normalization is performed during gating and is local to the specific cell subsets exhibiting variability. This improves peak alignment and the performance of the algorithm. The performance of this algorithm is demonstrated on two clinical trial datasets from the HIV Vaccine Trials Network (HVTN) and the Immune Tolerance Network (ITN). In the ITN data set we show that local normalization combined with template gating can account for sample-to-sample variability as effectively as manual gating. In the HVTN dataset, it is shown that local normalization mitigates false-positive vaccine response calls in an intracellular cytokine staining assay. In both datasets, local normalization performs better than global normalization. The normalization framework allows the use of template gates even in the presence of sample-to-sample staining variability, mitigates the subjectivity and bias of manual gating, and decreases the time necessary to analyze large datasets.

UNASSIGNED

The Second Universal Definition of Myocardial Infarction (MI) divides MIs into different types. Type 1 MIs result spontaneously from instability of atherosclerotic plaque, whereas type 2 MIs occur in the setting of a mismatch between oxygen demand and supply, as with severe hypotension. Type 2 MIs are uncommon in the general population, but their frequency in human immunodeficiency virus (HIV)-infected individuals is unknown.

UNASSIGNED

To characterize MIs, including type; identify causes of type 2 MIs; and compare demographic and clinical characteristics among HIV-infected individuals with type 1 vs type 2 MIs.

UNASSIGNED

This longitudinal study identified potential MIs among patients with HIV receiving clinical care at 6 US sites from January 1, 1996, to March 1, 2014, using diagnoses and cardiac biomarkers recorded in the centralized data repository. Sites assembled deidentified packets, including physician notes and electrocardiograms, procedures, and clinical laboratory tests. Two physician experts adjudicated each event, categorizing each definite or probable MI as type 1 or type 2 and identifying the causes of type 2 MI.

UNASSIGNED

The number and proportion of type 1 vs type 2 MIs, demographic and clinical characteristics among those with type 1 vs type 2 MIs, and the causes of type 2 MIs.

UNASSIGNED

Among 571 patients (median age, 49 years [interquartile range, 43-55 years]; 430 men and 141 women) with definite or probable MIs, 288 MIs (50.4%) were type 2 and 283 (49.6%) were type 1. In analyses of type 1 MIs, 79 patients who underwent cardiac interventions, such as coronary artery bypass graft surgery, were also included, totaling 362 patients. Sepsis or bacteremia (100 [34.7%]) and recent use of cocaine or other illicit drugs (39 [13.5%]) were the most common causes of type 2 MIs. A higher proportion of patients with type 2 MIs were younger than 40 years (47 of 288 [16.3%] vs 32 of 362 [8.8%]) and had lower current CD4 cell counts (median, 230 vs 383 cells/µL), lipid levels (mean [SD] total cholesterol level, 167 [63] vs 190 [54] mg/dL, and mean (SD) Framingham risk scores (8% [7%] vs 10% [8%]) than those with type 1 MIs or who underwent cardiac interventions.

UNASSIGNED

Approximately half of all MIs among HIV-infected individuals were type 2 MIs caused by heterogeneous clinical conditions, including sepsis or bacteremia and recent use of cocaine or other illicit drugs. Demographic characteristics and cardiovascular risk factors among those with type 1 and type 2 MIs differed, suggesting the need to specifically consider type among HIV-infected individuals to further understand MI outcomes and to guide prevention and treatment.

Latino immigrant men who have sex with men (MSM) are at risk for HIV and delayed diagnosis in the United States. This paper describes the evaluation of a pilot of the Tu Amigo Pepe, a multimedia HIV testing campaign aimed at Latino MSM in Seattle, WA particularly targeting immigrants who may not identify as gay, ages 18-30 years old. The 16-week campaign included Spanish-language radio public service announcements (PSAs), a Web site, social media outreach, a reminder system using mobile technology, print materials and a toll-free hotline. In developing the PSAs, the Integrated Behavioral Model was used as a framework to reframe negative attitudes, beliefs and norms towards HIV testing with positive ones as well as to promote self-efficacy towards HIV testing. The campaign had a significant and immediate impact on attitudes, beliefs, norms and self-efficacy towards HIV testing as well as on actual behavior, with HIV testing rates increasing over time.

Evidence suggests that specific vaginal bacteria associated with bacterial vaginosis (BV) may increase the risk of adverse health outcomes in women. Among women participating in a randomized, double-blinded trial, we assessed the effect of periodic presumptive treatment (PPT) on detection of select vaginal bacteria.

High-risk women from the United States and Kenya with a recent vaginal infection received intravaginal metronidazole 750 mg plus miconazole 200 mg or placebo for 5 consecutive nights each month for 12 months. Vaginal fluid specimens were collected via polyester/polyethylene terephthalate swabs every other month and tested for bacteria, using quantitative polymerase chain reaction (PCR) assays targeting the 16S ribosomal RNA gene. The effect of PPT on bacterium detection was assessed among all participants and stratified by country.

Of 234 women enrolled, 221 had specimens available for analysis. The proportion of follow-up visits with detectable quantities was lower in the PPT arm versus the placebo arm for the following bacteria: BVAB1, BVAB2, Atopobium vaginae, Leptotrichia/Sneathia, and Megasphaera. The magnitude of reductions was greater among Kenyan participants as compared to US participants.

Use of monthly PPT for 1 year reduced colonization with several bacteria strongly associated with BV. The role of PPT to improve vaginal health should be considered, and efforts to improve the impact of PPT regimens are warranted.

BACKGROUND

An accurate and rapid serologic method to differentiate HIV-2 from HIV-1 infection is required since the confirmatory HIV-1 Western Blot (WB) may demonstrate cross-reactivity with HIV-2 antibodies.

OBJECTIVE

To evaluate the performance of the Bio-Rad Multispot HIV-1/HIV-2 rapid assay as a supplemental test to correctly identify HIV-2 infection and identify HIV-1 WB cross-reactivity with HIV-2 in clinical samples tested at an academic medical center.

METHODS

Between August 2008 and July 2012, clinical samples were screened for HIV using either 3rd- or 4th-generation HIV-1/2 antibody or combination antibody and HIV-1 p24 antigen assays, respectively. All repeatedly reactive samples were reflexed for Multispot rapid testing. Multispot HIV-2 and HIV-1 and HIV-2-reactive samples were further tested using an HIV-2 immunoblot assay and HIV-1 or HIV-2 RNA assays when possible. The HIV-1 WB was performed routinely for additional confirmation and to assess for HIV-2 antibody cross-reactivity.

RESULTS

Of 46,061 samples screened, 890 (89.6%) of 993 repeatedly reactive samples were also Multispot-reactive: 882 for HIV-1; three for only HIV-2; and five for both HIV-1 and HIV-2. All three HIV-2-only Multispot-positives along with a single dually reactive HIV-1/2 Multispot-positive were also HIV-2 immunoblot-positive; the latter was HIV-1 RNA negative and HIV-2 RNA positive.

CONCLUSIONS

The Multispot rapid test performed well as a supplemental test for HIV-1/2 diagnostic testing. Four new HIV-2 infections (0.45%) were identified from among 890 Multispot-reactive tests. The use of HIV-1 WB alone to confirm HIV-1/2 screening assays may underestimate the true prevalence of HIV-2 infection in the United States.

Home HIV testing and counselling (HTC) achieves high levels of HIV testing and linkage to care. Periodic home HTC, particularly targeted to those with high HIV viral load, might facilitate expansion of antiretroviral therapy (ART) coverage. We used a mathematical model to assess the effect of periodic home HTC programmes on HIV incidence in KwaZulu-Natal, South Africa.

We developed a dynamic HIV transmission model with parameters, primary cost data, and measures of viral suppression collected from a prospective study of home HTC in KwaZulu-Natal. In our model, we assumed home HTC took place every 5 years with ART initiation for people with CD4 counts of 350 cells per μL or less. For individuals with CD4 counts of more than 350 cells per μL, we compared increasing ART coverage for those with 350-500 cells per μL with initiating treatment for those who have viral loads of more than 10 000 copies per mL.

Maintaining the presently observed level of 36% viral suppression in HIV-positive people, HIV incidence decreases by 33·8% over 10 years. Home HTC every 5 years with linkage to care with ART initiation at CD4 counts of 350 cells per μL or less reduces HIV incidence by 40·6% over 10 years. Expansion of ART to people with CD4 counts of more than 350 cells per μL who also have a viral load of 10 000 copies per mL or more decreases HIV incidence by 51·6%, and this was the most cost-effective strategy for prevention of HIV infections at US$2960 per infection averted. Expansion of ART eligibility CD4 counts of 350-500 cells per μL is cost-effective at $900 per quality-adjusted life-year gained. Following health economic guidelines, expansion of ART use to individuals who have viral loads of more than 10 000 copies per mL among those with CD4 counts of more than 350 cells per μL was cost-effective to reduce HIV-related morbidity.

Our results show that province-wide home HTC every 5 years can be a cost-effective strategy to increase ART coverage and reduce HIV burden. Expanded ART initiation criteria that includes individuals with high viral load will improve the effectiveness of home HTC in linking individuals to ART who are at high risk of transmitting HIV, thereby preventing morbidity and onward transmission.

National Institutes of Health.

BACKGROUND

The Centers for Disease Control and Prevention recommends at least annual HIV testing for men who have sex with men (MSM), but motivations for testing are not well understood.

METHODS

We evaluated data from MSM testing for HIV at a community-based program in King County, Washington. Correlates of regular testing were examined using generalized estimating equation regression models.

RESULTS

Between February 2004 and June 2011, 7176 MSM attended 12,109 HIV testing visits. When asked reasons for testing, 49% reported that it was time for their regular test, 27% reported unprotected sex, 24% were starting relationships, 21% reported sex with someone new, 21% sought sexually transmitted infection/hepatitis screening, 12% reported sex with an HIV-infected partner, 2% suspected primary HIV infection, and 16% reported other reasons. In multivariable analysis, factors associated with regular testing included having a regular health care provider and the following in the previous year: having only male partners, having 10 or more male partners, inhaled nitrite use, not injecting drugs, and not having unprotected anal intercourse with a partner of unknown/discordant status (P ≤ 0.001 for all). Men reporting regular testing reported shorter intertest intervals than men who did not (median of 233 vs. 322 days, respectively; P < 0.001).

CONCLUSIONS

Regular testing, sexual risk, and new partnerships were important drivers of HIV testing among MSM, and regular testing was associated with increased testing frequency. Promoting regular testing may reduce the time that HIV-infected MSM are unaware of their status, particularly among those who have sex with men and women or inject drugs.

BACKGROUND

Disclosure of HIV serostatus can have significant benefits for people living with HIV/AIDS. However, there is limited data on whether partner disclosure influences ART treatment response.

METHODS

We conducted a retrospective cohort study of newly diagnosed, ART-naïve HIV-infected adults (>18 years) who enrolled at the Coptic Hope Center in Nairobi, Kenya between January 1st 2009 and July 1st 2011 and initiated ART within 3 months. Analysis was restricted to adults who reported to have either disclosed or not disclosed their HIV status to their partner. Analysis of CD4 response at 6 and 12 months post-ART was stratified by age group.

RESULTS

Among 615 adults newly initiating ART with partner disclosure data and 12 month follow-up, mean age was 38 years and 52% were male; 76% reported that they had disclosed their HIV-status to their partner. Those who disclosed were significantly younger and more likely to be married/cohabitating than non-disclosers. At baseline, median CD4 counts were similar between disclosure groups. Among younger adults (< 38 years) those who disclosed had higher CD4 recovery than those who did not at 6 months post- ART (mean difference = 31, 95% CI 3 to 58 p = 0.03) but not at 12 months (mean difference = 17, 95% CI -19 to 52, p = 0.4). Among older adults (≥ 38years) there was no observed difference in CD4 recovery at 6 or 12 months between disclosure groups.

CONCLUSIONS

Among younger adults, disclosure of HIV status to partners may be associated with CD4 recovery following ART.

We conducted a systematic review to assess evidence for disparities for lesbian and bisexual women (i.e., sexual minority women [SMW]) in comparison with heterosexual women across a range of nine physical health conditions. Among the k = 11 studies meeting eligibility criteria, almost every comparison (i.e., heterosexual vs. (a) lesbian, (b) bisexual, or (c) both lesbian and bisexual women) was in a direction indicating SMW disparities. Despite limited power due to small samples of SMW, we found evidence of disparities as indicated by a statistically significant adjusted odds ratios for asthma (5 of 7 comparisons), obesity (8 of 12), arthritis (2 of 3), global ratings of physical health (4 of 7), and cardiovascular disease (1 of 1). Evidence was lacking for cancer (1 of 4), diabetes and hypertension (both 1 of 5), and high cholesterol (0 of 3). Future work should confirm findings in more diverse, larger samples and should examine potential explanatory factors.

BACKGROUND

With malaria declining, other causes of fever may account for a substantial portion of severe childhood illness in sub-Saharan Africa. We determined prevalence, etiologies, and correlates of bacteremia among children in Western Kenya.

METHODS

In a cross-sectional study, febrile children aged 6 months to 15 years presenting to Kisii (low malaria endemicity) and Homabay (high malaria endemicity) Hospitals were enrolled and screened for malaria, human immunodeficiency virus (HIV) infection and bacteremia. Correlates of bacteremia were evaluated using logistic regression.

RESULTS

Among 1476 children enrolled, 48 (3.3%) had bacteremia (23 of 734, 3.1% in Kisii and 25 of 734, 3.4% in Homabay). Salmonella spp (19 typhi and 21 nontyphoidal salmonella) accounted for 83% (40 of 48) of isolates. The distribution of Salmonella spp was similar between sites. Bacteremia was associated with incomplete vaccination (adjusted odds ratio [aOR] = 2.1; 95% confidence interval [CI], 1.1-4.1), before treatment with antimalarials (aOR = 2.7; 95% CI, 1.4-4.1), having sought care elsewhere (aOR = 2.2; 95% CI, 1.2-4.0) and lower education of caregiver (aOR = 2.5; 95% CI, 1.1-4.8). Nontyphoidal salmonella bacteremia was associated with HIV (aOR = 6.8; 95% CI, 1.1-35.1) and anemia (hemoglobin <8 g/dL) (aOR = 5.2; 95% CI, 1.4-18.9).

CONCLUSIONS

Bacteremia was relatively uncommon, but children with HIV, anemia, incomplete vaccination, and/or persistent fever despite malaria treatment may have higher risk and may benefit from targeted bacterial culture and/or empiric antibiotic therapy.

Cell culture growth competition assays of human immunodeficiency virus type 1 (HIV-1) are used to estimate viral fitness and quantify the impact of mutations conferring drug resistance and immunological escape. A comprehensive study of growth competition assays was conducted and identified experimental parameters that can impact measurements of relative fitness including multiplicity of infection, viral input ratio, number, timing and interval of time points used to evaluate selective outgrowth, and the algorithm for calculating fitness values. An optimized protocol is developed here that is a multi-point growth competition assay that resolves reproducibly small differences in viral fitness. The optimized protocol uses an MOI of 0.005, a consistent ratio of mutant: parental viruses (70:30), and a multipoint [1+s 4,7] algorithm that uses data points within the logarithmic phase of viral growth for assessing fitness differences.

We profiled the humoral response in the penis, an area that has been minimally explored but may be relevant for protecting insertive men against HIV and other sexually acquired infections. Comparing paired tissue samples from 20 men at risk of HIV infection, foreskin contains less immunoglobulin A (IgA) and more IgG2 than colon. Using foreskin dermal and epidermal explants and paired plasma from 17 men, we examined Ig accumulation by normalizing Ig to human serum albumin (HSA) transudation. Dermal IgM, IgG2, IgA, and IgE ratios were greater than that in plasma, suggesting there is local antibody secretion at the dermis. Local Ig transcription was concentrated at the inner rather than the outer foreskin, and inner foreskin Ig ratios did not correlate with blood, indicating that localized production can contribute to the foreskin response. IgM, IgG1, IgG3, and IgA have preferential access to the foreskin epidermis, whereas IgG2, IgG4, and IgE are restricted to the dermis. Lastly, Ad5-specific IgA was selectively present in the colon, whereas foreskin Ad5 IgG was mainly derived from blood, and reached the inner epidermis at higher ratios than the outer (P<0.002). In summary, the foreskin antibody response combines local and systemic sources, and there is selective isotype accumulation in the epidermis.

Daily oral tenofovir-based pre-exposure prophylaxis (PrEP) is high efficacious for HIV prevention among women with high adherence. However, the effect of abnormal vaginal microbiota on PrEP efficacy is of concern. We investigated whether bacterial vaginosis modified the efficacy of oral PrEP.

We used prospectively collected data from women in the Partners PrEP Study, a placebo-controlled trial of daily oral PrEP (either tenofovir monotherapy or a combination of tenofovir and emtricitabine) in HIV serodiscordant couples aged 18 years or older in Kenya and Uganda that showed high efficacy in women. We used Cox proportional hazards regression to assess PrEP efficacy among subgroups of women defined by bacterial vaginosis status based on yearly microscopy and Nugent scoring (0-3 indicated healthy microbiota, 4-6 intermediate, and 7-10 bacterial vaginosis). In separate efficacy analyses, we also investigated individual components of the score (ie, detection of Gardnerella vaginalis or Bacteroides spp and non-detection of Lactobacillus spp) as markers of abnormal microbiota.

Of 1470 women (median age 33 years), 357 (24%) had bacterial vaginosis at enrolment. 45 women seroconverted to HIV. The HIV prevention efficacy of PrEP did not differ significantly among women with healthy microbiota (incidence 0·6 per 100 person years in PrEP group and 2·5 per 100 person-years in the placebo group; efficacy 76·55% [95% CI 43·09 to 90·37]), intermediate microbiota (HIV incidence 1·8 per 100 person-years in the PrEP group and 3·5 per 100 person-years in the placebo group; efficacy 62·72% [95% CI -66·59 to 91·66]), or bacterial vaginosis (HIV incidence 0·9 per 100 person-years in the PrEP group and 3·5 per 100 person-years in the placebo group; efficacy 72·50% [95% CI 5·98 to 91·95]; pinteraction=0·871). PrEP efficacy was not significantly different between women with detected G vaginalis or Bacteroides spp morphotypes and those without these morphotypes (efficacy 68·62% vs 76·72%; pinteraction=0·652); or between those with Lactobacillus spp morphotypes and those without (70·48% vs 74·08%; pinteraction=0·86).

Among African women with a high prevalence of bacterial vaginosis and high adherence to PrEP, the efficacy of daily oral PrEP for HIV prevention did not differ significantly among women with abnormal versus healthy vaginal microbiota as defined by Nugent score. These data are reassuring that oral PrEP delivery to women can continue without the need for concurrent testing for bacterial vaginosis or vaginal dysbiosis.

Bill & Melinda Gates Foundation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, and National Institute of Allergy and Infectious Diseases.

Public health field services for sexually transmitted infections (STIs) have not adequately evolved to address the expanding scale of the STI problem, its concentration among men who have sex with men, the emergence of new communication technologies and the availability of antiretroviral therapy as a cornerstone of human immunodeficiency virus (HIV) prevention. Field services need to modernize. Modernization should seek to expand field services objectives beyond sex partner STI testing and treatment to include: HIV testing of persons with bacterial STI and their partners, including efforts to promote frequent HIV/STI testing; increased condom access; linkage and relinkage to HIV care and promotion of viral suppression; preexposure prophylaxis promotion; linkage to long-acting contraception; and referral for health insurance. Field services programs cannot advance these new objectives while simultaneously doing all of the work they have traditionally done. Modernization will require a willingness to reconsider some longstanding aspects of field services work, including the centrality of face-to-face interviews and field investigations. Health departments seeking to modernize will need to carefully assess their ongoing activities and reorganize to align the use of field services resources with program priorities. In some instances, this may require reorganization to allow the staff greater specialization and closer integration with surveillance activities. Adapting programs will require new staff training, improvements in data management systems, and a greater investment in monitoring and evaluation. Although modernization is likely to evolve over many years, the time to start is now.