Lisa M. Bebell

Plasma cytokine levels during acute HIV-1 infection predict HIV disease progression.

Background:Both T-cell activation during early HIV-1 infection and soluble markers of immune activation during chronic infection are predictive of HIV disease progression. Although the acute phase of HIV infection is associated with increased pro-inflammatory cytokine production, the relationship between cytokine concentrations and HIV pathogenesis is unknown. Objectives:To identify cytokine biomarkers measurable in plasma during acute HIV-1 infection that predict HIV disease progression. Design:Study including 40 South African women who became infected with HIV-1 and were followed longitudinally from the time of infection. Methods:The concentrations of 30 cytokines in plasma from women with acute HIV-1 infection were measured and associations between cytokine levels and both viral load set point 12 months postinfection and time taken for CD4 cell counts to fall below 350 cells/μl were determined using multivariate and Cox proportional hazards regression. Results: We found that the concentrations of five plasma cytokines, IL-12p40, IL-12p70, IFN-γ, IL-7 and IL-15 in women with acute infection predicted 66% of the variation in viral load set point 12 months postinfection. IL-12p40, IL-12p70 and IFN-γ were significantly associated with lower viral load, whereas IL-7 and IL-15 were associated with higher viral load. Plasma concentrations of IL-12p40 and granulocyte–macrophage colony-stimulating factor during acute infection were associated with maintenance of CD4 cell counts above 350 cells/μl, whereas IL-1α, eotaxin and IL-7 were associated with more rapid CD4 loss. Conclusion: A small panel of plasma cytokines during acute HIV-1 infection was predictive of long-term HIV disease prognosis in this group of South African women.

Rapid Diagnostic Tests for Malaria at Sites of Varying Transmission Intensity in Uganda

BACKGROUND In Africa, fever is often treated presumptively as malaria, resulting in misdiagnosis and the overuse of antimalarial drugs. Rapid diagnostic tests (RDTs) for malaria may allow improved fever management. METHODS We compared RDTs based on histidine-rich protein 2 (HRP2) and RDTs based on Plasmodium lactate dehydrogenase (pLDH) with expert microscopy and PCR-corrected microscopy for 7000 patients at sites of varying malaria transmission intensity across Uganda. RESULTS When all sites were considered, the sensitivity of the HRP2-based test was 97% when compared with microscopy and 98% when corrected by PCR; the sensitivity of the pLDH-based test was 88% when compared with microscopy and 77% when corrected by PCR. The specificity of the HRP2-based test was 71% when compared with microscopy and 88% when corrected by PCR; the specificity of the pLDH-based test was 92% when compared with microscopy and >98% when corrected by PCR. Based on Plasmodium falciparum PCR-corrected microscopy, the positive predictive value (PPV) of the HRP2-based test was high (93%) at all but the site with the lowest transmission rate; the pLDH-based test and expert microscopy offered excellent PPVs (98%) for all sites. The negative predictive value (NPV) of the HRP2-based test was consistently high (>97%); in contrast, the NPV for the pLDH-based test dropped significantly (from 98% to 66%) as transmission intensity increased, and the NPV for expert microscopy decreased significantly (99% to 54%) because of increasing failure to detect subpatent parasitemia. CONCLUSIONS Based on the high PPV and NPV, HRP2-based RDTs are likely to be the best diagnostic choice for areas with medium-to-high malaria transmission rates in Africa.

Relationship between Levels of Inflammatory Cytokines in the Genital Tract and CD4+ Cell Counts in Women with Acute HIV-1 Infection

Inflammatory responses at mucosal surfaces after human immunodeficiency virus type 1 (HIV-1) transmission may influence disease outcome. We evaluated levels of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha, IL-8, IL-10, and IL-12 in genital tract and plasma specimens from 44 women with acute HIV infection and 29 HIV-negative control women (13 of whom were women in the acute HIV infection cohort who had preinfection samples available for analysis). Women with acute HIV infection had significantly elevated levels of IL-6, IL-10, and IL-12 in genital tract specimens and elevated levels of IL-1beta, IL-8, and IL-10 in plasma specimens, compared with HIV-negative control women. Levels of IL-1beta, IL-6, and IL-8 in cervicovaginal specimens from women with acute HIV infection showed a significant inverse correlation with systemic CD4(+) cell counts, suggesting that mucosal inflammation is associated with low CD4(+) cell counts during acute HIV infection.

Genital Tract Inflammation During Early HIV-1 Infection Predicts Higher Plasma Viral Load Set Point in Women

BACKGROUND The biggest challenge in human immunodeficiency virus type 1 (HIV-1) prevention in Africa is the high HIV-1 burden in young women. In macaques, proinflammatory cytokine production in the genital tract is necessary for target cell recruitment and establishment of simian immunodeficiency virus (SIV) infection following vaginal inoculation. The purpose of this study was to assess if genital inflammation during early HIV-1 infection predisposes women to rapid disease progression. METHODS Inflammatory cytokine concentrations were measured in cervicovaginal lavage (CVL) from 49 women 6, 17, 30, and 55 weeks after HIV-1 infection and from 22 of these women before infection. Associations between genital inflammation and viral load set point and blood CD4 cell counts 12 months after infection were investigated. RESULTS Elevated genital cytokine concentrations 6 and 17 weeks after HIV-1 infection were associated with higher viral load set points and, to a lesser extent, with CD4 depletion. CVL cytokine concentrations during early infection did not differ relative to preinfection but were elevated in women who had vaginal discharge, detectable HIV-1 RNA in their genital tracts, and lower blood CD4 counts. CONCLUSION Genital inflammation during early HIV-1 infection was associated with higher viral load set point and CD4 depletion, which are markers of rapid disease progression. Strategies aimed at reducing genital inflammation during early HIV-1 infection may slow disease progression.

Gene expression during early ascidian metamorphosis requires signalling by Hemps, an EGF-like protein

Hemps, a novel epidermal growth factor (EGF)-like protein, is expressed during larval development and early metamorphosis in the ascidian Herdmania curvata and plays a direct role in triggering metamorphosis. In order to identify downstream genes in the Hemps pathway we used a gene expression profiling approach, in which we compared post-larvae undergoing normal metamorphosis with larval metamorphosis blocked with an anti-Hemps antibody. Molecular profiling revealed that there are dynamic changes in gene expression within the first 30 minutes of normal metamorphosis with a significant portion of the genome (approximately 49%) being activated or repressed. A more detailed analysis of the expression of 15 of these differentially expressed genes through embryogenesis, larval development and metamorphosis revealed that while there is a diversity of temporal expression patterns, a number of genes are transiently expressed during larval development and metamorphosis. These and other differentially expressed genes were localised to a range of specific cell and tissue types in Herdmania larvae and post-larvae. The expression of approximately 24% of the genes that were differentially expressed during early metamorphosis was affected in larvae treated with the anti-Hemps antibody. Knockdown of Hemps activity affected the expression of a range of genes within 30 minutes of induction, suggesting that the Hemps pathway directly regulates early response genes at metamorphosis. In most cases, it appears that the Hemps pathway contributes to the modulation of gene expression, rather than initial gene activation or repression. A total of 151 genes that displayed the greatest alterations in expression in response to anti-Hemps antibody were sequenced. These genes were implicated in a range of developmental and physiological roles, including innate immunity, signal transduction and in the regulation of gene transcription. These results suggest that there is significant gene activity during the very early stages of H. curvata metamorphosis and that the Hemps pathway plays a key role in regulating the expression of many of these genes.

Antibiotic use and emerging resistance—how can resource-limited countries turn the tide?

Antibiotic resistance is a global crisis driven by appropriate and inappropriate antibiotic use to treat human illness and promote animal growth. The antimicrobial resistance epidemic continues to spread due to the triple threat of unfettered access, minimal product regulation and oversight of antibiotic prescription, and lack of clinical diagnostic tools to support antibiotic de-escalation in low-resource settings. In high-resource settings, evidence-based strategies have improved the appropriateness of antibiotic use, limiting the spread of drug-resistant organisms and reducing hospital-associated infections, strategies which may also be effective to stop the spread of resistance in resource-poor countries. Current research and surveillance efforts on antimicrobial resistance and hospital-associated infections in low-resource settings are extremely limited and largely focused on intensive care units. Many challenges exist to improving antibiotic use and infection control in resource-limited settings, and turning the tide requires intensifying research and surveillance, antimicrobial stewardship, and developing new bedside diagnostic tools for bacterial infections and antimicrobial susceptibility.

Acute HIV-1 infection is highly prevalent in Ugandan adults with suspected malaria

Objectives:Acute febrile illnesses consistent with malaria are the most common presentation at health clinics in sub-Saharan Africa, accounting for 30–50% of outpatient visits. The symptoms of acute HIV infection can mimic acute malaria. We investigated whether acute HIV infections could be identified among adults with suspected malaria at rural health centers in Uganda. Design:A cross-sectional study of 1000 consecutive patients referred for malaria blood smears at each of seven government health centers, of which 2893 (41%) were 13 years or older and tested for HIV. Methods:HIV enzyme immunoassay antibody testing was performed on dried blood spots and confirmed by western blot. Enzyme immunoassay-nonreactive and enzyme immunoassay-reactive, western blot-unconfirmed samples were pooled (10/pool) and tested for HIV RNA by nucleic acid amplification testing. We defined acute HIV infection as HIV-1 RNA positive with a negative or indeterminate HIV-1 western blot pattern and early HIV infection as HIV-1 RNA positive with a positive western blot pattern, but with a BED-corrected optical density of below 0.8. Results:Of 2893 patients evaluated, 324 (11%) had test results indicating HIV infection. Overall, 30 patients (1.0%) had acute HIV infection, 56 (1.8%) had early HIV infection, and 238 (8%) had established HIV infection. Acute HIV infections were more prevalent at sites with higher HIV prevalence and lower malaria endemicity. Conclusion:At multiple sites in Uganda, 1–3% of adults with suspected malaria had acute or early HIV infection. These findings highlight a major opportunity for expanding recognition of acute and early HIV infection in Africa.

Ebola Virus Disease and Marburg Disease in Pregnancy: A Review and Management Considerations for Filovirus Infection

The largest-ever recorded outbreak of viral hemorrhagic fever is ongoing. As a result of the epidemic and rural nature of outbreaks, little is published about the Filovirus infections Ebola virus disease and Marburg disease in pregnancy. This review of viral hemorrhagic fever focusing on Marburg and Ebola uses knowledge of disease in nonpregnant individuals and pregnancy-specific data to inform management for pregnant women. Filovirus infection presentation is similar between pregnant and nonpregnant patients, although infections may be more severe in pregnancy. Although labeled as hemorrhagic fevers, Marburg and Ebola do not commonly cause gross bleeding and should be conceptualized as diseases of high gastrointestinal losses. Early, aggressive supportive care is the mainstay of Filovirus infection management with massive fluid resuscitation as the key management principle. Patients often require 5-10 L or more per day of intravenous or oral fluid to maintain circulating blood volume in the setting of ongoing gastrointestinal loss. Fluid shifts warrant aggressive monitoring and correction of potassium levels and acid-base disturbances to prevent life-threatening arrhythmias and metabolic complications. Regardless of maternal survival, fetal loss rates are nearly 100% in Filovirus infection, likely resulting from unchecked transplacental and hematogenous viral spread. High fetal loss rates support the placenta as a difficult-to-eradicate Filovirus infection reservoir. In conclusion, the management of Filovirus infection in pregnancy should focus on stabilizing the mother with intensive monitoring and aggressive fluid and electrolyte repletion as well as maintaining strict infection control to minimize transmission to others.

HIV-1 infection in patients referred for malaria blood smears at government health clinics in Uganda.

Background:HIV is associated with an increased incidence of malaria in adult African populations. In children, the relationship between HIV and malaria is less clear. We investigated the relationship between malaria and HIV-1 infection among adults and children referred for malaria blood smears at government health clinics in Uganda. Methods:This was a cross-sectional study in which 1000 consecutive patients referred for malaria blood smears over the course of 1 to 2 months at each of 7 government clinics (N = 7000) were tested for HIV-1 from dried blood spots using enzyme-linked immunosorbent assay (ELISA) screening and nucleic acid-based confirmatory testing. Risk factors for HIV-1 infection were identified using multivariate logistic regression. Results:Among 4467 children aged 16 years or younger, 77 (1.7%) were HIV-1 infected. Of 2533 adults, 270 (10.7%) were HIV-1 infected. In children, having a negative malaria blood smear was associated with higher odds of HIV-1 infection (odds ratio [OR] = 1.90, 95% confidence interval [CI]: 1.18 to 3.06) after controlling for age and gender. In adults, having a positive malaria blood smear was moderately associated with higher odds of HIV-1 infection (OR = 1.41, 95% CI: 1.01 to 1.97) after controlling for age and gender. Conclusions:In Ugandans evaluated for suspected malaria, associations between malaria smear results and HIV infection differed between children and adults. Although further operations research is needed, our results suggest that counseling and testing for HIV may be of particular importance in children suspected of malaria but with negative malaria smears and in adults with positive malaria smears.

Antimicrobial-resistant infections among postpartum women at a Ugandan referral hospital

Introduction Puerperal sepsis causes 10% of maternal deaths in Africa, but prospective studies on incidence, microbiology and antimicrobial resistance are lacking. Methods We performed a prospective cohort study of 4,231 Ugandan women presenting to a regional referral hospital for delivery or postpartum care, measured vital signs after delivery, performed structured physical exam, symptom questionnaire, and microbiologic evaluation of febrile and hypothermic women. Malaria rapid diagnostic testing, blood and urine cultures were performed aseptically and processed at Epicentre Mbarara Research Centre. Antimicrobial susceptibility and breakpoints were determined using disk diffusion per EUCAST standards. Hospital diagnoses, treatments and outcomes were abstracted from patient charts. Results Mean age was 25 years, 12% were HIV-infected, and 50% had cesarean deliveries. Approximately 5% (205/4176) with ≥1 temperature measurement recorded developed postpartum fever or hypothermia; blood and urine samples were collected from 174 (85%), and 17 others were evaluated clinically. Eighty-four (48%) had at least one confirmed source of infection: 39% (76/193) clinical postpartum endometritis, 14% (25/174) urinary tract infection (UTI), 3% (5/174) bloodstream infection. Another 3% (5/174) had malaria. Overall, 30/174 (17%) had positive blood or urine cultures, and Acinetobacter species were the most common bacteria isolated. Of 25 Gram-negatives isolated, 20 (80%) were multidrug-resistant and cefepime non-susceptible. Conclusions For women in rural Uganda with postpartum fever, we found a high rate of antibiotic resistance among cultured urinary and bloodstream infections, including cephalosporin-resistant Acinetobacter species. Increasing availability of microbiology testing to inform appropriate antibiotic use, development of antimicrobial stewardship programs, and strengthening infection control practices should be high priorities.