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OBJECTIVES: In high-income countries (HICs), sepsis endotypes defined by distinct pathobiological mechanisms, mortality risks, and responses to corticosteroid treatment have been identified using blood transcriptomics. The generalizability of these endotypes to low-income and middle-income countries (LMICs), where the global sepsis burden is concentrated, is unknown. We sought to determine the prevalence, prognostic relevance, and immunopathological features of HIC-derived transcriptomic sepsis endotypes in sub-Saharan Africa. DESIGN: Prospective cohort study. SETTING: Public referral hospital in Uganda. PATIENTS: Adults ( n = 128) hospitalized with suspected sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Using whole-blood RNA sequencing data, we applied 19-gene and 7-gene classifiers derived and validated in HICs (SepstratifieR) to assign patients to one of three sepsis response signatures (SRS). The 19-gene classifier assigned 30 (23.4%), 92 (71.9%), and 6 (4.7%) patients to SRS-1, SRS-2, and SRS-3, respectively, the latter of which is designed to capture individuals transcriptionally closest to health. SRS-1 was defined biologically by proinflammatory innate immune activation and suppressed natural killer-cell, T-cell, and B-cell immunity, whereas SRS-2 was characterized by dampened innate immune activation, preserved lymphocyte immunity, and suppressed transcriptional responses to corticosteroids. Patients assigned to SRS-1 were predominantly (80.0% [24/30]) persons living with HIV with advanced immunosuppression and frequent tuberculosis. Mortality at 30-days differed significantly by endotype and was highest (48.1%) in SRS-1. Agreement between 19-gene and 7-gene SRS assignments was poor (Cohen's kappa 0.11). Patient stratification was suboptimal using the 7-gene classifier with 15.1% (8/53) of individuals assigned to SRS-3 deceased at 30-days. CONCLUSIONS: Sepsis endotypes derived in HICs share biological and clinical features with those identified in sub-Saharan Africa, with major differences in host-pathogen profiles. Our findings highlight the importance of context-specific sepsis endotyping, the generalizability of conserved biological signatures of critical illness across disparate settings, and opportunities to develop more pathobiologically informed sepsis treatment strategies in LMICs.
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Sepse , Transcriptoma , Adulto , Humanos , Estudos Prospectivos , Uganda/epidemiologia , Perfilação da Expressão Gênica , CorticosteroidesRESUMO
BACKGROUND: The global burden of sepsis is concentrated in sub-Saharan Africa, where severe infections disproportionately affect young, HIV-infected adults and high-burden pathogens are unique. In this context, poor understanding of sepsis immunopathology represents a crucial barrier to development of locally-effective treatment strategies. We sought to determine inter-individual immunologic heterogeneity among adults hospitalized with sepsis in a sub-Saharan African setting, and characterize associations between immune subtypes, infecting pathogens, and clinical outcomes. METHODS: Among a prospective observational cohort of 288 adults hospitalized with suspected sepsis in Uganda, we applied machine learning methods to 14 soluble host immune mediators, reflective of key domains of sepsis immunopathology (innate and adaptive immune activation, endothelial dysfunction, fibrinolysis), to identify immune subtypes in randomly-split discovery (N = 201) and internal validation (N = 87) sub-cohorts. In parallel, we applied similar methods to whole-blood RNA-sequencing data from a consecutive subset of patients (N = 128) to identify transcriptional subtypes, which we characterized using biological pathway and immune cell-type deconvolution analyses. RESULTS: Unsupervised clustering consistently identified two immune subtypes defined by differential activation of pro-inflammatory innate and adaptive immune pathways, with transcriptional evidence of concomitant CD56(-)/CD16( +) NK-cell expansion, T-cell exhaustion, and oxidative-stress and hypoxia-induced metabolic and cell-cycle reprogramming in the hyperinflammatory subtype. Immune subtypes defined by greater pro-inflammatory immune activation, T-cell exhaustion, and metabolic reprogramming were consistently associated with a high-prevalence of severe and often disseminated HIV-associated tuberculosis, as well as more extensive organ dysfunction, worse functional outcomes, and higher 30-day mortality. CONCLUSIONS: Our results highlight unique host- and pathogen-driven features of sepsis immunopathology in sub-Saharan Africa, including the importance of severe HIV-associated tuberculosis, and reinforce the need to develop more biologically-informed treatment strategies in the region, particularly those incorporating immunomodulation.
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Infecções por HIV , Sepse , Tuberculose , Humanos , Prognóstico , Uganda/epidemiologiaRESUMO
BACKGROUND: In high-income countries, allergy-related diseases (ARDs) follow a typical sequence, the 'Atopic March'. Little is known about the life-course of ARDs in the markedly different, low-income, tropical environment. We describe ARDs in a tropical, African birth cohort. METHODS: Ugandan children were followed from birth to 9 years. ISAAC questionnaires were completed at intervals; doctor-diagnosed ARDs were recorded throughout follow-up. Skin prick tests (SPTs) were performed at 3 and 9 years. Atopy was defined as ≥1 positive SPT. RESULTS: Of the 2345 live-born children, 1214 (52%) were seen at 9 years. Wheeze and eczema were common in infancy, but by 9 years, only 4% reported recent wheeze, 5% eczema and 5% rhinitis. Between 3 and 9 years, atopy prevalence increased from 19% to 25%. Atopy at 3 or 9 years was associated with reported ARD events at 9 years, for example OR = 5.2 (95% CI 2.9-10.7) for atopy and recent wheeze at 9 years. Reported or doctor-diagnosed ARD events in early childhood were associated with the same events in later childhood, for example OR = 4.4 (2.3-8.4) for the association between reported wheeze before 3 years with reported recent wheeze at 9 years, but progression from early eczema to later rhinitis or asthma was not observed. CONCLUSION: Allergen sensitization started early in childhood and increased with age. Eczema and wheeze were common in infancy and declined with age. Atopy was strongly associated with ARD among the few affected children. The typical Atopic March did not occur. Environmental exposures during childhood may dissociate atopy and ARD.
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Hipersensibilidade Imediata/epidemiologia , Pobreza , África Subsaariana/epidemiologia , Alérgenos/imunologia , Criança , Pré-Escolar , Estudos de Coortes , Comorbidade , Países em Desenvolvimento , Feminino , Seguimentos , Humanos , Masculino , Prevalência , Sons Respiratórios , Testes Cutâneos , Inquéritos e Questionários , Uganda/epidemiologiaRESUMO
BACKGROUND: Helminth infections, common in low-income countries, may protect against allergy-related disease. Early exposure may be a key. In the Entebbe Mother and Baby Study, treating helminths during pregnancy resulted in increased eczema rates in early childhood. We followed the cohort to determine whether this translated to increased asthma rates at school age. METHODS: This randomized, double-blind, placebo-controlled trial, conducted in Entebbe, Uganda, had three interventions. During pregnancy, women were randomized, simultaneously, to albendazole vs placebo and to praziquantel vs placebo. Their children were independently randomized to quarterly albendazole vs placebo from age 15 months to 5 years. We here report follow-up to age 9 years. Primary outcomes at 9 years were recent reported wheeze, skin prick test positivity (SPT) to common allergens and allergen-specific IgE positivity to dust mite or cockroach. Secondary outcomes were doctor-diagnosed asthma and eczema rates between 5 and 9 years, recent eczema, rhinitis and urticaria at 9 years, and SPT and IgE responses to individual allergens. RESULTS: 2507 pregnant women were enrolled; 1215 children were seen at age nine, of whom 1188 are included in this analysis. Reported wheeze was rare at 9 years (3.7%) while SPT positivity (25.0%) and IgE positivity (44.1%) were common. There was no evidence of a treatment effect for any of the three interventions on any of the primary outcomes. CONCLUSIONS: Prenatal and early-life treatment of helminths, in the absence of change in other exposures, is unlikely to increase the risk of atopic diseases later in childhood in this tropical, low-income setting.
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Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Asma/etiologia , Helmintíase/tratamento farmacológico , Praziquantel/uso terapêutico , Complicações Parasitárias na Gravidez/tratamento farmacológico , Asma/diagnóstico , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Seguimentos , Helmintíase/imunologia , Humanos , Lactente , Masculino , Gravidez , Complicações Parasitárias na Gravidez/imunologia , Efeitos Tardios da Exposição Pré-Natal/etiologia , Fatores de Risco , Resultado do Tratamento , UgandaRESUMO
BACKGROUND: The malaria burden in sub-Saharan Africa (SSA) has fallen substantially. Nevertheless, malaria remains a serious health concern, and Uganda ranks third in SSA in total malaria burden. Epidemiological studies of adult malaria in Uganda are scarce and little is known about rates of malaria in non-pregnant adult women. This pilot study assessed malaria prevalence among adult women from Wakiso district, historically a highly malaria endemic region. METHODS: Adult women using public health services were screened for malaria, HIV and pregnancy. A physician-selected subset of women presenting to the Outpatient Department of Entebbe General Hospital (EGH) with current fever (axillary temperature ≥37.5 °C) or self-reporting fever during the previous 24 h, and a positive thick smear for malaria in the EGH laboratory were enrolled (n = 86). Women who self-identified as pregnant or HIV-positive were excluded from screening. Malaria infection was then assessed using HRP2/pLDH rapid diagnostic tests (RDTs) in all participants. Repeat microscopy and PCR were performed at a research laboratory for a subset of participants. In addition, 104 women without a history of fever were assessed for asymptomatic parasitaemia using RDT, and a subset of these women screened for parasitaemia using microscopy (40 women) and PCR (40 women). RESULTS: Of 86 women diagnosed with malaria by EGH, only two (2.3%) had malaria confirmed using RDT, subsequently identified as a Plasmodium falciparum infection by research microscopy and PCR. Subset analysis of hospital diagnosed RDT-negative participants detected one sub-microscopic infection with Plasmodium ovale. Compared to RDT, sensitivity, specificity and PPV of hospital microscopy were 100% (CI 19.8-100), 0% (CI 0-5.32) and 2.33% (CI 0.403-8.94) respectively. Compared to PCR, sensitivity, specificity and PPV of hospital microscopy were 100% (CI 31.0-100), 0% (CI 0-34.5) and 23.1% (CI 6.16-54.0), respectively. No malaria was detected among asymptomatic women using RDT, research microscopy or PCR. CONCLUSIONS: Malaria prevalence among adult women appears to be low in Wakiso, but is masked by high rates of malaria overdiagnosis. More accurate malaria testing is urgently needed in public hospitals in this region to identify true causes of febrile illness and reduce unnecessary provision of anti-malarial therapy.
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Malária/epidemiologia , Adolescente , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Prevalência , Uganda/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Worms may protect against allergy. Early-life worm exposure may be critical, but this has not been fully investigated. OBJECTIVES: To investigate whether worms in pregnancy and in early childhood are associated with childhood eczema incidence. METHODS: The Entebbe Mother and Baby Study, an anthelminthic treatment trial, enrolled pregnant women between 2003 and 2005 in Uganda. Mothers were investigated for worms during pregnancy and children annually. Eczema was doctor-diagnosed from birth to age five years. A planned observational analysis was conducted within the trial cohort to investigate associations between worms and eczema. RESULTS: Data for 2345 live-born children were analysed. Hookworm was the most prevalent maternal worm (45%). Childhood worms were less prevalent. Eczema incidence was 4.68/100 person-years. Maternal hookworm was associated with reduced eczema incidence [adjusted hazard ratio (95% confidence interval), p-value: 0.71(0.51-0.99), 0.04] and modified effects of known risk factors for eczema: Dermatophagoides-specific IgE in children was positively associated with eczema incidence if the mother had no hookworm [2.72(1.11-6.63), 0.03], but not if the mother had hookworm [0.41(0.10-1.69), 0.22], interaction p-value = 0.03. Similar interactions were seen for maternal history of eczema {[2.87(1.31-6.27, 0.008) vs. [0.73(0.23-2.30), 0.60], interaction p-value = 0.05}, female gender {[1.82(1.22-2.73), 0.004 vs. [0.96(0.60-1.53), 0.87], interaction p-value = 0.04} and allergen-specific IgE. Childhood Trichuris trichiura and hookworm were inversely associated with eczema. CONCLUSIONS: Maternal hookworm modifies effects of known risk factors for eczema. Mechanisms by which early-life worm exposures influence allergy need investigation. Worms or worm products, and intervention during pregnancy have potential for primary prevention of allergy.
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Eczema/epidemiologia , Infecções por Uncinaria/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Pré-Escolar , Estudos de Coortes , Método Duplo-Cego , Feminino , Infecções por Uncinaria/tratamento farmacológico , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Gravidez , Modelos de Riscos Proporcionais , Fatores de Risco , Uganda/epidemiologiaRESUMO
The COVID-19 vaccine rollout programme in Uganda was launched in March 2021 for priority groups: Healthcare Workers (HCWs), older persons (≥50 years), and persons with chronic conditions. Misinformation, distrust in healthcare systems, and cultural beliefs, pose significant challenges to vaccine uptake. We describe the social and structural factors affecting the uptake of COVID-19 vaccines among HCWs and older people in Uganda. Between September and October 2021, we conducted 33 in-depth interviews with 25 HCWs aged 21-63 years from three hospitals in central Uganda and eight older people from Wakiso district. Participant selection was purposive, based on sex, occupation, education, cadre of HCWs and vaccination status. We explored participants' knowledge, beliefs, personal experiences, barriers, and facilitators to vaccine uptake as well as suggestions for future COVID-19 vaccine rollout. Interviews were audio-recorded, transcribed and translated into English, coded, and analysed by theme. Twenty-two of the 25 (88%) HCWs and 3 of the 8 (38%) older people had received at least one dose of the COVID-19 vaccine at the time of interview. The structural facilitating factors to vaccine uptake included access to correct information, fear of a risky work environment, and mandatory vaccination requirements especially for frontline HCWs. Age, chronic health conditions, and the fear of death were facilitating factors for older people. Misconceptions about COVID-19 vaccines and fear of side effects were common social barriers for both groups. Long distances to vaccination centres, vaccine stock-outs, and long queues at the vaccination centres were specific barriers for older people. The prerequisite of signing a consent form was a specific structural barrier for HCWs. Future roll out of new vaccines should have a comprehensive information dissemination strategy about the vaccines. Improved access to vaccines through community outreach, reliable vaccine supplies and addressing vaccine misinformation, may enhance COVID-19 vaccine uptake.
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Little is known about the pathobiology of SARS-CoV-2 infection in sub-Saharan Africa, where severe COVID-19 fatality rates are among the highest in the world and the immunological landscape is unique. In a prospective cohort study of 306 adults encompassing the entire clinical spectrum of SARS-CoV-2 infection in Uganda, we profile the peripheral blood proteome and transcriptome to characterize the immunopathology of COVID-19 across multiple phases of the pandemic. Beyond the prognostic importance of myeloid cell-driven immune activation and lymphopenia, we show that multifaceted impairment of host protein synthesis and redox imbalance define core biological signatures of severe COVID-19, with central roles for IL-7, IL-15, and lymphotoxin-α in COVID-19 respiratory failure. While prognostic signatures are generally consistent in SARS-CoV-2/HIV-coinfection, type I interferon responses uniquely scale with COVID-19 severity in persons living with HIV. Throughout the pandemic, COVID-19 severity peaked during phases dominated by A.23/A.23.1 and Delta B.1.617.2/AY variants. Independent of clinical severity, Delta phase COVID-19 is distinguished by exaggerated pro-inflammatory myeloid cell and inflammasome activation, NK and CD8+ T cell depletion, and impaired host protein synthesis. Combining these analyses with a contemporary Ugandan cohort of adults hospitalized with influenza and other severe acute respiratory infections, we show that activation of epidermal and platelet-derived growth factor pathways are distinct features of COVID-19, deepening translational understanding of mechanisms potentially underlying SARS-CoV-2-associated pulmonary fibrosis. Collectively, our findings provide biological rationale for use of broad and targeted immunotherapies for severe COVID-19 in sub-Saharan Africa, illustrate the relevance of local viral and host factors to SARS-CoV-2 immunopathology, and highlight underemphasized yet therapeutically exploitable immune pathways driving COVID-19 severity.
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COVID-19 , Coinfecção , Infecções por HIV , Adulto , Humanos , SARS-CoV-2 , Coinfecção/epidemiologia , Uganda/epidemiologia , Pandemias , Estudos Prospectivos , Infecções por HIV/complicações , Infecções por HIV/epidemiologiaRESUMO
The global burden of sepsis is concentrated in sub-Saharan Africa (SSA), where epidemic HIV and unique pathogen diversity challenge the effective management of severe infections. In this context, patient stratification based on biomarkers of a dysregulated host response may identify subgroups more likely to respond to targeted immunomodulatory therapeutics. In a prospective cohort of adults hospitalized with suspected sepsis in Uganda, we applied machine learning methods to develop a prediction model for 30-day mortality that integrates physiology-based risk scores with soluble biomarkers reflective of key domains of sepsis immunopathology. After model evaluation and internal validation, whole-blood RNA sequencing data were analyzed to compare biological pathway enrichment and inferred immune cell profiles between patients assigned differential model-based risks of mortality. Of 260 eligible adults (median age, 32 years; interquartile range, 26-43 years; 59.2% female, 53.9% living with HIV), 62 (23.8%) died by 30 days after hospital discharge. Among 14 biomarkers, soluble tumor necrosis factor receptor 1 (sTNFR1) and angiopoietin 2 (Ang-2) demonstrated the greatest importance for mortality prediction in machine learning models. A clinicomolecular model integrating sTNFR1 and Ang-2 with the Universal Vital Assessment (UVA) risk score optimized 30-day mortality prediction across multiple performance metrics. Patients assigned to the high-risk, UVA-based clinicomolecular subgroup exhibited a transcriptional profile defined by proinflammatory innate immune and necroptotic pathway activation, T-cell exhaustion, and expansion of key immune cell subsets including regulatory and gamma-delta T cells. Clinicomolecular stratification of adults with suspected sepsis in Uganda enhanced 30-day mortality prediction and identified a high-risk subgroup with a therapeutically targetable immunological profile. Further studies are needed to advance pathobiologically informed sepsis management in SSA.
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Infecções por HIV , Sepse , Humanos , Adulto , Feminino , Masculino , Projetos Piloto , Estudos Prospectivos , Uganda/epidemiologia , Biomarcadores , Infecções por HIV/epidemiologiaRESUMO
Background: A significant overlap exists in the burden of Alcohol Use Disorders (AUDs) and the HIV epidemic in Sub-Saharan Africa. Over 60% of HIV infections occur in women, mostly through the cervical mucosa. Absorption and systemic circulation of alcohol induces global physiological and immune effects, including at the genital mucosa. Alcohol alters expression of cell surface receptors, mucosal barrier permeability, inflammatory responses, and lymphocyte trafficking and homing. However, a substantial knowledge gap exists on whether these cellular and or immunological effects of alcohol modify the consumers' CD4+ T cell susceptibility to HIV-1 entry at the cervical mucosa. HIV seronegative women, aged 18-49 years were recruited from Kasenyi and Kigungu fish landing sites of Lake Victoria. They were categorized as Alcohol Consumers (n=27) or non-Alcohol Consumers (n=26) based on the World Health Organization Alcohol-Use-Disorder-Test (WHO-AUDIT) at a cut-off score of >=8/40 and <8/40, respectively. Cytobrush-collected Cervical Mononuclear Cells [CMCs] and Peripheral Blood Mononuclear Cells [PBMCs] from heparinized whole-blood were surface stained for CD4+ T cell immunophenotyping. To measure susceptibility to HIV entry, CMCs and PBMCs were co-cultured overnight with equal amount of GFP-tagged HIV-1 pseudo-virus particles. Both immunophenotyping and HIV entry were measured on a BD LSR II flow cytometer. Results: There was no significant difference in the frequency of CD4+ T cells in blood (p=0.451) or mucosa (p=0.838) compartments across study groups. However, we observed a combined four-fold higher HIV entry (p=0.0001) into cervical versus blood-derived CD4+ T cells regardless of alcohol consumption status. More so, cervical-derived CD4+ T cells of alcohol-consumers showed a two-fold increase in susceptibility to HIV entry (P=0.0185) compared to the non-alcohol consumer group. Double positive α4ß7+CD4+T cells of alcohol consumers exhibited a higher HIV entry compared to those from alcohol non-consumers(p=0.0069). Conclusion: This study demonstrates that cervical CD4+ T cells are more susceptible to HIV entry than those from blood. Also, cervical CD4+ T cells of alcohol consumers are more susceptible than those of non-consumers. Differences in frequencies of α4ß7+ CD4+ T between alcohol consumers and non-consumers' cells may account for the increased susceptibility to HIV entry.
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BACKGROUND: The immunopathology of disseminated HIV-associated tuberculosis (HIV/TB), a leading cause of critical illness and death among persons living with HIV in sub-Saharan Africa, is incompletely understood. Reflective of hematogenously disseminated TB, detection of lipoarabinomannan (LAM) in urine is associated with greater bacillary burden and poor outcomes in adults with HIV/TB. METHODS: We determined the relationship between detection of urine TB-LAM, organ dysfunction, and host immune responses in a prospective cohort of adults hospitalized with severe HIV/TB in Uganda. Generalized additive models were used to analyze the association between urine TB-LAM grade and concentrations of 14 soluble immune mediators. Whole-blood RNA-sequencing data were used to compare transcriptional profiles between patients with high- vs. low-grade TB-LAM results. RESULTS: Among 157 hospitalized persons living with HIV, 40 (25.5%) had positive urine TB-LAM testing. Higher TB-LAM grade was associated with more severe physiologic derangement, organ dysfunction, and shock. Adjusted generalized additive models showed that higher TB-LAM grade was significantly associated with higher concentrations of mediators reflecting proinflammatory innate and T-cell activation and chemotaxis (IL-8, MIF, MIP-1ß/CCL4, and sIL-2Ra/sCD25). Transcriptionally, patients with higher TB-LAM grades demonstrated multifaceted impairment of antibacterial defense including reduced expression of genes encoding cytotoxic and autophagy-related proteins and impaired cross-talk between innate and cell-mediated immune effectors. CONCLUSIONS: Our findings add to emerging data suggesting pathobiological relationships between LAM, TB dissemination, innate cell activation, and evasion of host immunity in severe HIV/TB. Further translational studies are needed to elucidate the role for immunomodulatory therapies, in addition to optimized anti-TB treatment, in this often critically ill population.
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Infecções por HIV , Tuberculose , Humanos , Adulto , Infecções por HIV/epidemiologia , Estudos Prospectivos , Uganda , Insuficiência de Múltiplos Órgãos/complicações , Tuberculose/complicações , Lipopolissacarídeos/urina , Imunidade Inata , Sensibilidade e EspecificidadeRESUMO
Introduction: Understanding how spike (S)-, nucleoprotein (N)-, and RBD-directed antibody responses evolved in mild and asymptomatic COVID-19 in Africa and their interactions with SARS-CoV-2 might inform development of targeted treatments and vaccines. Methods: Here, we used a validated indirect in-house ELISA to characterise development and persistence of S- and N-directed IgG, IgM, and IgA antibody responses for 2430 SARS-CoV-2 rt-PCR-diagnosed Ugandan specimens from 320 mild and asymptomatic COVID-19 cases, 50 uninfected contacts, and 54 uninfected non-contacts collected weekly for one month, then monthly for 28 months. Results: During acute infection, asymptomatic patients mounted a faster and more robust spike-directed IgG, IgM, and IgA response than those with mild symptoms (Wilcoxon rank test, p-values 0.046, 0.053, and 0.057); this was more pronounced in males than females. Spike IgG antibodies peaked between 25 and 37 days (86.46; IQR 29.47-242.56 BAU/ml), were significantly higher and more durable than N- and RBD IgG antibodies and lasted for 28 months. Anti-spike seroconversion rates consistently exceeded RBD and nucleoprotein rates. Spike- and RBD-directed IgG antibodies were positively correlated until 14 months (Spearman's rank correlation test, p-values 0.0001 to 0.05), although RBD diminished faster. Significant anti-spike immunity persisted without RBD. 64% and 59% of PCR-negative, non-infected non-contacts and suspects, exhibited baseline SARS-CoV-2 N-IgM serological cross-reactivity, suggesting undetected exposure or abortive infection. N-IgG levels waned after 787 days, while N-IgM levels remained undetectable throughout. Discussion: Lower N-IgG seroconversion rates and the absence of N-IgM indicate that these markers substantially underestimate the prior exposure rates. Our findings provide insights into the development of S-directed antibody responses in mild and asymptomatic infections, with varying degrees of symptoms eliciting distinct immune responses, suggesting distinct pathogenic pathways. These longer-lasting data inform vaccine design, boosting strategies, and surveillance efforts in this and comparable settings.
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COVID-19 , Masculino , Feminino , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Uganda/epidemiologia , Anticorpos Antivirais , Imunoglobulina G , Imunoglobulina M , Imunoglobulina ARESUMO
OBJECTIVES: Understanding the immune response in very mild and asymptomatic COVID-19 is crucial for developing effective vaccines and immunotherapies, yet remains poorly characterized. This longitudinal study examined the evolution of interferon (IFN)-γ responses to SARS-CoV-2 peptides in 109 asymptomatic or mildly symptomatic Ugandan COVID-19 patients across 365 days and explored their association with antibody generation. METHODS: T-cell responses to spike-containing clusters of differentiation (CD4)-S and CD8 nCoV-A (CD8-A) megapools, and the non-spike CD4-R and CD8 nCoV-B (CD8-B) megapools, were assessed and correlated with demographic and temporal variables. RESULTS: SARS-CoV-2-specific IFN-γ responses were consistently detected in all peptide pools and time points, with the spike-targeted response exhibiting higher potency and durability than the non-spike responses. Throughout the entire 365-day infection timeline, a robust positive correlation was observed between CD4 T-cell responses to the spike-derived peptides and anti-spike immunoglobulin G antibody levels, underscoring their interdependent dynamics in the immune response against SARS-CoV-2; in contrast, CD8 T-cell responses exhibited no such correlation, highlighting their distinctive, autonomous role in defense. No meaningful variations in complete blood count parameters were observed between individuals with COVID-19 infection and those without, indicating clinical insignificance. CONCLUSIONS: This study highlights the dominant role of spike-directed T-cell responses in mild and asymptomatic disease and provides crucial longitudinal data from Sub-Saharan African settings. The findings provide valuable insights into the dynamics of T-cell responses and their potential significance in developing effective strategies for combating COVID-19.
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COVID-19 , Humanos , Estudos Longitudinais , Glicoproteína da Espícula de Coronavírus , SARS-CoV-2 , Linfócitos T CD8-Positivos , Interferon gama , Anticorpos AntiviraisRESUMO
BACKGROUND: The global burden of sepsis is concentrated in high HIV-burden settings in sub-Saharan Africa (SSA). Despite this, little is known about the immunopathology of sepsis in persons with HIV (PWH) in the region. We sought to determine the influence of HIV on host immune responses and organ dysfunction among adults hospitalized with suspected sepsis in Uganda. DESIGN: Prospective cohort study. METHODS: We compared organ dysfunction and 30-day outcome profiles of PWH and those without HIV. We quantified 14 soluble immune mediators, reflective of key domains of sepsis immunopathology, and performed whole-blood RNA-sequencing on samples from a subset of patients. We used propensity score methods to match PWH and those without HIV by demographics, illness duration, and clinical severity, and compared immune mediator concentrations and gene expression profiles across propensity score-matched groups. RESULTS: Among 299 patients, 157 (52.5%) were PWH (clinical stage 3 or 4 in 80.3%, 67.7% with known HIV on antiretroviral therapy). PWH presented with more severe physiologic derangement and shock, and had higher 30-day mortality (34.5% vs. 10.2%; P â<â0.001). Across propensity score-matched groups, PWH exhibited greater pro-inflammatory immune activation, including upregulation of interleukin (IL)-6, IL-8, IL-15, IL-17 and HMGB1 signaling, with concomitant T-cell exhaustion, prothrombotic pathway activation, and angiopoeitin-2-related endothelial dysfunction. CONCLUSIONS: Sepsis-related organ dysfunction and mortality in Uganda disproportionately affect PWH, who demonstrate exaggerated activation of multiple immunothrombotic and metabolic pathways implicated in sepsis pathogenesis. Further investigations are needed to refine understanding of sepsis immunopathology in PWH, particularly mechanisms amenable to therapeutic manipulation.
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Infecções por HIV , Sepse , Humanos , Adulto , Infecções por HIV/complicações , Insuficiência de Múltiplos Órgãos/complicações , Estudos Prospectivos , Uganda/epidemiologia , Sepse/complicações , Interleucina-6RESUMO
BACKGROUND: Helminth infections affect the human immune response. We investigated whether prenatal exposure to and treatment of maternal helminth infections affects development of an infant's immune response to immunisations and unrelated infections. METHODS: In this randomised, double-blind, placebo-controlled trial, we enrolled 2507 women in the second or third trimester of pregnancy who were planning to deliver in Entebbe General Hospital, Entebbe, Uganda. With a computer-generated random number sequence in blocks of 100, we assigned patients to 440 mg albendazole and 40 mg/kg praziquantel (n=628), 440 mg albendazole and a praziquantel-matching placebo (n=625), 40 mg/kg praziquantel and an albendazole-matching placebo (n=626), or an albendazole-matching placebo and praziquantel-matching placebo (n=628). All participants and hospital staff were masked to allocation. Primary outcomes were immune response at age 1 year to BCG, tetanus, and measles immunisation; incidence of infectious diseases during infancy; and vertical HIV transmission. Analysis was by intention-to-treat. This trial is registered, number ISRCTN32849447. FINDINGS: Data were available at delivery for 2356 women, with 2345 livebirths; 2115 (90%) of liveborn infants remained in follow-up at 1 year of age. Neither albendazole nor praziquantel treatments affected infant response to BCG, tetanus, or measles immunisation. However, in infants of mothers with hookworm infection, albendazole treatment reduced interleukin-5 (geometric mean ratio 0·50, 95% CI 0·30-0·81, interaction p=0·02) and interleukin-13 (0·52, 0·34-0·82, 0·0005) response to tetanus toxoid. The rate per 100 person-years of malaria was 40·9 (95% CI 38·3-43·7), of diarrhoea was 134·1 (129·2-139·2), and of pneumonia was 22·3 (20·4-24·4). We noted no effect on infectious disease incidence for albendazole treatment (malaria [hazard ratio 0·95, 95% CI 0·79-1.14], diarrhoea [1·06, 0·96-1·16], pneumonia [1·11, 0·90-1·38]) or praziquantel treatment (malaria [1·00, 0·84-1·20], diarrhoea [1·07, 0·98-1·18], pneumonia [1·00, 0·80-1·24]). In HIV-exposed infants, 39 (18%) were infected at 6 weeks; vertical transmission was not associated with albendazole (odds ratio 0·70, 95% CI 0·35-1·42) or praziquantel (0·60, 0·29-1·23) treatment. INTERPRETATION: These results do not accord with the recently advocated policy of routine antenatal anthelmintic treatment, and the value of such a policy may need to be reviewed. FUNDING: Wellcome Trust.
Assuntos
Anti-Helmínticos/administração & dosagem , Doenças Transmissíveis/imunologia , Infecções por HIV/imunologia , Complicações Parasitárias na Gravidez/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Adulto , Albendazol/administração & dosagem , Albendazol/efeitos adversos , Anti-Helmínticos/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Lactente , Transmissão Vertical de Doenças Infecciosas , Praziquantel/administração & dosagem , Praziquantel/efeitos adversos , Gravidez , Complicações Parasitárias na Gravidez/tratamento farmacológico , Vacinação , Adulto JovemRESUMO
BACKGROUND: Post-exposure treatment for dog bites in humans aims at alleviating the risk of rabies and promoting wound healing. Wound healing may be complicated by bacteria. This study identified the different bacteria and their antibiotic susceptibilities in infected dog bite wounds (DBWs) in Uganda. METHODS: A cross-sectional study was conducted among 376 dog bite patients. Wound swabs from patients with infected DBWs were collected and inoculated into recommended media. They were cultured for both aerobic and anaerobic bacteria. All isolated bacteria were identified based on colony characteristics, gram stain, and standard biochemical tests. Molecular identification was performed for strains that were resistant to three or more antibiotics. Antibiotic susceptibility testing was conducted using the disc diffusion method following the modified Kirby-Bauer method. The data were analysed using Stata version 15 software. RESULTS: Approximately half of the patients (52.9%, 199/376) presented with infected wounds. Majority of the swabs (84.4%, 168/199) were culture positive, and yielded a total of 768 isolates where about half (52.9%, 406/768) were gram positive bacteria, and about two-thirds (64.6%, 496/768) were recovered from category II wounds. Among the gram positive bacteria, 339 (83.5%) were aerobes where Staphylococcus aureus (103, 30.4%), Coagulase-negative staphylococci (68, 20.1%), and Corynebacterium spp (33, 9.7%) had the highest prevalence. For the 362 Gram negative isolates, 217 (59.9%) were aerobes and the commonest isolates were P. maltocida (64, 29.5%), Capnocytophaga canimorsus (36, 16.6%) and P. canis (26, 12.0%). Gram-positive isolates were resistant to metronidazole (93.6%), oxacillin (68.5%), ceftriaxone (14.6%) and amoxicillin/clavulanic acid (14.0%). Gram negative isolates were resistant to metronidazole (100%), ampicillin (30.7%), oxacillin (29.3%), and doxycycline (22.9%). Multidrug resistance was in 105 (29.0%) and 121/406 (29.8%) of the gram-negative and gram-positive isolates, respectively. All gram-positive isolates were susceptible to vancomycin and ciprofloxacin. CONCLUSIONS: Infection rates of DBWs in Uganda are high and the dominant bacterial isolates are Staphylococcus aureus, Pasteurella spps, and Capnocytophaga canimorsus. Multidrug resistance to commonly used antibiotics is high. The recommendation in the Uganda Clinical Guidelines to use metronidazole in the management of DBWs should be reviewed. DBWs should be enlisted for routine antimicrobial resistance surveillance and rational use of antimicrobial agents should be promoted.
Assuntos
Raiva , Infecções Estafilocócicas , Animais , Humanos , Cães , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana , Estudos Transversais , Raiva/tratamento farmacológico , Raiva/epidemiologia , Metronidazol , Uganda/epidemiologia , Bactérias Gram-Positivas , Oxacilina , Bactérias , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureusRESUMO
BACKGROUND: Allergy is commoner in developed than in developing countries. Chronic worm infections show inverse associations with allergy, and prenatal exposures may be critical to allergy risk. OBJECTIVE: To determine whether anthelminthic treatment during pregnancy increases the risk of allergy in infancy. METHODS: A randomised, double-blind, placebo-controlled trial on treatment in pregnancy with albendazole versus placebo and praziquantel versus placebo was conducted in Uganda, with a 2 × 2 factorial design; 2507 women were enrolled; infants' allergy events were recorded prospectively. The main outcome was doctor-diagnosed infantile eczema. RESULTS: Worms were detected in 68% of women before treatment. Doctor-diagnosed infantile eczema incidence was 10.4/100 infant years. Maternal albendazole treatment was associated with a significantly increased risk of eczema [Cox HR (95% CI), p: 1.82 (1.26-2.64), 0.002]; this effect was slightly stronger among infants whose mothers had no albendazole-susceptible worms than among infants whose mothers had such worms, although this difference was not statistically significant. Praziquantel showed no effect overall but was associated with increased risk among infants of mothers with Schistosoma mansoni [2.65 (1.16-6.08), interaction p = 0.02]. In a sample of infants, skin prick test reactivity and allergen-specific IgE were both associated with doctor-diagnosed eczema, indicating atopic aetiology. Albendazole was also strongly associated with reported recurrent wheeze [1.58 (1.13-2.22), 0.008]; praziquantel showed no effect. CONCLUSIONS: The detrimental effects of treatment suggest that exposure to maternal worm infections in utero may protect against eczema and wheeze in infancy. The results for albendazole are also consistent with a direct drug effect. Further studies are required to investigate mechanisms of these effects, possible benefits of worms or worm products in primary prevention of allergy, and the possibility that routine deworming during pregnancy may promote allergic disease in the offspring.
Assuntos
Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Dermatite Atópica/epidemiologia , Helmintíase/tratamento farmacológico , Praziquantel/uso terapêutico , Complicações Parasitárias na Gravidez/tratamento farmacológico , Adulto , Dermatite Atópica/diagnóstico , Método Duplo-Cego , Feminino , Helmintíase/parasitologia , Humanos , Imunoglobulina E/sangue , Incidência , Gravidez , Complicações Parasitárias na Gravidez/parasitologia , Sons Respiratórios , Testes Cutâneos , Resultado do Tratamento , Uganda , Adulto JovemRESUMO
In 1994 and 2002, respectively, the World Health Organisation proposed that treatment for hookworm and schistosomiasis could be provided during pregnancy. It was hoped that this might have benefits for maternal anaemia, fetal growth and perinatal mortality; a beneficial effect on the infant response to immunisation was also hypothesised. Three trials have now been conducted. Two have examined the effects of benzimidazoles; one (the Entebbe Mother and Baby Study) the effects of albendazole and praziquantel. All three were conducted in settings of high prevalence but low intensity helminth infection. Results suggest that, in such settings and given adequate provision of haematinics, the benefit of routine anthelminthics during pregnancy for maternal anaemia may be small; none of the other expected benefits has yet been demonstrated. The Entebbe Mother and Baby Study found a significant adverse effect of albendazole on the incidence of infantile eczema in the whole study population, and of praziquantel on the incidence of eczema among infants of mothers with Schistosoma mansoni. Further studies are required in settings that differ in helminth species and infection intensities. Further research is required to determine whether increased rates of infantile eczema translate to long-term susceptibility to allergy, and to explore the underlying mechanisms of these effects. The risks and benefits of routine anthelminthic treatment in antenatal clinics may need to be reconsidered.
Assuntos
Anti-Helmínticos/uso terapêutico , Infecções por Uncinaria/tratamento farmacológico , Complicações Parasitárias na Gravidez/tratamento farmacológico , Esquistossomose mansoni/tratamento farmacológico , Albendazol/efeitos adversos , Albendazol/uso terapêutico , Ancylostomatoidea/efeitos dos fármacos , Anemia/parasitologia , Animais , Anti-Helmínticos/efeitos adversos , Benzimidazóis/efeitos adversos , Benzimidazóis/uso terapêutico , Peso ao Nascer/efeitos dos fármacos , Criança , Dermatite Atópica/induzido quimicamente , Método Duplo-Cego , Feminino , Humanos , Lactente , Mortalidade Perinatal , Praziquantel/efeitos adversos , Praziquantel/uso terapêutico , Gravidez , Resultado da Gravidez , Prevalência , Schistosoma mansoni/efeitos dos fármacos , Resultado do Tratamento , UgandaRESUMO
The global burden of sepsis is concentrated in sub-Saharan Africa, where extensive pathogen diversity and limited laboratory capacity challenge targeted antimicrobial management of life-threatening infections. In this context, established and emerging rapid pathogen diagnostics may stratify sepsis patients into subgroups with prognostic and therapeutic relevance. In a prospective cohort of adults (age ≥18 years) hospitalized with suspected sepsis in Uganda, we stratified patients using rapid diagnostics for HIV, tuberculosis (TB), malaria, and influenza, and compared clinical characteristics and 30-day outcomes across these pathogen-driven subgroups. From April 2017 to August 2019, 301 adults were enrolled (median age, 32 years [interquartile range, 26-42 years]; female, n = 178 [59%]). A total of 157 patients (53%) were HIV infected. Sixty-one patients (20%) tested positive for malaria, 52 (17%), for TB (including 49 of 157 [31%] HIV-infected patients), and 17 (6%), for influenza. Co-infection was identified in 33 (11%) patients. The frequency of multi-organ failure, including shock and acute respiratory failure, was greatest among patients with HIV-associated TB. Mortality at 30 days was 19% among patients with malaria, 40% among patients with HIV-associated TB, 32% among HIV-infected patients without microbiological evidence of TB, 6% among patients with influenza, and 11% among patients without a pathogen identified. Despite improvements in anti-retroviral delivery, the burden of sepsis in Uganda remains concentrated among young, HIV-infected adults, with a high incidence of severe HIV-associated TB. In parallel with improvements in acute-care capacity, use of rapid pathogen diagnostics may enhance triage and antimicrobial management during emergency care for sepsis in sub-Saharan Africa, and could be used to enrich study populations when trialing pathogen-specific treatment strategies in the region.