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1.
Front Public Health ; 12: 1332319, 2024.
Article in English | MEDLINE | ID: mdl-38584932

ABSTRACT

Background: Enterotoxigenic E. coli (ETEC) is a leading cause of diarrheal morbidity and mortality in children, although the data on disease burden, epidemiology, and impact on health at the community level are limited. Methods: In a longitudinal birth cohort study of 345 children followed until 24 months of age in Lima, Peru, we measured ETEC burden in diarrheal and non-diarrheal samples using quantitative PCR (LT, STh, and STp toxin genes), studied epidemiology and measured anthropometry in children. Results: About 70% of children suffered from one or more ETEC diarrhea episodes. Overall, the ETEC incidence rate (IR) was 73 per 100 child-years. ETEC infections began early after birth causing 10% (8.9-11.1) ETEC-attributable diarrheal burden at the population level (PAF) in neonates and most of the infections (58%) were attributed to ST-ETEC [PAF 7.9% (1.9-13.5)] and LT + ST-ETEC (29%) of which all the episodes were associated with diarrhea. ETEC infections increased with age, peaking at 17% PAF (4.6-27.7%; p = 0.026) at 21 to 24 months. ST-ETEC was the most prevalent type (IR 32.1) with frequent serial infections in a child. The common colonization factors in ETEC diarrhea cases were CFA/I, CS12, CS21, CS3, and CS6, while in asymptomatic ETEC cases were CS12, CS6 and CS21. Only few (5.7%) children had repeated infections with the same combination of ETEC toxin(s) and CFs, suggested genotype-specific immunity from each infection. For an average ETEC diarrhea episode of 5 days, reductions of 0.060 weight-for-length z-score (0.007 to 0.114; p = 0.027) and 0.061 weight-for-age z-score (0.015 to 0.108; p = 0.009) were noted in the following 30 days. Conclusion: This study showed that ETEC is a significant pathogen in Peruvian children who experience serial infections with multiple age-specific pathotypes, resulting in transitory growth impairment.


Subject(s)
Enterotoxigenic Escherichia coli , Escherichia coli Infections , Infant, Newborn , Humans , Enterotoxigenic Escherichia coli/genetics , Peru/epidemiology , Cohort Studies , Diarrhea/epidemiology , Enterotoxins/genetics , Escherichia coli Infections/epidemiology
2.
Am J Trop Med Hyg ; 105(5): 1187-1192, 2021 09 07.
Article in English | MEDLINE | ID: mdl-34491223

ABSTRACT

The mechanism of vertical transmission of Trypanosoma cruzi is poorly understood. In this study, we evaluated the role of IgG subclasses in the congenital transmission of Chagas disease. We conducted a case-control study in a public maternity hospital in Santa Cruz, Bolivia, enrolling women at delivery. Thirty women who transmitted T. cruzi to their newborns (cases), and 51 women who did not (controls) were randomly selected from 676 total seropositive women. Trypanosoma cruzi-specific IgG1, IgG2, and IgG3 levels were measured by in-house ELISA. The IgG4 levels were unmeasurable as a result of low levels in all participants. Quantitative polymerase chain reaction results and demographic factors were also analyzed. One-unit increases in normalized absorbance ratio of IgG1 or IgG2 levels increased the odds of congenital T. cruzi transmission in Chagas-seropositive women by 2.0 (95% CI: 1.1-3.6) and 2.27 (95% CI: 0.9-5.7), adjusted for age and previous blood transfusion. Odds of congenital transmission were 7.0 times higher in parasitemic mothers (95% CI: 2.3-21.3, P < 0.01) compared with nonparasitemic mothers. We observed that all mothers with IgG1 ≥ 4 were transmitters (sensitivity = 20%, specificity = 100%). Additionally, no mothers with IgG2 < 1.13 were transmitters (sensitivity = 100%, specificity = 21.6%). We demonstrated that IgG subclasses and parasite presence in blood are associated with vertical transmission of T. cruzi and could identify women at increased risk for congenital transmission by measuring IgG subclasses. These measures have potential as objective screening tests to predict the congenital transmission of Chagas.


Subject(s)
Chagas Disease/diagnosis , Chagas Disease/immunology , Chagas Disease/transmission , Immunoglobulin G/blood , Infectious Disease Transmission, Vertical , Pregnancy Complications, Parasitic/diagnosis , Pregnancy Complications, Parasitic/immunology , Trypanosoma cruzi/immunology , Adult , Bolivia , Case-Control Studies , Chagas Disease/blood , Female , Healthy Volunteers , Humans , Infant, Newborn , Male , Pregnancy , Risk Factors
3.
J Autism Dev Disord ; 51(3): 994-1006, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33591436

ABSTRACT

Most children with autism spectrum disorder (ASD), in resource-limited settings (RLS), are diagnosed after the age of four. Our work confirmed and extended results of Pierce that eye tracking could discriminate between typically developing (TD) children and those with ASD. We demonstrated the initial 15 s was at least as discriminating as the entire video. We evaluated the GP-MCHAT-R, which combines the first 15 s of manually-coded gaze preference (GP) video with M-CHAT-R results on 73 TD children and 28 children with ASD, 36-99 months of age. The GP-MCHAT-R (AUC = 0.89 (95%CI: 0.82-0.95)), performed significantly better than the MCHAT-R (AUC = 0.78 (95%CI: 0.71-0.85)) and gaze preference (AUC = 0.76 (95%CI: 0.64-0.88)) alone. This tool may enable early screening for ASD in RLS.


Subject(s)
Autism Spectrum Disorder/diagnosis , Checklist/methods , Eye-Tracking Technology , Fixation, Ocular/physiology , Health Resources , Mass Screening/methods , Autism Spectrum Disorder/epidemiology , Autism Spectrum Disorder/physiopathology , Checklist/standards , Child , Child, Preschool , Eye-Tracking Technology/standards , Female , Health Resources/standards , Humans , Male , Mass Screening/standards , Peru/epidemiology
4.
Int J Infect Dis ; 105: 357-373, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33618005

ABSTRACT

BACKGROUND: Vertical transmission of Trypanosoma cruzi infection from mother to infant accounts for a growing proportion of new Chagas disease cases. However, no systematic reviews of risk factors for T. cruzi vertical transmission have been performed. METHODS: We performed a systematic review of the literature in PubMed, LILACS, and Embase databases, following PRISMA guidelines. Studies were not excluded based on language, country of origin, or publication date. RESULTS: Our literature review yielded 27 relevant studies examining a wide variety of risk factors, including maternal age, parasitic load, immunologic factors and vector exposure. Several studies suggested that mothers with higher parasitic loads may have a greater risk of vertical transmission. A meta-analysis of 2 studies found a significantly higher parasitic load among transmitting than non-transmitting mothers with T. cruzi infection. A second meta-analysis of 10 studies demonstrated that maternal age was not significantly associated with vertical transmission risk. CONCLUSIONS: The literature suggests that high maternal parasitic load may be a risk factor for congenital Chagas disease among infants of T. cruzi seropositive mothers. Given the considerable heterogeneity and risk of bias among current literature, additional studies are warranted to assess potential risk factors for vertical transmission of T. cruzi infection.


Subject(s)
Chagas Disease/transmission , Infectious Disease Transmission, Vertical , Pregnancy Complications, Parasitic , Adult , Female , Humans , Infant , Infant, Newborn , Parasite Load , Pregnancy , Risk Factors
5.
Am J Trop Med Hyg ; 103(5): 1827-1833, 2020 11.
Article in English | MEDLINE | ID: mdl-32815504

ABSTRACT

Lung ultrasound (LUS) is highly portable and has excellent diagnostic accuracy for pneumonia compared with conventional radiography, but the literature on its use in pulmonary tuberculosis (PTB) is limited. This study characterized LUS lesions in patients with PTB and compared them with chest X-ray (CXR) findings. Adult patients in Lima, Peru, with PTB were recruited within 1 week of starting antituberculosis treatment. Comprehensive LUS was performed in all patients at enrollment and assessed for consolidation, small subpleural consolidation (SPC, hypothesized to be a marker of CXR consolidation), cavity, pleural effusion, pathologic B-lines, and miliary pattern. Patient CXRs were digitized and interpreted by a board-certified radiologist. Fifty-one patients were included in the final analysis. Lung ultrasound detected either consolidation or SPC in 96.1% of participants. No significant difference was found between the LUS detection of a composite of consolidation or SPC, and CXR detection of consolidation (96.1% versus 98%, P > 0.99). The proportion of patients with cavity detected by LUS was significantly lower than that detected by CXR (5.9% versus 51%, P < 0.001). Overall, LUS detection of consolidation or SPC may be a sensitive marker for diagnosis of PTB. Lung ultrasound demonstrated poor ability to detect radiographically identified cavity, although previous studies suggest SPC could add specificity for the diagnosis of PTB. Based on its portability and evidence base for diagnosing other pulmonary diseases, LUS may have a role in screening and diagnosis of PTB in areas without ready access to CXR. Further studies should evaluate its diagnostic accuracy in patients with and without PTB.


Subject(s)
Radiography, Thoracic , Tuberculosis, Pulmonary/diagnostic imaging , Tuberculosis, Pulmonary/pathology , Ultrasonography , Adolescent , Adult , Aged , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Risk Factors , Young Adult
6.
J Infect Dis ; 219(4): 609-618, 2019 01 29.
Article in English | MEDLINE | ID: mdl-30252099

ABSTRACT

Background: Congenital Trypanosoma cruzi infection accounts for an estimated 22% of new cases of Chagas disease in Latin America. However, neonatal diagnosis is challenging, as 9-month follow-up for immunoglobulin G testing is poor, quantitative polymerase chain reaction (qPCR) analysis is not routinely performed, and the micromethod misses ≥40% of congenital infections. Methods: Biorepository samples from new mothers and their infants from Piura, Peru, (an area of nonendemicity), and Santa Cruz, Bolivia (an area of endemicity) were accessed. Infant specimens were assessed using the micromethod, qPCR analysis, and a trypomastigote excretory secretory antigen (TESA) blot for detection of immunoglobulin M (IgM)-specific shed acute phase antigen (SAPA) bands, using qPCR as the gold standard. Results: When compared to qPCR, IgM TESA blot was both sensitive and specific for congenital Chagas disease diagnosis. Cumulative sensitivity (whether only 4 bands or all 6 bands were present) was 80% (95% confidence interval [CI], 59%-92%). Specificity was 94% (95% CI, 92%-96%) in the area of endemicity and 100% in the area of nonendemicity. SAPA bands occurred sequentially and in pairs, and parasite loads correlated highly with the number of SAPA bands present. The micromethod detected infection in fewer than half of infected infants. Conclusions: The IgM TESA blot for detection of SAPA bands is rapid, relatively inexpensive, and more sensitive than the micromethod and may be a useful point-of-care test for detection of congenital T. cruzi infection.


Subject(s)
Chagas Disease/congenital , Chagas Disease/diagnosis , Diagnostic Tests, Routine/methods , Glycoproteins/blood , Immunoblotting/methods , Immunoglobulin M/immunology , Neuraminidase/blood , Trypanosoma cruzi/immunology , Antibodies, Protozoan/immunology , Bolivia , Female , Humans , Infant , Infant, Newborn , Male , Peru , Pregnancy , Sensitivity and Specificity
7.
Oncotarget ; 8(24): 38501-38516, 2017 Jun 13.
Article in English | MEDLINE | ID: mdl-28418867

ABSTRACT

Clinically useful molecular tools to triage gastric cancer patients are not currently available. We aimed to develop a molecular tool to predict gastric cancer risk in endoscopy-driven biopsies obtained from high-risk gastric cancer clinics in low resource settings.We discovered and validated a DNA methylation biomarker panel in endoscopic samples obtained from 362 patients seen between 2004 and 2009 in three high-risk gastric cancer clinics in Lima, Perú, and validated it in 306 samples from the Cancer Genome Atlas project ("TCGA"). Global, epigenome wide and gene-specific DNA methylation analyses were used in a Phase I Biomarker Development Trial to identify a continuous biomarker panel that combines a Global DNA Methylation Index (GDMI) and promoter DNA methylation levels of IRF4, ELMO1, CLIP4 and MSC.We observed an inverse association between the GDMI and histological progression to gastric cancer, when comparing gastritis patients without metaplasia (mean = 5.74, 95% CI, 4.97-6.50), gastritis patients with metaplasia (mean = 4.81, 95% CI, 3.77-5.84), and gastric cancer cases (mean = 3.38, 95% CI, 2.82-3.94), respectively (p < 0.0001). Promoter methylation of IRF4 (p < 0.0001), ELMO1 (p < 0.0001), CLIP4 (p < 0.0001), and MSC (p < 0.0001), is also associated with increasing severity from gastritis with no metaplasia to gastritis with metaplasia and gastric cancer.Our findings suggest that IRF4, ELMO1, CLIP4 and MSC promoter methylation coupled with a GDMI>4 are useful molecular tools for gastric cancer risk stratification in endoscopic biopsies.


Subject(s)
Adenocarcinoma/diagnosis , Biomarkers, Tumor/genetics , Early Detection of Cancer/methods , Stomach Neoplasms/diagnosis , Adaptor Proteins, Signal Transducing/genetics , Adenocarcinoma/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Basic Helix-Loop-Helix Transcription Factors/genetics , Biopsy , Carrier Proteins/genetics , DNA Methylation/genetics , Female , Gastroscopy , Genome-Wide Association Study , Humans , Interferon Regulatory Factors/genetics , Male , Membrane Proteins , Middle Aged , Stomach Neoplasms/genetics , Young Adult
8.
Pediatrics ; 139(3)2017 Mar.
Article in English | MEDLINE | ID: mdl-28223373

ABSTRACT

CONTEXT: Parents whose infants are being treated in the NICU are at high risk for depression and anxiety, with negative implications for parenting and infant development. OBJECTIVE: We conducted a systematic review and meta-analysis of NICU-based interventions to reduce maternal depressive or anxiety symptoms. DATA SOURCES: PubMed, Embase, PsychInfo, Cochrane, and CINAHL were searched for relevant studies. Reference lists from selected studies were reviewed. STUDY SELECTION: Inclusion criteria included randomized controlled design, a parent-focused intervention delivered in the NICU, valid maternal depressive or anxiety symptom measures at pre- and postintervention, and publication in a peer-reviewed journal in English. DATA EXTRACTION: Data extraction was conducted independently by 2 coders. RESULTS: Twelve studies met inclusion criteria for qualitative review; 2 were excluded from quantitative analyses for high risk of bias. Fixed- and random-effects models, with 7 eligible studies assessing depressive symptoms, indicated an effect of -0.16 (95% confidence interval [CI], -0.32 to -0.002; P < .05) and, with 8 studies assessing anxiety symptoms, indicated an effect of -0.12 (95% CI, -0.29 to 0.05; P = .17). The subset of interventions using cognitive behavioral therapy significantly reduced depressive symptoms (effect, -0.44; 95% CI, -0.77 to -0.11; P = .01). LIMITATIONS: The small number and methodological shortcomings of studies limit conclusions regarding intervention effects. CONCLUSIONS: Combined intervention effects significantly reduced maternal depressive but not anxiety symptoms. The evidence is strongest for the impact of cognitive behavioral therapy interventions on maternal depressive symptoms.


Subject(s)
Anxiety/prevention & control , Depression, Postpartum/prevention & control , Intensive Care Units, Neonatal , Mothers/psychology , Cognitive Behavioral Therapy , Female , Humans , Infant, Newborn , Kangaroo-Mother Care Method , Phototherapy , Psychotherapy/methods
9.
Clin Child Fam Psychol Rev ; 18(4): 395-412, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26377209

ABSTRACT

The aim of this systematic review and meta-analysis was to synthesize the available evidence on embedded family therapy interventions in pediatrics and impacts on parental mental health and family functioning outcomes. The Cochrane Collaboration guidelines for systematic reviews and meta-analysis were used for this study. Six electronic databases were searched for randomized controlled trials and cluster randomized trials. The Cochrane Collaboration's Risk of Bias Tool and GRADE system were used to rate the quality of evidence of the included studies. The primary outcomes included parental distress, parental depressive symptoms, and dysfunctional parent-child interaction. Fixed effects models showed statistically significant reductions in parental distress at 6-month and 12-month post-intervention in favor of the intervention group. Family therapy model, intervention level, delivery modality, and dosage moderated intervention impacts on parental distress. Fixed effects models showed statistically significant reductions in parental depressive symptoms and in dysfunctional parent-child interaction in favor of the intervention group. Family therapy interventions can be successfully embedded in general pediatric primary care, and intended outcomes are achieved in this setting. Recommendations for future research and implications for policy development are discussed.


Subject(s)
Family Therapy/methods , Outcome Assessment, Health Care/statistics & numerical data , Parent-Child Relations , Parents/psychology , Pediatrics/methods , Humans
10.
Trans R Soc Trop Med Hyg ; 107(7): 444-50, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23740241

ABSTRACT

INTRODUCTION: Installation of deltamethrin-impregnated screens and curtains was assessed as a preventive measure against transmission of anthroponotic cutaneous leishmaniasis (ACL) by Phlebotomus sergenti in Bam, a well-known focus of ACL in Iran with a population of nearly 100,000. METHODS: This was a quasi-experiment based on official data from an ACL control program in which one section of the city with about one-quarter of the population received the intervention. In the analysis, the rest of the city was used as control. Data covered June 2007 through October 2010. RESULTS: Comparison of cumulative incidence between the intervention and control areas before and after installation indicate a significant differential reduction in the cumulative ACL incidence in the intervention area and a reversal of the relative risk, beginning four months after the completion of installation, from RR = 1.14 (95% CI:1.05-1.23) to RR = 0.84 (95% CI:0.72-0.98). Results also indicate a return to a higher cumulative relative risk, RR = 1.51 (95% CI:1.30-1.77), several months after the loss of the preventive effect. CONCLUSIONS: Findings indicate the short-term effectiveness of such preventive measures but highlight the necessity of long-term, sustainable strategies. Results also suggest that shrinkage in the human reservoir pool in response to the intervention may play a significant role in prolongation of the preventive effect beyond the insecticidal life of impregnated materials in foci of anthroponotic cutaneous leishmaniasis and possibly anthroponotic visceral leishmaniasis due to L. donovani.


Subject(s)
Bedding and Linens , Insect Control/methods , Insect Vectors/drug effects , Insecticide-Treated Bednets , Insecticides , Leishmaniasis, Cutaneous/prevention & control , Nitriles , Pyrethrins , Animals , Humans , Incidence , Iran , Leishmaniasis, Cutaneous/epidemiology , Retrospective Studies
11.
Trans R Soc Trop Med Hyg ; 104(1): 1-2, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19712953

ABSTRACT

Instead of relying on drugs to reduce the parasite burden of leishmaniasis, and waiting for the effector immune response to develop in time to control the parasites, immunotherapy in conjunction with chemotherapy can rapidly induce the effector immune response. With a safe and potent drug plus an affordable therapeutic vaccine (immunostimulant), which remains to be developed, a single visit by patients with visceral or cutaneous leishmaniasis might be sufficient to induce a quick and lasting recovery. Drug toxicity and the emergence of resistance could also be dramatically reduced compared with present long-term monotherapy. Immunotherapy could be an effective addition to chemotherapy for leishmaniasis.


Subject(s)
Immunization/methods , Leishmaniasis Vaccines/immunology , Leishmaniasis, Cutaneous/therapy , Animals , Antiparasitic Agents/therapeutic use , Humans , Leishmaniasis, Cutaneous/immunology
12.
Vaccine ; 27(35): 4747-53, 2009 Jul 30.
Article in English | MEDLINE | ID: mdl-19540273

ABSTRACT

Despite decades of investigation in countries on three continents, an efficacious vaccine against Leishmania infections has not been developed. Although some indication of protection was observed in some of the controlled trials conducted with "first-generation" whole, inactivated Leishmania parasite vaccines, convincing evidence of protection was lacking. After reviewing all previously published or unpublished randomized, controlled field efficacy clinical trials of prophylactic candidate vaccines, a meta-analysis of qualified trials was conducted to evaluate whether there was some evidence of protection revealed by considering the results of all trials together. The findings indicate that the whole-parasite vaccine candidates tested do not confer significant protection against human leishmaniasis.


Subject(s)
Leishmaniasis Vaccines/immunology , Leishmaniasis/prevention & control , Animals , Humans , Leishmania/immunology , Randomized Controlled Trials as Topic , Vaccines, Inactivated/immunology
13.
Vaccine ; 26(52): 6759-67, 2008 Dec 09.
Article in English | MEDLINE | ID: mdl-18950671

ABSTRACT

First generation candidate vaccines against leishmaniasis, prepared using inactivated whole parasites as their main ingredient, were considered as promising because of their relative ease of production and low cost. These vaccines have been the subject of many investigations over several decades and are the only leishmaniasis vaccine candidates which have undergone phase 3 clinical trial evaluation. Although the studies demonstrated the safety of the vaccines and several studies showed reasonable immunogenicity and some indication of protection, an efficacious prophylactic vaccine is yet to be identified. Despite this overall failure, these trials contributed significantly to increasing knowledge on human leishmaniasis immunology. To provide a collective view, this review discusses the methods and findings of field efficacy trials of first generation leishmaniasis vaccine clinical trials conducted in the Old and New Worlds.


Subject(s)
Leishmaniasis Vaccines/therapeutic use , Leishmaniasis/immunology , Leishmaniasis/prevention & control , Africa/epidemiology , Animals , Asia/epidemiology , Clinical Trials as Topic , Humans , Leishmania/immunology , Randomized Controlled Trials as Topic , South America/epidemiology
14.
Trans R Soc Trop Med Hyg ; 102(1): 58-63, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17963805

ABSTRACT

Post-kala-azar dermal leishmaniasis (PKDL) is a recognized dermatosis that follows successful treatment of visceral leishmaniasis in the Sudan. This randomized and double-blind study aimed to assess safety, immunogenicity and curative potentials of a novel immunochemotherapy regimen in patients with persistent PKDL. Following informed consent, 30 patients were randomized to receive alum-precipitated autoclaved Leishmania major (Alum/ALM) vaccine+Bacille Calmette-Guérin (BCG) and sodium stibogluconate (SSG) or vaccine diluent and SSG. The SSG+Alum/ALM+BCG proved safe with minimal local adverse events. In the SSG+vaccine group, 87% of the patients were cured by day 60 compared with 53% in the SSG alone group (SSG+vaccine efficacy=71%, 95% CI for risk ratio 0.7-1.16). On day 90 of follow-up there were two relapses in the SSG alone arm and none in the SSG+vaccine arm. Pre-treatment cytokines showed high IFN-gamma or high IFN-gamma/IL-10 levels and leishmanin skin test (LST) non-reactivity, while healing/clinical improvement were associated with LST reactivity and low IFN-gamma levels in both study groups (P=0.004). In conclusion, SSG+Alum/ALM+BCG is safe and immunogenic with significant healing potentials in persistent PKDL lesions. Immunochemotherapy probably augmented IFN-gamma production, which induced healing. Leishmanin skin reactivity is a good surrogate marker of cure in persistent PKDL lesions.


Subject(s)
Antimony Sodium Gluconate/therapeutic use , Antiprotozoal Agents/therapeutic use , BCG Vaccine/immunology , Leishmaniasis Vaccines/immunology , Leishmaniasis, Visceral/prevention & control , Adolescent , Adult , Child , Double-Blind Method , Female , Humans , Interferon-gamma/blood , Interleukin-10/blood , Leishmaniasis, Visceral/immunology , Male , Middle Aged , Statistics as Topic , Sudan , Treatment Outcome , Vaccines, Combined
15.
Vaccine ; 24(47-48): 6944-54, 2006 Nov 17.
Article in English | MEDLINE | ID: mdl-17049693

ABSTRACT

BACKGROUND: In the screening of vaccine candidates it is important to select candidates that evoke immune responses associated with protection. Valid surrogate markers against human leishmaniasis are still lacking. METHODS: A controlled injection of live Leishmania known as leishmanization, (LZ), was used to evaluate vaccine (alum-precipitated autoclaved Leishmania major with BCG) efficacy and more accurately define surrogate markers of immunity to leishmaniasis in humans. Cellular immune responses to this artificial infection were monitored in the volunteers prior to and 9 months post infection. Comparisons were made between those who developed a lesion after infection and those who did not. RESULTS: In the volunteers monitored there was no significant difference in LST, IFNgamma production, or source of IFNgamma between those who developed a lesion and those who did not after LZ, with the exception that ulcer development was associated with an enhanced number of IFNgamma secreting CD4(+) CD45RA(-) (memory) T cells. DISCUSSION: Ulcer development following LZ was lower than anticipated by a pilot study (47% versus 78%) using the same stabilate several years earlier. While this may be an effect of low viability/virulence of the LZ inocula, alternative explanations are also possible. The IFNgamma responses in the study subjects were significantly lower compared to volunteers with previous history of cutaneous leishmaniasis. The findings raise the possibility that the selection of LST-negative volunteers in an endemic area may bias the study towards potentially non/low L. major-reactive volunteers.


Subject(s)
Leishmania major/immunology , Leishmaniasis, Cutaneous/immunology , Skin Tests , Adjuvants, Immunologic/pharmacology , Adolescent , Adult , Alum Compounds , Animals , Antigens, Protozoan/immunology , Biomarkers/analysis , Cytokines/biosynthesis , Double-Blind Method , Endemic Diseases , Enzyme-Linked Immunosorbent Assay , Female , Humans , Interferon-gamma/biosynthesis , Leishmaniasis, Cutaneous/parasitology , Male , Mycobacterium bovis/immunology , Phenotype
16.
Vaccine ; 23(28): 3642-8, 2005 May 25.
Article in English | MEDLINE | ID: mdl-15882524

ABSTRACT

To establish the safety and reproducibility of live challenge with Leishmania major, a single frozen stabilate was used in two open, single-arm leishmanization (LZ) trials. A total of 42 inoculations in 28 male adult volunteers were followed until complete healing. Lesions induced by LZ are as diverse as natural infection, but much milder. Total protection was seen in 100% (11/11) of recovered volunteers. LZ used as live challenge to test vaccine candidates reduces the required sample size, is cost effective for surrogate markers studies and will induce protection in the participants who are not protected by candidate vaccines.


Subject(s)
Leishmania major/immunology , Leishmaniasis, Cutaneous/prevention & control , Protozoan Vaccines/immunology , Adult , Animals , Humans , Iran , Leishmania major/pathogenicity , Leishmaniasis, Cutaneous/pathology , Male , Mice , Mice, Inbred BALB C , Middle Aged , Protozoan Vaccines/adverse effects , Skin Tests , Virulence
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