36 research outputs found
Longitudinal Analysis of Antibody Responses to Trachoma Antigens Before and After Mass Drug Administration.
Blinding trachoma, caused by the bacteria Chlamydia trachomatis, is a neglected tropical disease targeted for elimination by 2020. A major component of the elimination strategy is mass drug administration (MDA) with azithromycin. Currently, program decisions are made based on clinical signs of ocular infection, but we have been investigating the use of antibody responses for post-MDA surveillance. In a previous study, IgG responses were detected in children lacking clinical evidence of trachoma, suggesting that IgG responses represented historical infection. To explore the utility of serology for program evaluation, we compared IgG and IgA responses to trachoma antigens and examined changes in IgG and IgA post-drug treatment. Dried blood spots and ocular swabs were collected with parental consent from 264 1-6 year olds in a single village of Kongwa District, central Tanzania. Each child also received an ocular exam for detection of clinical signs of trachoma. MDA was given, and six months later an additional blood spot was taken from these same children. Ocular swabs were analyzed for C. trachomatis DNA and antibody responses for IgA and total IgG were measured in dried bloods spots. Baseline antibody responses showed an increase in antibody levels with age. By age 6, the percentage positive for IgG (96.0%) was much higher than for IgA (74.2%). Antibody responses to trachoma antigens declined significantly six months after drug treatment for most age groups. The percentage decrease in IgA response was much greater than for IgG. However, no instances of seroreversion were observed. Data presented here suggest that focusing on concordant antibody responses in children will provide the best serological surveillance strategy for evaluation of trachoma control programs
Quantification of HIV-1 RNA Among Men Who Have Sex With Men Using an At-Home Self-Collected Dried Blood Spot Specimen: Feasibility Study
Background: Suboptimal antiretroviral therapy (ART) adherence and disengagement in care present significant public health challenges because of the increased probability of HIV transmission. In the United States, men who have sex with men (MSM) continue to be disproportionately affected by HIV, highlighting a critical need to engage high-risk MSM living with HIV who are not engaged or retained in care.
Objective: The aim of the study was to assess the feasibility of at-home blood self-collection and laboratory quantification of HIV-1 RNA viral load (VL) to report laboratory-based VL outcomes and compare self-reported and laboratory-reported VL
Methods: Between 2016 and 2017, 766 US HIV-positive MSM enrolled in a Web-based behavioral intervention were invited to participate in an at-home dried blood spot (DBS) collection study using HemaSpot-HF kits (Spot On Sciences, Inc, Austin, TX) for laboratory-quantified VL.
Results: Of those invited to participate, 72.3% (554/766) enrolled in the DBS study. Most (79.2%, 439/554) men enrolled reported attempting to collect their blood, 75.5% (418/554) of participants mailed a DBS specimen to the research laboratory, and 60.8% (337/554) had an adequate blood sample for VL testing. Of the 337 specimens tested for VL by the laboratory, 52.5% (177/337) had detectable VL (median: 3508 copies/mL; range: 851-1,202,265 copies/mL). Most men (83.9%, 135/161) who returned a DBS specimen with laboratory-quantified detectable VL self-reported an undetectable VL during their last clinical visit.
Conclusions: Home collection of DBS samples from HIV-positive MSM is feasible and has the potential to support clinical VL monitoring. Discrepant laboratory HIV-1 RNA values and self-reported VL indicate a need to address perceived VL status, especially in the era of treatment as prevention. Most participants were willing to use an at-home DBS kit in the future, signaling an opportunity to engage high-risk MSM in long-term HIV care activities
Rapid Diagnosis of Trichomonas vaginalis by Testing Vaginal Swabs in an Isothermal Helicase-Dependent AmpliVue Assay
The AmpliVue™ Trichomonas Assay (Quidel) is a new FDA cleared rapid test for qualitative detection of Trichomonas vaginalis (TV) DNA in female vaginal specimens. The assay is based on BioHelix’s Helicase-Dependent Amplification (HDA) isothermal technology in conjunction with a disposable lateral-flow detection device, with a total turn-around time of approximately 45 minutes
Field Evaluation of the Cepheid GeneXpert Chlamydia trachomatis assay for Detection of Infection in a Trachoma Endemic Community in Tanzania.
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To determine the sensitivity, specificity, and field utility of the Cepheid GeneXpert Chlamydia trachomatis (CT) Assay (GeneXpert) for ocular chlamydia infection compared to Roche Amplicor CT assay (Amplicor). In a trachoma-endemic community in Kongwa Tanzania, 144 children ages 0 to 9 were surveyed to assess clinical trachoma and had two ocular swabs taken. One swab was processed at Johns Hopkins University, Baltimore MD, using Amplicor, (Roche Molecular Diagnostics) and the other swab was processed at a field station in Kongwa using the GeneXpert Chlamydia trachomatis/Neisseria gonorrhoeae assay (Cepheid). The sensitivity and specificity of GeneXpert was compared to the Amplicor assay. Of the 144 swabs taken the prevalence of follicular trachoma by clinical exam was 43.7%, and by evidence of infection according to Amplicor was 28.5%. A total of 17 specimens (11.8%) could not be processed by GeneXpert in the field due to lack of sample volume, other specimen issues or electricity failure. The sensitivity of GeneXpert when compared to Amplicor was 100% and the specificity was 95%. The GeneXpert test identified more positives in individuals with clinical trachoma than Amplicor, 55% versus 52%. The GeneXpert test for C. trachomatis performed with high sensitivity and specificity and demonstrated excellent promise as a field test for trachoma control.\u
Clinical and Epidemiologic Research Measuring Trachomatous Inflammation-Intense (TI) When Prevalence Is Low Provides Data on Infection With Chlamydia trachomatis
PURPOSE. Clinical trachoma is the current measure of effectiveness of antibiotic and environmental improvements in trachoma endemic communities. Impact assessments measure only trachomatous inflammation-follicular (TF). Trachomatous inflammation-intense (TI) is not used for decisions on stopping mass drug administration (MDA) or achieving intervention goals. We tested the supposition that TI was not associated with Chlamydia trachomatis when disease prevalence is low. METHODS. In 35 communities undergoing MDA as part of a larger project, 110 children ages 1 to 9 years were randomly selected in each community for surveys at baseline, 6, and 12 months. Both eyelids were graded for TF and TI, and a swab for detection of C. trachomatis infection was taken. RESULTS. Overall TF prevalence was 5% at baseline. Cases of TI alone constituted 15% of trachoma; 37% of TI cases had infection. At 6 and 12 months, the proportion of trachoma cases that had TI only was 13% and 20%; infection rates were similar to the rates in cases with TF alone. CONCLUSIONS. Despite low prevalence of trachoma, infection rates for TF alone and TI alone were similar at each time point. The exclusion of cases of TI alone when reporting trachoma prevalence discards additional information on infection. Trachomatous inflammation-intense could be considered as part of impact surveys
Pooling ocular swab specimens from Tanzania for testing by Roche Amplicor and Aptima Combo 2 assays for the detection of Chlamydia trachomatis: accuracy and cost-savings
Measuring Trachomatous Inflammation-Intense (TI) When Prevalence Is Low Provides Data on Infection With Chlamydia trachomatis
Cilj je ovog rada utvrditi kakav su utjecaj eterična ulja imala na porast micelija gljive Rhizoctonia solani i koja su eterična ulja i pri kojoj količini imala antifungalan učinak. Radilo se sa sljedećim eteričnim uljima: anis, bor, cimet kora, citronela, čajevac, čempres, eukaliptus, klinčić, lavanda, naranča slatka, ružmarin i timijan. Ulja su se primjenjivala u količinama od 5, 10, 15, 25 i 50 µl, a zona inhibicije mjerila se četvrti i sedmi dan. Učinci dvanaest eteričnih ulja na gljivu Rhizoctonia solani rađeni su u uvjetima in vitro. Najjači antifungalan učinak imalo je eterično ulje timijana i anisa koje je izuzetno inhibiralo rast micelija i s primjenom u najmanjoj količini. Uz eterično ulje timijana i anisa jak utjecaj imala su i ulja lavande, citronele i čajevca. Najslabije antifungalno djelovanje imalo je eterično ulje eukaliptusa, bora i naranče slatke koja pri određenim količinama nisu ni imala antifungalni učinak.The aim of this study was to determine what kind of effect did the essential oils have on the mycelial growth of the fungus Rhizoctonia solani, which essential oils and at what quantity had an antifungal effect. The study was done with the following essential oils: anise, pine, cinnamon bark, citronella, tea tree, cypress, eucalyptus, clove, lavender, sweet orange, rosemary and thyme. Oils were applied in quantities of 5, 10, 15, 25 and 50 µL, and the zone of inhibition was measured on the fourth and the seventh day of incubation. The effects of twelve essential oils on the fungus Rhizoctonia solani were performed in vitro. The strongest antifugal effect had the essential oil of thyme and anise which completely inhibited the mycelial growth even in the smallest amount of application. Along with the essential oil of thyme and anise, the lavender, citronella and tea tree oils also had a strong impact. The weakest antifungal effect had the essential oil of eucalyptus, pine and sweet orange, which in certain quantities did not even have an antifungal effect
Treating village newcomers and travelers for trachoma: Results from ASANTE cluster randomized trial.
Trachoma is targeted for global elimination. Infection rates with Chlamydia trachomatis are higher in new arrivals to a community and in travelers who leave for extended periods, suggesting they are sources of re-infection. This community-randomized, clinical trial was designed to determine if a surveillance program that targeted newcomers and travelers, identified weekly, would result in more communities achieving levels of infection of ≤1%.52 communities were randomly allocated 1:1 to the control (annual MDA alone if warranted) or intervention arm (annual MDA if warranted, plus a surveillance program to identify and treat newcomers and travelers). In each community, surveys were completed every six months on a random sample of 100 children ages 1-9 years for trachoma and infection. The primary outcome was the proportion of communities in the intervention arm, compared to the control arm, which had a prevalence of infection at ≤1% by 24 months. Registered: clinicaltrials.gov(NCT01767506).Intervention communities experienced an average of 110 surveillance events per month. At 24 months, 7 (27%) of 26 intervention communities achieved a prevalence of infection ≤1% compared to 4 (15%) of the 26 control communities (odds ratio = 2·6, 95%CI = 0·56-11·9). At 24 months, the average infection prevalence in the intervention communities was 4·8, compared to 6·9 in the control communities (p = ·06).Despite surveillance programs for community newcomers and travelers, the proportion of intervention communities with a level of infection ≤1% was lower than expected and not significantly different from control communities
Can We Use Antibodies to Chlamydia trachomatis as a Surveillance Tool for National Trachoma Control Programs? Results from a District Survey.
BACKGROUND:Trachoma is targeted for elimination by 2020. World Health Organization advises districts to undertake surveillance when follicular trachoma (TF) <5% in children 1-9 years and mass antibiotic administration has ceased. There is a question if other tools could be used for surveillance as well. We report data from a test for antibodies to C. trachomatis antigen pgp3 as a possible tool. METHODOLOGY:We randomly sampled 30 hamlets in Kilosa district, Tanzania, and randomly selected 50 children ages 1-9 per hamlet. The tarsal conjunctivae were graded for trachoma (TF), tested for C. trachomatis infection (Aptima Combo2 assay: Hologic, San Diego, CA), and a dried blood spot processed for antibodies to C. trachomatis pgp3 using a multiplex bead assay on a Luminex 100 platform. PRINCIPAL FINDINGS:The prevalence of trachoma (TF) was 0.4%, well below the <5% indicator for re-starting a program. Infection was also low, 1.1%. Of the 30 hamlets, 22 had neither infection nor TF. Antibody positivity overall was low, 7.5% and increased with age from 5.2% in 1-3 year olds, to 9.3% in 7-9 year olds (p = 0.015). In 16 of the 30 hamlets, no children ages 1-3 years had antibodies to pgp3. CONCLUSIONS:The antibody status of the 1-3 year olds indicates low cumulative exposure to infection during the surveillance period. Four years post MDA, there is no evidence for re-emergence of follicular trachoma