Diagnosis of \u3cem\u3eSchistosoma mansoni\u3c/em\u3e without the Stool: Comparison of Three Diagnostic Tests to Detect \u3cem\u3eSchiostosoma mansoni\u3c/em\u3e Infection from Filtered Urine in Zambia

Diagnosis for intestinal Schistosoma mansoni lacks sensitivity and is arduous to conduct. The standard diagnostic tests, Kato-Katz (KK) and circulating cathodic antigen (CCA) both lack sensitivity and with KK, require obtaining, transporting, and examining fresh stool. We compared diagnostic efficacy of KK, CCA, and polymerase chain reaction (PCR) to detect S. mansoni infection (species-specific DNA) from 89 filtered urine samples collected in Zambia. The PCR was the strongest indicator of positive cases with sensitivity and specificity of 100% in comparison to CCA (67% and 60%) and KK (50% and 100%). High positive and negative predictive values (100%) were also indicative of robustness of PCR. The same pattern was observed when stratified for sex and age group-specific analysis. Diagnosis of S. mansoni from filtered urine samples by PCR is an effective means to detect low intensity infection and would enhance the effectiveness of surveillance and control programs of schistosomiasis

Malaria Research Challenges in Low Prevalence Settings

The prevalence of malaria has reduced significantly in some areas over the past decade. These reductions have made local elimination possible and the research agenda has shifted to this new priority. However, there are critical issues that arise when studying malaria in low transmission settings, particularly identifying asymptomatic infections, accurate detection of individuals with microparasitaemic infections, and achieving a sufficient sample size to have an adequately powered study. These challenges could adversely impact the study of malaria elimination if they remain unanswered

Malaria Research Challenges in Low Prevalence Settings

The prevalence of malaria has reduced significantly in some areas over the past decade. These reductions have made local elimination possible and the research agenda has shifted to this new priority. However, there are critical issues that arise when studying malaria in low transmission settings, particularly identifying asymptomatic infections, accurate detection of individuals with microparasitaemic infections, and achieving a sufficient sample size to have an adequately powered study. These challenges could adversely impact the study of malaria elimination if they remain unanswered

Designing a sustainable strategy for malaria control?

Malaria in the 21st century is showing signs of declining over much of its distribution, including several countries in Africa where previously this was not thought to be feasible. Yet for the most part the strategies to attack the infection are similar to those of the 1950s. Three major Journals have recently drawn attention to the situation, stressing the importance of research, describing the successes and defining semantics related to control. But there is a need to stress the importance of local sustainability, and consider somewhat urgently how individual endemic countries can plan and implement the programmes that are currently financed, for the most part, by donor institutions. On an immediate basis research should be more focused on a data driven approach to control. This will entail new thinking on the role of local infrastructure and in training of local scientists in local universities in epidemiology and field malariology so that expanded control programmes can become operational. Donor agencies should encourage and facilitate development of career opportunities for such personnel so that local expertise is available to contribute appropriately

Comparison of a PfHRP2-Based Rapid Diagnostic Test and Pcr for Malaria in a Low Prevalence Setting in Rural Southern Zambia: Implications for Elimination

Background: Rapid diagnostic tests (RDTs) detecting histidine-rich protein 2 (PfHRP2) antigen are used to identify individuals with Plasmodium falciparum infection even in low transmission settings seeking to achieve elimination. However, these RDTs lack sensitivity to detect low-density infections, produce false negatives for P. falciparum strains lacking pfhrp2 gene and do not detect species other than P. falciparum. Methods: Results of a PfHRP2-based RDT and Plasmodium nested PCR were compared in a region of declining malaria transmission in southern Zambia using samples from community-based, cross-sectional surveys from 2008 to 2012. Participants were tested with a PfHRP2-based RDT and a finger prick blood sample was spotted onto filter paper for PCR analysis and used to prepare blood smears for microscopy. Species-specific, real-time, quantitative PCR (q-PCR) was performed on samples that tested positive either by microscopy, RDT or nested PCR. Results: Of 3,292 total participants enrolled, 12 (0.4%) tested positive by microscopy and 42 (1.3%) by RDT. Of 3,213 (98%) samples tested by nested PCR, 57 (1.8%) were positive, resulting in 87 participants positive by at least one of the three tests. Of these, 61 tested positive for P. falciparum by q-PCR with copy numbers ≤ 2 × 103 copies/μL, 5 were positive for both P. falciparum and Plasmodium malariae and 2 were positive for P. malariae alone. RDT detected 32 (53%) of P. falciparum positives, failing to detect three of the dual infections with P. malariae. Among 2,975 participants enrolled during a low transmission period between 2009 and 2012, sensitivity of the PfHRP2-based RDT compared to nested PCR was only 17%, with specificity of \u3e99%. The pfhrp gene was detected in 80% of P. falciparum positives; however, comparison of copy number between RDT negative and RDT positive samples suggested that RDT negatives resulted from low parasitaemia and not pfhrp2 gene deletion. Conclusions: Low-density P. falciparum infections not identified by currently used PfHRP2-based RDTs and the inability to detect non-falciparum malaria will hinder progress to further reduce malaria in low transmission settings of Zambia. More sensitive and specific diagnostic tests will likely be necessary to identify parasite reservoirs and achieve malaria elimination

Responders vs clinical response: a critical analysis of data from linaclotide phase 3 clinical trials in IBS-C

Background: US Food and Drug Administration (FDA) set a rigorous standard for defining patient responders in irritable bowel syndrome-C (IBS-C; i.e., FDA's Responder Endpoint) for regulatory approval. However, this endpoint's utility for health-care practitioners to assess clinical response has not been determined. We analyzed pooled IBS-C linaclotide trial data to evaluate clinically significant responses in linaclotide-treated patients who did not meet the FDA responder definition. Methods: Percentages of FDA non-responders reporting improvement in abdominal pain, bowel function and/or global relief measures were determined using pooled data from two linaclotide Phase 3 IBS-C trials. Key Results 1602 IBS-C patients enrolled; 34% of linaclotide-treated and 17% of placebo-treated patients met the FDA Responder Endpoint (p < 0.0001). Among FDA non-responders at week 12, 63% of linaclotide-treated patients reported their abdominal pain was at least somewhat relieved, compared with 48% of placebo-treated patients. For stool frequency, 62% of linaclotide-treated patients reported that they were at least somewhat improved at week 12, compared with 46% of placebo-treated patients. For global IBS symptoms, 65% of linaclotide-treated patients reported at least some IBS-symptom relief, 43% reported adequate relief of IBS symptoms, and 57% reported being satisfied with linaclotide treatment, vs placebo rates of 48%, 34%, and 41% respectively. Conclusions & Inferences Most linaclotide-treated IBS-C patients who were FDA non-responders reported some improvement in abdominal pain and stool frequency, and global relief/satisfaction. In addition to the FDA Responder Endpoint, differing response thresholds and symptom-specific change from baseline should be considered by clinicians for a complete understanding of clinical response to linaclotide and other IBS-C therapies

Gravitational Collapse of a Shell of Quantized Matter

The semi-classical collapse, including lowest order back-reaction, of a thin shell of self-gravitating quantized matter is illustrated. The conditions for which self-gravitating matter forms a thin shell are first discussed and an effective Lagrangian for such matter is obtained. The matter-gravity system is then quantized, the semi-classical limit for gravitation is taken and the method of adiabatic invariants is applied to the resulting time dependent matter Hamiltonian. The governing equations are integrated numerically, for suitable initial conditions, in order to illustrate the effect of back-reaction, due to the creation of matter, in slowing down the collapse near the horizon.Comment: 20 pages, 1 eps figure. Problem with figure fixe

Isothermal Recombinase Polymerase amplification (RPA) of Schistosoma haematobium DNA and oligochromatographic lateral flow detection

© 2015 Rosser et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

Malaria Antifolate Resistance With Contrasting Plasmodium Falciparum Dihydrofolate Reductase (DHFR) Polymorphisms in Humans and Anopheles Mosquitoes

Surveillance for drug-resistant parasites in human blood is a major effort in malaria control. Here we report contrasting antifolate resistance polymorphisms in Plasmodium falciparum when parasites in human blood were compared with parasites in Anopheles vector mosquitoes from sleeping huts in rural Zambia. DNA encoding P. falciparum dihydrofolate reductase (EC 1.5.1.3) was amplified by PCR with allele-specific restriction enzyme digestions. Markedly prevalent pyrimethamine-resistant mutants were evident in human P. falciparum infections - S108N (\u3e90%), with N51I, C59R, and 108N+51I+59R triple mutants (30-80%). This resistance level may be from selection pressure due to decades of sulfadoxine/pyrimethamine use in the region. In contrast, cycloguanil-resistant mutants were detected in very low frequency in parasites from human blood samples - S108T (13%), with A16V and 108T+16V double mutants (∼4%). Surprisingly, pyrimethamine-resistant mutants were of very low prevalence (2-12%) in the midguts of Anopheles arabiensis vector mosquitoes, but cycloguanil-resistant mutants were highly prevalent - S108T (90%), with A16V and the 108T+16V double mutant (49-57%). Structural analysis of the dihydrofolate reductase by in silico modeling revealed a key difference in the enzyme within the NADPH binding pocket, predicting the S108N enzyme to have reduced stability but the S108T enzyme to have increased stability. We conclude that P. falciparum can bear highly host-specific drug-resistant polymorphisms, most likely reflecting different selective pressures found in humans and mosquitoes. Thus, it may be useful to sample both human and mosquito vector infections to accurately ascertain the epidemiological status of drug-resistant alleles

Effect of Intravenous Golimumab on Fatigue and the Relationship with Clinical Response in Adults with Active Ankylosing Spondylitis in the Phase 3 GO-ALIVE Study

INTRODUCTION: We studied the effect of intravenous (IV)-golimumab on fatigue and the association of fatigue improvement with clinical response post hoc in adults with active ankylosing spondylitis (AS) in the GO-ALIVE trial. METHODS: Patients were randomized to IV-golimumab 2 mg/kg (N = 105) at week (W) 0, W4, then every 8 W (Q8W) or placebo (N = 103) at W0, W4, W12, crossover to IV-golimumab 2 mg/kg at W16, W20, then Q8W through W52. Fatigue measures included Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Question #1 (fatigue; 0 [none], 10 [worst]; decrease indicates improvement) and 36-Item Short Form Health Survey (SF-36) vitality subscale (0 [worst], 100 [best]; increase indicates improvement). Minimum clinically important difference is ≥ 1 for BASDAI-fatigue and ≥ 5 for SF-36 vitality. GO-ALIVE primary endpoint was Assessment of SpondyloArthritis international Society ≥ 20% improvement criteria (ASAS20). Other clinical outcomes assessed included other ASAS responses, Ankylosing Spondylitis Disease Activity Score, and Bath Ankylosing Spondylitis Functional Index score. The distribution-based minimally important differences (MIDs) were determined for BASDAI-fatigue and SF-36 vitality. The relationship between improvement in fatigue and clinical outcomes was assessed via multivariable logistic regression. RESULTS: Mean changes in BASDAI-fatigue/SF-36 vitality scores were greater with IV-golimumab versus placebo at W16 (- 2.74/8.46 versus - 0.73/2.08, both nominal p ≤ 0.003); by W52 (after crossover), differences between groups narrowed (- 3.18/9.39 versus - 3.07/9.17). BASDAI-fatigue/SF-36 vitality MIDs were achieved by greater proportions of IV-golimumab-treated versus placebo-treated patients at W16 (75.2%/71.4% versus 42.7%/35.0%). A one-point/five-point improvement in BASDAI-fatigue/SF-36 vitality scores at W16 increased likelihood of achieving ASAS20 (odds ratios [95% confidence intervals]: 3.15 [2.21, 4.50] and 2.10 [1.62, 2.71], respectively) and ASAS40 (3.04 [2.15, 4.28] and 2.24 [1.68, 3.00], respectively) responses at W16; concurrent improvements and clinical response at W52 were consistent. A one-point/five-point improvement in BASDAI-fatigue/SF-36 vitality scores at W16 predicted increased likelihood of achieving ASAS20 (1.62 [1.35, 1.95] and 1.52 [1.25, 1.86], respectively) and ASAS40 (1.62 [1.37, 1.92] and 1.44 [1.20, 1.73], respectively) responses at W52. CONCLUSIONS: IV-golimumab provided important and sustained fatigue improvement in patients with AS that positively associated with achieving clinical response. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02186873