Toward Improving Early Diagnosis of Congenital Chagas Disease in an Endemic Setting.

BACKGROUND: Congenital Trypanosoma cruzi transmission is now estimated to account for 22% of new infections, representing a significant public health problem across Latin America and internationally. Treatment during infancy is highly efficacious and well tolerated, but current assays for early detection fail to detect >50% of infected neonates, and 9-month follow-up is low. METHODS: Women who presented for delivery at 2 urban hospitals in Santa Cruz Department, Bolivia, were screened by rapid test. Specimens from infants of infected women were tested by microscopy (micromethod), quantitative PCR (qPCR), and immunoglobulin (Ig)M trypomastigote excreted-secreted antigen (TESA)-blots at birth and 1 month and by IgG serology at 6 and 9 months. RESULTS: Among 487 infants of 476 seropositive women, congenital T. cruzi infection was detected in 38 infants of 35 mothers (7.8%). In cord blood, qPCR, TESA-blot, and micromethod sensitivities/specificities were 68.6%/99.1%, 58.3%/99.1%, and 16.7%/100%, respectively. When birth and 1-month results were combined, cumulative sensitivities reached 84.2%, 73.7%, and 34.2%, respectively. Low birthweight and/or respiratory distress were reported in 11 (29%) infected infants. Infants with clinical signs had higher parasite loads and were significantly more likely to be detected by micromethod. CONCLUSIONS: The proportion of T. cruzi-infected infants with clinical signs has fallen since the 1990s, but symptomatic congenital Chagas disease still represents a significant, albeit challenging to detect, public health problem. Molecular methods could facilitate earlier diagnosis and circumvent loss to follow-up but remain logistically and economically prohibitive for routine screening in resource-limited settings

Sustained Domestic Vector Exposure Is Associated With Increased Chagas Cardiomyopathy Risk but Decreased Parasitemia and Congenital Transmission Risk Among Young Women in Bolivia

Vector exposure showed a direct association with Chagas cardiomyopathy, but an inverse relationship with maternal parasitemia and congenital transmission. We hypothesize that repeated antigen exposure maintains an inflammatory response, increasing cardiomyopathy, but this upregulation improves control of parasitemia during pregnanc

Innate immune activation by tissue injury and cell death in the setting of hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) with donor lymphocyte infusion is the mainstay of treatment for many types of hematological malignancies, but the therapeutic effect and prevention of relapse is complicated by donor T-cell recognition and attack of host tissue in a process known as graft-versus-host disease (GvHD). Cytotoxic myeloablative conditioning regimens used prior to Allo-HSCT result in the release of endogenous innate immune activators that are increasingly recognized for their role in creating a pro-inflammatory milieu. This increased inflammatory state promotes allogeneic T-cell activation and the induction and perpetuation of GvHD. Here, we review the processes of cellular response to injury and cell death that are relevant following Allo-HSCT and present the current evidence for a causative role of a variety of endogenous innate immune activators in the mediation of sterile inflammation following Allo-HSCT. Finally, we discuss the potential therapeutic strategies that target the endogenous pathways of innate immune activation to decrease the incidence and severity of GvHD following Allo-HSCT

Trypanosoma cruzi-infected pregnant women without vector exposure have higher parasitemia levels: implications for congenital transmission risk.

Congenital transmission is a major source of new Trypanosoma cruzi infections, and as vector and blood bank control continue to improve, the proportion due to congenital infection will grow. A major unanswered question is why reported transmission rates from T. cruzi-infected mothers vary so widely among study populations. Women with high parasite loads during pregnancy are more likely to transmit to their infants, but the factors that govern maternal parasite load are largely unknown. Better understanding of these factors could enable prioritization of screening programs to target women most at risk of transmission to their infants.We screened pregnant women presenting for delivery in a large urban hospital in Bolivia and followed infants of infected women for congenital Chagas disease. Of 596 women screened, 128 (21.5%) had confirmed T. cruzi infection; transmission occurred from 15 (11.7%) infected women to their infants. Parasite loads were significantly higher among women who transmitted compared to those who did not. Congenital transmission occurred from 31.3% (9/29), 15.4% (4/26) and 0% (0/62) of women with high, moderate and low parasite load, respectively (χx2 for trend 18.2; p<0.0001). Twin births were associated with higher transmission risk and higher maternal parasite loads. Infected women without reported vector exposure had significantly higher parasite loads than those who had lived in an infested house (median 26.4 vs 0 parasites/mL; p<0.001) with an inverse relationship between years of living in an infested house and parasite load.We hypothesize that sustained vector-borne parasite exposure and repeated superinfection by T. cruzi may act as an immune booster, allowing women to maintain effective control of the parasite despite the down-regulation of late pregnancy

Factors associated with estimated parasite load in blood of <i>T</i>. <i>cruzi</i>-infected mothers at the time of delivery.

<p>The limit of detection for the quantitative PCR assay was 1 parasite/mL. Parasite load values below this cutoff were assumed to be 0 for the purpose of analysis.</p><p>^aqPCR data were missing for 2 women who transmitted and 6 women who did not transmit to their infants. Four mother-infant pairs with ambiguous transmission status are excluded (see text).</p><p>^bComparison of parasite load distributions by maternal characteristic by Wilcoxon signed rank test.</p><p>^cComparison of years of exposure by parasite load category by Kruskal-Wallis test.</p><p>Factors associated with estimated parasite load in blood of <i>T</i>. <i>cruzi</i>-infected mothers at the time of delivery.</p

Maternal factors associated with congenital <i>Trypanosoma cruzi</i> transmission risk.

<p>The limit of detection for the quantitative PCR assay was 1 parasite/mL. Parasite load values below this cutoff were assumed to be 0 for the purpose of analysis.</p><p>^aqPCR data were missing for 2 women who transmitted and 6 women who did not transmit to their infants. Four mother-infant pairs with ambiguous transmission status are excluded (see text).</p><p>Maternal factors associated with congenital <i>Trypanosoma cruzi</i> transmission risk.</p

Sperm whale population structure in the eastern and central North Pacific inferred by the use of single-nucleotide polymorphisms, microsatellites and mitochondrial DNA

No description availabl

Recruitment and retention in a multicentre randomised controlled trial in Bell's palsy: A case study

<p>Abstract</p> <p>Background</p> <p>It is notoriously difficult to recruit patients to randomised controlled trials in primary care. This is particularly true when the disease process under investigation occurs relatively infrequently and must be investigated during a brief time window.</p> <p>Bell's palsy, an acute unilateral paralysis of the facial nerve is just such a relatively rare condition. In this case study we describe the organisational issues presented in setting up a large randomised controlled trial of the management of Bell's palsy across primary and secondary care in Scotland and how we managed to successfully recruit and retain patients presenting in the community.</p> <p>Methods</p> <p>Where possible we used existing evidence on recruitment strategies to maximise recruitment and retention. We consider that the key issues in the success of this study were; the fact that the research was seen as clinically important by the clinicians who had initial responsibility for recruitment; employing an experienced trial co-ordinator and dedicated researchers willing to recruit participants seven days per week and to visit them at home at a time convenient to them, hence reducing missed patients and ensuring they were retained in the study; national visibility and repeated publicity at a local level delivered by locally based principal investigators well known to their primary care community; encouraging recruitment by payment to practices and reducing the workload of the referring doctors by providing immediate access to specialist care; good collaboration between primary and secondary care and basing local investigators in the otolarnygology trial centres</p> <p>Results</p> <p>Although the recruitment rate did not meet our initial expectations, enhanced retention meant that we exceeded our planned target of recruiting 550 patients within the planned time-scale.</p> <p>Conclusion</p> <p>While difficult, recruitment to and retention within multi-centre trials from primary care can be successfully achieved through the application of the best available evidence, establishing good relationships with practices, minimising the workload of those involved in recruitment and offering enhanced care to all participants. Primary care trialists should describe their experiences of the methods used to persuade patients to participate in their trials when publishing their results.</p