Diagnosis concealment is prevalent in MS, and associated with diagnosis experience.

BACKGROUND: Receiving a diagnosis of multiple sclerosis (MS) can be stressful; later, patients may conceal their diagnosis. Here, we aimed to (1) assess prevalence of disclosure and concealment behaviors, and (2) explore whether diagnosis experience is associated with later concealment and if MS provider engagement on this topic modifies concealment. METHODS: In a survey-based study, MS patients completed DISCO-MS assessing disclosure and concealment and responded to questions about diagnosis experience and practitioner attention to disclosure. Frequency analysis and Pearson's correlations were used in exploratory analyses. RESULTS: 428 adults with MS participated. 49% (N = 201) conceal their diagnosis. Higher education [t(405) = 3.66, p < 0.001], younger age (r = -0.15, p = 0.002), and shorter disease duration (r = -0.18, p = 0.010) were associated with higher concealment. 39% (N = 159) anticipate negative consequences of disclosure. Individuals reporting positive diagnosis experience (26%, N = 102) were less likely to conceal later in disease course compared to those with negative experience (34%, N = 136) [t(233) = 2.483, p = 0.014]. Patients whose MS providers discussed disclosure (23%, N = 73) anticipated less negative consequences of disclosure [t(323) = 2.475, p = 0.014]. CONCLUSIONS: Diagnosis concealment is common in MS. Favorable diagnosis experience and provider attention to the topic of disclosure throughout the MS disease course may influence diagnosis concealment.

High chromosomal mobility of rDNA clusters in holocentric chromosomes of Triatominae, vectors of Chagas disease (Hemiptera-Reduviidae).

The subfamily Triatominae (Hemiptera-Reduviidae) includes more than 150 blood-sucking species, potential vectors of the protozoan Trypanosoma cruzi, causative agent of Chagas disease. A distinctive cytogenetic characteristic of this group is the presence of extremely stable chromosome numbers. Unexpectedly, the analyses of the chromosomal location of ribosomal gene clusters and other repetitive sequences place Triatominae as a significantly diverse hemipteran subfamily. Here, we advance the understanding of Triatominae chromosomal evolution through the analysis of the 45S rDNA cluster chromosomal location in 92 Triatominae species. We found the 45S rDNA clusters in one to four loci per haploid genome with different chromosomal patterns: On one or two autosomes, on one, two or three sex chromosomes, on the X chromosome plus one to three autosomes. The movement of 45S rDNA clusters is discussed in an evolutionary context. Our results illustrate that rDNA mobility has been relatively common in the past and in recent evolutionary history of the group. The high frequency of rDNA patterns involving autosomes and sex chromosomes among closely related species could affect genetic recombination and the viability of hybrid populations, which suggests that the mobility of rDNA clusters could be a driver of species diversification.

EAN guideline on palliative care of people with severe, progressive multiple sclerosis.

BACKGROUND AND PURPOSE: Patients with severe, progressive multiple sclerosis (MS) have complex physical and psychosocial needs, typically over several years. Few treatment options are available to prevent or delay further clinical worsening in this population. The objective was to develop an evidence-based clinical practice guideline for the palliative care of patients with severe, progressive MS. METHODS: This guideline was developed using the Grading of Recommendations Assessment, Development and Evaluation methodology. Formulation of the clinical questions was performed in the Patients-Intervention-Comparator-Outcome format, involving patients, carers and healthcare professionals (HPs). No uniform definition of severe MS exists: in this guideline, constant bilateral support required to walk 20 m without resting (Expanded Disability Status Scale score > 6.0) or higher disability is referred to. When evidence was lacking for this population, recommendations were formulated using indirect evidence or good practice statements were devised. RESULTS: Ten clinical questions were formulated. They encompassed general and specialist palliative care, advance care planning, discussing with HPs the patient's wish to hasten death, symptom management, multidisciplinary rehabilitation, interventions for caregivers and interventions for HPs. A total of 34 recommendations (33 weak, 1 strong) and seven good practice statements were devised. CONCLUSIONS: The provision of home-based palliative care (either general or specialist) is recommended with weak strength for patients with severe, progressive MS. Further research on the integration of palliative care and MS care is needed. Areas that currently lack evidence of efficacy in this population include advance care planning, the management of symptoms such as fatigue and mood problems, and interventions for caregivers and HPs.

Italian consensus on treatment of spasticity in multiple sclerosis.

BACKGROUND: Spasticity is a frequent multifactorial manifestation of multiple sclerosis (MS), affecting mostly the chronic courses of the disease. Its impact on patient functioning and quality of life is profound. Treatment of spasticity includes oral and intrathecal anti-spastic drugs, muscle injections with relaxant agents, physical therapy, electrical and magnetic stimulation and peripheral nerve stimulation, alone or in various combinations. METHODS: This Italian consensus on the treatment of spasticity in MS was produced by a large group of Italian MS experts in collaboration with neurophysiologists, experts in the production of guidelines and patients' representatives operating under the umbrella of the Italian Neurological Society, the Associazione Italiana Sclerosi Multipla and the European Charcot Foundation. This guideline was developed in accordance with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. A total of 11 questions were formulated following the PICO framework (patients, intervention, comparator, outcome). Controlled studies only were included in the analysis. RESULTS: Despite some consistent limitations due to the poor methodological quality of most studies, there was a consensus on a strong recommendation for the use of intrathecal baclofen, oromucosal spray of nabiximols and intramuscular injection of botulinum toxin. The level of recommendation was weak for oral baclofen, tizanidine, gabapentin, benzodiazepines and transcranial magnetic stimulation. CONCLUSIONS: There is a clear need for new larger multicentre well-designed clinical trials with a duration that allows the persistence of the effects and the long-term safety of the interventions to be evaluated.

Survivorship of wild caught Mepraia spinolai nymphs: The effect of seasonality and Trypanosoma cruzi infection after feeding and fasting in the laboratory.

Chagas disease is caused by Trypanosoma cruzi. Vector survival is an important variable affecting vectorial capacity to determine parasite transmission risk. The aims of this study are to evaluate vector survival under fasting/starvation conditions of wild-caught Mepraia spinolai after feeding and fasting, the pathogenicity of T. cruzi infection, the parasite burden and seasonal variation in parasite discrete typing units (DTU). The survivorship of M. spinolai nymphs after two continuous artificial feedings was evaluated, assessing their infection with microscopic observation of fecal samples and PCR. Later, insects were fasted/starved until death. We performed qPCR analyses of parasite load in the fecal samples and dead specimens. T. cruzi genotyping was performed using conventional PCR amplicons and hybridization tests. Infection rate was higher in M. spinolai nymphs in summer and spring than in fall. Parasite burden varied from 3 to 250,000 parasites/drop. Survival rate for starved nymph stage II was lower in insects collected in the spring compared to summer and fall. TcII was the most frequent DTU. Mainly metacyclic trypomastigotes were excreted. We conclude that M. spinolai infection rate in nymphs varies among seasons, suggesting higher transmission risk in warmer seasons. However, nymphs stage II collected in spring are more sensitive to starvation compared to other seasons. TcII in single or mixed infection does not seem relevant to determine vector pathogenicity. These results of vector survivorship after fasting/starvation are important to determine the competence of M. spinolai as a vector of T. cruzi, since they excrete metacyclic trypomastigotes and the parasitism with T. cruzi seems to be poorly pathogenic to the vector under a severe fasting/starvation condition.

Initiating disease-modifying treatments in multiple sclerosis: Measuring the decision process using decisional conflict and decisional regret scales.

INTRODUCTION: Initiating disease-modifying treatments (DMTs) in multiple sclerosis (MS) is a major decision for people with (pw)MS but little is known about how the decision is perceived by the individual. OBJECTIVES: The aim of the study was to determine if decisional conflict (DC) and decisional regret reflect different stages of the decision-making process when initiating DMTs. METHODS: This was a cross-sectional study of three cohorts of pwMS (n = 254), a 'MS conference attendees', 'on treatment' and an 'offered treatment' cohort. Questionnaires assessing DC, decisional regret and control preference were performed. RESULTS: Forty-four per cent (113/254) of pwMS were dissatisfied with their treatment status and 53% (135/254) had DC. DC (p = 0.013) and decisional regret (p = 0.027) increase in treatment-naïve pwMS and also in those 'offered treatment' dissatisfied with their treatment status (p < 0.0001), whilst those 'on treatment' have low Decisional Regret Scale (DRS) score (p = 0.0005). DC and DRS were only correlated with treatment status in those on treatment and not in treatment-naïve patients. F (58/135) pwMS satisfied with treatment had DC. DC (n = 236, adjusted R 2 0.137, p = 0.000) and DRS (n = 235, adjusted R 2 0.232, p = 0.000) were increased by dissatisfaction with treatment, lower potency treatment, being from the 'MS conference attendees' cohort and reliance on the doctor's decision, with DC additionally associated with being employed. CONCLUSIONS: DC and decisional regret vary in populations at different stages of initiating DMTs and are impacted by non-treatment issues.

Selective advantage of euploid spermatocytes I in an azoospermic 47,XYY man with gonadal mosaicism.

Although most XYY men have normal sperm counts and are fertile (supposedly due to the loss of the extra Y before meiosis), there is a minority who are infertile. In these cases, the XYY spermatocytes are able to enter meiosis and form different synaptic configurations. With regard to mosaics, there is scarce well-defined information on the presence of the second Y and its meiotic behaviour. In this study, the chromosome constitution and the synaptic behaviour of pachytene spermatocytes from an azoospermic man with testicular hypotrophy and non-mosaic 47,XYY karyotype were analysed. Furthermore, we determined the chromosome constitution of the somatic Sertoli cells. Five karyotypically normal men with obstructive azoospermia, but having complete spermatogenesis, were included as controls. Immuno-FISH using specific protein markers of synapsis and recombination (SYCP3, SYCP1, BRCA1, MLH1, CREST) and a specific Yq12 DNA probe were used. In addition, we used the newly developed Super-Resolution Structured Illumination Microscopy (SR-SIM) to clearly define the synaptic configurations. FISH analysis was also performed on Sertoli cells. The histopathological analysis showed variable degrees of spermatogenesis development in the testicular tissue of the propositus. Immuno-FISH analysis showed that most of the primary spermatocytes were euploid 46, XY. The use of SR-SIM confirmed the existence of this euploidy. Only a few pachytene spermatocytes showed an aneuploid X + YY constitution. Sertoli cells showed two different populations with one or two Y chromosomes, in similar proportions. Thus an abnormal niche of sex-trisomic Sertoli cells should be also considered when searching for the origin of spermatogenesis failure in XYY men.

Patient and caregiver involvement in the formulation of guideline questions: findings from the European Academy of Neurology guideline on palliative care of people with severe multiple sclerosis.

BACKGROUND AND PURPOSE: Patient and public involvement in clinical practice guideline development is recommended to increase guideline trustworthiness and relevance. The aim was to engage multiple sclerosis (MS) patients and caregivers in the definition of the key questions to be answered in the European Academy of Neurology guideline on palliative care of people with severe MS. METHODS: A mixed methods approach was used: an international online survey launched by the national MS societies of eight countries, after pilot testing/debriefing on 20 MS patients and 18 caregivers, focus group meetings of Italian and German MS patients and caregivers. RESULTS: Of 1199 participants, 951 (79%) completed the whole online survey and 934 from seven countries were analysed: 751 (80%) were MS patients (74% women, mean age 46.1) and 183 (20%) were caregivers (36% spouses/partners, 72% women, mean age 47.4). Participants agreed/strongly agreed on inclusion of the nine pre-specified topics (from 89% for 'advance care planning' to 98% for 'multidisciplinary rehabilitation'), and <5% replied 'I prefer not to answer' to any topic. There were 569 free comments: 182 (32%) on the pre-specified topics, 227 (40%) on additional topics (16 guideline-pertinent) and 160 (28%) on outcomes. Five focus group meetings (three of MS patients, two of caregivers, and overall 35 participants) corroborated the survey findings. In addition, they allowed an explanation of the guideline production process and the exploration of patient-important outcomes and of taxing issues. CONCLUSIONS: Multiple sclerosis patient and caregiver involvement was resource and time intensive, but rewarding. It was the key for the formulation of the 10 guideline questions and for the identification of patient-important outcomes.

What should a person with relapsing-remitting multiple sclerosis know? - Focus group and survey data of a risk knowledge questionnaire (RIKNO 2.0).

BACKGROUND: Risk knowledge is relevant to make informed decisions in multiple sclerosis (MS). The risk knowledge questionnaire for relapsing-remitting MS (RIKNO 1.0) was developed and piloted in Germany. OBJECTIVE: To produce a revised RIKNO 2.0 questionnaire using mixed methodology in a European setting. METHODS: The questionnaire was translated in seven languages. MS patient and health professional (HP) expert feedback was obtained from Germany, Italy, Estonia, Serbia, and the UK. A German web-based survey of RIKNO 2.0 compared the tool with the MS Knowledge Questionnaire (MSKQ), each one used with two versions (with/without a "don't know" DN option). RESULTS: While RIKNO 2.0 was considered difficult, it was rated as highly educational. One item was reframed, and two new items were added. The web-based German survey (n = 708 completers) showed that the DN version did not increase participation rate and did not produce significantly higher scores. Internal consistency (Cronbach alpha) without SN response was 0.73. RIKNO 2.0 scores showed normality distribution irrespective of the answering format. Item difficulty was high ranging from 0.07 to 0.79. Less than 50% of questions were answered correctly (mean 8.9) compared to 80.4% in the MSKQ (mean 20.1). Higher numeracy competency and education were significantly, albeit weakly, associated to higher scores for both RIKNO 2.0 and MSKQ. CONCLUSION: Including "don't know" options in knowledge questionnaires does not increase percentage of correct replies. RIKNO 2.0 is a complex questionnaire to be used in an educational context and studies on patient information. The tool is now available in seven languages.

Minicircle classes heterogeneity within the TcIII and TcIV discrete typing units of Trypanosoma cruzi.

The taxon Trypanosoma cruzi, causative agent of Chagas disease, is composed of several discrete typing units (DTUs) named TcI-TcVI, and Tcbat. The history of the taxon T. cruzi is known, even though several controversial aspects remain as the relationships between TcIII and TcIV. We analyzed cloned T. cruzi stocks pertaining to the seven DTUs by filter hybridization tests of PCR amplicons from minicircle variable regions and kinetoplast DNA probes. Minicircle DNA blots from the cloned stocks and filter hybridization with one TcI, one TcII, one TcV, one TcVI, three TcIII, one TcIV from North America and one TcIV kinetoplast DNA probes from South America revealed minicircle variable region cross-reaction in some T. cruzi DTUs probed. TcIII was heterogeneous in minicircle class composition, even though two TcIII probes revealed that a small fraction of minicircles cross-hybridized with the minicircles from the TcIII, TcV and TcVI DTUs. The minicircles of TcIV from North America cross-reacted only with TcIV from North America but not with TcIV stocks from Brazil and Bolivia. The results on minicircle cross-hybridizations are discussed in the context of RNA editing, mitochondrial function in T. cruzi DTUs.

Effect of organizational features on patient satisfaction with care in Italian multiple sclerosis centres.

BACKGROUND AND PURPOSE: Receiving clear, complete and up-to-date information and having a satisfying relationship with the health professional (HP) are of primary importance for MS patients. Healthcare organization plays a key role in promoting an effective relationship and communication between patients and HPs. The present study aims to explore which care organization and service characteristics provided by Italian MS centres best predict patients' satisfaction with healthcare. METHODS: Eighty-one centres and 707 patients (502 women, mean age 40.5 years, SD 10.2; mean education 12.2 years, SD 3.6; time since diagnosis 5.9 years, SD 1.5) were included in the analysis. The care organization and service provided by each centre were evaluated in comparison with the National Institute for Health and Care Excellence (NICE) guidelines on management of MS. Patients' satisfaction with care was measured using the patient self-assessed questionnaire 'Comunicazione medico-paziente nella Sclerosi Multipla, revised' section 2 (COSM-R section 2). RESULTS: The clinical characteristics of patients significantly affected their satisfaction. A multivariate regression model showed that higher patients' satisfaction (COSM-R score) was inversely associated with hospital size (number of patients under care) (ß = -0.21, 95% confidence interval -0.35; -0.07) and directly associated with psychological interventions (ß = 2.44, 95% confidence interval 0.29; 4.59). CONCLUSIONS: Multiple sclerosis patients from larger hospitals are less satisfied with the information received and the relationship with HPs. Building an individualized relationship between patients and HPs and tailoring the communication of information improve patients' satisfaction. Such a goal is probably less likely to be accomplished in larger centres with many incoming patients. Moreover, when the centres also provide structured psychological interventions, the patients are more satisfied.

Nerve conduction velocity in CMT1A: what else can we tell?

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) type 1A is characterized by uniformly reduced nerve conduction velocity (NCV) that is fully penetrant since the first years of life, remains fairly stable through the life and does not correlate with disability whereas compound muscular action potential (CMAP) amplitude does. The aim of the present study was to analyze the large amount of electrophysiological data collected in the ascorbic acid trial in Italy and the UK (CMT-TRIAAL/CMT-TRAUK) and to use these data to gain insights into the pathophysiology of NCV in CMT1A. METHODS: Baseline electrophysiological data from 271 patients were analysed. Electrophysiological recordings were taken from the motor ulnar, median and peroneal nerves and the sensory ulnar nerve. Distal motor latency (DML), motor (MNCV) and sensory (SNCV) nerve conduction velocity, and amplitudes of CMAPs and sensory action potentials were assessed. Electrophysiological findings were correlated with age of patients at examination and the Charcot-Marie-Tooth Examination Score (CMTES). RESULTS: NCV was markedly and uniformly reduced. CMAP amplitudes were overall reduced but more severely in lower limbs. DML decreased and MNCV and SNCV increased with age of the patients, whereas CMAP amplitudes worsened with age and also correlated with CMTES. CONCLUSIONS: This is the largest sample of electrophysiological data obtained so far from CMT1A patients. Axonal degeneration as assessed by means of CMAP amplitude reflected clinical impairment and was consistent with a slowly progressive length-dependent neuropathy. All patients typically had markedly slowed NCV that did, however, slightly increase with age of the patients. The improvement of NCV might depend on myelin thickness remodelling that occurs during the adult life of CMT1A patients.

Individualized quality of life of severely affected multiple sclerosis patients: practicability and value in comparison with standard inventories.

PURPOSE: Individualized quality of life (QoL) measures differ from traditional inventories in that QoL domains/weights are not predetermined, but identified by the individual. We assessed practicability of the Schedule for the Evaluation of Individual QoL-Direct Weighting (SEIQoL-DW) interview in severely affected multiple sclerosis (MS) patients; the key QoL dimensions identified; and the correlation of the SEIQoL-DW index score with standard patient-reported outcome measures (PROMs). METHODS: Participants were people with severe MS who performed the baseline visit of the PeNSAMI trial (ISRCTN73082124). The SEIQoL-DW was administered at the patient's home by a trained examiner. Patients then received the following PROMs: the Core-Palliative care Outcome Scale (Core-POS), the Palliative care Outcome Scale-Symptoms-MS (POS-S-MS), the European Quality of Life Five Dimensions-3L (EQ-5D-3L), and the Hospital Anxiety and Depression Scale (HADS). RESULTS: Of 59 enrolled patients, 11 (19 %) did not receive the SEIQoL-DW (and the other PROMs) because of severe cognitive compromise or inability to communicate. SEIQoL-DW administration was completed and deemed valid in all 48 cases (mean age 60 years, 58 % women, median Expanded Disability Status Scale score 8.5). Mean SEIQoL-DW index score was 59.1 (SD 25.5). The most commonly nominated SEIQoL-DW areas were family (94 % of the patients), relationships, and leisure activities (both 65 %). Core-POS and POS-S-MS contained 70 % of the SEIQoL-DW-nominated areas. Nevertheless, correlations between SEIQoL-DW index, Core-POS, and POS-S-MS (and the other PROMs) were negligible. CONCLUSIONS: Individualized QoL can be assessed in severely affected MS patients, providing information that is not tracked by the standard inventories Core-POS, POS-S-MS, EQ-5D-3L, and HADS.

Fish diversity in the Río de la Plata and adjacent waters: an overview of environmental influences on its spatial and temporal structure.

The fish diversity and the main environmental factors affecting the spatial distribution of species, life history stages and community structure in the Río de la Plata (RdP) and adjacent waters are reviewed and analysed, with emphasis on the functional guild classification. The functional guild classification indicated that most species in the RdP were marine stragglers, zoobenthivores and oviparous species, although the biomass was dominated by estuarine species. Salinity had a stronger influence than temperature on the spatial pattern for all life stages, shallower and fresher waters are the preferred habitats of neonates and juveniles. During the breeding season (spring-summer), adults showed an intrusion into the inner part of RdP or to its adjacent nearshore waters from the offshore waters for spawning or mating, respectively. Variations in river discharge and wind patterns greatly affected the spatial extent of estuarine water, which ultimately influenced the domain of the main life-history stages (juveniles or adults) for both marine and estuarine fishes, as well as species and fish assemblage composition. The strong environmental gradient restricts some species and life-history stages to a particular section and defines three main fish assemblage areas. The composition of the fish assemblage is indicative of the recruitment of freshwater and marine species to the estuary in opposite ways, determined by the vertical stratification. Seasonal changes in the species composition were related to migration as a result of salinity and temperature variations and reproductive migrations to spawning and mating areas. This overview reveals that the RdP is under environmental variations that are likely to produce modifications to fish distribution and abundance that affect its fisheries. This context plus fish stock declines and changes in exploitation patterns could amplify the magnitude of the variations in the fisheries resources availability and affect the sustainability of fishing communities.

Trypanosoma cruzi diversity in infected dogs from areas of the north coast of Chile.

As part of a multi-site research program on the eco-epidemiology and control of Chagas disease in northern Chile, we sought to identify the Trypanosoma cruzi discrete typing units (DTUs) infecting rural and peridomestic dogs, using direct methods without grown of the parasite in the laboratory and thus to assess the use of this species as a sentinel of the disease in well-defined endemic areas of T. cruzi in Chile. Infected dogs (35) from three villages were included in the study. The studied villages were Caleta Río Seco and Caleta San Marcos, both in the Tarapacá Region, and La Serena in the Coquimbo Region. These villages were selected based on previous evidence of Mepraia infection reports of the Chilean Ministry of Health. Amplicons from nested-PCR positive samples were used as targets to determine the infective T. cruzi DTUs circulating in blood using PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). Results of hybridization with dog samples from Caleta Rio Seco showed single infections in 2 out of 16 and mixed infections in 14 out of 16. TcVI was the most frequent DTU found in this area. A highlight is that for the first time the presence of TcIII is reported in this area. Samples from Caleta San Marcos showed single infections in 5 out of 9 and mixed infections in 4 out of 9. TcVI was the most frequent DTU found in this area. Samples from La Serena showed single infections in 5 out of 10 and mixed infections in 2 out of 10; we were unable to genotype the other 3 samples. Our results indicate that infection by T. cruzi DTUs in dogs is not homogeneously distributed but rather specific to each region of our country, as demonstrated by the differences in the T. cruzi DTU distribution in some localities.

Risk Knowledge in Relapsing Multiple Sclerosis (RIKNO 1.0)--Development of an Outcome Instrument for Educational Interventions.

BACKGROUND: Adequate risk knowledge of patients is a prerequisite for shared decision making but few attempts have been made to develop assessment tools. Multiple Sclerosis (MS) is a chronic inflammatory disease of young adults with an increasing number of partially effective immunotherapies and therefore a paradigmatic disease to study patient involvement. OBJECTIVE/METHODS: Based on an item bank of MS risk knowledge items and patient feedback including perceived relevance we developed a risk knowledge questionnaire for relapsing remitting (RR) MS (RIKNO 1.0) which was a primary outcome measure in a patient education trial (192 early RRMS patients). RESULTS: Fourteen of the RIKNO 1.0 multiple-choice items were selected based on patient perceived relevance and item difficulty indices, and five on expert opinion. Mean item difficulty was 0.58, ranging from 0.14 to 0.79. Mean RIKNO 1.0 score increased after the educational intervention from 10.6 to 12.4 (p = 0.0003). Selected items were particularly difficult (e.g. those on absolute risk reductions of having a second relapse) and were answered correctly in only 30% of the patients, even after the intervention. CONCLUSION: Despite its high difficulty, RIKNO 1.0 is a responsive instrument to assess risk knowledge in RRMS patients participating in educational interventions.

Responsiveness of clinical outcome measures in Charcot-Marie-Tooth disease.

BACKGROUND AND PURPOSE: Charcot-Marie-Tooth disease (CMT) is a very slowly progressive neuropathy which makes it difficult to detect disease progression over time and to assess intervention efficacy. Experience from completed clinical trials with ascorbic acid and natural history studies confirm difficulties in detecting such changes. Consequently, sensitive-to-change outcome measures (OMs) are urgently needed. METHODS: The relative responsiveness of clinical scales of the Italian-UK ascorbic acid trial (placebo arm) were assessed by using the standardized response mean (SRM), which is the ratio of the paired scores mean change over time to the standard deviation of the score change (0 is worst responsiveness). RESULTS: Little worsening of OM scores was found over 2 years. In detail, the primary OM of the trial, the CMT Neuropathy Score version 1 (CMTNSv1), showed low responsiveness (SRM 0.13). Some CMTNS items showed slightly greater responsiveness (CMT Examination Score 0.17; CMTNS Signs 0.19). Myometric assessments of handgrip and foot dorsiflexion strength were the most responsive (SRM -0.31 and -0.38, respectively). Amongst the other measures, the nine-hole peg test, which assesses upper limb functioning, showed the best sensitivity to change (SRM 0.28). CONCLUSIONS: Overall these OMs showed low or negligible responsiveness, confirming the need to improve current OMs and to develop novel ones for prognostic and interventional studies. However, handgrip and foot dorsiflexion myometry are worth retaining for future trials as they were the most responsive and are likely to be clinically relevant for patients.

Effects of mammal host diversity and density on the infection level of Trypanosoma cruzi in sylvatic kissing bugs.

Several reports have described host species diversity and identity as the most important factors influencing disease risk, producing either dilution or amplification of the pathogen in a host community. Triatomine vectors, mammals and the protozoan Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) Chagas are involved in the wild cycle of Chagas disease, in which infection of mammals occurs by contamination of mucous membranes or skin abrasions with insect-infected faeces. We examined the extent to which host diversity and identity determine the infection level observed in vector populations (i.e. disease risk in humans). We recorded infection in triatomine colonies and on the coexisting host mammalian species in semi-arid Chile. Host diversity, and total and infected host species densities are used as predictor variables for disease risk. Disease risk did not correlate with host diversity changes. However, the densities of each infected rodent species were positively associated with disease risk. We suggest that the infected host density surrounding the vector colonies is a relevant variable for disease risk and should be considered to understand disease dynamics. It is crucial to pay attention on the spatial scale of analysis, considering the pattern of vector dispersal, when the relationship between host diversity and disease risk is studied.