Establishment of the Ivermectin Research for Malaria Elimination Network: updating the research agenda

The potential use of ivermectin as an additional vector control tool is receiving increased attention from the malaria elimination community, driven by the increased importance of outdoor/residual malaria transmission and the threat of insecticide resistance where vector tools have been scaled-up. This report summarizes the emerging evidence presented at a side meeting on “Ivermectin for malaria elimination: current status and future directions” at the annual meeting of the American Society of Tropical Medicine and Hygiene in New Orleans on November 4, 2014. One outcome was the creation of the “Ivermectin Research for Malaria Elimination Network” whose main goal is to establish a common research agenda to generate the evidence base on whether ivermectin-based strategies should be added to the emerging arsenal to interrupt malaria transmission.

Screening for an ivermectin slow-release formulation suitable for malaria vector control

BACKGROUND

The prospect of eliminating malaria is challenged by emerging insecticide resistance and vectors with outdoor and/or crepuscular activity. Ivermectin can simultaneously tackle these issues by killing mosquitoes feeding on treated animals and humans. A single oral dose, however, confers only short-lived mosquitocidal plasma levels.

METHODS

Three different slow-release formulations of ivermectin were screened for their capacity to sustain mosquito-killing levels of ivermectin for months. Thirty rabbits received a dose of one, two or three silicone implants containing different proportions of ivermectin, deoxycholate and sucrose. Animals were checked for toxicity and ivermectin was quantified periodically in blood. Potential impact of corresponding long-lasting formulation was mathematically modelled.

RESULTS

All combinations of formulation and dose released ivermectin for more than 12 weeks; four combinations sustained plasma levels capable of killing 50% of Anopheles gambiae feeding on a treated subject for up to 24 weeks. No major adverse effects attributable to the drug were found. Modelling predicts a 98% reduction in infectious vector density by using an ivermectin formulation with a 12-week duration.

CONCLUSIONS

These results indicate that relatively stable mosquitocidal plasma levels of ivermectin can be safely sustained in rabbits for up to six months using a silicone-based subcutaneous formulation. Modifying the formulation of ivermectin promises to be a suitable strategy for malaria vector control.

Psychological status in female carriers of premutation FMR1 allele showing a complex relationship with the size of CGG expansion

We utilized a sample of 299 adult females aged between 19 and 86 years, carrying fragile X mental retardation (FMR1) alleles with small CCG expansions ranging from 50 to 141 repeats to analyse the relationships between psychological symptoms as assessed by the Symptom Checklist-90-Revised (SCL-90-R) and the size of the CGG repeat in the FMR1 gene. There were highly significant (negative) correlations between the size of the CGG repeat and a great majority of SCL-90-R subscale scores and all the global indices, suggesting that carriers of premutations in the mid-size CGG repeat range may be at greatest risk for the development of psychiatric disorder.

Psychological status in female carriers of premutation FMR1 allele showing a complex relationship with the size of CGG expansion

We utilized a sample of 299 adult females aged between 19 and 86 years, carrying fragile X mental retardation (FMR1) alleles with small CCG expansions ranging from 50 to 141 repeats to analyse the relationships between psychological symptoms as assessed by the Symptom Checklist-90-Revised (SCL-90-R) and the size of the CGG repeat in the FMR1 gene. There were highly significant (negative) correlations between the size of the CGG repeat and a great majority of SCL-90-R subscale scores and all the global indices, suggesting that carriers of premutations in the mid-size CGG repeat range may be at greatest risk for the development of psychiatric disorder.

Offering fragile X syndrome carrier screening: a prospective mixed-methods observational study comparing carrier screening of pregnant and non-pregnant women in the general population

INTRODUCTION

Fragile X syndrome (FXS) is the leading cause of inherited intellectual and developmental disability. Policy development relating to carrier screening programmes for FXS requires input from large studies examining not only test uptake but also psychosocial aspects. This study will compare carrier screening in pregnant and non-pregnant populations, examining informed decision-making, psychosocial issues and health economics.

METHODS AND ANALYSIS

Pregnant and non-pregnant women are being recruited from general practices and obstetric services. Women receive study information either in person or through clinic mail outs. Women are provided pretest counselling by a genetic counsellor and make a decision about testing in their own time. Data are being collected from two questionnaires: one completed at the time of making the decision about testing and the second 1 month later. Additional data are gathered through qualitative interviews conducted at several time points with a subset of participating women, including all women with a positive test result, and with staff from recruiting clinics. A minimum sample size of 500 women/group has been calculated to give us 88% power to detect a 10% difference in test uptake and 87% power to detect a 10% difference in informed choice between the pregnant and non-pregnant groups. Questionnaire data will be analysed using descriptive statistics and multivariate logistic regression models. Interview data will be thematically analysed. Willingness-to-pay and cost effectiveness analyses will also be performed. Recruitment started in July 2009 and data collection will be completed by December 2013.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Universities of Melbourne and Western Australia and by recruiting clinics, where required. Results will be reported in peer-reviewed publications, conference presentations and through a website http://www.fragilexscreening.net.au. The results of this study will make a significant contribution to discussions about the wider introduction of population carrier screening for FXS.

Rethinking private speech in preschoolers: the effects of social presence

Private speech utterances (PS) from 24 preschool children and 24 adults were obtained under (noninteracting) listener present and listener absent conditions using 2 tasks with an identical structure. Children produced significantly more PS in the listener present condition. Similar results were obtained with adults, albeit with a reduced incidence of private speech. The children's PS was further subdivided into 4 main categories: task irrelevant, task relevant general, task relevant focused, and incoherent mutterings. The last 2 of these categories accounted for 75% of PS in the absent condition, offering a more conservative coding of speech that could be regarded truly "private," i.e., only for "self." This subset of utterances, however, was still significantly more prevalent in the listener present condition. The results are interpreted as showing a social motive in talking out loud during problem solving and are considered in terms of a reappraisal of what is implied by the term "private speech."

The effect of massage on heart rate variability in preterm infants

OBJECTIVE

To test the hypothesis that massage would improve autonomic nervous system (ANS) function as measured by heart rate variability (HRV) in preterm infants.

STUDY DESIGN

Medically stable, 29- to 32-week preterm infants (17 massage, 20 control) were enrolled in a masked, randomized longitudinal study. Licensed massage therapists provided the massage or control condition twice a day for 4 weeks. Weekly HRV, a measure of ANS development and function, was analyzed using SPSS generalized estimating equations.

RESULTS

Infant characteristics were similar between groups. HRV improved in massaged infants but not in the control infants (P<0.05). Massaged males had a greater improvement in HRV than females (P<0.05). HRV in massaged infants was on a trajectory comparable to term-born infants by study completion.

CONCLUSION

Massage-improved HRV in a homogeneous sample of hospitalized, medically stable, preterm male infants and may improve infant response to exogenous stressors. We speculate that massage improves ANS function in these infants.

Low back pain-related beliefs and likely practice behaviours among final-year cross-discipline health students

BACKGROUND

Evidence points to clinicians' beliefs and practice behaviours related to low back pain (LBP), which are discordant with contemporary evidence. While interventions to align beliefs and behaviours with evidence among clinicians have demonstrated effectiveness, a more sustainable and cost-effective approach to positively developing workforce capacity in this area may be to target the emerging workforce. The aim of this study was to investigate beliefs and clinical recommendations for LBP, and their alignment to evidence, in Australian university allied health and medical students.

METHODS

Final-year students in chiropractic, medicine, occupational therapy, pharmacy and physiotherapy disciplines in three Western Australian universities responded to a survey. Demographic data, LBP-related beliefs data [modified Health Care Providers Pain and Impact Relationship Scale (HC-PAIRS) and the Back Pain Beliefs Questionnaire (BBQ)] and activity, rest and work clinical recommendations for an acute LBP clinical vignette were collected.

RESULTS

Six hundred two students completed the survey (response rate 74.6%). Cross-discipline differences in beliefs and clinical recommendations were observed (p > 0.001). Physiotherapy and chiropractic students reported significantly more helpful beliefs compared with the other disciplines, while pharmacy students reported the least helpful beliefs. A greater proportion of chiropractic and physiotherapy students reported guideline-consistent recommendations compared with other disciplines. HC-PAIRS and BBQ scores were strongly associated with clinical recommendations, independent to the discipline of study and prior experience of LBP.

CONCLUSIONS

Aligning cross-discipline university curricula with current evidence may provide an opportunity to facilitate translation of this evidence into practice with a focus on a consistent, cross-discipline approach to LBP management.

Tactile/kinesthetic stimulation (TKS) increases tibial speed of sound and urinary osteocalcin (U-MidOC and unOC) in premature infants (29-32weeks PMA)

Preterm delivery (<37 weeks post-menstrual age) is associated with suboptimal bone mass. We hypothesized that tactile/kinesthetic stimulation (TKS), a form of infant massage that incorporates kinesthetic movement, would increase bone strength and markers of bone accretion in preterm infants. Preterm, AGA infants (29-32 weeks) were randomly assigned to TKS (N=20) or Control (N=20). Twice daily TKS was provided 6 days per week for 2 weeks. Control infants received the same care without TKS treatment. Treatment was masked to parents, health care providers, and study personnel. Baseline and week two measures were collected for tibial speed of sound (tSOS, m/sec), a surrogate for bone strength, by quantitative ultrasound (Sunlight8000) and urine markers of bone metabolism, pyridinium crosslinks and osteocalcin (U-MidOC and unOC). Infant characteristics at birth and study entry as well as energy/nutrient intake were similar between TKS and Control. TKS intervention attenuated the decrease in tSOS observed in Control infants (p<0.05). Urinary pyridinium crosslinks decreased over time in both TKS and CTL (p<0.005). TKS infants experienced greater increases in urinary osteocalcin (U-MidOC, p<0.001 and unOC, p<0.05). We conclude that TKS improves bone strength in premature infants by attenuating the decrease that normally follows preterm birth. Further, biomarkers of bone metabolism suggest a modification in bone turnover in TKS infants in favor of bone accretion. Taken together, we speculate that TKS improves bone mineralization.

Predicting the current and future potential distributions of lymphatic filariasis in Africa using maximum entropy ecological niche modelling

Modelling the spatial distributions of human parasite species is crucial to understanding the environmental determinants of infection as well as for guiding the planning of control programmes. Here, we use ecological niche modelling to map the current potential distribution of the macroparasitic disease, lymphatic filariasis (LF), in Africa, and to estimate how future changes in climate and population could affect its spread and burden across the continent. We used 508 community-specific infection presence data collated from the published literature in conjunction with five predictive environmental/climatic and demographic variables, and a maximum entropy niche modelling method to construct the first ecological niche maps describing potential distribution and burden of LF in Africa. We also ran the best-fit model against climate projections made by the HADCM3 and CCCMA models for 2050 under A2a and B2a scenarios to simulate the likely distribution of LF under future climate and population changes. We predict a broad geographic distribution of LF in Africa extending from the west to the east across the middle region of the continent, with high probabilities of occurrence in the Western Africa compared to large areas of medium probability interspersed with smaller areas of high probability in Central and Eastern Africa and in Madagascar. We uncovered complex relationships between predictor ecological niche variables and the probability of LF occurrence. We show for the first time that predicted climate change and population growth will expand both the range and risk of LF infection (and ultimately disease) in an endemic region. We estimate that populations at risk to LF may range from 543 and 804 million currently, and that this could rise to between 1.65 to 1.86 billion in the future depending on the climate scenario used and thresholds applied to signify infection presence.

The use of esmarch exsanguination for the treatment of extremity wound burns

Tourniquets are routinely used during the excising and grafting of burn wounds located on the limbs in order to decrease blood loss. It has been postulated that the exsanguination of extremities by using Esmarch bandages might further reduce blood loss. However, there are concerns about a decrease in graft quality when Esmarch bandages are applied. The purpose of this prospective, double-blinded randomized study was to compare Esmarch application in addition to tourniquet (exsanguinated extremities) with the application of tourniquet alone. Thirty-eight excisions of bilateral extremity wounds were performed. Both limbs were tangentially excised after tourniquet application with one limb randomly chosen for prior Esmarch exsanguination. Blood loss was estimated during this procedure. Graft take was assessed twice: on post-operative days 3 and 7. The burn surface area and total area grafted were equivalent in the extremities with Esmarch bandages when compared to the extremities without them. Total blood loss was less in the extremities where Esmarch was applied. Graft take was similar in the two groups. Statistical analysis was performed with a two-tailed paired T-test. It is concluded that the use of Esmarch exsanguination in addition to tourniquet further reduces blood loss without affecting the quality of the engraftment.

Preinjury Behavioral and Emotional Problems Among Pediatric Burn Patients

Standardized behavior rating scales have been used in the routine care of children during medical visits because they provide an objective, norm-based index for the child's behavioral functioning. The purpose of this study was to examine behavior problems among children (aged 2.5-18 years) with burn injuries using the Behavioral Assessment System for Children, a multi-informant system of standardized rating scales that assesses clinical and adaptive behavior areas. Parents and youth (ages 8-18) completed the Behavioral Assessment System for Children with reference to the pediatric patient's behavioral functioning before hospital admission for a burn injury. In total, data were collected on 94 children. Results suggested that a substantial portion of the sample endorsed significantly elevated levels of behavioral difficulties across a broad range of problem behaviors. On the basis of parent report, preschoolers exhibited concerns related to hyperactivity, anxiety, aggression, and attention problems, whereas school-aged children were reported to have these same concerns as well as depression and conduct problems. Twenty percent of our adolescent sample (ages 12-18 years) were described to be experiencing even more internalizing and externalizing behavior problems relative to the two groups of their younger counterparts. Boys were found to contribute to the cause of their burn injury significantly more often than girls. The strengths, limitations, and clinical implications of our findings are discussed.

Analysis of deep vein thrombosis in burn patients

OBJECTIVE

Deep vein thrombosis (DVT) represents a major cause of morbidity in surgical patients. Controversial reports exist on the incidence of DVT in burn patients. We report our experience over a 10-year period.

METHODS

Patients admitted to our Burn Unit over the period 1991-2001 and diagnosed with DVT were identified. Their records were retrospectively reviewed for demographic factors, extent and severity of burn injury and outcome.

RESULTS

A total of 4102 patients were admitted to the WPH Burn unit during the study period. All patients received routine subcutaneous heparin prophylaxis. Ten patients were diagnosed with DVT (0.25%). Compared to our total burn population, these patients were older (mean age 47 +/- 22.7 years versus 35 +/- 22 years P = 0.14) and had more extensive burns (mean total body surface area (TBSA) 34.7 +/- 25.3% versus 12 +/- 15.7% P = 0.02). Two patients developed non-fatal pulmonary embolism (PE). There were three deaths, none due to thromboembolic disease. There were no complications from the routine administration of subcutaneous heparin.

CONCLUSION

The incidence of DVT in our study is much less than the incidence reported in other critically ill patients and less than that of most reports on burn patients. In our experience, routine heparin prophylaxis is effective for the prevention of DVT in burn patients.

Effect of diagnosis and treatment of sinusitis in critically ill burn victims

The purpose of this study was to assess the incidence of diagnosed sinusitis and the effect of diagnosis and treatment on the outcome in critically ill burn victims. Chart analysis of 84 consecutive burn victims requiring mechanical ventilation for greater than 7 days was performed. Sinusitis was diagnosed in 13/84 patients (15%). There was no difference in age or total body surface area burned, or the incidence of inhalation injury, ARDS, pneumonia and sepsis (P>0.05). Co-morbid disease was similar in both the groups. The number of ventilator-dependent days and hospital length of stay were higher in the sinusitis group (P<0.05). The hospital mortality in those diagnosed and treated for sinusitis was 23% (3/13) as opposed to 48% (34/71) in those not diagnosed with sinusitis (P<0.05). Increased number of ventilator-dependent days and longer hospital stay are associated with the diagnosis of sinusitis. Our findings suggest an improved survival in those diagnosed and treated for sinusitis.