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Spine stabilisation exercises, in which patients are taught to preferentially activate the transversus abdominus (TrA) during "abdominal hollowing” (AH), are a popular treatment for chronic low back pain (cLBP). The present study investigated whether performance during AH differed between cLBP patients and controls to an extent that would render it useful diagnostic tool. 50patients with cLBP (46.3±12.5years) and 50healthy controls (43.6±12.7years) participated in this case-control study. They performed AH in hook-lying. Using M-mode ultrasound, thicknesses of TrA, and obliquus internus and externus were determined at rest and during 5s AH (5measures each body side). The TrA contraction-ratio (TrA-CR) (TrA contracted/rest) and the ability to sustain the contraction [standard deviation (SD) of TrA thickness during the stable phase of the hold] were investigated. There were no significant group differences for the absolute muscle thicknesses at rest or during AH, or for the SD of TrA thickness. There was a small but significant difference between the groups for TrA-CR: cLBP 1.35±0.14, controls 1.44±0.24 (p<0.05). However, Receiver Operator Characteristics (ROC) analysis revealed a poor and non-significant ability of TrA-CR to discriminate between cLBP patients and controls on an individual basis (ROC area under the curve, 0.60 [95% CI 0.495; 0.695], p=0.08). In the patient group, TrA-CR showed a low but significant correlation with Roland Morris score (Spearman Rho=0.328; p=0.02). In conclusion, the difference in group mean values for TrA-CR was small and of uncertain clinical relevance. Moreover, TrA-CR showed a poor ability to discriminate between control and cLBP subjects on an individual basis. We conclude that the TrA-CR during abdominal hollowing does not distinguish well between patients with chronic low back pain and healthy controls

The rapid succession of the pandemic of arbovirus diseases, such as dengue, West Nile fever, chikungunya, and Zika fever, has intensified research on these and other arbovirus diseases worldwide. Investigating the unique mode of vector-borne transmission requires a clear understanding of the roles of vertebrates. One major obstacle to this understanding is the ambiguity of the arbovirus definition originally established by the World Health Organization. The paucity of pertinent information on arbovirus transmission at the time contributed to the notion that vertebrates played the role of reservoir in the arbovirus transmission cycle. Because this notion is a salient feature of the arbovirus definition, it is important to reexamine its validity. This review addresses controversial issues concerning vertebrate reservoirs and their role in arbovirus persistence in nature, examines the genesis of the problem from a historical perspective, discusses various unresolved issues from multiple points of view, assesses the present status of the notion in light of current knowledge, and provides options for a solution to resolve the issue.

Background: There is an urgent need to enhance our armamentarium to prevent dengue infections in children. Since dengue vectors (Aedes mosquitoes) are active mainly during the day, a potential target for control should be schools where children spend a considerable amount of their day. School uniforms are the cultural norm in most developing countries, worn throughout the day. We hypothesized that insecticide-treated school uniforms will reduce the incidence of dengue infection in school-aged children. Our objective was to determine the impact of impregnated school uniforms on dengue incidence. Methods: A randomised controlled trial was conducted in 10 schools in eastern Thailand in 2012. Pre-fabricated school uniforms were commercially treated to ensure consistent high quality of insecticide impregnation with permethrin. The 1-h-knock-down effect and 24 h mortality of Aedes mosquitoes by the impregnated cloth was tested at baseline and then once per month using WHOPES cone test. Blood samples were taken at baseline and at the end of the school-term for the hemagglutination-inhibition assay to identify serologically confirmed dengue infections during the study period. Students were randomized into intervention schools (all students wearing impregnated uniforms) versus control schools (uniforms had the same appearance and odor, but were not impregnated). Results: A total of 1808 students in 10 schools were enrolled, mean age 10.07 years. Of these, 1651 had paired blood samples taken, which showed an incidence of new dengue infection of 3.3 % over the school term (5 months). There was no difference in the incidence of dengue infections in intervention versus control schools. Both the knock-down and mortality at baseline were close to 100%, but rapidly waned after only 8 washes to 20% e.g. after only 1 month of wearing the uniform. Conclusion: Although the results of mosquitoes’ knock-down and mortality of impregnated schools looked very promising, we did not see a pr

Introduction: Dengue poses a significant socioeconomic and disease burden in Sri Lanka, where the geographic spread, incidence and severity of disease has been increasing since the first dengue hemorrhagic fever (DHF) epidemic occurred in 1989. Periodic epidemics have become progressively larger, peaking in 2012 with 44 456 cases. Passive surveillance was established nationwide more than a decade ago but dengue notifications have been based on clinical diagnosis, with infrequent laboratory confirmation. To obtain more accurate data on the disease burden, a laboratory-based enhanced sentinel surveillance system was established in Colombo Municipality, the area with the highest dengue incidence. Here we describe the study design and the results of the first 2 years (2012–2014). Methods: Three government hospitals and two outpatient clinics in Colombo District were selected for the sentinel surveillance. All patients presenting with undifferentiated fever were enrolled, if consent given, capped at a maximum of 60 patients per week. Acute blood samples were taken from all enrolled subjects and tested by dengue-specific PCR, and NS1, and IgM – ELISA at the time of first presentation. A sub-set of 536 samples was sent to Duke-NUS Singapore for quality assurance, virus isolation and serotyping. Results: Between 1 April, 2012 and 31 March, 2014, 3127 patients were enrolled, 964 (30.9%) as outpatients and 2160 (69.1%) as inpatients. The mean age was 22.3 years (SD = 17.5) and the time of first presentation was at day 4 of illness. For inpatients, 1687 (78.1%) of all febrile cases had laboratory-confirmed dengue. For outpatients, the proportion of confirmed dengue was 237 (24.6%). The mean duration of hospitalization was 4.1 days (SD = 1.85). The proportion of DHF in lab-confirmed hospitalized dengue cases was 22.1% and 4 patients (0.21%) died. Serotypes 1 and 4 were the only viruses detected in this sample (serotype 1: 85%; serotype 4: 15%). The clinicians’ diagnosis for dengue at time

Introduction: Dengue is a major acute febrile illness in Sri Lanka and reported in epidemic proportions. From 2009 to 2013 an average of 35 000 cases were reported annually with over 60% above 15 years of age. Clinical case classification of dengue was originally based on paediatric patients. Here we assess severity of dengue illness among adults according to both WHO classical and TDR classifications. Methods: A study was conducted in 100 adult patients presenting to ID Hospital, Colombo with fever <7 days, in 2013. All were tested for dengue ELISA NS1/IgM and RT-PCR. Of them 88 were confirmed as having dengue, and were classified into two WHO classifications. Type of care received was categorized into three levels as: Category 1 – general ward, Category 2 – special dengue unit, Category 3 – intensive care unit. Results: According to classical classification, 47 (53.4%) were Dengue Fever (DF) patients. Of them 31and 16 received Category 1 and 2 care respectively. None received Category 3 care. 41 (46.6%) Dengue Haemorrhagic Fever (DHF) patients. Of them 14 received category 1 care while 25 and two received Category 2 and Category 3 care respectively. Classical classification and level of care sensitivity was 62.8% (CI 48–78) while specificity was 68.9% (CI 55–82). According to TDR classification 29 (32.9%) were Dengue patients without warning signs. Of them 22 and 07 received Category 1 and 2 level of care respectively and none went into category 3. 48 (55%) were Dengue with warning signs and 11 (13%) severe dengue patients. Of them 18 received Category 1 care while 39 and two received category 2 and category 3 care respectively. TDR classification and level of care sensitivity was 85.4% (CI 75–95) Specificity 55% (CI 39–70). Conclusions: WHO TDR classification captures more patients who need closer observation in Category 2 and three levels of care than classical classification. This may warrant additional hospital resources in developing country settings. Disclosure: This

Introduction: Sri Lanka has experienced confirmed dengue outbreaks since the 1960s although severe dengue disease (DHF/DSS) didn’t appear until 1989. Since then, cyclical outbreaks associated with severe disease have occurred throughout the island. The most recent epidemic began in 2009 with the apparent introduction of a new genotype of DENV-1. To better understand the mechanisms underlying the persistence of this ongoing epidemic, a longitudinal study was conducted in hospitals in the Colombo district from April 2012 to March 2014. In order to glean as much information as possible about the viral genetics from this large cohort, we developed a novel Next Generation Sequencing (NGS) platform that can function without any a priori knowledge of the target dengue genome. Methods: The principle problem encountered when employing NGS directly on patient samples is the high ratio of host to viral RNA. To compensate for this, we developed a hybridization-based enrichment strategy consisting of DENV-specific 120nt, biotinylated oligodeoxynucleotides to capture DENV genomic material from an NGS library prepared directly from patient sera. Results: The strategy developed here allowed us to enrich DENV genomic material over 5000 fold relative to unenriched material. Full genome data and phylogenetic analysis indicate that the DENV-1 are predominantly genotype 1 although a smaller number of genotype 5 isolates was also identified. Conclusion: The platform developed for this study has the inherent ability to capture all four serotypes of DENV and can significantly increase the virus to host RNA ratio. The principle driver of the current dengue epidemic in Sri Lanka is the same DENV-1 genotype that has been in circulation since 2009. This research was funded by the Singapore Infectious Disease Initiative (SIDI/2013/012) and the European Union 7th Framework Programme through ‘DengueTools’. (www.dengue-tools.net). Disclosure: Nothing to disclose.

Infection with dengue virus is a major public health problem in the Asia-Pacific region and throughout tropical and sub-tropical regions of the world. Vaccination represents a major opportunity to control dengue and several candidate vaccines are in development. Experts in dengue and in vaccine introduction gathered for a two day meeting during which they examined the challenges inherent to the introduction of a dengue vaccine into the national immunisation programmes of countries of the Asia-Pacific. The aim was to develop a series of recommendations to reduce the delay between vaccine licensure and vaccine introduction. Major recommendations arising from the meeting included: ascertaining and publicising the full burden and cost of dengue; changing the perception of dengue in non-endemic countries to help generate global support for dengue vaccination; ensuring high quality active surveillance systems and diagnostics; and identifying sustainable sources of funding, both to support vaccine introduction and to maintain the vaccination programme. The attendees at the meeting were in agreement that with the introduction of an effective vaccine, dengue is a disease that could be controlled, and that in order to ensure a vaccine is introduced as rapidly as possible, there is a need to start preparing now. © 2011 Elsevier Ltd.

BACKGROUND: A life-shortening strain of the obligate intracellular bacteria Wolbachia, called wMelPop, is seen as a promising new tool for the control of Aedes aegypti. However, developing a vector control strategy based on the release of mosquitoes transinfected with wMelPop requires detailed knowledge of the demographics of the target population. METHODOLOGY/PRINCIPAL FINDINGS: In Tri Nguyen village (611 households) on Hon Mieu Island in central Vietnam, we conducted nine quantitative entomologic surveys over 14 months to determine if Ae. aegypti populations were spatially and temporally homogenous, and to estimate population size. There was no obvious relationship between mosquito (larval, pupal or adult) abundance and temperature and rainfall, and no area of the village supported consistently high numbers of mosquitoes. In almost all surveys, key premises produced high numbers of Ae. aegypti. However, these premises were not consistent between surveys. For an intervention based on a single release of wMelPop-infected Ae. aegypti, release ratios of infected to uninfected adult mosquitoes of all age classes are estimated to be 1.8-6.7ratio1 for gravid females (and similarly aged males) or teneral adults, respectively. We calculated that adult female mosquito abundance in Tri Nguyen village could range from 1.1 to 43.3 individuals of all age classes per house. Thus, an intervention could require the release of 2-78 wMelPop-infected gravid females and similarly aged males per house, or 7-290 infected teneral female and male mosquitoes per house. CONCLUSIONS/SIGNIFICANCE: Given the variability we encountered, this study highlights the importance of multiple entomologic surveys when evaluating the spatial structure of a vector population or estimating population size. If a single release of wMelPop-infected Ae. aegypti were to occur when wild Ae. aegypti abundance was at its maximum, a preintervention control program would be necessary to ensure that there was no net

Spine stabilization exercises, in which patients are taught to perform isolated contractions of the transverses abdominus (TrA) during "abdominal hollowing", are a popular physiotherapeutic treatment for low back pain (LBP). Successful performance is typically judged by the relative increase in TrA thickness compared with that of the internal (OI) and external (OE) oblique muscles, measured using ultrasound. The day-to-day measurement error (imprecision) associated with these indices of preferential activation has not been assessed but is important to know since it influences the interpretation of changes after treatment. On 2 separate days, 14 controls and 14 patients with chronic LBP (cLBP) performed abdominal hollowing exercises in hook-lying, while M-mode ultrasound images superimposed with tissue Doppler imaging (TDI) data were recorded from the abdominal muscles (N = 5 on each side). The fascial lines bordering the TrA, OI and OE were digitized, and muscle thicknesses were calculated. The between-day error (intra-observer) was expressed as the standard error of measurement, SEM; SEM as a percentage of the mean gave the coefficient of variation (CV). There were no significant between-day differences for the mean values of resting or maximal thickness for any muscle, in either group (P > 0.05). The median SEM and CV of all thickness variables was 0.71 mm and 10.9%, respectively for the controls and 0.80 mm or 11.3%, respectively for the cLBP patients. For the contraction ratios (muscle thickness contracted/thickness at rest), the CVs were 3-11% (controls) and 5-12% (patients). The CVs were unacceptably high (30-50%, both groups) for the TrA preferential activation ratio (TrA proportion of the total lateral abdominal muscle thickness when contracted minus at rest). In both the controls and patients, the precision of measurement of absolute muscle thickness and relative change in thickness during abdominal hollowing was acceptable, and commensurate with that typic