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21.
David W. Dowdy Ismat Lotia Andrew S. Azman Jacob Creswell Suvanand Sahu Aamir J. Khan 《PloS one》2013,8(10)
Background
The potential population-level impact of private-sector initiatives for tuberculosis (TB) case finding in Southeast Asia remains uncertain. In 2011, the Indus Hospital TB Control Program in Karachi, Pakistan, undertook an aggressive case-finding campaign that doubled notification rates, providing an opportunity to investigate potential population-level effects.Methods
We constructed an age-structured compartmental model of TB in the intervention area. We fit the model using field and literature data, assuming that TB incidence equaled the estimated nationwide incidence in Pakistan (primary analysis), or 1.5 times greater (high-incidence scenario). We modeled the intervention as an increase in the rate of formal-sector TB diagnosis and evaluated the potential impact of sustaining this rate for five years.Results
In the primary analysis, the five-year intervention averted 24% (95% uncertainty range, UR: 18-30%) of five-year cumulative TB cases and 52% (95% UR: 45-57%) of cumulative TB deaths. Corresponding reductions in the high-incidence scenario were 12% (95% UR: 8-17%) and 27% (95% UR: 21-34%), although the absolute number of lives saved was higher. At the end of five years, TB notification rates in the primary analysis were below their 2010 baseline, incidence had dropped by 45%, and annual mortality had fallen by 72%. About half of the cumulative impact on incidence and mortality could be achieved with a one-year intervention.Conclusions
Sustained, multifaceted, and innovative approaches to TB case-finding in Asian megacities can have substantial community-wide epidemiological impact. 相似文献22.
Andrew S. Azman Francisco J. Luquero Amabelia Rodrigues Pedro Pablo Palma Rebecca F. Grais Cunhate Na Banga Bryan T. Grenfell Justin Lessler 《PLoS neglected tropical diseases》2012,6(11)
Background
Use of cholera vaccines in response to epidemics (reactive vaccination) may provide an effective supplement to traditional control measures. In Haiti, reactive vaccination was considered but, until recently, rejected in part due to limited global supply of vaccine. Using Bissau City, Guinea-Bissau as a case study, we explore neighborhood-level transmission dynamics to understand if, with limited vaccine and likely delays, reactive vaccination can significantly change the course of a cholera epidemic.Methods and Findings
We fit a spatially explicit meta-population model of cholera transmission within Bissau City to data from 7,551 suspected cholera cases from a 2008 epidemic. We estimated the effect reactive vaccination campaigns would have had on the epidemic under different levels of vaccine coverage and campaign start dates. We compared highly focused and diffuse strategies for distributing vaccine throughout the city. We found wide variation in the efficiency of cholera transmission both within and between areas of the city. “Hotspots”, where transmission was most efficient, appear to drive the epidemic. In particular one area, Bandim, was a necessary driver of the 2008 epidemic in Bissau City. If vaccine supply were limited but could have been distributed within the first 80 days of the epidemic, targeting vaccination at Bandim would have averted the most cases both within this area and throughout the city. Regardless of the distribution strategy used, timely distribution of vaccine in response to an ongoing cholera epidemic can prevent cases and save lives.Conclusions
Reactive vaccination can be a useful tool for controlling cholera epidemics, especially in urban areas like Bissau City. Particular neighborhoods may be responsible for driving a city''s cholera epidemic; timely and targeted reactive vaccination at such neighborhoods may be the most effective way to prevent cholera cases both within that neighborhood and throughout the city. 相似文献23.
Spinal and pelvis motion has been studied by a variety of different methods, the majority of which have a number of limitations. The present study investigated motion characteristics of the lumbar spine and pelvis using a three-dimensional optoelectronic system. The aim of our study was to determine kinematic parameters of spine and pelvis during trunk flexion, extension and lateral bending in normal, healthy subjects. Kinematic motion analysis was performed on 63 asymptomatic volunteers for four different trunk motions. This study has shown that the pelvis range of motion is affected by the gender Contribution of pelvic movement to trunk flexion was 50%, while pelvic angle was significantly higher in women. During lateral bending female subjects had statistically significant higher values of vertebral arc with respect to male subjects. During extension the contribution of pelvic movement was 45%. There was no significant difference found in total angle, pelvic angle and vertebral arc. 相似文献
24.
Parastu Kasaie Barun Mathema W. David Kelton Andrew S. Azman Jeff Pennington David W. Dowdy 《PloS one》2015,10(12)
In any setting, a proportion of incident active tuberculosis (TB) reflects recent transmission (“recent transmission proportion”), whereas the remainder represents reactivation. Appropriately estimating the recent transmission proportion has important implications for local TB control, but existing approaches have known biases, especially where data are incomplete. We constructed a stochastic individual-based model of a TB epidemic and designed a set of simulations (derivation set) to develop two regression-based tools for estimating the recent transmission proportion from five inputs: underlying TB incidence, sampling coverage, study duration, clustered proportion of observed cases, and proportion of observed clusters in the sample. We tested these tools on a set of unrelated simulations (validation set), and compared their performance against that of the traditional ‘n-1’ approach. In the validation set, the regression tools reduced the absolute estimation bias (difference between estimated and true recent transmission proportion) in the ‘n-1’ technique by a median [interquartile range] of 60% [9%, 82%] and 69% [30%, 87%]. The bias in the ‘n-1’ model was highly sensitive to underlying levels of study coverage and duration, and substantially underestimated the recent transmission proportion in settings of incomplete data coverage. By contrast, the regression models’ performance was more consistent across different epidemiological settings and study characteristics. We provide one of these regression models as a user-friendly, web-based tool. Novel tools can improve our ability to estimate the recent TB transmission proportion from data that are observable (or estimable) by public health practitioners with limited available molecular data. 相似文献
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Anbu Jeba Sunilson John Samuel Suraj Radhamani Rejitha Gopinath Anandarajagopal Kalusalingam Anita Gnana Kumari Anbumani Vimala Hj Azman Husain 《The Korean journal of parasitology》2009,47(4):377-380
Growing patterns of pediculocidal drug resistance towards head louse laid the foundation for research in exploring novel anti-lice agents from medicinal plants. In the present study, various extracts of Pongamia pinnata leaves were tested against the head louse Pediculus humanus capitis. A filter paper diffusion method was conducted for determining the potential pediculocidal and ovicidal activity of chloroform, petroleum ether, methanol, and water extracts of P. pinnata leaves. The findings revealed that petroleum ether extracts possess excellent anti-lice activity with values ranging between 50.3% and 100% where as chloroform and methanol extracts showed moderate pediculocidal effects. The chloroform and methanol extracts were also successful in inhibiting nymph emergence and the petroleum ether extract was the most effective with a complete inhibition of emergence. Water extract was devoid of both pediculocidal and ovicidal activities. All the results were well comparable with benzoyl benzoate (25% w/v). These results showed the prospect of using P. pinnata leave extracts against P. humanus capitis in difficult situations of emergence of resistance to synthetic anti-lice agents. 相似文献
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Sharif Shahin Victor Tosin Okomoda Sairatul Dahlianis Ishak Khor Waiho Hanafiah Fazhan Mohamad Nor Azra B. Abdul Rahim Azman Koraon Wongkamhaeng Muyassar H. Abualreesh Nadiah W. Rasdi Hongyu Ma Mhd Ikhwanuddin 《Invertebrate Biology》2023,142(2):e12398
The search for alternative live feed for aquaculture stocks has inspired research into marine amphipods. In this study, the life history of Ceradocus mizani was evaluated to better understand how this amphipod might be used in aquaculture as an alternative feed. The amphipods did not display copulatory behavior during the study period. The females were multivoltine and attained sexual maturity on average in 23.6 days at a mean length of 4.64 mm. The incubation period lasted 8.8 days, and the mean number of juveniles produced per brood during that incubation period was relatively low (7.58). Females produced a mean of 5.2 consecutive broods and 39.4 total juveniles over the life span. (i.e., 0.33 juveniles/day). Sex ratio was female skewed (1.55:1). Female size and the number of juveniles produced per brood were positively correlated (R2 = 0.63). The mean life span for females and males was 119.4 and 91.2 days, respectively. Mean maximum length was 9.26 mm for males and 8.18 mm for females. This is the first account of the life history of C. mizani and forms the basis for future studies of this marine amphipod. 相似文献
29.
Reactive vaccination has recently been adopted as an outbreak response tool for cholera and other infectious diseases. Owing to the global shortage of oral cholera vaccine, health officials must quickly decide who and where to distribute limited vaccine. Targeted vaccination in transmission hotspots (i.e. areas with high transmission efficiency) may be a potential approach to efficiently allocate vaccine, however its effectiveness will likely be context-dependent. We compared strategies for allocating vaccine across multiple areas with heterogeneous transmission efficiency. We constructed metapopulation models of a cholera-like disease and compared simulated epidemics where: vaccine is targeted at areas of high or low transmission efficiency, where vaccine is distributed across the population, and where no vaccine is used. We find that connectivity between populations, transmission efficiency, vaccination timing and the amount of vaccine available all shape the performance of different allocation strategies. In highly connected settings (e.g. cities) when vaccinating early in the epidemic, targeting limited vaccine at transmission hotspots is often optimal. Once vaccination is delayed, targeting the hotspot is rarely optimal, and strategies that either spread vaccine between areas or those targeted at non-hotspots will avert more cases. Although hotspots may be an intuitive outbreak control target, we show that, in many situations, the hotspot-epidemic proceeds so fast that hotspot-targeted reactive vaccination will prevent relatively few cases, and vaccination shared across areas where transmission can be sustained is often best. 相似文献