South Sudan implemented Ebola virus disease preparedness interventions aiming at preventing and rapidly containing any importation of the virus from the Democratic Republic of Congo starting from ...August 2018. One of these interventions was a surveillance system which included an Ebola alert management system. This study analyzed the performance of this system. A descriptive cross-sectional study of the Ebola virus disease alerts which were reported in South Sudan from August 2018 to November 2019 was conducted using both quantitative and qualitative methods. As of 30 November 2019, a total of 107 alerts had been detected in the country out of which 51 (47.7%) met the case definition and were investigated with blood samples collected for laboratory confirmation. Most (81%) of the investigated alerts were South Sudanese nationals. The alerts were identified by health workers (53.1%) at health facilities, at the community (20.4%) and by screeners at the points of entry (12.2%). Most of the investigated alerts were detected from the high-risk states of Gbudwe (46.9%), Jubek (16.3%) and Torit (10.2%). The investigated alerts commonly presented with fever, bleeding, headache and vomiting. The median timeliness for deployment of Rapid Response Team was less than one day and significantly different between the 6-month time periods (K-W = 7.7567; df = 2; p = 0.0024) from 2018 to 2019. Strengths of the alert management system included existence of a dedicated national alert hotline, case definition for alerts and rapid response teams while the weaknesses were occasional inability to access the alert toll-free hotline and lack of transport for deployment of the rapid response teams which often constrain quick response. This study demonstrates that the Ebola virus disease alert management system in South Sudan was fully functional despite the associated challenges and provides evidence to further improve Ebola preparedness in the country.
To assess the safety and acceptance of the PrePex device for medical male circumcision (MMC) in rural Uganda.
In an observational study, HIV-uninfected, uncircumcised men aged 18 and older who ...requested elective MMC were informed about the PrePex and dorsal slit methods and offered a free choice of their preferred procedure. 100 men received PrePex to assess preliminary safety (aim 1). An additional 329 men, 250 chose PrePex and 79 chose Dorsal slit, were enrolled following approval by the Safety Monitoring Committee (aim 2). Men were followed up at 7 days to assess adverse events (AEs) and to remove the PrePex device. Wound healing was assessed at 4 weeks, with subsequent weekly follow up until completed healing.
The PrePex device was contraindicated in 5.7% of men due to a tight prepuce or phimosis/adhesions. Among 429 enrolled men 350 (82.0%) got the PrePex device and 79 (18.0%) the dorsal slit procedure. 250 of 329 men (76.0%) who were invited to choose between the 2 procedures chose Prepex. There were 9 AEs (2.6%) with the PrePex, of which 5 (1.4%) were severe complications, 4 due to patient self-removal of the device leading to edema and urinary obstruction requiring emergency surgical circumcision, and one due to wound dehiscence following device removal. 71.8% of men reported an unpleasant odor prior to PrePex removal. Cumulative rates of completed wound healing with the PrePex were 56.7% at week 4, 84.8% week 5, 97.6% week 6 and 98.6% week 7, compared to 98.7% at week 4 with dorsal slit (p<0.0001).
The PrePex device was well accepted, but healing was slower than with dorsal slit surgery. Severe complications, primarily following PrePex self-removal, required rapid access to emergency surgical facilities. The need to return for removal and delayed healing may increase Program cost and client burden.
This ecological study describes the cholera epidemic in Harare during 2008-2009 and identifies patterns that may explain transmission. Rates ratios of cholera cases by suburb were calculated by a ...univariate regression Poisson model and then, through an Empirical Bayes modelling, smoothed rate ratios were estimated and represented geographically. Mbare and southwest suburbs of Harare presented higher rate ratios. Suburbs attack rates ranged from 1.2 (95% Cl
=
0.7–1.6) cases per 1000 people in Tynwald to 90.3 (95% Cl
=
82.8–98.2) in Hopley. The identification of this spatial pattern in the spread, characterised by low risk in low density residential housing, and a higher risk in high density south west suburbs and Mbare, could be used to advocate for improving water and sanitation conditions and specific preparedness measures in the most affected areas.
The generalized linear chirp process Robertson, Stephen D.; Gray, Henry L.; Woodward, Wayne A.
Journal of statistical planning and inference,
12/2010, Letnik:
140, Številka:
12
Journal Article
Recenzirano
The linear chirp process is an important class of time series for which the instantaneous frequency changes linearly in time. Linear chirps have been used extensively to model a variety of physical ...signals such as radar, sonar, and whale clicks (see
Altes, 1990; Kay and Boudreaux-Bartels, 1985; Papandreou-Suppappola, 2003). We introduce the stochastic linear chirp model and then define the generalized linear chirp (GLC) process as a special case of the G-stationary process studied by
Jiang et al. (2006) to model data with time-varying frequencies. We then define GLC(
p,
q) processes and show that the relationship between stochastic linear chirp processes and GLC(
p,
q) processes is analogous to that between harmonic and ARMA models. The new methods are then applied to both simulated and actual data sets.
Following the West Africa Ebola virus disease (EVD) outbreak (2013-2016), WHO developed a preparedness checklist for its member states. This checklist is currently being applied for the first time on ...a large and systematic scale to prepare for the cross border importation of the ongoing EVD outbreak in the Democratic Republic of Congo hence the need to document the lessons learnt from this experience. This is more pertinent considering the complex humanitarian context and weak health system under which some of the countries such as the Republic of South Sudan are implementing their EVD preparedness interventions.
We identified four main lessons from the ongoing EVD preparedness efforts in the Republic South Sudan. First, EVD preparedness is possible in complex humanitarian settings such as the Republic of South Sudan by using a longer-term health system strengthening approach. Second, the Republic of South Sudan is at risk of both domestic and cross border transmission of EVD and several other infectious disease outbreaks hence the need for an integrated and sustainable approach to outbreak preparedness in the country. Third, a phased and well-prioritized approach is required for EVD preparedness in complex humanitarian settings given the costs associated with preparedness and the difficulties in the accurate prediction of outbreaks in such settings. Fourth, EVD preparedness in complex humanitarian settings is a massive undertaking that requires effective and decentralized coordination.
Despite a very challenging context, the Republic of South Sudan made significant progress in its EVD preparedness drive demonstrating that it is possible to rapidly scale up preparedness efforts in complex humanitarian contexts if appropriate and context-specific approaches are used. Further research, systematic reviews and evaluation of the ongoing preparedness efforts are required to ensure comprehensive documentation and application of the lessons learnt for future EVD outbreak preparedness and response efforts.
For nonstationary time series consisting of multiple time-varying frequency (TVF) components where the frequency of components overlaps in time, classical linear filters fail to extract components. ...The G-filter based on time deformation has been developed to extract components of multicomponent G-stationary processes. In this paper, we explore the wide application of the G-filter for filtering different types of nonstationary processes with multiple time-frequency structure. Simulation examples illustrate that the G-filter can be applied to filter a broad range of multicomponent nonstationary process where TVF components may in fact overlap in time.
Methods such as wavelets, short term Fourier transforms and time deformation Gray and Zhang, 1988. On a class of nonstationary processes. J. Time Ser. Anal. 9(2), 133–154 and Gray, Vijverberg and ...Woodward, 2005. Nonstationary data analysis by time deformation. Commun. Statist. A, to appear have been developed to analyze the time-frequency properties of a process where frequency changes with time. When the frequencies of a process are either monotonically increasing or monotonically decreasing with time, a rather general time deformation approach is to apply an appropriate Box–Cox transformation to the time axis for the given signal in order to obtain a new stationary data set. This data set can then be analyzed by standard methods. Processes which are transformed to a stationary process after Box–Cox transformation of the time scale are called
G
(
λ
)
-stationary processes, where
λ
is the corresponding parameter of the Box–Cox transformation. In this paper it is shown that the standard concept of stationarity can be viewed as stationarity under a linear transformation of the index set, while transforming time (time deformation) by a non-linear monotonic transformation introduces the concept of stationarity on a non-linear index set. Thus the notion of stationarity is broadened considerably to allow stationarity on different scales. The method is illustrated with analysis of both simulated and real data. Finally, it is shown that such processes can be transformed to stationarity by sampling properly. The software for performing the analysis discussed in this paper can be downloaded from the website
http://faculty.smu.edu/hgray/research.htm.
To assess the efficacy of anti-inflammatory approaches, comprising a topical corticosteroid and omega-3 supplements, for modulating the inflammatory overlay associated with contact lens discomfort ...(CLD).
This randomized controlled trial involved 72 adults with CLD, randomized (1:1:1:1) to one of the following: placebo (oral olive oil), oral fish oil (900 mg/d eicosapentaenoic acid EPA + 600 mg/d docosohexaenoic acid DHA), oral combined fish+flaxseed oils (900 mg/d EPA + 600 mg/d DHA + 900 mg/d alpha-linolenic acid), or omega-3 eye-drops (0.025% EPA + 0.0025% DHA four times per day qid) for 12 weeks, with visits at baseline, weeks 4 and 12. At week 12, participants who received placebo were assigned a low-potency corticosteroid (fluorometholone FML 0.1%, drops, three times per day tid) for 2 weeks (week 14).
Sixty-five participants completed the primary endpoint. At week 12, contact lens dry-eye questionnaire (CLDEQ-8) score was reduced from baseline with oral fish oil (-7.3 ± 0.8 units, n = 17, P < 0.05), compared with placebo (-3.5 ± 0.9 units, n = 16). FML produced significant reductions in tear IL-17A (-71.1 ± 14.3%, n = 12) and IL-6 (-47.6 ± 17.5%, n = 12, P < 0.05) relative to its baseline (week 12). At week 12, tear IL-17A levels were reduced from baseline in the oral fish oil (-63.2 ± 12.8%, n = 12, P < 0.05) and topical omega-3 (-76.2 ± 10.8%, n = 10, P < 0.05) groups, compared with placebo (-3.8 ± 12.7%, n = 12). Tear IL-6 was reduced with all omega-3 interventions, relative to placebo (P < 0.05) at week 12.
CLD was attenuated by oral long-chain omega-3 supplementation for 12 weeks. Acute (2 week) topical corticosteroids and longer-term (12 week) omega-3 supplementation reduced tear levels of the proinflammatory cytokines IL-17A and IL-6, demonstrating parallels in modulating ocular inflammation with these approaches.
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