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1.
Electrophoresis ; 43(16-17): 1746-1754, 2022 09.
Article in English | MEDLINE | ID: mdl-35656648

ABSTRACT

The laser print, cut, and laminate (PCL) method for microfluidic device fabrication can be leveraged for rapid and inexpensive prototyping of electrophoretic microchips useful for optimizing separation conditions. The rapid prototyping capability allows the evaluation of fluidic architecture, applied fields, reagent concentrations, and sieving matrix, all within the context of using fluorescence-compatible substrates. Cyclic olefin copolymer and toner-coated polyethylene terephthalate (tPeT) were utilized with the PCL technique and bonding methods optimized to improve device durability during electrophoresis. A series of separation channel designs and centrifugation conditions that provided successful loading of sieving polymer in less than 3 min was described. Separation of a 400-base DNA sizing ladder provided calculated base resolution between 3 and 4 bases, a greater than 18-fold improvement over separations on similar substrates. Finally, the accuracy and precision capabilities of these devices were demonstrated by separating and sizing DNA fragments of 147 and 167 bases as 148.62 ± 2 and 166.48 ± 3 bases, respectively.


Subject(s)
DNA , Lab-On-A-Chip Devices , Centrifugation , DNA/analysis , Electrophoresis , Polymers
2.
J Ultrasound Med ; 40(2): 359-367, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32725845

ABSTRACT

OBJECTIVES: To characterize fluctuations in peak systolic velocities (PSVs) in Doppler waveforms of the carotid artery in patients with and without obstructive airway disease and in volunteers subjected to incremental levels of airway resistance in an experimental model. METHODS: The PSV variation in common carotid waveforms was measured in 100 patients who had had a carotid ultrasound examination and no respiratory or carotid disease. This was compared to that of patients who had this study during an admission for acute exacerbation of chronic obstructive pulmonary disease (COPD). The PSV variation was correlated with pulmonary function testing. In addition, 14 healthy volunteers were asked to breathe through 5 resistors. Simultaneous recordings were made of Doppler waveforms in the common carotid artery, cardiac activity, and respiration. Peak systolic velocity changes from inspiration to expiration were calculated. RESULTS: Of the 100 patients without respiratory disease, the magnitude of the PSV variation averaged 6.3 cm/s. Of the 33 patients with COPD, the PSV variation averaged 16.5 cm/s. Nineteen of the 33 patients with COPD had concurrent pulmonary function testing; there was a statistically significant correlation between the PSV variation and forced vital capacity and forced expiratory volume indices. For the volunteers, mean velocity changes were 7.1, 6.6, 8.3, 15.1, and 16.1 cm/s for 0.00-, 2.15-, 3.27-, 3.58-, and 5.77-cm H2 O/L/s levels of breathing resistance, respectively. There was a statistically significant relationship between an increasing airway load and the decline in PSV during inspiration (P = .02). CONCLUSIONS: The PSV variation is greater in patients with increased airway resistance. Similar changes are evident in volunteers breathing into resistors. These findings likely reflect pulsus paradoxus.


Subject(s)
Carotid Stenosis , Pulmonary Disease, Chronic Obstructive , Blood Flow Velocity , Carotid Artery, Common/diagnostic imaging , Humans , Lung , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Respiration , Systole , Ultrasonography, Doppler, Duplex
3.
J Arthroplasty ; 35(2): 465-470, 2020 02.
Article in English | MEDLINE | ID: mdl-31629624

ABSTRACT

BACKGROUND: The influence of total hip arthroplasty surgical approach on postoperative recovery is not well understood and often debated. This study compares anterior and posterior approach (PA) gait and patient-reported Hip Osteoarthritis Outcome scores (HOOS) in the early phases of recovery. METHODS: A prospective study evaluated 20 control subjects, 35 direct anterior approach (DAA), and 34 PA total hip arthroplasty patients. Subjects were assessed preoperatively and at 1 and 4 months postoperatively with HOOS and smartphone gait assessments of gait speed, step length, cadence, step symmetry, and horizontal and vertical center of mass displacements. RESULTS: The DAA and PA groups were not different in baseline HOOS or gait characteristics except for less horizontal center of mass displacement in the DAA group. At 1 month postoperatively, the DAA group had significantly faster gait speed at self-selected (P = .02) and fastest possible gait (P = .01) and longer step length at self-selected (P = .047) and fastest gait (P = .003) compared to the PA. At 4 months, there were no differences in DAA and PA gait measures. At 1 month postoperatively there were no significant differences in HOOS, but after 4 months HOOS were significantly higher in the DAA group. CONCLUSION: There were minimal differences between the two approaches in the recovery of gait mechanics with some gait parameters particularly gait speed and step length recovery favoring the DAA at 1 month postsurgery in this nonrandomized study.


Subject(s)
Antiviral Agents , Arthroplasty, Replacement, Hip , Hepatitis C, Chronic , Accelerometry , Arthroplasty, Replacement, Hip/adverse effects , Gait , Humans , Prospective Studies , Recovery of Function , Smartphone , Treatment Outcome
4.
Lab Chip ; 19(22): 3834-3843, 2019 11 21.
Article in English | MEDLINE | ID: mdl-31595287

ABSTRACT

In laser-induced fluorescence (LIF) detection, optimal alignment is essential in maximizing the fluorescent signal and, hence, detection sensitivity. Micro-total analysis systems (µTAS) involving microchip electrophoresis (ME) are challenged with alignment of the optics to the separation channel each run due to the single-use nature. Furthermore, µTAS devices that are designed to operate autonomously and by non-experts face additional challenges in performing alignment with micrometer resolution without human intervention. As part of the development of a total DNA analysis system, we set out to develop an automated alignment (AA) method to locate a 50-by-50 µm separation channel on a freely rotating microfluidic device in the absence of a fluorescent dye, accomplished without additional hardware. We detail the innate fluorescent signature attainable from laser excitation and the optimization of the algorithm to achieve AA at 84.6% success rate from 26 microchips. This AA method was a key element in realizing complete automation of the DNA analysis process in order to advance our instrument to a technology readiness level of 7. This is the first description of an AA method for ME (and centrifugal ME) with the purpose of providing transparent technical details to bridge the gap from 'fully integrated' to 'fully automated' instruments for point-of-detection, sample in-answer-out use cases. Written in the context of a forensic application, the AA method is adaptable for a wide range of bioanalytical applications involving LIF detection.


Subject(s)
Automation , DNA/analysis , Electrophoresis, Microchip , Microfluidic Analytical Techniques , Electrophoresis, Microchip/instrumentation , Fluorescent Dyes/chemistry , Humans , Microfluidic Analytical Techniques/instrumentation
5.
J Orthop Trauma ; 33(7): 346-350, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30844953

ABSTRACT

OBJECTIVE: To report the mortality data and life expectancy of geriatric hip fracture patients who underwent nonoperative management and compare that with a matched operative cohort. DESIGN: Retrospective cohort study. SETTING: Level 1 trauma center. PATIENTS: Geriatric (65 years of age and older) femoral neck or intertrochanteric fracture (OTA/AO 31A and 31B) patients. INTERVENTION: Operative treatment with either arthroplasty, cannulated screws, sliding hip screw device, or cephalomedullary nail compared with nonoperative cohort. MAIN OUTCOME MEASUREMENTS: In-hospital, 30-day, and 1-year mortality. RESULTS: Two hundred thirty-one patients, comprising 154 operative and 77 nonoperative patients, were compared. There were no significant differences among age, sex, fracture location, Charlson Comorbidity Index, preinjury living location, dementia, and history of cardiac arrhythmia between the 2 cohorts. Nonoperatively managed patients were found to have a significantly higher percent in-hospital (28.6 vs. 3.9; P < 0.0001), 30-day (63.6 vs. 11.0; <0.0001), and 1-year (84.4 vs. 36.4; P < 0.0001) mortality. The mean life expectancy after a hip fracture for the nonoperative cohort was significantly shorter than the operative group (221 vs. 1024 days; P < 0.0001). CONCLUSIONS: Nonoperatively treated hip fracture patients had an 84.4% 1-year mortality that was significantly higher than a matched operative cohort. Our results demonstrate the bleak overall prognosis for nonoperatively treated geriatric hip fractures as well as the associated reduction in mortality with surgical treatment. Our findings offer helpful information by providing updated mortality data when discussing nonoperative hip fracture management with patients and their family. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


Subject(s)
Fracture Fixation/methods , Geriatric Assessment/methods , Hip Fractures/therapy , Aged , Aged, 80 and over , Female , Follow-Up Studies , Hip Fractures/mortality , Humans , Male , Retrospective Studies , Survival Rate/trends , Treatment Outcome , United States/epidemiology
6.
Electrophoresis ; 38(22-23): 2996-3002, 2017 11.
Article in English | MEDLINE | ID: mdl-28722238

ABSTRACT

A microfluidic device (MD) has been developed which features a porous silica (PS) monolithic disk synthesized from tetramethyl orthosilicate, incorporated into the device post-fabrication and sealed in place with a second PS monolithic layer, synthesized from potassium silicate. This dual porous silica (DPS) structure provides a pathway for sample introduction to the MD and offers an ideal platform for solid phase extraction (SPE) methodologies which can be rapidly and efficiently integrated into a chip-based format. All silica disk manufacture and functionalization was carried out in batch to provide a readily scalable method of production. Application of this design for processing samples was demonstrated using two alternative nucleic acid purification chemistries, yielding polymerase chain reaction amplifiable DNA extracted from 150 µL of human urine in less than 35 min. It is proposed that this DPS system could be further developed for a diverse range of chip-based SPE applications, providing an interface facilitating sample delivery and enabling SPE on-chip. Furthermore, to the author's knowledge it is the first reporting of two different types of PS amalgamated in a single MD.


Subject(s)
DNA/urine , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Silicon Dioxide/chemistry , DNA/chemistry , DNA/isolation & purification , Humans , Porosity , Solid Phase Extraction
7.
Anal Chim Acta ; 980: 41-49, 2017 Aug 08.
Article in English | MEDLINE | ID: mdl-28622802

ABSTRACT

Forensic DNA analysis requires several steps, including DNA extraction, PCR amplification, and separation of PCR fragments. Intuitively, there are numerous situations where it would be beneficial to speed up the overall DNA analysis process; in this work, we focus on the most time-consuming component in the analysis pipeline, namely the polymerase chain reaction (PCR). Primers were specially designed to target 10 human genomic loci, all yielding amplicons shorter than 350 bases, for ease of downstream integration with on-board microchip electrophoresis. Primer concentrations were adjusted specifically for microdevice amplification, resulting in well-balanced short tandem repeat (STR) profiles. Furthermore, studies were performed to push the limits of the DNA polymerase to achieve rapid, multiplexed PCR on various substrates, including transparent and black polyethylene terephthalate (Pe), and with two distinct adhesives, toner and heat sensitive adhesive (HSA). Rapid STR-based multiplexed PCR amplification is demonstrated in 15 min on a Pe microdevice using a custom-built system for fluid flow control and thermocycling for the full 10-plex, and in 10 min for a smaller multiplex consisting of six core CODIS loci plus Amelogenin with amplicons shorter than 200bp. Lastly, preliminary studies indicate the capability of this PCR microdevice platform to be integrated with both upstream DNA extraction, and downstream microchip electrophoresis. This, coupled to the use of reagents that are compatible with lyophilization (lyo-compatible) for PCR, represents the potential for a fully integrated rotationally-driven microdevice for complete forensic DNA analysis.


Subject(s)
Electrophoresis, Microchip , Forensic Genetics , Microsatellite Repeats , Nucleic Acid Amplification Techniques , DNA , Humans , Polymerase Chain Reaction
8.
Hip Int ; 27(6): 578-583, 2017 Nov 21.
Article in English | MEDLINE | ID: mdl-28574123

ABSTRACT

BACKGROUND: Periprosthetic femoral shaft fractures are a significant complication after total hip arthroplasty (THA). Plate osteosynthesis has been the mainstay of treatment around well-fixed stems. Nonunions are a rare and challenging complication of this fixation method. We report the outcomes of a novel orthogonal plating surgical technique for Vancouver B1 and C-type periprosthetic fractures that previously failed open reduction internal fixation (ORIF). METHODS: A retrospective review identified all patients with Vancouver B1/C THA periprosthetic femoral nonunions from 2010 to 2015. Exclusion criteria included open fractures and periprosthetic infections. The technique utilised a mechanobiologic strategy of atraumatic exposure, resection of necrotic tissue, bone grafting with adjuvant bone morphogenetic protein (BMP) and revision open reduction internal fixation with orthogonal plate osteosynthesis. RESULTS: 6 Vancouver B1/C periprosthetic femoral nonunions were treated. 5 patients were female with an average age of 80.3 years (range 72-91 years). The fractures occurred at a mean of 5.8 years (range 1-10 years) from their initial arthroplasty procedure. No patients underwent further revision surgery; there were no perioperative complications. All patients had a minimum of 11 months follow-up (mean 18.6, range 11-36 months). All fractures achieved osseous union, defined as solid bridging callus over at least 2 cortices and pain free, independent ambulation, at an average of 24.4 weeks (range 6.1-39.7 weeks). CONCLUSIONS: This is the 1st series describing orthogonal locked compression plating using modern implants for periprosthetic femoral nonunions. This technique should be considered in periprosthetic femur fracture nonunions around a well-fixed stem.


Subject(s)
Arthroplasty, Replacement, Hip/adverse effects , Bone Plates , Femoral Fractures/surgery , Fracture Fixation, Internal/methods , Fractures, Ununited/surgery , Periprosthetic Fractures/surgery , Aged , Aged, 80 and over , Female , Femoral Fractures/diagnosis , Follow-Up Studies , Fracture Healing , Fractures, Ununited/diagnosis , Humans , Male , Periprosthetic Fractures/diagnosis , Radiography , Reoperation , Retrospective Studies , Time Factors
9.
Lab Chip ; 16(23): 4569-4580, 2016 11 15.
Article in English | MEDLINE | ID: mdl-27766331

ABSTRACT

Current conventional methods utilized for forensic DNA analysis are time consuming and labor-intensive requiring large and expensive equipment and instrumentation. While more portable Rapid DNA systems have been developed, introducing them to a working laboratory still necessitates a high cost of initiation followed by the recurrent cost of the devices. This has highlighted the need for an inexpensive, rapid and portable DNA analysis tool for human identification in a forensic setting. In order for an integrated DNA analysis system such as this to be realized, device operations must always be concluded by a rapid separation of short-tandem repeat (STR) DNA fragments. Contributing to this, we report the development of a unique, multi-level, centrifugal microdevice that can perform both reagent loading and DNA separation. The fabrication protocol was inspired by the print, cut and laminate (PCL) technique described previously by our group, and in accordance, offers a rapid and inexpensive option compared with existing approaches. The device comprises multiple polyester-toner fluidic layers, a cyclic olefin copolymer separation domain and integrated gold leaf electrodes. All materials are commercially-available and complement the PCL process in a way that permits fabrication of increasingly sought after single-use devices. All reagents, including a viscous sieving matrix, are loaded centrifugally, eliminating external pneumatic pumping, and the sample is separated in <5 minutes using an effective separation length of only 4 cm (reagent loading to completed separation, is <37 minutes). The protocol for gold leaf electrode manufacture yielded up to 30 electrodes for less than $3 (cost of a 79 mm × 79 mm gold leaf sheet) and when using a device combining these electrodes and centrifugal reagent/polymer loading, the electrophoretic separation of STR fragments with two base resolution was demonstrated. This exemplary performance makes the device an ideal candidate for further integration and development of an inexpensive, portable and rapid forensic human identification system.


Subject(s)
Centrifugation/instrumentation , DNA/isolation & purification , Electrophoresis/instrumentation , Gold , Lab-On-A-Chip Devices , Electrodes , Equipment Design , Time Factors
10.
Analyst ; 141(15): 4667-75, 2016 Aug 07.
Article in English | MEDLINE | ID: mdl-27250903

ABSTRACT

To date, the forensic community regards solid phase extraction (SPE) as the most effective methodology for the purification of DNA for use in short tandem repeat (STR) polymerase chain reaction (PCR) amplification. While a dominant methodology, SPE protocols generally necessitate the use of PCR inhibitors (guanidine, IPA) and, in addition, can demand timescales of up to 30 min due to the necessary load, wash and elution steps. The recent discovery and characterization of the EA1 protease has allowed the user to enzymatically extract (not purify) DNA, dramatically simplifying the task of producing a PCR-ready template. Despite this, this procedure has yet to make a significant impact on microfluidic technologies. Here, we describe a microfluidic device that implements the EA1 enzyme for DNA extraction by incorporating it into a hybrid microdevice comprising laminated polyester (Pe) and PMMA layers. The PMMA layer provides a macro-to-micro interface for introducing the biological sample into the microfluidic architecture, whilst also possessing the necessary dimensions to function as the swab acceptor. Pre-loaded reagents are then introduced to the swab chamber centrifugally, initiating DNA extraction at 75 °C. The extraction of DNA occurs in timescales of less than 3 min and any external hardware associated with the transportation of reagents by pneumatic pumping is eliminated. Finally, multiplexing is demonstrated with a circular device containing eight separate chambers for the simultaneous processing of eight buccal swab samples. The studies here provide DNA concentrations up to 10 ng µL(-1) with a 100% success rate in less than 3 minutes. The STR profiles generated using these extracted samples demonstrate that the DNA is of PCR forensic-quality and adequate for human identification.


Subject(s)
DNA/isolation & purification , Enzymes , Microfluidic Analytical Techniques , Polymethyl Methacrylate , Humans , Polyesters , Polymerase Chain Reaction
11.
JBJS Essent Surg Tech ; 6(1): e11, 2016 Mar 23.
Article in English | MEDLINE | ID: mdl-30237921

ABSTRACT

Slipped capital femoral epiphysis (SCFE), a common cause of adolescent hip pain, is a displacement of the femoral head through the proximal femoral physis. The exact etiology of SCFE is unknown, but both biochemical and biomechanical factors, including obesity, femoral retroversion, increased physeal obliquity, puberty, and endocrinopathies, play a role. Patients often present with hip, groin, or knee pain and an antalgic gait. On physical examination, obligate external rotation of the lower limb with passive hip flexion is a hallmark of SCFE. The diagnosis is confirmed with radiographs, with advanced imaging reserved for atypical presentations. Any degree of SCFE is an indication for internal stabilization. Percutaneous in situ fixation remains the gold-standard treatment for slipped capital femoral epiphysis. The procedure is performed with the following steps: (1) the patient is positioned supine on a fracture table with the contralateral lower limb in the hemilithotomy position; (2) a 1-cm longitudinal incision is made over the anterolateral aspect of the proximal part of the femur; (3) under fluoroscopic guidance, a guidewire is advanced freehand into the "center-center" of the epiphysis, stopping approximately 3 mm short of the articular surface; (4) the guidewire is overdrilled, and a 6.5-mm partially threaded cannulated screw of appropriate length is inserted into the epiphysis; (5) the proximal part of the femur is brought through a full range of internal-external rotation under fluoroscopy to confirm that the screw has not violated the joint cavity; and (6) the wound is closed in layers and a sterile dressing is applied. Postoperatively, the patient's weight-bearing status is advanced on the basis of the stability of the SCFE. Radiographic follow-up is performed at six-month intervals to monitor the contralateral hip until skeletal maturity. Treatment outcomes and complications such as osteonecrosis and chondrolysis correlate with the severity and stability of the slip on presentation. Long-term follow-up has shown good-to-excellent outcomes after in situ screw fixation of stable slips.

12.
Injury ; 46(8): 1689-94, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25816707

ABSTRACT

BACKGROUND: Femoral head fractures with subchondral impaction and cartilage loss are difficult to treat successfully. Although multiple surgical management options have been described, no one technique has proven superior, particularly in the young high-demand population. TECHNIQUE: A femoral head reduction osteoplasty was performed following a surgical dislocation of the hip. A peripherally based wedge of bone was resected off the damaged central third of the head followed by reduction and fixation of the remaining fragments. This technique resulted in a smaller yet congruent femoral head. METHODS: A healthy 40-year old labourer sustained a traumatic crush injury while at work, resulting in a left femoral head fracture dislocation with an associated posterior wall acetabular fracture. Significant femoral head impaction and cartilage loss limited the treatment options. RESULTS: Intraoperative reduction and postoperative imaging demonstrated near anatomic reconstruction of femoral head with a congruent hip joint. Superiorly at the level of resection, the medial-lateral diameter was reduced by 5-6mm (approximately 12-15% the diameter of the original head) by the osteoplasty. At five years, Harris Hip Score was 86, Oxford Hip Score 36, and UCLA score 89. Hip abductor strength was full, range of motion near normal, and the patient ambulated without antalgia. Radiographs demonstrate a congruent joint and patchy avascular necrosis without collapse. The patient maintained full employment as a labourer. CONCLUSIONS: Femoral head reduction osteoplasty is a viable option that may produce durable intermediate-term results for complex femoral head fracture with superior impaction and chondral damage. LEVEL OF EVIDENCE: Level V.


Subject(s)
Femur Head/injuries , Fracture Fixation, Internal/methods , Hip Fractures/surgery , Hip Joint/surgery , Joint Dislocations/surgery , Accidents, Occupational , Adult , Femur Head/surgery , Hip Fractures/etiology , Hip Fractures/pathology , Hip Joint/pathology , Humans , Joint Dislocations/pathology , Male , Treatment Outcome
13.
Hepatology ; 57(3): 944-52, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23111904

ABSTRACT

UNLABELLED: Acute hepatitis C virus (HCV) infection is underdiagnosed because most patients are asymptomatic. The majority of new infections occur among people who inject drugs (PWID), many of whom have a history of incarceration. In a previous pilot study, we identified symptomatic HCV cases, mainly among Caucasian inmates. We designed a cross-sectional study to evaluate whether risk factor-based screening of newly incarcerated inmates would enhance identification of asymptomatic acute HCV infection and elucidate any demographic shifts in HCV acquisition. From October 2006 to March 2008, 6,342 inmates underwent health assessments and 3,470 inmates (55%) were screened. The racial distribution was as follows: African American, 24.0%; Caucasian, 49.5%; Hispanic, 22.2%. One hundred seventy-one inmates (4.9%) were classified as high-risk. After further evaluation, 35 (20.5%) inmates were diagnosed with acute HCV with a mean age of 29 years; 62.9% were female and 91% were Caucasian. No African Americans were diagnosed with acute HCV. Our case-finding rate was 1.9 patients/month nearly a three-fold increase compared with our historical control period with a higher proportion of asymptomatic cases. We estimate a prevalence of ∼1.0% (95% confidence interval, 0.7%-1.4%) of acute HCV infections among newly incarcerated inmates. CONCLUSION: Within the correctional system, systematic screening based on risk factors successfully identifies acute HCV infection among PWID, including asymptomatic patients. Our data also reflect changing nationwide patterns of injection drug use that vary by age, ethnicity, and race, leading to a marked reduction of acute HCV infections among African Americans compared with non-Hispanic whites. The nationwide implementation of this simple low-cost strategy in prison-based settings could identify more than 7,000 acute HCV infections among PWID, provide insight into changing epidemiologic trends, and facilitate appropriate therapeutic and preventive interventions.


Subject(s)
Hepacivirus/isolation & purification , Hepatitis C/diagnosis , Hepatitis C/epidemiology , Prisoners/statistics & numerical data , Substance-Related Disorders/epidemiology , Acute Disease , Adult , Cross-Sectional Studies , Drug Users/statistics & numerical data , Female , Hepacivirus/immunology , Hepatitis C Antibodies/blood , Humans , Male , Mass Screening/methods , Mass Screening/organization & administration , Middle Aged , Pilot Projects , Program Evaluation , Risk Factors , Self Report , Seroepidemiologic Studies , Young Adult
14.
Commun Dis Intell Q Rep ; 36(3): E277-80, 2012 Sep 30.
Article in English | MEDLINE | ID: mdl-23186239

ABSTRACT

Measles virus (MV) eradication is biologically, technically and operationally feasible. An essential feature in understanding the chain of MV transmission is its incubation period, that is, the time from infection to the onset of symptoms. This period is important for determining the likely source of infection and directing public health measures to interrupt ongoing transmission. Long measles incubation periods have rarely been documented in the literature. We report on a previously healthy 11-year-old Australian boy who was confirmed with measles genotype D9 infection following travel in the Philippines. Epidemiological evidence supported an unusually long incubation period of at least 23 days and virological evidence was consistent with this finding. Although public health control measures such as post exposure prophylaxis, isolation and surveillance of susceptible individuals should continue to be based on the more common incubation period, a longer incubation period may occasionally explain an unexpected measles case.


Subject(s)
Contact Tracing , Infectious Disease Incubation Period , Measles/epidemiology , Measles/transmission , Australia/epidemiology , Child , Genotype , Humans , Male , Measles/diagnosis , Morbillivirus/genetics , Travel
15.
Emerg Infect Dis ; 17(6): 963-8, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21749755

ABSTRACT

In Australia, the outbreak of pandemic (H1N1) 2009 began in Melbourne, Victoria; in the first 17 days, the Victorian Infectious Diseases Reference Laboratory detected 977 cases. Although the laboratory had a pandemic plan in place, a retrospective evaluation found 3 major variations from plan assumptions: 1) higher peak demand not limited by a case definition, 2) prolonged peak demand because containment attempts continued despite widespread influenza, and 3) unexpected influence of negative test results on public health actions. Although implementation of the plan was generally successful, the greatest challenges were limited availability of skilled staff and test reagents. Despite peak demand of 1,401 tests per day, results were provided within the usual 24 hours of specimen receipt; however, turnaround time seemed slower because of slow transport times (>3 days for 45% of specimens). Hence, effective laboratory capability might be enhanced by speeding transport of specimens and improving transmission of clinical data.


Subject(s)
Clinical Laboratory Techniques , Health Planning/standards , Influenza A Virus, H1N1 Subtype , Influenza, Human/epidemiology , Pandemics , Program Evaluation , Australia/epidemiology , Clinical Laboratory Techniques/standards , Diagnostic Tests, Routine , Humans , Population Surveillance
16.
Clin Infect Dis ; 52(3): 361-3, 2011 Feb 01.
Article in English | MEDLINE | ID: mdl-21189425

ABSTRACT

We report a case of acute hepatitis C virus infection that occurred after a traumatic altercation among prison inmates. This report has significant implications for infection control policies and procedures in prisons and jails, where the estimated prevalence of hepatitis C virus infection is ∼20 times that of the general population.


Subject(s)
Hepatitis C/diagnosis , Wounds and Injuries/complications , Humans , Male , Middle Aged , Prisoners , Prisons
17.
Clin Infect Dis ; 49(7): 1051-60, 2009 Oct 01.
Article in English | MEDLINE | ID: mdl-19725787

ABSTRACT

BACKGROUND: The diagnosis of acute hepatitis C virus (HCV) infection is imprecise because antibody testing does not differentiate between acute and chronic infection. Although virologic features, such as viral load fluctuations and low levels of viremia, have been noted to be characteristic of acute HCV infection, these parameters have not been used for diagnosis. METHODS: We validated the use of these novel parameters (ie, viral load fluctuations >1 log and HCV RNA levels <100,000 IU/mL) in a cohort of acute HCV seroconverters. We then applied standard diagnostic criteria for acute HCV infection in a cohort of high-risk injection drug users entering prison with suspected acute HCV infection (n=37). We subsequently assessed whether these novel virologic parameters, measured serially over a 10-week period, could enhance the diagnosis of acute infection. RESULTS: Low-level viremia and viral load fluctuations were highly prevalent in our cohort of acute seroconverters (81% and 86%, respectively), whereas low-level viremia occurred in only 13% of control patients with chronic infection. With use of standard criteria, 37 inmates received a diagnosis of acute HCV infection. Among the 35 patients with HCV RNA detectable at baseline, we found low-level viremia to be highly prevalent (n=27; 77%); among patients with a minimum of 2 HCV RNA samples, we demonstrated viral fluctuations in more than one-third (n=9; 36%). CONCLUSIONS: The diagnosis of acute infection in HCV-seropositive patients is strengthened by the use of virologic parameters that are uncommon in chronic disease. Viral load fluctuations and low levels of HCV RNA should be incorporated into standard diagnostic criteria.


Subject(s)
Hepacivirus/isolation & purification , Hepatitis C/diagnosis , Viral Load , Adolescent , Adult , Female , Humans , Male , Middle Aged , Prisoners , RNA, Viral/blood , Substance Abuse, Intravenous , Young Adult
18.
J Infect Dis ; 200(6): 877-81, 2009 Sep 15.
Article in English | MEDLINE | ID: mdl-19673649

ABSTRACT

Treatment of acute hepatitis C virus (HCV) infection leads to a sustained virologic response (SVR) in the vast majority of patients, although the clinical predictors of these favorable responses are not well understood. In chronic infection, the most potent predictor of a SVR is complete viral suppression after 4 weeks of treatment, also known as a rapid virologic response (RVR). However, few patients with HCV genotype 1 infection and high-level viremia ever achieve this benchmark. In 2 separate cohorts of patients with acute HCV infection, we demonstrate that rapid virologic clearance and low-level viremia (HCV RNA level, <400,000 IU/mL) are highly prevalent, regardless of HCV genotype.


Subject(s)
Antiviral Agents/therapeutic use , Hepacivirus/genetics , Hepatitis C/drug therapy , Interferon-alpha/therapeutic use , Polyethylene Glycols/therapeutic use , RNA, Viral/blood , Ribavirin/therapeutic use , Acute Disease , Adult , Antiviral Agents/administration & dosage , Cohort Studies , Female , Genotype , Hepacivirus/drug effects , Hepatitis C/blood , Hepatitis C/virology , Humans , Interferon alpha-2 , Interferon-alpha/administration & dosage , Male , Middle Aged , Polyethylene Glycols/administration & dosage , Recombinant Proteins , Ribavirin/administration & dosage , Viremia/drug therapy , Young Adult
19.
Clin Infect Dis ; 48(3): 285-91, 2009 Feb 01.
Article in English | MEDLINE | ID: mdl-19115974

ABSTRACT

BACKGROUND: Although pandemic and avian influenza are known to be transmitted via human hands, there are minimal data regarding the effectiveness of routine hand hygiene (HH) protocols against pandemic and avian influenza. METHODS: Twenty vaccinated, antibody-positive health care workers had their hands contaminated with 1 mL of 10(7) tissue culture infectious dose (TCID)(50)/0.1 mL live human influenza A virus (H1N1; A/New Caledonia/20/99) before undertaking 1 of 5 HH protocols (no HH [control], soap and water hand washing [SW], or use of 1 of 3 alcohol-based hand rubs [61.5% ethanol gel, 70% ethanol plus 0.5% chlorhexidine solution, or 70% isopropanol plus 0.5% chlorhexidine solution]). H1N1 concentrations were assessed before and after each intervention by viral culture and real-time reverse-transcriptase polymerase chain reaction (PCR). The natural viability of H1N1 on hands for >60 min without HH was also assessed. RESULTS: There was an immediate reduction in culture-detectable and PCR-detectable H1N1 after brief cutaneous air drying--14 of 20 health care workers had H1N1 detected by means of culture (mean reduction, 10(3-4) TCID(50)/0.1 mL), whereas 6 of 20 had no viable H1N1 recovered; all 20 health care workers had similar changes in PCR test results. Marked antiviral efficacy was noted for all 4 HH protocols, on the basis of culture results (14 of 14 had no culturable H1N1; (P< .002) and PCR results (P< .001; cycle threshold value range, 33.3-39.4), with SW statistically superior (P< .001) to all 3 alcohol-based hand rubs, although the actual difference was only 1-100 virus copies/microL. There was minimal reduction in H1N1 after 60 min without HH. CONCLUSIONS: HH with SW or alcohol-based hand rub is highly effective in reducing influenza A virus on human hands, although SW is the most effective intervention. Appropriate HH may be an important public health initiative to reduce pandemic and avian influenza transmission.


Subject(s)
Disinfectants/pharmacology , Disinfection/methods , Hand Disinfection/methods , Hand/virology , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H1N1 Subtype/isolation & purification , Alcohols/pharmacology , Chlorhexidine/pharmacology , Human Experimentation , Humans , RNA, Viral/genetics , Soaps/pharmacology , Virus Cultivation
20.
Hepatology ; 48(6): 1769-78, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19026009

ABSTRACT

UNLABELLED: Resistance mutations to hepatitis C virus (HCV) nonstructural protein 3 (NS3) protease inhibitors in <1% of the viral quasispecies may still allow >1000-fold viral load reductions upon treatment, consistent with their reported reduced replicative fitness in vitro. Recently, however, an R155K protease mutation was reported as the dominant quasispecies in a treatment-naïve individual, raising concerns about possible full drug resistance. To investigate the prevalence of dominant resistance mutations against specifically targeted antiviral therapy for HCV (STAT-C) in the population, we analyzed HCV genome sequences from 507 treatment-naïve patients infected with HCV genotype 1 from the United States, Germany, and Switzerland. Phylogenetic sequence analysis and viral load data were used to identify the possible spread of replication-competent, drug-resistant viral strains in the population and to infer the consequences of these mutations upon viral replication in vivo. Mutations described to confer resistance to the protease inhibitors Telaprevir, BILN2061, ITMN-191, SCH6 and Boceprevir; the NS5B polymerase inhibitor AG-021541; and to the NS4A antagonist ACH-806 were observed mostly as sporadic, unrelated cases, at frequencies between 0.3% and 2.8% in the population, including two patients with possible multidrug resistance. Collectively, however, 8.6% of the patients infected with genotype 1a and 1.4% of those infected with genotype 1b carried at least one dominant resistance mutation. Viral loads were high in the majority of these patients, suggesting that drug-resistant viral strains might achieve replication levels comparable to nonresistant viruses in vivo. CONCLUSION: Naturally occurring dominant STAT-C resistance mutations are common in treatment-naïve patients infected with HCV genotype 1. Their influence on treatment outcome should further be characterized to evaluate possible benefits of drug resistance testing for individual tailoring of drug combinations when treatment options are limited due to previous nonresponse to peginterferon and ribavirin.


Subject(s)
Antiviral Agents/therapeutic use , Drug Resistance, Viral/genetics , Hepacivirus/enzymology , Hepatitis C/drug therapy , Mutation/genetics , Protease Inhibitors/therapeutic use , Antiviral Agents/pharmacology , Carbamates/pharmacology , Carbamates/therapeutic use , Cohort Studies , Female , Genetic Testing , Hepacivirus/genetics , Hepacivirus/pathogenicity , Hepatitis C/blood , Hepatitis C/virology , Humans , Macrocyclic Compounds/pharmacology , Macrocyclic Compounds/therapeutic use , Male , Oligopeptides/pharmacology , Oligopeptides/therapeutic use , Phenylthiourea/analogs & derivatives , Phenylthiourea/pharmacology , Phenylthiourea/therapeutic use , Phylogeny , Proline/analogs & derivatives , Proline/pharmacology , Proline/therapeutic use , Quinolines/pharmacology , Quinolines/therapeutic use , Thiazoles/pharmacology , Thiazoles/therapeutic use , Viral Load , Viral Nonstructural Proteins/antagonists & inhibitors
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