scholarly journals Variola Virus-Specific Diagnostic Assays: Characterization, Sensitivity, and Specificity

2015 ◽  
Vol 53 (4) ◽  
pp. 1406-1410 ◽  
Author(s):  
Ashley V. Kondas ◽  
Victoria A. Olson ◽  
Yu Li ◽  
Jason Abel ◽  
Miriam Laker ◽  
...  
Keyword(s):  
Public Health ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Variola Virus ◽  
Public Health Response ◽  
Diagnostic Assays ◽  
Health Response ◽  
Pcr Assays

A public health response relies upon rapid and reliable confirmation of disease by diagnostic assays. Here, we detail the design and validation of two variola virus-specific real-time PCR assays, since previous assays cross-reacted with newly identified cowpox viruses. The assay specificity must continually be reassessed as other closely related viruses are identified.

scholarly journals Increased PCR screening capacity using a multi-replicate pooling scheme

2020 ◽  
Author(s):  
A. Viehweger ◽  
F. Kühnl ◽  
C. Brandt ◽  
B. König ◽  
A. C. Rodloff
Keyword(s):  
Public Health ◽  
Real Time ◽  
Real Time Pcr ◽  
Public Health Response ◽  
Pcr Screening ◽  
Feasible Method ◽  
Test Sensitivity ◽  
Health Response ◽  
Large Populations ◽  
Effective Public Health

AbstractEffective public health response to viral outbreaks such as SARS-CoV-2 require reliable information about the spread of the infecting agent. Often real-time PCR screening of large populations is a feasible method to generate this information. Since test capacities are usually limited, pooling of test specimens is often necessary to increase screening capacity, provided that the test sensitivity is not significantly compromised. However, when a traditional pool is tested positive, all samples in the pool need individual retesting, which becomes ineffective at a higher proportion of positive samples. Here, we report a new pooling protocol that mitigates this problem by replicating samples across multiple pools. The resulting pool set allows the sample status to be resolved more often than with traditional pooling. At 2% prevalence and 20 samples per pool, our protocol increases screening capacity by factors of 5 and 2 compared to individual testing and traditional pooling, respectively. The corresponding software to layout and resolve samples is freely available under a BSD license (https://github.com/phiweger/clonepool).

scholarly journals A collaborative multiyear, multimodel assessment of seasonal influenza forecasting in the United States

2019 ◽  
Vol 116 (8) ◽  
pp. 3146-3154 ◽  
Author(s):  
Nicholas G. Reich ◽  
Logan C. Brooks ◽  
Spencer J. Fox ◽  
Sasikiran Kandula ◽  
Craig J. McGowan ◽  
...  
Keyword(s):  
Public Health ◽  
United States ◽  
Real Time ◽  
Forecast Accuracy ◽  
The United States ◽  
Public Health Response ◽  
Public Health Decision ◽  
Health Decision Making ◽  
Health Response ◽  
Health Decision

Influenza infects an estimated 9–35 million individuals each year in the United States and is a contributing cause for between 12,000 and 56,000 deaths annually. Seasonal outbreaks of influenza are common in temperate regions of the world, with highest incidence typically occurring in colder and drier months of the year. Real-time forecasts of influenza transmission can inform public health response to outbreaks. We present the results of a multiinstitution collaborative effort to standardize the collection and evaluation of forecasting models for influenza in the United States for the 2010/2011 through 2016/2017 influenza seasons. For these seven seasons, we assembled weekly real-time forecasts of seven targets of public health interest from 22 different models. We compared forecast accuracy of each model relative to a historical baseline seasonal average. Across all regions of the United States, over half of the models showed consistently better performance than the historical baseline when forecasting incidence of influenza-like illness 1 wk, 2 wk, and 3 wk ahead of available data and when forecasting the timing and magnitude of the seasonal peak. In some regions, delays in data reporting were strongly and negatively associated with forecast accuracy. More timely reporting and an improved overall accessibility to novel and traditional data sources are needed to improve forecasting accuracy and its integration with real-time public health decision making.

scholarly journals Triplex Real-Time PCR without DNA Extraction for the Monitoring of Meningococcal Disease

Diagnostics ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 58 ◽  
Author(s):  
Melissa Whaley ◽  
Laurel Jenkins ◽  
Fang Hu ◽  
Alexander Chen ◽  
Seydou Diarra ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Real Time ◽  
Dna Extraction ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
Detection Range ◽  
Clinical Specimens ◽  
Large Numbers ◽  
Pcr Assays

Detection of Neisseria meningitidis has become less time- and resource-intensive with a monoplex direct real-time PCR (drt-PCR) to amplify genes from clinical specimens without DNA extraction. To further improve efficiency, we evaluated two triplex drt-PCR assays for the detection of meningococcal serogroups AWX and BCY. The sensitivity and specificity of the triplex assays were assessed using 228 cerebrospinal fluid (CSF) specimens from meningitis patients and compared to the monoplex for six serogroups. The lower limit of detection range for six serogroup-specific drt-PCR assays was 178–5264 CFU/mL by monoplex and 68–2221 CFU/mL by triplex. The triplex and monoplex showed 100% agreement for six serogroups and the triplex assays achieved similar sensitivity and specificity estimates as the monoplex drt-PCR assays. Our triplex method reduces the time and cost of processing CSF specimens by characterizing six serogroups with only two assays, which is particularly important for testing large numbers of specimens for N. meningitidis surveillance.

Evaluation of a Diagnostic Polymerase Chain Reaction Assay for Neisseria meningitidis in North America and Field Experience During an Outbreak

2002 ◽  
Vol 126 (10) ◽  
pp. 1209-1215
Author(s):  
Andrew J. Pollard ◽  
Gary Probe ◽  
Colleen Trombley ◽  
Annette Castell ◽  
Sue Whitehead ◽  
...  
Keyword(s):  
Public Health ◽  
North America ◽  
Neisseria Meningitidis ◽  
Sensitivity And Specificity ◽  
Meningococcal Disease ◽  
Pcr Assay ◽  
Public Health Response ◽  
The Public ◽  
Laboratory Confirmation ◽  
Health Response

Abstract Context.—Meningococcal infection has a high public profile because of its dramatic presentation, high fatality rate, and propensity to occur in outbreaks and clusters of cases. Use of a diagnostic polymerase chain reaction (PCR) assay could enhance laboratory confirmation of cases and guide the public health response in North America. Objective.—To assess the performance of a PCR assay for the diagnosis of meningococcal disease after its implementation in a North American setting and to evaluate sensitivity and specificity of the assay for the detection of prevalent bacterial isolates. Design.—Laboratory evaluation of the sensitivity and specificity of a PCR assay for Neisseria meningitidis and observational study of a series of cases comparing molecular diagnosis against the criterion standard of conventional laboratory diagnostic tests. Setting.—A Canadian province with a population of 4 million people. Patients.—Children and adults presenting with suspected meningococcal disease in British Columbia. Main Outcome Measures.—The sensitivity and specificity of the PCR assay when compared against standard laboratory methods. Results.—The PCR assay correctly identified all of 38 Canadian isolates of Neisseria meningitidis and correctly assigned the serogroup to each isolate. None of 57 other gram-positive or gram-negative bacteria or yeasts were detected by the PCR assay. In a clinical evaluation, for diagnosis of meningococcal disease, the PCR assay had a sensitivity and specificity of 91% and 76%, respectively, against conventional methods of diagnosis. Use of the PCR assay increased the laboratory confirmation of clinically suspected cases by 36%. During an outbreak, the PCR assay allowed serogroup determination in 3 of 7 cases, aiding in the public health decision to launch an immunization campaign. Conclusions.—The PCR assay is more sensitive than conventional methods for the diagnosis of meningococcal disease, and enhanced surveillance may help direct the public health response to the changing epidemiology of disease in North America.

Using Surveillance With Near–Real-Time Alerts During a Cluster of Overdoses From Fentanyl-Contaminated Crack Cocaine, Connecticut, June 2019

2021 ◽  
Vol 136 (1_suppl) ◽  
pp. 18S-23S
Author(s):  
Peter Canning ◽  
Suzanne Doyon ◽  
Sarah Ali ◽  
Susan B. Logan ◽  
Aliese Alter ◽  
...  
Keyword(s):  
Public Health ◽  
Harm Reduction ◽  
Real Time ◽  
Crack Cocaine ◽  
State Department ◽  
Poison Control ◽  
Opioid Overdose ◽  
Public Health Response ◽  
Mapping Tool ◽  
Health Response

In 2019, Connecticut launched an opioid overdose–monitoring program to provide rapid intervention and limit opioid overdose–related harms. The Connecticut Statewide Opioid Response Directive (SWORD)—a collaboration among the Connecticut State Department of Public Health, Connecticut Poison Control Center (CPCC), emergency medical services (EMS), New England High Intensity Drug Trafficking Area (HIDTA), and local harm reduction groups—required EMS providers to call in all suspected opioid overdoses to the CPCC. A centralized data collection system and the HIDTA overdose mapping tool were used to identify outbreaks and direct interventions. We describe the successful identification of a cluster of fentanyl-contaminated crack cocaine overdoses leading to a rapid public health response. On June 1, 2019, paramedics called in to the CPCC 2 people with suspected opioid overdose who reported exclusive use of crack cocaine after being resuscitated with naloxone. When CPCC specialists in poison information followed up on the patients’ status with the emergency department, they learned of 2 similar cases, raising suspicion that a batch of crack cocaine was mixed with an opioid, possibly fentanyl. The overdose mapping tool pinpointed the overdose nexus to a neighborhood in Hartford, Connecticut; the CPCC supervisor alerted the Connecticut State Department of Public Health, which in turn notified local health departments, public safety officials, and harm reduction groups. Harm reduction groups distributed fentanyl test strips and naloxone to crack cocaine users and warned them of the dangers of using alone. The outbreak lasted 5 days and tallied at least 22 overdoses, including 6 deaths. SWORD’s near–real-time EMS reporting combined with the overdose mapping tool enabled rapid recognition of this overdose cluster, and the public health response likely prevented additional overdoses and loss of life.

scholarly journals Real-time genomic investigation underlying the public health response to a Shiga toxin-producingEscherichia coliO26:H11 outbreak in a nursery

2017 ◽  
Vol 145 (14) ◽  
pp. 2998-3006 ◽  
Author(s):  
J. MORAN-GILAD ◽  
A. ROKNEY ◽  
D. DANINO ◽  
M. FERDOUS ◽  
F. ALSANA ◽  
...  
Keyword(s):  
Public Health ◽  
Real Time ◽  
Shiga Toxin ◽  
Horizontal Transmission ◽  
Molecular Techniques ◽  
Public Health Response ◽  
The Public ◽  
Young Infants ◽  
Health Response ◽  
Animal Contact

SUMMARYShiga toxin-producingEscherichia coli(STEC) is a significant cause of gastrointestinal infection and the haemolytic-uremic syndrome (HUS). STEC outbreaks are commonly associated with food but animal contact is increasingly being implicated in its transmission. We report an outbreak of STEC affecting young infants at a nursery in a rural community (three HUS cases, one definite case, one probable case, three possible cases and five carriers, based on the combination of clinical, epidemiological and laboratory data) identified using culture-based and molecular techniques. The investigation identified repeated animal contact (animal farming and petting) as a likely source of STEC introduction followed by horizontal transmission. Whole genome sequencing (WGS) was used for real-time investigation of the incident and revealed a unique strain of STEC O26:H11 carryingstx2aand intimin. Following a public health intervention, no additional cases have occurred. This is the first STEC outbreak reported from Israel. WGS proved as a useful tool for rapid laboratory characterization and typing of the outbreak strain and informed the public health response at an early stage of this unusual outbreak.

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