Abstract
Objectives
To establish the optimal parameters for group testing of pooled specimens for the detection of SARS-CoV-2.
Methods
The most efficient pool size was determined to be five specimens ...using a web-based application. From this analysis, 25 experimental pools were created using 50 µL from one SARS-CoV-2 positive nasopharyngeal specimen mixed with 4 negative patient specimens (50 µL each) for a total volume of 250 µL. Viral RNA was subsequently extracted from each pool and tested using the CDC SARS-CoV-2 RT-PCR assay. Positive pools were consequently split into individual specimens and tested by extraction and PCR. This method was also tested on an unselected group of 60 nasopharyngeal specimens grouped into 12 pools.
Results
All 25 pools were positive with cycle threshold (Ct) values within 0 and 5.03 Ct of the original individual specimens. The analysis of 60 specimens determined that 2 pools were positive followed by identification of 2 individual specimens among the 60 tested. This testing was accomplished while using 22 extractions/PCR tests, a savings of 38 reactions.
Conclusions
When the incidence rate of SARS-CoV-2 infection is 10% or less, group testing will result in the saving of reagents and personnel time with an overall increase in testing capability of at least 69%.
Abstract
A male patient with distant history of extensive rabbit contact and pulmonary nodules for 6 years developed empyema. Francisella tularensis holarctica was isolated from thoracentesis fluid. ...Retrospective immunohistochemical examination of a pulmonary nodule, biopsied 3 years prior, was immunoreactive for F. tularensis. These findings suggest the potential for chronic tularemia.
A male patient with nodules for six years developed empyema. Francisella tularensis holarctica was isolated from thoracentesis fluid. Retrospective immunohistochemical examination of a pulmonary nodule, biopsied three years prior, was immunoreactive for F. tularensis, suggesting the potential for chronic tularemia.
Histoplasmosis is one of the most common mycoses endemic to the United States, but it was reportable in only 10 states during 2016, when a national case definition was approved. To better ...characterize the epidemiologic features of histoplasmosis, we analyzed deidentified surveillance data for 2011-2014 from the following 12 states: Alabama, Arkansas, Delaware, Illinois, Indiana, Kentucky, Michigan, Minnesota, Mississippi, Nebraska, Pennsylvania, and Wisconsin. We examined epidemiologic and laboratory features and calculated state-specific annual and county-specific mean annual incidence rates. A total of 3,409 cases were reported. Median patient age was 49 (interquartile range 33-61) years, 2,079 (61%) patients were male, 1,273 (57%) patients were hospitalized, and 76 (7%) patients died. Incidence rates varied markedly between and within states. The high hospitalization rate suggests that histoplasmosis surveillance underestimates the true number of cases. Improved surveillance standardization and surveillance by additional states would provide more comprehensive knowledge of histoplasmosis in the United States.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The B.1.1.529 (Omicron) variant of SARS-CoV-2 (the virus that causes COVID-19) was first detected in specimens collected on November 11, 2021, in Botswana and on November 14 in South Africa;* the ...first confirmed case of Omicron in the United States was identified in California on December 1, 2021 (1). On November 29, the Nebraska Department of Health and Human Services was notified of six probable cases
of COVID-19 in one household, including one case in a man aged 48 years (the index patient) who had recently returned from Nigeria. Given the patient's travel history, Omicron infection was suspected. Specimens from all six persons in the household tested positive for SARS-CoV-2 by reverse transcription-polymerase chain reaction (RT-PCR) testing on December 1, and the following day genomic sequencing by the Nebraska Public Health Laboratory identified an identical Omicron genotype from each specimen (Figure). Phylogenetic analysis was conducted to determine if this cluster represented an independent introduction of Omicron into the United States, and a detailed epidemiologic investigation was conducted. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.
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Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Acinetobacter baumannii is an emerging bacterial pathogen of considerable health care concern. Nonetheless, relatively little is known about the organism's virulence factors or their regulatory ...networks. Septicemia and ventilator-associated pneumonia are two of the more severe forms of A. baumannii disease. To identify virulence factors that may contribute to these disease processes, genetically diverse A. baumannii clinical isolates were evaluated for the ability to proliferate in human serum. A transposon mutant library was created in a strain background that propagated well in serum and screened for members with decreased serum growth. The results revealed that disruption of A. baumannii phospholipase D (PLD) caused a reduction in the organism's ability to thrive in serum, a deficiency in epithelial cell invasion, and diminished pathogenesis in a murine model of pneumonia. Collectively, these results suggest that PLD is an A. baumannii virulence factor.
Primary amebic meningoencephalitis (PAM) is a rare and lethal infection caused by Naegleria fowleri. We report an epidemiological and environmental investigation relating to a case of PAM in a ...previously healthy boy age 8 years. An interview of the patient's family was conducted to determine the likely exposure site and to assess risk factors. Data from the United States Geological Survey site at Waterloo, NE, on the Elkhorn River were used to estimate water temperature and streamflow at the time and site of exposure. Data from the National Weather Service were used to estimate precipitation and ambient air temperature at the time and site of exposure. Despite conventional treatment, the patient died 2 days after hospital admission. The patient participated in recreational water activities in the Elkhorn River in northeastern Nebraska 5 days before symptom onset. In the week before exposure, water and ambient air high temperatures reached annual highs, averaging 32.4°C and 35.8°C, respectively. The day before infection, 2.2 cm of precipitation was reported. Streamflow was low (407 ft3/s). Infections in several northern states, including Nebraska, suggest an expanding geographic range of N. fowleri transmission, which may lead to increased incidence of PAM in the United States. Similar environmental investigations at suspected exposure sites of future cases will allow data aggregation, enabling investigators to correlate environmental factors with infection risk accurately.
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