News
Natural disasters may hasten the spread of flesh-eating fungus
As residents recover from the devastation of Hurricanes Harvey, Irma, and now Maria, there’s an emergent danger of a flesh-eating fungus linked to natural disasters. The disease, mucormycosis, is listed by the Infectious Diseases Society of America as one of the possible hazards from Hurricane Harvey and may increase in occurrence with climate change. People with wounds exposed to floodwaters or those who have weakened immune systems and inhale spores could get mucormycosis.
The first documented cases of the disease after a disaster was in 1985 after a volcanic eruption in Colombia. People also were sickened with mucormycosis after the 2004 Indian Ocean tsunami. Once inside the body, the fungus can spread through the bloodstream, causing everything from sinus pain and fever to black pus drainage from eyes. Mortality rates range from about 46%-96% depending on the health of the patient, the type of fungus and what part of the body the fungus is attacking. A person’s chances of survival hinge on treatment with antifungal medication, often amphotericin B, and cutting away the flesh infected by the fungus.
A blood test by soundwaves? New device protoyped
A new type of blood test, based on using sound waves, has been prototyped and the development could lead to a significant reduction in the time required to obtain a batch of medical tests. The device is an automated, point-of-care system that enables single-step, on-chip isolation of exosomes from whole biological fluids with good purity and a high yield. Analysis is achieved by tailoring the angle and frequency of sound waves to the length of the channel and size of the exosomes.
The test means that samples, once taken from a patient, do not need to be sent away to a laboratory for analysis. The lead researcher behind this is Professor Tony Jun Huang from Duke University. The new technology could be the beginning of a boon for scientific research and for everyday medical applications. The device has been described in the journal Proceedings of the National Academy of Sciences.
Transfusion Medicine
Massive Transfusion Protocol competency assessment
A massive blood transfusion has been defined as one that requires either a full replacement of the patient’s blood volume or 10 or more units of packed red blood cells in a 24-hour period. While this definition is adequate in describing transfusion volume over time, rate of transfusion is also a critical metric in evaluation of both the patient’s medical need and the demand on blood bank staff.
Massive Transfusion Protocol (MTP) is a term which is used to activate delivery of compatible blood products at a rapid rate (less than five minutes) in emergency situations. This high-pressure situation requires blood bank staff to follow a complex procedure with speed and precision. Complicating the matter further is the relative rarity of MTP activations at community affiliates and the difficulty of observing staff execution of the protocol in a controlled setting. In a lab where many cross-trained laboratorians cover the blood bank (nights and weekends), competency assessment for this procedure includes an exam and drills or practice sessions. Read this protocol commentary and reflect on your lab’s practice.
Frequent blood donations safe for some, but not all
Some people may safely donate blood as often as every eight weeks but that may not be a healthy choice for all, a new study suggests. A new UK study, published in The Lancet, recommend that blood donors wait 12 to 16 weeks before giving again, in contrast to the USA eight weeks recommendation.
A large clinical trial involving more than 45,000 blood donors was designed to answer a critical question: Do frequent donors suffer ill health effects? The answer, researchers found, was ‘nuanced’. There was no evidence that frequent donations (every eight weeks for men and every 12 weeks for women, over two years) caused major adverse effects, such as draining donors' physical energy, dimming their mental sharpness or harming their general quality of life. On the other hand, one-quarter of frequent donors did develop iron deficiency by the two-year mark. And some complained of symptoms like fatigue, dizziness and trouble breathing. "The shorter interval between donations is probably not ideal," said Dr. Edward Murphy, a researcher with the Blood Systems Research Institute, in San Francisco. The new study is the first clinical trial to test the effects of different donation intervals. "That's the innovation of this research," Murphy said.
Microbiology
TB: Rapid test for multidrug resistance shows promise
A rapid test that can detect tuberculosis (TB) resistance to multiple drugs showed promise in a study published the New England Journal of Medicine. The multicenter study included 308 patients from South Korea and China who were positive for tuberculosis based on a culture test. Sputum samples from participants were tested with the experimental assay and a rapid test for rifampicin resistance. The results were then compared to standard methods for drug resistance testing. When DNA sequencing was used as the standard for comparison, the experimental test was 99.6% specific for resistance to all the target drugs and 98.1% sensitive for resistance to isoniazid, 95.8% sensitive for fluoroquinolones, 92.7% sensitive for kanamycin, and 96.8% sensitive for amikacin.
The experimental rapid test can deliver results in 2 hours without much technical expertise or laboratory equipment, which might allow same-day decisions about which therapies to use, the authors write. These results could aid in the implementation of a new shorter treatment regimen for multidrug-resistant TB, which is resistant to rifampicin and isoniazid.
Study examines the relationship between bacteriology report time and length of hospital stay
In a retrospective study in the Journal of Diagnostic Microbiology and Infectious Disease, a team of researchers examined the relationship between the time a bacteriology report was made available and a patient’s length of stay (LOS) following the report.
A total of 18,624 patients were analyzed and divided into two groups: LOS below or equal to one week vs LOS was more than one week. For patients with total hospital stays of one week or less, the average time for last bacteriology report to discharge was 1.4 ± 1.2 days in comparison to 3.9 ± 1.6 days for patients admitted for more than 1 week. The authors found that for patients whose total hospital stay was less than one week, a strong, positive correlation existed between the time of the last bacteriology report and LOS until discharge. On the other hand, for patients who were admitted for more than one week, there was no correlation between bacteriology report time and LOS until discharge. The authors caution readers that although they determined a correlation between bacteriology report time and subsequent LOS, this does not necessarily establish causation.
Cytology
Screening for cervical abnormalities in women offered HPV vaccination
Human papillomavirus (HPV) testing detects a higher number of precancerous cervical lesions than cytology-based Pap smears in a female population including a proportion offered HPV vaccination, according to a study published in PLOS Medicine.
In the new Compass pilot study, researchers randomized cervical samples and analyzed them by either cytology (with HPV testing of low-grade abnormalities), HPV testing with partial genotyping of the virus for the highest risk types HPV16 and 18, and cytology (for participants with other high-risk HPV genotypes), or HPV testing with partial genotyping and dual-stained cytology.
For the cytology group, the overall referral and detected CIN2+ rates were 2.7% and 0.1%, respectively; for the HPV testing and cytology group these were 3.8% and 1.0%; and for the HPV and dual-stained cytology group these were 3.9% and 1.2%. The researchers found that, in the first round of screening, detection of CIN2+ was significantly increased with HPV testing as compared with cytology, while referral was non-significantly increased. Adverse events were rare, and the one case of early-stage cervical cancer (in the HPV testing plus cytology group) was detected as appropriate by screening.
Molecular Genetics
Genetic testing helps determine cause of epilepsy in the very young
A study published in JAMA Pediatrics supports the use of genetic testing, especially with DNA sequencing, as the first-line diagnostic method for children under 3 years of age presenting with seizures.
Led by Dr. Anne Berg, a team of researchers sought to determine the patterns of use and diagnostic effectiveness of genetic tests for early-life epilepsies. Medical records for 775 children with seizure onset before their third birthday being treated at one of 17 American Pediatric Epilepsy Research Consortium centers were examined. 725 children had undergone neuroimaging, however only 38% of these tests yielded a specific diagnosis or indicated a developmental or progressive brain disorder. Dr. Berg and her colleagues found whole genome sequencing and epileptic gene panel testing provided a diagnosis 33% and 27% of the time, compared to microarray and karyotyping which did so just 17% of the time. This study also showed that specific genetic factors were found to be the cause of 40% of patients and that genetic testing provided a diagnosis in 25% of the children whose cause would have otherwise remained unknown.
Research
Researchers learn how the immune system is alerted to viruses
New work has revealed how viruses trigger our innate immunity to launch an attack. Reporting in the journal Immunity, an international team of researchers found that a protein called SIDT2 helps cells recognize viral particles in their environment and can aid in the stimulation of an immune response.
The work could help create a new class of therapeutics that are inspired by dsRNA. "For more than a decade there have been attempts to use modified dsRNA to switch off genes that cause disease - an approach called RNA interference. While there have been many clinical trials utilizing RNA interference, delivering RNA into cells has been a huge challenge, and the lack of effective delivery has meant that these trials have all ultimately failed," said co-author Dr. Ken Pang explained. "Now that we know SIDT2 is important in trafficking double-stranded RNA into cells, future RNA-based therapeutics can hopefully be designed to maximize their transport by SIDT2," Dr. Pang concluded.
Video: Watch as Dr. Tan Nguyen explains how SIDT2 enables viral RNA to migrate.
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