News
A USB stick that can test HIV levels in under 30 minutes
Scientists have developed a type of HIV test on a USB stick. The device, created by scientists at Imperial College London and DNA Electronics, uses a drop of blood to detect HIV, and then creates an electrical signal that can be read by a computer, laptop or handheld device. The disposable test could be used for HIV patients to monitor their own treatment. Furthermore, the technology could enable patients with HIV to be managed more effectively in remote locations.
New research, published in the journal Scientific Reports, shows the device is not only very accurate, but can produce a result in under 30 minutes. In the latest research, the technology tested 991 blood samples with 95% accuracy. The average time to produce a result was 20.8 minutes. The new technology monitors the amount of virus in the bloodstream. This is crucial to monitoring a patient's treatment. Current tests to detect the amount of virus take at least three days, often longer, and involves sending a blood sample to a laboratory. In many parts of the world, particularly those with the highest number of HIV infections, such testing does not exist at all.
The team are also investigating whether the device can be used to test for other viruses such as hepatitis. The technology was developed in conjunction with the Imperial spinout company DNA Electronics which is using the same technology to develop a device for detecting bacterial and fungal sepsis and antibiotic resistance.
Quality
Utilizing mobile technology to upgrade critical value reporting
One of the key areas of laboratory to physician communication is that of reporting critical values. Since regulators and accreditation organizations define critical values as abnormal test results that are potentially life threatening and require a rapid response from caregivers, any steps taken to improve this process impacts the quality of patient care. This not only refers to the timeliness of reporting test results, but ensuring that these results reach the intended physicians no matter where they are and that the information sent and received is secure.
Thanks to the rapid spread of mobile technology, including mobile phones, pagers, tablets, and computers linked to electronic health records, new more secure messaging systems to report critical values are available. Another new application of mobile technology is in real-time patient monitoring using wearables, such as watches and wristbands synced to mobile phones. In these cases, if critical values are detected, it can be immediately transmitted to the laboratory’s electronic health records system (EHR), and the physician notified immediately.
However, along with these advances have come issues of information overload which can act as a counter-force to the progress that these devices provide. In the same way that laboratories often feel frustrated when they are not able to reach physicians to release critical results, physicians increasingly feel overwhelmed with the high volume of alerts, calls, and other messages that they are receiving. As a result, even with the increasing number of high-tech tools available, labs often struggle to optimize critical value reporting. Realistically, this cannot be solved unilaterally by the laboratory. There must be active ongoing collaboration with physicians to identify problem areas, and seek solutions through mutually agreed upon strategies. The problem with information overload is how to distinguish laboratory alerts from all the other alerts that are coming in as well. This collaboration should produce uniform policies applicable to all physicians on staff, not customized for individual physicians.
Pre-Analytical
The future of fingerprick testing
Many reasons exist for why expanding the range of available fingerprick tests could benefit patients. Fingerprick POCT are ideal for limited-resource countries due to factors such as their low cost and simplicity. Even in the U.S., there are low-resource settings that need an alternative to centralized testing, such as inner cities, drug clinics, and Native American reservations.
DNA Medicine Institute (DMI) was founded by Eugene Chan, MD, CEO and head scientist of DMI. It is home of the rHEALTH suite of instruments—three portable testing devices, two of which are handheld, that each run 16 different tests using only a few microliters of blood. The rHEALTH menu covers a wide range of assays, from hematology and basic blood chemistry tests to those for small molecules (e.g., vitamin D), large molecules (e.g., IgG), and biomarkers such as parathyroid hormone. DMI developed this varied offering of tests because when the company started out, Chan said, he and his colleagues wanted to demonstrate the broad capabilities of their platform. Now they are seeking Food and Drug Administration approval, one test at a time, and are focusing on the rHEALTH’s hematology assays first, as this is where they see the greatest need.
Read more about the future and challenges of fingerprick testing by clicking on the article above.
Microbiology
Most rapid diagnostic tests fail to detect P. falciparum malaria parasites in asymptomatic children
Rapid diagnostic tests (RDTs) account for more than 70% of diagnostic testing for malaria in Africa. Most RDTs rely on the detection of histidine-rich protein 2 (HRP2), an antigen specific to Plasmodium falciparum malaria. However, one of every 15 children infected with P. falciparum malaria parasites in the Democratic Republic of the Congo is infected by a pfhrp2-deleted mutant, producing a false-negative result when an RDT is used, say investigators from the University of North Carolina at Chapel Hill.
Their results were published in the Journal of Infectious Diseases and discussed during a recent World Health Organization meeting during the American Society of Tropical Medicine and Hygiene's annual conference.
"This is the first nationwide study to demonstrate the presence and estimate the prevalence of malaria caused by pfhrp2-deleted P. falciparum in asymptomatic children," said Jonathan Parr, M.D., M.P.H., the study's lead author. "We identified 149 P. falciparum isolates with a deletion of the pfhrp2 gene, representing a country-wide prevalence of 6.4%," Parr said. "This proved that pfhrp2-deleted P. falciparum is a common cause of rapid diagnostic test negative, but PCR positive malaria test results among asymptomatic children in the Democratic Republic of the Congo. Surveillance for these deletions is needed and alternatives to HRP2-specific rapid diagnostic tests may be necessary."
It is important to note that these mutated parasites have only been found in a small number of places in the world and that HRP2-based rapid tests continue to play a key role in malaria control and elimination efforts.
Analysis of human microbiome yields potential new antibiotics
A research team at Rockefeller University led by Sean Brady head of the Laboratory of Genetically Encoded Small Molecules, interrogated public databases containing the genomes of bacteria that live in the human body. They wanted to find clusters of genes that were predicted to produce molecules, non-ribosomal peptides, which are the basis of myriad antibiotics.
Scientists also wanted to determine how to manipulate the proper genes of a bacterium to make them express the antimicrobial molecules. The team found 57 candidate gene clusters, from which 30 were chosen. Using a technique called solid-phase synthesis, 25 compounds were produced. Those compounds were then tested with human pathogens, enabling the investigators to identify the two antibiotics the scientists named humimycin A and humimycin B. The findings were published in Nature Chemical Biology.
Humimycin A and B are closely related being from a family of bacteria named Rhodococcus, which have not previously yielded anything resembling the humimycins when grown with typical laboratory protocols. The humimyics proved very effective combating Staphylococcus and Streptococcus bacteria, microbes that can result in serious infections in humans and tend to become antibiotic resistant. Experiments determined that the humimycins act to inhibit an enzyme that aids in buildings cell walls in bacteria; without that cell-wall-building power, the bacteria die. Researchers also found, however, that humimycins can actually re-sensitize bacteria to the action of beta-lactams they had become resistant to.
Related Article: Supercomputer Modeling Could Revive Current Antibiotics and Decrease Antibiotic Resistance in Bacteria
Anatomic Pathology
Scientists advance a novel urine test to predict high-risk cervical cancer
Johns Hopkins Medicine specialists report they have developed a urine test for the likely emergence of cervical cancer that is highly accurate compared to other tests based on genetic markers derived directly from cervical tissue. The new urine test, they say, is different because it analyzes not only multiple sources of human cellular DNA altered by precancerous changes, but also DNA from HPV that is sexually transmitted and causes virtually all cases of the disease.
In a proof-of-concept study, described online in Cancer Prevention Research, the investigators say their genetic markers test showed a "sensitivity" or accuracy rate of 90.9% in identifying so-called CIN2 lesions - cervical lesions with abnormal cells likely to not only develop into cancer, but also to develop into cancers likely to spread. Additionally, they demonstrated that the DNA for all three human genes and one viral gene could be successfully extracted from urine, and they could identify such lesions with 75% sensitivity.
Two commercial tests based on markers of DNA chemical changes called methylation, released in Europe last summer, require Pap smears or swabs of cervical tissue, and show 64% sensitivity in identifying similar lesions, according to senior investigator Rafael Guerrero-Preston, Dr.P.H., M.P.H., assistant professor at the Johns Hopkins University School of Medicine. "When developing a new cancer screening test, we want something in the range of 90 to 95 percent sensitivity, which is competitive with the effectiveness of tests developed and now marketed in Europe," says Guerrero-Preston.
Safety
Research finds Zika virus can live for hours on hard, non-porous surfaces
Research presented at the 2016 American Association of Pharmaceutical Scientist (AAPS) Annual Meeting and Exposition, found that under certain conditions, the Zika virus can live for several hours on hard non-porous surfaces and still be highly contagious, but that some commonly used disinfectants are extremely effective in killing the virus.
The study looked at isopropyl alcohol, diluted bleach, quaternary ammonium/alcohol, peracetic acid, and pH 4 or pH 10 solutions, which are commonly used in clinical, laboratory, and industrial settings. Findings showed that when the virus was in an environment without blood, these methods of inactivating Zika, except pH 4 and pH 10, were largely effective, but in environments where virus was associated with blood, the results were dramatically different. The research also found that bleach and peracetic acid were not as effective in killing Zika virus when the virus is associated with blood.
"The data were important to know especially for healthcare providers and researchers," said the study’s lead researcher S. Steve Zhou, PhD. "One must bear the organic load of the environment such as blood, in mind, before reaching a conclusion about the Zika virus inactivation efficacy by a particular product." The next stage of the research will be to take a more in-depth look at how long Zika survives on hard non-porous surfaces in the heat and how best to inactivate the virus.
Related Article: Zika No Longer 'Global Health Emergency,' WHO Says
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