A new proof-of-concept device from researchers at Washington University in St. Louis monitors air samples for COVID-19 virus variant detection in about 5 minutes, according to a study today in Nature Communications.

The work is based on an inter-disciplinary team's previous construction of a micro-immunoelectrode (MIE) biosensor that detects amyloid beta as a biomarker for Alzheimer’s disease. Researchers exchanged the antibody that recognizes amyloid beta for a nanobody from a llama that recognizes the spike protein from the SARS-CoV-2 virus.

Using wet cyclone technology, the biosensor allows air samples to mix at high velocities creating a surface vortex trapping the virus aerosols. This allows the biosensor to detect virus particles in collected fluids.

"The high virus recovery by the wet cyclone can be attributed to its extremely high flow rate, which allows it to sample a larger volume of air over a 5-minute sample collection compared with commercially available samplers," said co-senior author Rajan Chakrabarty, PhD, in a press release. Chakrabarty leads the Complex Aerosol Systems Research Laboratory at Washington University.

You can know essentially in real time, or every 5 minutes, if there is a live virus.

The researchers tested the biosensor in the bedrooms of two people who had recently tested positive for COVID-10 and seven air samples taken from the patients' bedrooms correctly identified virus particles in the air.

Compact, portable device

The device is compact, standing at 12 inches wide and 10 inches tall, and has a flow rate of 1,000 liters per minute. The authors of the study said the device could be used by schools, hospitals, and public places to detect SARS-CoV-2, as well as other airborne viruses including RSV and influenza. It lights up when a virus is detected, alerting its operators to increase air flow in the room.

"If you are in a room with 100 people, you don't want to find out five days later whether you could be sick or not. The idea with this device is that you can know essentially in real time, or every 5 minutes, if there is a live virus," said co-senior author John Cirrito, PhD.

Inappropriate dental antibiotic prescriptions to prevent infective endocarditis cost the US healthcare system nearly $31 million a year, according to a modeling study published today on Infection Control & Hospital Epidemiology.

Although guidelines from the American Heart Association and the American Dental Association limit the use of prophylactic antibiotics to prevent infective endocarditis to those with cardiac conditions at highest risk, research has shown that 83.1% of dental antibiotics prescribed for that reason are inappropriate.

To estimate the costs associated with this practice, researchers used 2018 US Census data on adults aged 18 and older who had a dental visit with an antibiotic prescribed and on the reported incidence of infective endocarditis among those without predisposing cardiac conditions who underwent dental procedures. They calculated drug costs; adverse event costs associated with prescriptions of amoxicillin, cephalexin, and clindamycin; and out-of-pocket costs (co-pays).

About 5% of patients get preventive antibiotics

In their base case, 167 million US adults have a dental visit each year, and 7.9 million (4.8%) receive prophylactic (preventive) antibiotics. They calculated that if 83.1% of those prescriptions are inappropriate, antibiotic costs for the healthcare system would amount to $2.69 million, and costs of adverse events (eg, Clostridioides difficile and hypersensitivity) would amount to $5.82 million for amoxicillin, $1.99 million for clindamycin, and $380,849 for cephalexin. Patient out-of-pocket expenses for the antibiotic prescriptions would total $20.5 million.

Dentists account for 6%–10% of all antibiotic prescriptions in the United States.

The researchers also estimated that, without any inappropriate dental antibiotic use for infective endocarditis, there would be roughly three excess cases of infective endocarditis a year, costing $131,149.

"Overall, while the estimated costs associated with inappropriate antibiotic use in dentistry may not be significant, dentists account for 6%–10% of all antibiotic prescriptions in the United States,  resulting in a nontrivial burden of preventable adverse effects," the study authors wrote.

The International AIDS Vaccine Initiative (IAVI) recently announced the launch of the first human trial of a Sudan Ebola virus vaccine, an investigational vesicular stomatitis virus (VSV) vector vaccine donated by Merck and licensed by IAVI.

Currently, there are no approved vaccines or treatments for Sudan Ebola. An outbreak in Uganda last year resulted in 164 cases, 55 of them fatal. During the outbreak, a World Health Organization (WHO) working group recommended that ring vaccine trials with three potential candidate vaccines prioritize the VSV-EBOV vaccine licensed by IAVI, because it is made with the sample platform as the approved VSV-EBOV vaccine for the Zaire strain, which has shown to be safe and effective.

In a statement, IAVI said the first-in-human phase 1 trial is funded by the US Biomedical Advanced Research and Development Authority (BARDA), which is part of the Department of Health and Human Services (HHS). IAVI said it is the vaccine candidate's regulatory sponsor and is responsible for all future aspects of its clinical development, including how it measures up against IAVI's other Sudan Ebola vaccine, which uses the same virus vector but is made using a new production platform.

The trial will enroll 36 healthy adults at two clinical sites in the United States. The blinded placebo-controlled study will assess three dosage levels of the intramuscular shot, and researchers will track safety and immune response in the participants for 6 months after vaccination.