The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.
Study suggests possible coronavirus link to type 1 diabetes
A small study in Britain suggests researchers should be on the look-out over whether COVID-19 increases the risk of type 1 diabetes. Cases of type 1 diabetes among children may have risen during the peak of Britain's COVID-19 outbreak, scientists said on Monday in the Diabetes Care journal in a study based on 30 cases at two hospitals. In comparison with a typical year, this represented an 80% increase, they said.
"When we investigated further, some of these children had active coronavirus or had previously been exposed to the virus," study co-author Karen Logan of St. Mary's Hospital in London said. In type 1 diabetes - once known as juvenile diabetes - insulin-producing cells in the pancreas are destroyed, preventing the body from producing enough insulin to regulate blood sugar levels.
The researchers said one explanation could be that the novel coronavirus might attack insulin-making cells in the pancreas. "More research is needed to establish whether there is a definitive link ... but in the meantime we hope clinicians will be mindful of this," Logan said.
Breath test screening for COVID-19 shows early promise
It may be possible someday to screen large populations for COVID-19 using breath tests, researchers said. Their new breathalyzer device has sensors made of gold nanoparticles linked to specially selected molecules that can detect disease-specific chemical biomarkers from exhaled breath, they reported on Tuesday in the journal ACS Nano. In a pilot study in Wuhan, China in March, a team of Chinese and Israeli researchers tested the device in 49 COVID-19 patients, 58 healthy controls and 33 people with non-COVID lung infections. In this small study, the device showed 100 percent sensitivity for identifying patients with COVID-19 and for distinguishing them from patients with other lung infections but was less effective at correctly identifying those without COVID-19.
The researchers said their device is not intended to replace gold-standard diagnostic tests, but if its reliability can be proven in larger studies it might be useful "for rapid large population screening in a short period of time" in public places such as airports, shopping centers and train stations or in the community, for early detection of the disease in asymptomatic contagious people.
Smell and taste loss differ with COVID-19 versus colds
The smell and taste impairments associated with the novel coronavirus differ from what people experience with a cold and is likely linked with nerve damage, a new study suggests. Researchers gave smell and taste tests to 10 COVID-19 patients, 10 people with bad colds and 10 healthy people. Unlike people with colds, COVID-19 patients could breathe freely and did not tend to have a runny or blocked nose. Furthermore, they could not detect bitter or sweet tastes, and they had more severe taste impairment overall.
The original SARS virus, which caused a global respiratory disease outbreak in 2003, can enter the brain, the researchers noted in a report on Wednesday in the journal Rhinology, and they said their new findings lend weight to the hypothesis that COVID-19 also infects the brain and central nervous system. "It is particularly interesting that COVID-19 seems to particularly affect sweet and bitter taste receptors, because these are known to play an important role in innate immunity," study co-author Carl Philpott of the University of East Anglia's Norwich Medical School in Britain said in a statement. "More research is needed to see whether genetic variation in people's bitter and sweet taste receptors might predispose them to COVID-19."
Blood-vessel cells break off in severe COVID-19
Blood clots, a well-known complication of COVID-19, are at least partially due to damage to the endothelium, or blood vessel lining, researchers have suspected. Now a study confirms that severe COVID-19 is linked with "marked and widespread" injury to blood vessels, with high numbers of cells that usually comprise blood-vessel linings becoming detached and found circulating in the blood.
As reported on Wednesday in the Journal of Infectious Diseases, researchers in France measured levels of so-called circulating endothelial cells detached from injured vessels in 99 hospitalized COVID-19 patients. Levels were significantly higher in patients in intensive care units and were correlated with patients' levels of inflammatory proteins, illness severity scores and length of hospitalization. The researchers tested each patient's blood only once, so they could not discern how injuries to blood vessel linings might evolve as the illness worsens. Still, they said, the blood vessel lining plays key roles in maintaining vascular stability and function, delivering blood to organs and regulating blood clotting, and any endothelial injury would impair those functions.