By Nancy Lapid

(Reuters) – 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.

Narrow hallways present higher infection risks

An unmasked coronavirus-infected person walking fast down a narrow corridor leaves a long stream of virus-laden droplets trailing behind, a new computer simulation suggests. Even if social distancing guidelines are followed, it might still be risky to follow someone down a narrow corridor, researchers advised in a report published on Tuesday in Physics of Fluids. “The transmission of COVID-19 is highly influenced by the airflow,” said coauthor Xiaolei Yang of the Chinese Academy of Sciences in Beijing. “A slight change of airflow can significantly alter the virus spreading pattern,” he said. Such changes can be caused by a minor difference in corridor width, walking speed, indoor architectural structure, temperature, humidity or other factors. Staying six feet (1.83 m) behind the person in front of you “is not enough for narrow corridors, and wearing a face mask is recommended even if you do not see people around, he said. In addition, the viral droplets behind a walking person tend to hover at the waist height, so short kids are exposed to higher risk than adults, he added. “When you are with a child, you may want to hold him or her in your arms.”

Hospitalized COVID-19 patients often need readmission

Soon after leaving the hospital, COVID-19 survivors are at higher risk for requiring readmission or dying than survivors of other high-risk medical conditions, new data suggest. Researchers studied patients admitted to 132 U.S. Veterans Affairs hospitals across the country from March through May, including 2,179 admitted for COVID-19. Another 1,799 had pneumonia unrelated to COVID-19 and 3,505 had heart failure, conditions associated with high readmission rates. Within 10 days after discharge, roughly 14% of COVID-19 patients had been readmitted or died, compared to roughly 10% of the other patients, researchers reported on Monday in JAMA. By day 60 after discharge, roughly one in four COVID-19 patients had been readmitted or died, but the rate was slightly higher among the other patients. “Recovery can be a bumpy road,” coauthor Dr. Hallie Prescott of University of Michigan Health System told Reuters. But a lot has changed since June, she added. “We have better treatments so it’s possible … we will see fewer cases where patients have late worsening of symptoms requiring readmission.”

U.S. Black communities missing out on COVID-19 testing

COVID-19 testing is essential for identification and isolation of infected people, but testing may be less common among U.S. Blacks than among whites, a Missouri study suggests. Between March and September, nearly one million COVID-19 tests were conducted in the St. Louis and Kansas City regions. In the first three months of that period, areas (identified by postal zip codes) with higher proportions of residents who were Black, without insurance, and with lower median incomes accounted for 25% of COVID-19 cases but only 9% to 12% of the tests performed for the virus, researchers found. “Even within the same zip codes, testing rates were lower among Black residents compared to white residents,” said Dr. Aaloke Mody of Washington University School of Medicine in St. Louis. The disparities persisted through the summer, he said. “Studies have repeatedly shown greater burden of COVID-19 cases, hospitalizations, and mortality in minority communities,” Mody and colleagues wrote on Monday in Clinical Infectious Diseases. “Testing disparities may be important driver of disparities in disease burden,” Mody said. “We need proactive public health strategies that really help to ensure equitable testing, such as making community-based testing widely available. This can also be extended to thinking about equity in vaccine distribution,” he said.

(Reporting by Nancy Lapid and Linda Carroll; Editing by Bill Berkrot)