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. New saliva test for Covid-19 avoids supply chain shortages A new saliva test for Covid-19 will cost less and, because it can use several readily available reagents, it will not be as affected by supply chain shortages as other PCR tests, researchers said in a paper posted ahead of peer review. According to Dr. Nathan Grubaugh of Yale University, the new test uses enzymes and heat to break open the virus and expose its nucleic acids for molecular detection, rather than extracting the nucleic acids from the sample. This “saves 1-2 hours of work and removes up to 75% of the costs,” Grubaugh said, adding that the saliva test is also less invasive than the nasal swab. Because virus detection in saliva is stable for many days and at high temperatures, expensive collection tubes with preservatives are not required. The researchers said they expect to receive an FDA Emergency Use Authorization later this week. Covid-19 strokes hitting younger, low-risk patients A large study of strokes associated with Covid-19 found that many strokes occur in relatively young people without risk factors, the Multinational Covid-19 Stroke Study Group reported on Friday ahead of peer review. Researchers in 32 countries identified 432 Covid-19 patients with strokes caused either by blocked blood flow to the brain – called ischemic strokes – or by blood hemorrhage in the brain. Among those with ischemic strokes, more than one-third had no coronavirus symptoms. About one in four had none of the traditional risk factors for stroke – such as heart disease, high blood pressure or smoking – and more than one-third were under age 55. Among patients with hemorrhagic stroke, 70% had “spontaneous” bleeding not explained by breaks in weakened artery walls. Usually, spontaneous bleeding accounts for only 15% of hemorrhagic strokes. Strokes were more severe in patients without typical risk factors. A separate study published on Saturday in the Journal of Neurology looking at people who do have the most significant stroke risk factors – either a previous stroke, or diseased arteries – found they have high rates of poor Covid-19 outcomes and should take “extra precautions” during the pandemic. HIV infection more than doubles Covid-19 death risk People with HIV have a “markedly raised” risk of Covid-19 death, according to a UK study posted on Friday ahead of peer review. Researchers in England analyzed data on 17.3 million adults, including 27,480 with HIV. Overall, there were 14,882 Covid-19 deaths from February through late June. People living with HIV had a more than two-fold higher risk of dying, even after accounting for social and health factors, and the risk was even higher for Black HIV patients. Given that British people have access to free healthcare, “the impact of HIV on the progression of the pandemic in other settings will need to be carefully monitored,” the researchers wrote. They added, “People living with HIV may also need priority consideration if and when a vaccine against SARS-CoV-2 becomes available.” Pediatricians know masks can be scary In a survey of nearly 400 pediatricians in Israel, 82% said face masks affect their ability to interact with children, 63% felt children are more fearful of doctors wearing masks, and 59% had experienced difficulty assessing or treating children while wearing a mask. Doctors should use their eyes and body language, and consider temporarily removing their masks to smile when appropriate, said Dr. Leo Arkush of Wilf Children’s Hospital in Jerusalem, who coauthored a report published on Saturday in the Journal of Paediatrics and Child Health. “Verbal communication is more important than ever to keep infants engaged, calm and entertained and to reassure them and their parents. With older children, jokes and rapport play an even greater role than usual.” Parents can prepare their children, he added, by role-playing and by offering age-appropriate explanations of why doctors are wearing masks.