Antibody test accuracy unclear; COVID-19 risks higher for pregnant women

By Nancy Lapid

(Reuters) - The following is a brief 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.

COVID-19 antibody tests not backed by solid data

Studies assessing the accuracy of COVID-19 antibody tests had major shortcomings, an analysis released on Thursday found, indicating that existing research does not prove the tests can confirm with certainty whether people have been infected with the novel coronavirus. Cochrane, a British-based journal that reviews research evidence, looked at 54 studies that sought to measure the reliability of the antibody blood tests. The studies were often small, did not use the most reliable methods, and their results were often incomplete, the analysis found. The analyzed studies looked at nearly 16,000 blood samples, 89% of which had a high risk of bias because patients were unlikely to match the general population. The review identified data from 25 commercial COVID-19 tests, a fraction of the roughly 300 such tests that exist. The review did not include tests offered by Roche or Abbott Laboratories, which were approved by regulators after the analysis began. (https://reut.rs/2CAXSf1; https://bit.ly/2YyTxlb)

Pregnant women have greater risk for severe COVID-19

Pregnant women face an increased risk of severe coronavirus infections, a U.S. Centers for Disease Control and Prevention study released on Thursday showed. Pregnant women with COVID-19 are 50% more likely to need intensive care and 70% more likely to be put on mechanical ventilators than non-pregnant women, although pregnant women did not have a higher risk of death, CDC researchers reported in the agency's Morbidity and Mortality Weekly Report. Hispanic and non-Hispanic Black pregnant women appear to be disproportionately affected by the coronavirus infection during pregnancy, the study also found. Earlier in the pandemic, researchers in China and Britain reported no extra risk for pregnant women. But last month, a large study in Sweden found pregnant women infected with the virus were more than five times as likely to need intensive care and four times more likely to need invasive mechanical ventilation. The CDC study did not include data on how COVID-19 affects the outcomes of pregnancies. (https://reut.rs/38aqHe3; https://bit.ly/2CKVF0P)

Coronavirus traces found in Spanish sewage from March 2019

Spanish researchers have found traces of the novel coronavirus in Barcelona wastewater collected in March 2019, nine months before COVID-19 was identified in the Chinese city of Wuhan. University of Barcelona virologists led by Albert Bosch had been monitoring wastewater since April of this year. When they decided to test older samples, they said they found genetic material from the virus in one sample from March 12, 2019. The presence of the virus genome so early in Spain, if confirmed, would indicate the pathogen appeared much earlier than previously thought. In their not-yet-peer-reviewed paper posted on Friday on medRxiv, the researchers also said they found the virus in Barcelona wastewater from Jan. 15 of this year, 41 days before the first case was officially reported there. Joan Ramon Villalbi of the Spanish Society for Public Health and Sanitary Administration said it was still early to draw definitive conclusions based on these findings. "When it's just one result, you always want more data, more studies, more samples to confirm it and rule out a laboratory error or a methodological problem," he said. (https://reut.rs/2Zb8sBb; https://bit.ly/382ZNot)

Flu vaccine use in elderly may be linked to community coronavirus mortality

COVID-19 death rates may be lower in communities where large proportions of elderly residents received flu vaccines, based on data from more than 2,000 counties around the United States. Researchers found that a 10% increase in vaccination coverage among people older than 65 was associated on average with a 28% decrease in the COVID-19 death rate in a given county. It is possible that social, economic and health factors contributed to lower coronavirus mortality in counties where more seniors got flu vaccines, the researchers said. Their findings were based on data reported by counties, not by individuals. Still, the researchers said, "The significant public health implications of this possibility point to an urgent need for studying the relationship between influenza vaccination and COVID-19 mortality at the individual level, to investigate both the epidemiology and any underlying biological mechanism." On Friday, the U.S. Centers for Disease Control and Prevention said flu vaccination during the pandemic is very important to reduce the overall impact of respiratory illnesses on the population and ease burdens on the healthcare system. (https://bit.ly/3dBQnkP)

Bring sick kids for medical care during lockdown, doctors say

With lockdown orders in place, parents may hesitate to take sick children to the doctor. But research by pediatricians in Britain concluded that if medical care is delayed - particularly when a child appears seriously ill - "the unintended consequences of the lockdown will do more harm and claim more children's lives than COVID-19." Among nearly 2,500 pediatricians surveyed for the study published on Thursday in Archives of Disease in Childhood, one in three said they had dealt with medical emergencies in children who probably would have sought medical care before becoming so ill were it not for the pandemic. Children with diabetes were most often involved, but also those with life threatening blood infections and cancer, survey responses indicated. (https://bit.ly/3i4CSNY)

Open https://graphics.reuters.com/HEALTH-CORONAVIRUS/yxmvjqywprz/index.html in an external browser for a Reuters graphic on vaccines and treatments in development.

(Reporting by Nancy Lapid, John Miller, Caroline Humer, Emma Pinedo, Nathan Allen and Inti Landauro; Editing by Will Dunham)