posted on 10/15/2020 06:00
(credit: AFP / GIL COHEN-MAGEN)
The blood type can increase the risk of a person having covid-19 and suffering greater complications during the treatment of the disease. This is what the investigations of Canadian and Danish scientists signal. In two surveys published in the journal Blood Advances, they show how they analyzed the profile of those infected with the new coronavirus and noticed a smaller number of people with type O blood among the patients. The experts also detected a greater number of more severe complications among individuals with blood A and AB. For them, the findings may help to develop better medical approaches.
The role of blood type in predicting the risk and complications of Sars-CoV-2 infection is still poorly understood. In search of answers, researchers compared the health record data of more than 473,000 Danes who tested positive for covid-19 and more than 2 million people without the disease (control group). They found, in the infected, a smaller number of people with blood type and a greater number of people with types A, B and AB.
New analyzes have led to the conclusion that people in group O are 13% less at risk of being affected by covid-19. On the other hand, group A is 9% more likely to have the disease, and AB, 15%. The group B rate was not significant. The team found no significant difference in the infection rate between types A, B and AB. “Among these three subtypes, none of them obtained rates considered to be very high, which pointed to a greater risk than the others”, they point out in the article.
The researchers explain that blood group distributions vary between ethnic subgroups. This caused them to remain attentive to the ethnicity of those analyzed during the study. “The prevalence of blood type can vary considerably in different ethnic groups and in different countries. Denmark is a small country, but, very ethnically diverse, this made it possible for us to carry out an appropriate screening to maintain a solid base of our analyzes ”, says, in a statement, Torben Barington, a researcher at the University of Southern Denmark and one of study authors.
In another investigation, researchers from Canada found that blood groups A and AB appear to be associated with an increased risk of complications from covid-19. The scientists examined data from 95 patients – all hospitalized in Vancouver for complications from the disease. Those who belonged to both blood groups spent more time in the intensive care unit (ICU), needed more dialysis to treat kidney failure and demanded more use of mechanical ventilation.
“We observed these damages in the lungs and kidneys and, in future studies, we want to investigate the effect of the blood group and covid-19 on other vital organs.” These data are of particular importance as we continue to go through the pandemic (…) We need more weapons to help increase the chances of a cure ”, says in a statement, Mypinder S. Sekhon, a researcher at the University of British Columbia and one of authors.
David Urbaez, an infectologist at the Exame Laboratory in Brasília, explains that, with the emergence of a new disease, it is normal to try to detect a possible influence of the blood type. “Blood groups always have important implications in this regard, whether from a genetic point of view, or in relation to the proteins present in the red blood cell. These factors can influence the virulence factor of an infection and its mortality. They are also a trademark of human beings, and it is normal that they may be correlated with the evolution of an illness ”, he details.
The doctor points out that the results of the research need to be deepened. “All of this is an initial research front, which, for sure, will continue. The data seen so far point to this possible susceptibility in people in group A, but we need this to be further studied. We have to know why this occurs at the molecular level, what is the factor that can make this difference ”, he justifies.
The infectologist also believes that if the relationship between blood type and vulnerability to covid-19 is proven, new forms of treatment may emerge. “We already know about some characteristics of patients that can have major complications, and this has already changed the way care is done. This may be information that adds to these other data and, in the future, we may have some other medical intervention, such as a medication that helps to minimize this risk ”, he says.
»Word of expert
More studies needed
“Information from this type of study has been emerging since the beginning of the pandemic, but the reasons why these differences occur are still speculative. For example, in relation to group A and AB, we know that these people have an enzyme that stabilizes some clotting factors. Her presence can cause complications that occur in cases of covid-19, such as thrombosis, to be more frequent. It would be interesting to carry out larger studies, with an even greater number of analysts, and in other places in the world, to better understand these data. Denmark is able to do this type of analysis because they have this culture of gathering medical data from the entire population, and this is something very valuable. This broad and ethnically diverse database is essential for studies like this. ” Eduardo Flávio Ribeiro, hematologist and Hematology coordinator at the Oncology Center at Hospital Santa Lúcia, in Brasília.
»Russians register second vaccine
Russia registered the second vaccine against coronavirus, a step that, in the country, precedes the final phase of clinical trials in humans. The formula, entitled EpiVacCorona, has a “sufficiently high level of security”, according to Russian Deputy Prime Minister for Health Tatiana Golikova. The next stage consists of tests with 40 thousand volunteers. As with the first vaccine, Sputnik V, the Russian government did not give details about the new formula, a stance that arouses skepticism in the scientific community. The announcement was made at a time when the country is facing a resurgence of the disease and a record number of infected: 14,231 new
cases in 24 hours.
Covid-19: risk of becoming seasonal
credit: Michael Ciaglo / AFP
Covid-19 can become a seasonal disease, when most cases are concentrated at a specific time of year. This is what American scientists are considering in an article published in the latest issue of the journal Proceedings of the National Academy of Sciences (PNAS). The researchers came to the conclusion by analyzing climate models and data on the pandemic. For them, if a vaccine against Sars-CoV-2 does not appear and the isolation measures are weakened, infections should be more frequent in the cold than in the heat, as with the flu.
The scientists used data on the evolution of covid-19 since its emergence and information on climate variations that occurred in the same period. They built statistical models that help to predict in which scenario the covid-19 can reach its maximum transmission potential worldwide, throughout the year. “To make projections, we also use monthly average climatic data of temperature and humidity from 2015 to 2019, assuming that these last years are the most adequate to predict a closer future”, explain the authors in the study, which has as its first author Cory Merow, researcher in the Department of Ecology at the University of Connecticut, in the United States.
Through the analyzes, the researchers observed that ultraviolet light is associated with a decrease in the rate of growth of infections in relation to other factors analyzed. “Based on these associations with the climate, we predict that the covid-19 will temporarily decrease during the summer, recover in the fall and reach its peak next winter (…). It is important to note that our forecasts refer to the possible rate of growth in the absence of social distance or other control measures ”, they state.
The researchers also point out that there are still doubts about the possible seasonality of Sars-CoV-2, since factors other than the climate, such as social interventions, can influence the transmission of the virus. “Therefore, the world must remain vigilant, and ongoing interventions are likely to be necessary until a vaccine is available,” they emphasize.
Historical drop in CO2 emissions
The social restrictions generated by the pandemic caused an unprecedented drop in CO2 emissions in the first half of this year – even greater than the reductions that occurred during the 2008 financial crisis and World War II. The calculation was made by a group of international researchers and released yesterday, in the British magazine Nature Communications. According to the authors, the decrease is a consequence of the effects of social confinement, such as a reduction in the use of transport, for example.
The researchers conducted analyzes based on data on electricity production and road traffic in 416 cities in 56 countries, including Brazil. They accounted for the number of flights and records on production and consumption. Calculations showed that, in the first half of 2020, CO2 emissions from transport fell by 40%; those from energy production, 22%; and industry, 17%. Emissions associated with housing decreased by 3%, even with mass teleworking. Scientists attribute this fall to an unusual mild winter (Northern Hemisphere), which limited the need for heaters.
However, emissions returned to normal levels in July, when most countries eased social isolation measures. “Although the reduction in human activities has generated this unprecedented decline, the long-term answer cannot be that because it is not viable. We need changes that are generated by the transformation of our energy production and consumption systems ”, defends, in a statement, Hans Joachim Schellnhuber, a researcher at the Potsdam Institute for Climate Impact Research, in Germany, and co-author of the study.