New Delhi: Though it’s been five months since the coronavirus pandemic set in, claiming over 3.52 lakh lives worldwide, new lessons are still being learned every day on how to tackle the virus.
Here are some of the recent research findings around Covid-19.
Dementia gene linked to increased risk of severe Covid-19
A faulty gene associated with dementia may double the risk of developing severe Covid-19 infection, a large scale study from the UK has found.
Researchers at the University of Exeter and the University of Connecticut found high risk of severe Covid-19 infection among participants with European ancestry who carry two faulty copies of the APOE gene (termed e4e4).
According to the team, one in 36 people of European ancestry have two faulty copies of this gene. This faulty gene is also known to increase risks of Alzheimer’s disease and heart disease.
The team had previously found that people with dementia are three times more likely to get a severe infection. Part of the increased risk effect may have been due to exposure to the high prevalence of the virus in care homes.
However, the study, published in the Journal of Gerontology: Medical Sciences, indicates the APOE e4e4 genotype doubled the risk of developing severe Covid-19, when compared to the common e3e3 form of the APOE gene.
RT-PCR tests gives faulty Covid test result 1 in 5 times
Researchers have found that the most commonly used diagnostic tools to test for Covid-19 have a chance of showing false negative results at least one in five times.
A false negative result is when a virus is not detected in a person who is infected.
The team from Johns Hopkins Medicine caution that the reverse transcriptase polymerase chain reaction (RT-PCR) test may not always yield accurate results.
They found that the timing of when a person takes the test affects the accuracy of the results.
The study, published in the journal Annals of Internal Medicine, found that the probability of a false negative result decreases from 100 per cent on day one of being infected to 67 per cent on day four.
The false negative rate decreased to 20 per cent on day eight, which is about three days after a person begins experiencing symptoms. They also found that on the day a person started experiencing actual symptoms of illness, the average false negative rate was 38 per cent.
In addition, the false negative rate began to increase again from 21 per cent on day nine to 66 per cent on day 21.
N95 mask may be reused after ozone sterilisation
Ozone sterilisation can be used to clean N95 masks if the need for reusing them arises, researchers say.
In an editorial published in The Open Dermatology Journal, Craig. G. Burkhart, from University of Toledo recommends that faced with shortage of protective N95 masks, the best cleansing solution for protective masks is treating them with chemical sterilising agents.
Ozone or activated oxygen (O3) is a sterilising agent that has proved successful in destroying bacteria, fungi, viruses, and protozoa. The ozone diffuses into the fatty envelope of the virus. The ribonucleic acid (RNA) content of the virus, the genetic material that determines how the virus will behave, cannot live without this envelope.
Other viruses that cannot withstand the activated oxygen include poliovirus 1 and 2, human rotavirus, Norwalk virus, Parvoviruses, and Hepatitis A and B.
US Covid patients are hospitalised longer than in China
Hospitalised Covid-19 patients in the US face higher rates of ICU admission and stay longer in hospitals than patients in China, a study has found.
The study, led by researchers at the University of California, Berkeley, and Kaiser Permanente, suggests that the US may be harder hit by the coronavirus pandemic than initially thought.
Many of the forecasts of disease burden were based on data out of China, but which did not provide a sufficient basis for anticipating the US health care demand.
Of the 1,277 patients studied, 42 per cent required care in the ICU, and 18 per cent died from the disease. Modelling estimates based on observations in China assume that only about 30 per cent of hospitalised patients will require ICU care.
Similarly, the data showed that hospital stays lasted an average of 10.7 days for survivors and 13.7 days for non-survivors, compared to an average of 7.5 days among non-survivors in China.
However, 25 per cent of patients were hospitalised for 16 days or more.
A widely-used modelling study from Imperial College London, which projects health care needs, assumes an average stay of eight days, researchers said.
While the underlying reasons for these discrepancies remain unclear, the findings show that there is a need to collect data in different regions and under different health care settings instead of relying on data from other countries.