Search Results for coronavirus

Primary COVID-19 transmission is by close contact with infected people; nasopharyngeal swab-based testing provides the highest diagnostic accuracy

Respiratory droplets are considered the main mode of COVID-19 transmission, which can be prevented by protective measures, including physical distancing, good ventilation, and the use of face masks. In parallel, diagnostic testing to identify and isolate infected individuals and their close contacts is a key strategy to slow the spreading of the disease. While alternative methods are under study, nasopharyngeal swab-based RT-PCR testing remains the most accurate and the gold standard method for COVID-19 diagnosis.

A proportion of COVID-19 survivors are likely to suffer from long-term health problems, but the actual risks are still unknown

COVID-19 infections can have multiple outcomes besides death and complete recovery. Although the vast majority of patients survive the infection, a significant proportion continue to suffer from potentially lifelong health problems, such as heart and lung damage and neurological deficits. Hence it is important to take transmission control measures seriously to minimize our risk of infection. However, there is currently not enough information to calculate with certainty the risks of developing the different sequelae of infection.

Infant deaths did not decrease during the pandemic due to a reduced use of vaccines; vaccines are not associated with sudden infant death syndrome

Vaccines are safe and scientific studies have found no association between vaccination and sudden infant death syndrome (SIDS). Blaxill and Becker’s report is based on incomplete data, as they did not account for the lag time that occurs between a death and its reporting to the U.S. CDC. Their findings that child deaths have significantly decreased compared to previous years are therefore spurious and premature. The duo also failed to account for other factors which may have contributed to changes in child mortality, such as stay-at-home orders, which would have limited the spread of other infectious diseases besides COVID-19.

Despite a decline in COVID-19 deaths from a peak in Spring 2020, the number of deaths in July 2020 may not be as low as preliminary data suggest

Weekly deaths due to COVID-19 as reported by various sources have been steadily declining since their peak in April 2020. However, death reporting is a lengthy and complex process. It can take several weeks for deaths to be reported to the U.S. federal government and to reach a reliable estimate of the death count. In contrast, state-level estimates report higher, even increasing numbers of deaths for July 2020. It is thus impossible to draw conclusions on the COVID-19 death counts for very recent periods.

Saliva might be an accurate, less-invasive alternative to nasopharyngeal swabs for COVID-19 diagnosis; more research is needed to standardize its use in molecular testing

Due to its reliability and relative ease of specimen collection, the nasopharyngeal swab is considered the gold-standard procedure for collecting cells and secretions from the back of the throat for COVID-19 diagnostic testing. In contrast, the accuracy of less invasive testing of alternative specimens, such as saliva, is still under evaluation. Several laboratories have developed at-home kits for the collection of nasal mucus and saliva samples that are then shipped to a laboratory for analysis. However, specimen collection is a key step in clinical diagnosis, and experts have raised concerns about how potential flaws in at-home sample collection may impact the accuracy of these tests.

Nasal swab used for COVID-19 testing does not reach the brain

Nasal swabs are used to collect biological samples from the back of the nasopharynx in order to test for the presence of SARS-CoV-2 infection. The nasal swab has to be inserted far into the nasal cavity until it reaches the nasopharynx located behind it. The human brain is separated from the nasopharynx by several layers of hard tissue, including bone. It is therefore not possible for nasal swabs to reach the brain or the blood-brain barrier.

The June 2020 spike in U.S. COVID-19 cases indicates a rising percentage of infections and is not simply an artifact of more testing

Detecting more COVID-19 cases alone does not necessarily indicate that the epidemic is worsening, as it could merely result from an expanded testing capacity. A more useful metric for understanding the recent spike in U.S. cases is the proportion of tests with a positive result—called the positivity rate—which takes into account any variations in the total number of tests being performed so that actual epidemiological dynamics can be assessed. During the second half of June 2020, the positivity rate, together with the number of people visiting hospitals due to COVID-19-like illness increased. Taken together, both observations indicate that the COVID-19 epidemic is regaining strength, and that the increase in reported cases is not solely due to increased testing capacity, but due to more infections in the community.

Videos use gas sensors to misleadingly claim that wearing a face mask causes oxygen deficiency

Cloth face coverings and face masks are generally safe. Except in the case of unusual environments such as confined or closed spaces, using face coverings or face masks is very unlikely to place someone at risk of oxygen deficiency. The gas sensors used in these videos are not intended for measuring rapid changes in oxygen and carbon dioxide levels that occur with breathing, hence the measurements shown in the videos do not accurately reflect oxygen and carbon dioxide levels of inhaled air. The pores in cloth coverings and face masks are large enough to permit gas molecules like oxygen and carbon dioxide to flow freely.

COVID-19 cases in the U.S. are mainly detected by highly specific molecular testing, not antibody testing

The number of COVID-19 cases in the U.S. is a combination of both confirmed and probable cases. Confirmed cases are detected by highly specific molecular testing for SARS-CoV-2, whereas probable cases may involve antibody testing in part. It is correct that antibody testing is prone to false-positives, because such tests may also detect antibodies against other coronaviruses besides SARS-CoV-2, such as those that cause the common cold. However, the breakdown of COVID-19 case numbers clearly shows that confirmed cases, rather than probable cases, comprise the bulk of COVID-19 cases.

Internet memes based on hearsay claim that hospital laboratories falsify COVID-19 tests to inflate numbers without evidence

There is no evidence that hospital laboratories have falsified the number of COVID-19 positives. While false-positives can occur, experts agree that they are a rare event. On the contrary, false-negatives are hard to control as they can be due to many different factors. Failing to correctly identify infected people may favor the spreading of the disease and constitute a public health risk.