covid Archives - SciWriteGlobal

Jun, 2020

COVID 19: A battle between heat and humidity Vs Sunshine

Though some experts suggest that heat and humidity can help in slowing down COVID-19, others argue that long hours of sunshine can risk a higher incidence of the disease. Let’s investigate further.

With the deadly COVID-19 affecting the economy all over the world, lockdowns are slowly being lifted to compensate for the damage. People are slowly crawling back to public places like the beaches and soaking in the much-needed vitamin D from sunshine. But there is a price to pay.

A sign of a sunny day attracts many people to go out, in turn increasing the risk of infection due to a lack of social distancing. Experts speculate long exposure to sunlight also poses a high risk of contracting the virus. While on the other hand, reports state that heat and humidity can potentially slow down the spread of COVID-19.

A recent report published in the journal Geographical Analysis gives insights on how seasonal changes influence the spread of the novel virus.

Temperature a crucial factor:

For several weeks now, research has been conducted revolving around the effect of temperature and humidity on COVID-19. Several experimental studies explain that it is possible for the COVID-19 virus to be sensitive to heat and humidity, and with further study, experts are convinced that the rate at which the virus spreads can vary in places with different temperatures and humidity.

Studies reveal that humidity and temperature may make the COVID-19 virus less viable by disrupting their surface proteins and outer membranes. On the other hand, the change in infection rate might differ due to the ways people change their behavior from being enclosed in spaces to spending more time outdoors. But currently, there is no solid proof to confirm that summertime can bring improvement in this current pandemic.

Not all Pandemics or diseases follow the same seasonal patterns seen more commonly in seasonal flu outbreaks. Spanish flu, for example back in 1918, peaked during the summer months, while most of the common flu outbreaks erupt during winter.

COVID-19:

At high levels of humidity and heat, the authors of this study noticed a steady decline of 3% in the confirmed COVID-19 cases, possibly due to the virus dying under warmer temperatures. The opposite was observed at long exposure to the sun. More the sunshine more the rate at which the virus spread, raising concerns if it’s due to the human behavior post lockdown measures.

The authors of the study stated that “We will likely see a decrease in the incidence of COVID-19 as the weather warms up, which is an argument for relaxing social distancing to take advantage of the lower incidence associated with higher temperatures” he says. “But a more conservative approach would be to use the months of summer to continue to follow strict orders to remain in place and to crush this pandemic.”

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Jun, 2020

COVID-19: Loss of smell, a new symptom added to the list

New evidence finds that anosmia- loss of smell as a new symptom caused by the COVID-19 virus. Experts believe that it can be added as a potential screening tool for the novel viral infection, and here’s why!

Cases of post-viral anosmia are one of the leading causes of loss of smell among adults suffering from viral infection. This has been associated with previous coronaviruses which are usually known to cause upper respiratory tract infections and have accounted for 10-15% of the cases. Therefore it comes off as no surprise that the current novel COV ID-19 virus also causes anosmia in the infected.

A significant number of cases from South Korea, Italy, and China prove as good evidence for COVID-19 patients developing anosmia. More than 2 out of 3 confirmed cases in Europe have been diagnosed with anosmia. It is also noticed that several COVID-19 cases also present anosmia as the only symptom. Given the above evidence, experts contemplate using anosmia of a screening tool to diagnose people with COVID-19 at the early stages.

Cases of anosmia reflect how COVID-19 affects the brain:

“There’s something unusual about the relationship between COVID-19 and smell,” states Sandeep Robert Datta a neuroscientist from Harvard Medical School and one of the leading scientists in the study. It is well known that common cold, is associated with stuffy noses leading to a temporary loss of smell, but it found that the COVID-19 virus leaves the nose free. “But recently lots of people are complaining about losing their sense of smell when they don’t feel stuffed up at all,” Datta says.

The team further experimented on nose cells, including the support cells and nerve cells sending messages to the brain using both mice and human models. This was especially performed to see if there were any signs of a link between the cells and the ACE2 receptor. A small recap: ACE2 receptor is the primary receptor in humans which the COVID-19 viruses used to attach to the host and cause infection.

The researchers from the study found that the results demonstrated a molecular signal showing that ACE2 receptors were present in nose cells and the subsidiary cells. These cells generally maintain a chemical balance in the nose, which allows the nerve cells to send smell signals to the brain.

A Contradicting study published by a team from Nicolaus Copernicus University, Poland resulted that the olfactory neurons did not pose any ACE2 receptors, implying that the novel virus cant infect the cells themselves.

It was also noticed that the timing of the onset of anosmia symptoms was varied, with some patients developing the symptoms at early stages, while another group of patients reported the loss of smell in the later stages of their illness.

How will this help in the fight against COIVD-19?

More studies need to be conducted regarding the frequency of the symptoms and the exact science behind how the COVID-19 virus affects the olfactory senses. To collect more data on the cases posing these symptoms, the AOS-HNS Infectious Disease and Patient Safety Quality Improvement Committees have developed a COVID-19 anosmia detecting tool for health care workers. Using this tool the clinicians of all specialties will be able to confidently confirm cases portraying the loss of smell.

The idea of adding the symptoms of unexplained anosmia as an official symptom of COVID-19 can help with earlier detection and isolation of potential carriers of the virus and improve safety by containing the spread of the virus.

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Jun, 2020

COVID-19 patients with hypertension have more severe disease: a multicenter retrospective observational study

Late last year, a number of unexplained pneumonia cases surfaced in Wuhan, China. Later scientists revealed that it is caused by a familiar group of pathogens, coronavirus. The WHO later named this virus, COVID-19. The virus is highly contagious, infecting millions in the last couple of months.

From previous studies, it is considered that angiotensin-converting enzyme (ACE2) is the receptor for the COVID-19 virus to enter the host cell. ACE2 is a widely expressed receptor in several organ systems of the human body, including cardiovascular and respiratory systems. The enzyme helps in catalyzing angiotensin II to angiotensin 1-7, which is the peptide counteracting proinflammation caused by Angiotensin II.

Studies have proven that hypertension is a common condition that co-occurs in patients with COVID-19. A previously conducted study, involving 1099 COVID-19 patients reported that 23.4% of the population also suffered from hypertension. Due to the coexisting status of hypertension and COVID-19 and the involvement of ACE2 in hypertension, the authors of this study speculate that hypertension may directly be involved with the pathogenesis of COVID-19.

To confirm if hypertension affects the progress and prognosis of COVID-19, the published study was conducted. The study involved 310 patients from the Central Hospital of Wuhan and Wuhan Jinyintan Hospital. All the participants according to the WHO were tested positive for COVID-19. The study was later divided according to high blood pressure (hypertensive and non-hypertensive group). To avoid unwanted complications, the hypertension group was further segregated to exclude patients with other complications other than hypertension.

All the participants were monitored closely and the entire course of the disease was recorded. The median age of the participants in the study was 62 years and the prevalence rate of hypertension was 36.5%. The authors speculate that the high prevalence rate of hypertension in the study group could be due to the high median age. The study also revealed that COVID-19 patients with high blood pressure showed higher mortality.

Evidence suggests that an imbalance of cytokines could be a possible correlation between COVID-19 and hypertension. An increase in cytokines like IL-6, IL-7, and tumor necrosis factor is associated with the development of hypertension. It should also be noted that the increased levels of cytokines, may potentially activate excessive inflammatory reactions, resulting in cell and lung damage.

Overall the comparative study conducted using COVID-19 patients with and without hypertension showed that patients who were hypertensive were more likely to be severely affected with COVID-19 compared to the non-hypertensive group. It must be brought to light that there might be a small number of people with hypertension not recorded because the diagnosis of hypertension in this study was extracted from medical history data.

Finally, the authors conclude that much larger groups need to be studied since the current result could be due to the higher aged participants. In the future, additional complications also need to be analyzed like ARDS, renal injury focusing on its risks associated with hypertension and COVID-19.

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Jun, 2020

Risk Factors and Biomarkers of Ischemic Stroke in Cancer Patients

Numerous types of cancer are associated with ischemic stroke and are popularly known to be co-morbid conditions. They are two of the most frequent causes of death among the elderly population. A previous report of autopsies on cancer patients indicated that around 7.4% of the population suffered from stroke symptoms. With further analysis it was noticed that about 3.5% of the cancer patients were paralysed from strokes.

The causes of ischemic stroke in cancer and non-cancer patients are highly different. Reports suggest, most of the cancer patients suffer from stroke mainly due to hypercoagulation. The blood clot formed restricts the blood flow to the brain, causing the cells in the brain to perish. This in turn paralyses the parts of the body controlled by the dead cells. While on the other hand, some reports suggest that stroke and cancer pathogenesis may be due to coagulopathy and atherosclerosis. The aim of this study is to study ischemic stroke in cancer patients using relevant biomarkers and compare it with non cancer patients with stroke.

The study involved cancer patients with ischemic stroke from General Hospital in Busan, Korea. All the patients had active cancer with an onset of stroke symptoms. The control group used were patients from the same hospital, non cancer patients suffering from ischemic stroke. For examining the biomarkers, patients’ blood was collected and serum was assessed.

The study found that biomarkers such as D-dimer levels, erythrocyte sedimentation rate (ESR), fibrinogen and Brain natriuretic peptide (BNP) were significantly higher in the cancer patients when compared to non cancer patients with stroke.

D-dimer are one of the basic bio-markers for stroke due to their discovery as by-products of fibrinolysis. As a fibrin degradation product, dimer is directly associated with coagulation and plays a major role in hypercoagulation. Compared to non cancer ischemic stroke patients, D-dimer levels were found to be higher in cancer patients diagnosed with stroke.

Blood coagulation in cancer patients is activated by inflammation. In this study, the authors used ESR, because of its well known use as a marker for infection and inflammation. An increased level of ESR indicating fibrinolysis was noticed in cancer stroke patients when compared to the control group.

From previous papers, it is well known that fibrinogen plays a major role in inflammation and platelet aggregation. An increase in fibrinogen is directly associated with increased risk of stroke in patients. In the current study cancer patients with ischemic stroke had a significant increase in fibrinogen than non cancer patients.

Cancer patients with ischemic stroke portrayed high levels of stroke biomarkers when compared to the non cancer patients with ischemic stroke- control group. The above results showcase a strong relationship between the cancer patients and conditions like hypercoagulation and inflammation, which could possibly explain the frequency of paralysis in aged cancer patients leading to death. Therefore, in order to reduce any incidence of ischemic stroke in cancer patients, doctors should focus on reducing inflammation and platelet coagulation.

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May, 2020

Artificial intelligence-enabled rapid diagnosis of patients with COVID-19

Since December 2019, multiple cases of pneumonia due to unknown reasons have emerged in Wuhan, China. Through testing multiple patient samples, scientists extrapolated a new coronavirus termed COVID-19. With no FDA approved therapeutics or treatment available for the disease, diagnosis plays an important role in containing COCVID-19, giving a path to the rapid implementation of control measures to limit the spread. With the disease spreading to almost 100 countries, a million cases have been confirmed worldwide to date. Imaging is one of the main principles used in diagnosing and evaluating the disease, with the final diagnosis depending on reverse transcriptase-polymerase chain reaction (RT-PCR).

In response to the growing number of COVID-19 cases, there is currently a shortage of diagnostic kits worldwide. Multiple industries are coming forward to develop rapid, easy to use diagnostic kits to facilitate testing. However before these kits can be commercialized, they must be tested and validated. With the current available tests taking almost 2 days to complete and produce a result, serial testing is required to rule out any negative cases. Additionally, it is a mystery as to whether an RT-PCR is a gold standard and whether a false positive/ negative result is common. The above reasons highlight the need for alternative testing methods to produce rapid and accurate results to identify, isolate, and treat the affected people.

Chest computed tomography is also a much-used valuable component in testing COVID-19. With some of the patients showing early-stage symptoms in radiological finding, limits the CT ability to differentiate between a positive and negative case. In this current study, the authors have used Artificial Intelligence (AI) algorithms to help in integrating CT scanning in finding the symptoms of the virus, exposure history and reliable lab testing to rapidly diagnose the patients affected with COVID-19.

A trial was performed on 905 patients diagnosed using RT-PCR and next-generation RT-PCR and around 46% (419) people were declared positive for COVID-19. Parallelly in a test set of 279 participants, the AI system managed to achieve accuracy to about 92% of the population and had equal or even better sensitivity than a senior radiologist. The AI system also improved the detection of COVID-19 positive patients with negative CT scans, identifying 17 out of 25 participants who were tested positive via RT-PCR but negative with normal CT scans. In comparison, the radiologists’ declared the said 17 participants to be COVID negative.

AI shows signs of analyzing huge amounts of data quickly, a quality that is much needed in the current pandemic. A major limitation of the above study is the small sample size, with available CT scans and clinical history data, the AI system can help in diagnosing COVID-19 patients rapidly. Though a promising tool, further data collection is required to test the generalization of AI mapping on other patient populations.

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