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Coronavirus

Ct values indicate disease severity

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There have been a lot of discussions on the cycle threshold (Ct) values in recent times because when anyone receives a positive RTPCR test result, the only measure one can see is the Ct value. This value determines if a person is positive for COVID-19 or not and not the severity level of the disease.

RT PCR is considered the gold standard for detection of the Coronavirus responsible for COVID-19. Ct is a value that emerges during RT-PCR test, in which RNA is extracted from the swabs collected from the patient, converted into DNA and then amplified. Amplification here refers to the process of creating multiple copies of the genetic material which improves the ability of the test to detect the presence of virus. Amplification takes place through a series of cycles — one copy becomes two, two becomes four, and so on — and it is after multiple cycles that a detectable amount of virus is produced.

According to the ICMR advisory, simply put, the Ct value refers to the number of cycles after which the virus can be detected. If higher number of cycles is required, it implies that the virus went undetected when the number of cycles was lower. The lower the Ct value, the higher the viral load — because the virus was spotted after fewer cycles.

According to the ICMR, a patient is considered Covid-positive if the Ct value is below 35. In other words, if the virus is detectable after 35 cycles or earlier, then the patient is considered positive.

In simpler terms, Ct value is a measure of transmission potential, according to leading virologist Dr Shahid Jameel. For e.g., if there is more virus in the throat and nose, transmission is faster according to Dr. Jameel who is Director of the Trivedi School of Biosciences at Ashoka University.

So, does the Ct value also tell you about the severity of the disease? No – that is not true. Despite being inversely correlated with viral load, the Ct value does not have any bearing on the severity of the disease. A patient can have a low Ct value, which means the viral load is high enough to be detected rapidly, though the patient may still be asymptomatic.

A small study published in the Indian Journal of Medical Microbiology found that there was no correlation between Ct values and severity of disease or mortality in patients with Covid-19. The study further found that the Ct values have a stronger relationship with time since the onset of symptoms than to the severity of the disease. Therefore, the correlation is more with infectivity of COVID-19 than the severity of the infection.

Many factors are important in interpreting an RT-PCR test, and the results may also depend on the method of specimen collection and time from infection to collection and to analysis.

A poorly collected sample may reflect inappropriate Ct values. Besides, Ct values are also determined by the technical competence of the person performing the test, calibration of the equipment, and the analytical skills of the interpreters.Again, Ct values may differ between nasal and oropharyngeal specimens collected from the same individual. The temperature of transportation, as well as the time taken from collection to receipt in the lab, can also adversely impact Ct values. The ICMR has also released an advisory on the correlation of COVID-19 severity with Ct values, which currently states that the evidence is not robust enough to definitively support this assumption. Recent discussions about guiding the clinical decision-making process based on the Ct values of RT-PCR test reported by laboratories has several limitations. The complete report can be accessed here.

UIN: 249HP67F

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Coronavirus

Double masking offers better protection

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In January this year, we had carried out a story on how double masking can improve protection from the deadly Coronavirus. Top infectious disease specialist from the US, Dr. Anthony Fauci, Director, National Institute of Allergy, and Infectious Diseases (NIAID) and chief medical advisor on COVID-19 for President Joe Biden said that the trend of wearing two masks to prevent the spread of the coronavirus, can be considered the “common sense approach”.

Newer data from the US Centers for Disease Control and Prevention (CDC) had shown that double masking can significantly improve protection, wherein researchers found that layering a cloth mask over a medical procedural mask, such as a disposable blue surgical mask, can block 92.5% of potentially infectious particles from escaping by creating a tighter fit and eliminating leakage.

With the recent surge in COVID-19 cases in India, there are speculations around what exactly went wrong with the anti-COVID-19 measures we were taking including wearing masks, social distancing, and regular hand hygiene. A major contributory factor is the way we wear masks. The idea is to have a snugly fit mask that can prevent any sort of transmission – but were we doing this? Not exactly! More so, because most of the people have been wearing single layer, not to be reused masks or wearing it the wrong way (not covering nose or just pushed down to the chin and then reusing it to cover the mouth), etc. Double masking therefore sounds like a logical way out for a more optimum protection and better fit to cover the nose and mouth areas.

The Indian Ministry of Information & Broadcasting has released dos and don’ts for double masking which include the following:

Do’s

  1. Do use a surgical mask PLUS a double/triple layered cloth mask
  2. Do press the mask gently on your nose bridge to ensure a snug fit
  3. Do ensure breathing is not blocked and you are able to talk without feeling breathless

Don’ts

  1. Do not pair 2 masks of the same type together.
  2. Do not use the same mask for 2 consecutive days without washing
  3. Do not use an unwashed mask; always ensure one mask is disposable so you can discard it after use at the end of the day.

UIN: 264HP148R

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Coronavirus

What should I do about mucormycosis?

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Amid the rise in cases of mucormycosis or ‘black fungus’ infection among COVID-19 survivors, the government has released an evidence-based advisory for screening, diagnosis and management of the disease. Stating that it may turn fatal if not cared for, the government said mucormycosis is a fungal infection that mainly affects people who are on any kind of medication that reduces their ability to fight environmental pathogens. The common symptoms seen in patients of mucormycosis include sinuses or lungs affected with fungal spores inhaled from air. The advisory was prepared by the Union Health Ministry and ICMR and includes the following warning signs:

  • Pain and redness around eyes and/or nose
  • Fever
  • Headache
  • Coughing
  • Shortness of breath
  • Bloody vomits
  • Altered mental status

The most common group of patients who are found to be affected include patients with uncontrolled diabetes mellitus, immunosuppressed by steroids individuals, patients who have had a prolonged ICU stay, patients on voriconazole therapy or patients with comorbidities that can arise post transplants or in case of cancer or other malignancies. The advisory further adds the Do’s and Don’ts for treating clinicians of patients presenting with mucormycosis or black fungus disease. These are enlisted below:

Do’s

  1. Control hyperglycemia
  2. Monitor blood glucose level post COVID-19 discharge and in diabetics
  3. Use steroid judiciously – correct timing, correct dose and duration
  4. Use clean, sterile water for humidifiers during oxygen therapy
  5. Use antibiotics/antifungals judiciously

Don’ts

The advisory further highlights the importance of not missing out on the warning signs and symptoms. These include:

  1. Do not consider all the cases with blocked nose as cases of bacterial sinusitis, particularly in the context of immunosuppression and/or COVID-19 patients on immunomodulators
  2. Do not hesitate to seek aggressive investigations, as appropriate (KOH staining & microscopy, culture, MALDITOF), for detecting fungal etiology
  3. Do not lose crucial time to initiate treatment for mucormycosis

For patients, the advisory contains preventive measures that include but are not limited to the following:

  1. Use masks if you are visiting dusty construction sites
  2. Wear shoes, long trousers, long sleeve shirts and gloves while handling soil (gardening), moss or manure
  3. Maintain personal hygiene, including thorough scrub bath

Management approach to mucormycosis includes measures to:

  1. Control diabetes and diabetic ketoacidosis
  2. Reduce steroids (if patient is still on) with aim to discontinue rapidly
  3. Discontinue immunomodulating drugs
  4. No antifungal prophylaxis needed
  5. Extensive Surgical Debridement – to remove all necrotic materials
  6. Medical treatment

Note: Mucormycosis is a rare condition and not all clinicians are equipped to handle them. In case you experience any of any signs mentioned, you should consult with an expert in the subject (ophthalmologist for eye complaints, ENT specialist for sinuses and nasal blockage, internal medicine specialist for headache, vomiting, altered mental status, etc.

UIN: 265HP13G

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Coronavirus

A new drug ‘2-DG’ can reduce supplemental oxygen dependence in COVID-19 patients

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The ongoing pandemic is threatening the global human population, including in countries with resource-limited health facilities, such as India. One of the main features of severe COVID-19 infection is severe bilateral pneumonia, which requires immediate ventilatory support for patient survival. Key message in the management approach to these patients includes supplemental oxygen as a first essential step for the treatment of hypoxemia. Over the last few weeks, India has seen an unprecedented rise in the number of COVID-19 patients requiring supplemental oxygen and the scarcity of oxygen cylinders.

In such trying times, the Defence Research & Development Organisation (DRDO) laboratory called Institute of Nuclear Medicine & Allied Sciences (INMAS) has come up with the therapeutic application of the drug 2- deoxy-D-glucose (2-DG) for emergency use. This has been done in collaboration with the Dr. Reddy’s Laboratories in Hyderabad, India.

The Drugs Controller General of India (DCGI) has granted permission for the emergency use of the drug 2-deoxy-D-glucose (2-DG) as an adjunct therapy in moderate to severe COVID-19 cases.

According to the INMAS Labs, clinical trials have shown that a significantly higher proportion of patients administered with the 2-DG drug “became free from supplemental oxygen dependence” by the third day of their treatment, in comparison to those who were not administered with the drug.This indicated an early relief from oxygen therapy/dependence, according to the Ministry of Defence.

In a release issued on Saturday, the Ministry of Defence said that as per the order, emergency use of this drug as adjunct therapy in moderate to severe COVID-19 patients is permitted. It added that being a generic molecule and analogue of glucose, it can be easily produced and made available in plenty in the country. 

Based on successful results, Drugs Controller General of India (DCGI) further permitted the Phase-III clinical trials in November 2020. The Phase-III clinical trial was conducted on 220 patients between December 2020 to March 2021 at 27 COVID hospitals in Delhi, Uttar Pradesh, West Bengal, Gujarat, Rajasthan, Maharashtra, Andhra Pradesh, Telangana, Karnataka, and Tamil Nadu. The detailed data of phase-III clinical trial was presented to DCGI. In 2-DG arm, significantly higher proportion of patients improved symptomatically and became free from supplemental oxygen dependence (42% vs. 31%) by Day-3 in comparison to standard of care, indicating an early relief from Oxygen therapy/dependence. A similar trend was observed in patients aged more than 65 years.

The drug comes in powder form in sachet, which is taken orally by dissolving it in water. It accumulates in the virus infected cells and prevents virus growth by stopping viral synthesis and energy production. Its selective accumulation in virally infected cells makes this drug unique.

UIN: 263HP147R

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Coronavirus

Can we use Oxygen Concentrators on our own?

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The answer here would be a NO – because this should not be done without the supervision of a chest physician or pulmonologist. As per the World Health Organisation (WHO), oxygen therapy is recommended for all severe and critical COVOD-19 patients, with low doses from 1-2 litres per minute in children to starting with 5 litres per minute in adults using nasal cannula. This rate can be altered basis the patient’s condition—acute respiratory discomfort or if saturation drops. However, it is to be noted that this is not to be exercised without the supervision of a medical practitioner even if it is on a video call to assist you with the right way to handle oxygen concentrators.

Oxygen concentrator is a device capable of concentrating oxygen from ambient air i.e. 78% nitrogen and 21% oxygen. It accumulates air, filters it via a sieve, releases the nitrogen back into the air and collects the oxygen. This oxygen can be dispensed through a nasal cannula using a pressure valve that regulates its flow. It can deliver oxygen typically, at a flow rate between 1-10 litres per minute. Oxygen concentrator is a very useful medical equipment because of its size, portability, and no requirement of any kind of refilling.

Oxygen concentrators couId be used for non-severe conditions, or after discharge from the hospital for home care and for an interim use whilst waiting for medical guidance & supervision. They can even be a lifesaver for cases in which a patient needs appropriate oxygen flow and concentration based upon his/her condition. One way to look at it could be that using an oxygen concentrator effectively can also ensure reduced occupancy in hospitals as such patients can continue treatment at home.

Experts from a webinar titled ‘COVID-19: Myths Versus Reality’ that was organized by Press Information Bureau, in collaboration with the Government College of Arts, Science and Commerce, Goa, to tackle the infodemic situation said that a lot of people are thinking that having an oxygen concentrator at home can help them to tide over the crisis. This may be true for patients whose oxygen saturation is less than 94 which classifies as a moderate COVID, so giving supplemental oxygen will be beneficial for the interim period before hospital admission.

Speaking on the appropriate usage of concentrators, Professor and Head of Department Anesthesia, B. J. Medical College, Pune, Prof. Sanyogita Naik said: “Oxygen concentrators can be used only in moderate cases of COVID-19, when the patient experiences drop in oxygen levels, where the oxygen requirement is a maximum of 5 litres per minute.” The professor added that oxygen concentrators are also very useful for patients experiencing post-COVID complications which necessitate oxygen therapy.

However, the big problem is that people tend to use it themselves without accurate guidance from a chest physician or an internal medicine specialist. Doing this can potentially be harmful. This is because some people having long-term respiratory diseases may have normal oxygen saturation between 88 to 92 but due to the over-exchange of information and availability of doctors online, patients and caregivers really need to be told how and when to raise the alarm.

Note:

  1. Oxygen concentrator is not a replacement for oxygen cylinder or ventilator.
  2. Patients with moderate and severe health conditions will need higher doses of oxygen and this device cannot meet those requirements.
  3. Experts advise against the use of oxygen concentrators for patients who have oxygen saturation below 85%.

UIN: 266HP12G

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Coronavirus

Unnecessary CT scans raise cancer risk

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Computed tomography, also known as computed axial tomography or CT scan, is a tool doctors use to diagnose several types of health problems. It creates detailed images of structures inside your body which helps doctors get a look at your internal organs and then advise further treatment. A CT scan exposes your body to some radiation that involves an amount of risk.

During the second wave of COVID-19 in India, there has been a rampant rise in the number of CT scans being done at various centers in India. A rising concern here is because a lot of these centers do not require a prescription or do not validate the prescriptions before posting a patient for the scan. Considering these developments and unnecessary CT scans being done, experts have warned against unnecessary CT scans by patients having mild Covid-19 symptoms and said that overuse of CT scans increases exposure to radiation which in turn escalates the risk of cancer. This is also because the treating physicians know better about the timing of the HRCT and whether it is required at all or not.

A lot of patients are going for CT scans as soon as they receive a positive RTPCR report and some of these patients go for repeat CT every 3-4 days, to check progress of their recovery or infection, which does more harm than good. This is not the first time that experts have cautioned against the misuse or dangerous effects of CT scan which may lead to cancer.

Harvard Health had also reported that scans expose people to X-rays, and this can damage cells and lead to cancer down the road. In one of its reports, it said most of the increased exposure in the United States is due to CT scanning and nuclear imaging, which require larger radiation doses than traditional X-rays. A chest X-ray, for example, delivers 0.1 mSv, while a chest CT scan delivers 7 mSv — 70 times as much.

In another report, Harvard Health described the risks by mentioning the body regions where CT-related cancer is most likely to occur and these include the chest, abdomen, and pelvis, where faster-growing cells are more vulnerable to radiation.

Similarly, a report by the Yale School of Medicine reported each CT scan exposes patients to between 100-500 times the amount of radiation in an X-ray.

A WebMD report also concurs and reports one chest CT scan delivers the same radiation amount as 100-200 X-rays.

The American College of Radiology recommends limiting lifetime diagnostic radiation exposure to 100 mSv. That is equal to 10,000 chest x-rays, or up to 25 chest CTs.

Harvard Health also adds that even though the benefits of CTs in adult men, particularly those older than 50, may outweigh the risks, no one—even a man in his 70s or 80s—should have CTs without a good reason because caution with ionizing radiation is always recommended. If you don’t need it, why get more of it? they ask!

In conclusion, a single scan may rarely be concerning, but the way people are going about getting their scans done without the supervision of a registered medical practitioner, multiple or unnecessary repetitive CT scans can turn out to be hazardous and may increase the risk of developing a cancer in the near future.

UIN: 261HP145R

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