Now, barcode scanner microscope for better disease imaging

Beijing, Jun 18:  Besides washing hands and wearing masks, it is also important to close the toilet lid before flushing to contain the spread of COVID-19, as per a new study.

According to a new study cited by The Washington Post, scientists who simulated toilet water and airflows, have found that flushing a toilet can generate a plume of virus-containing aerosol particles that is widespread and can linger in the air long enough to be inhaled by others. The novel coronavirus has been found in the faeces of COVID-19 patients, but it remains unknown whether such clouds could contain enough virus to infect a person.

"Flushing will lift the virus up from the toilet bowl," co-author Ji-Xiang Wang, who researches fluids at Yangzhou University in Yangzhou, China, said in an email. Wang stressed that bathroom users "need to close the lid first and then trigger the flushing process" and wash hands properly if the closure is not possible. As one flushes the toilet with the lids open, bits of faecal matter swish around so violently that they can be propelled into the air, become aerosolised and then settle on the surroundings.

Experts call it the "toilet plume".Age-old studies have been made to understand the potential for airborne transmission of infectious disease via sewage, and the toilet plume's role. Scientists who have seeded toilet bowls with bacteria and viruses have found contamination of seats, flush handles, bathroom floors and nearby surfaces. This is one reason we are told to wash our hands after visiting the toilet. Public bathrooms are well known to contribute to the spread of viruses that transmit via ingestion, such as the noroviruses that haunt cruise ships. However, their role in the transmission of respiratory viruses has not been established, said Charles P Gerba, a microbiologist at the University of Arizona."The risk is not zero, but how great a risk it is, we do not know. The big unknown is how much virus is infectious in the toilet when you flush it ... and how much virus does it take to cause an infection," said Gerba, who has studied the intersection of toilets and infectious disease for 45 years.

A study published in March in the journal Gastroenterology found significant amounts of coronavirus in the stool of patients and determined that viral RNA lasted in faeces even after the virus cleared from the patients` respiratory tracts. While another study in the journal Lancet found coronavirus in faeces up to a month after the illness had passed.

Scientists around the world are now studying sewage to track the spread of the virus. According to the researchers, the presence of the virus in excrement and the gastrointestinal tract raises the prospect of transmission via toilets, because many COVID-19 patients experience diarrhoea or vomiting.

A study of air samples in two hospitals in Wuhan, China found that although coronavirus aerosols in isolation wards and ventilated patient rooms were very low, "it was higher in the toilet areas used by the patients".The Centers for Disease Control and Prevention (CDC) says it remains "unclear whether the virus found in faeces may be capable of causing COVID-19," and "there has not been any confirmed report of the virus spreading from faeces to a person".For now, the CDC characterises the risk as low based on observations from previous outbreaks of other coronaviruses such as severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS). Wang decided to use computer models to simulate toilet plumes while isolating at home, as per Chinese government orders and thinking about how a fluids researcher "could contribute to the global fight against the virus".

Published in the journal Physics of Fluids, the study found that flushing of both single-inlet toilets, which push water into the bowl from one port, and annular-inlet toilets, which pour water into the bowl from the rim's surrounding edge with even greater energy, results in "massive upward transport of virus".

Particles can reach heights of more than three feet and float in the air for more than a minute, it found. The paper recommends not just lid-closing and hand-washing, it urges manufacturers to produce toilets that close and self-clean automatically. It also suggests that toilet-users should wipe down the seat. Gerba, however, said seats should not be a major concern.

Research has found that public and household toilet seats are typically the cleanest surfaces in restrooms, he said, probably because so many people already wipe them off before using them. Also, he said of SARS-CoV-2, the virus that causes COVID-19, "I don't think it's butt-borne, so I don`t think you have to worry."Gerba, who has been studying coronavirus transmission for two decades to investigate the role of a toilet flushing in a SARS outbreak stresses "flush and run" when using a public toilet without a lid. Gerba also said that people should wash hands well post-flushing and use hand sanitiser after leaving the restroom. "Choose well-ventilated bathrooms if possible and do not hang around the restroom in any case," added Gerba.

New Delhi, Jul 13: The Income Tax Department has facilitated a new functionality for banks and post offices to ascertain TDS applicability rates on cash withdrawal of above Rs 20 lakh in case of a non-filer of the income-tax return and that of above Rs 1 crore in case of a filer of the income-tax return.

In a statement, the Central Board of Direct Taxes (CBDT) said that now banks and post offices have to only enter the PAN of the person who is withdrawing cash for ascertaining the applicable rate of TDS.

So far, more than 53,000 verification requests have been executed successfully on this facility, a statement by the CBDT said.

"CBDT today said that this functionality available as 'Verification of applicability u/s 194N' on www.incometaxindiaefiling.gov.in since 1st July 2020, is also made available to the Banks through web-services so that the entire process can be automated and be linked to the Bank's internal core banking solution," it said.

On entering PAN by the bank or the post office, a message will be instantly displayed on the departmental utility: "TDS is deductible at the rate of 2 per cent if cash withdrawal exceeds Rs 1 crore", in case the person withdrawing cash is a filer of the income-tax return.

In case the person withdrawing cash is a non-filer of income tax return, the message shown would be: "TDS is deductible at the rate of 2 per cent if cash withdrawal exceeds Rs 20 lakh and at the rate of 5 per cent if it exceeds Rs 1 crore."

The CBDT said that the data on cash withdrawal indicated that huge amount of cash is withdrawn by the persons who have never filed income-tax returns.

To ensure filing of return by these persons and to keep track on cash withdrawals by the non-filers, and to curb black money, the Finance Act, 2020 with effect from July 1, 2020 further amended IT Act to lower threshold of cash withdrawal to Rs 20 lakh for the applicability of this TDS for the non-filers and also mandated TDS at the higher rate of 5 per cent on cash withdrawal exceeding Rs 1 crore by the non-filers.

Los Angeles, Apr 28: People who experience loss of smell as one of the COVID-19 symptoms are likely to have a mild to moderate clinical course of the disease, according to a study which may help health care providers determine which patients require hospitalisation.

The findings, published in the journal International Forum of Allergy & Rhinology, follows an earlier study that validated the loss of smell and taste as indicators of infection with the novel coronavirus, SARS-CoV-2.

According to the scientists from the University of California (UC) San Diego Health in the US, patients who reported loss of smell were 10 times less likely to be hospitalised for COVID-19 compared to those without the symptom.

"One of the immediate challenges for health care providers is to determine how to best treat persons infected by the novel coronavirus," said Carol Yan, first author of the current study and rhinologist from the UC San Diego Health.

"If they display no or mild symptoms, can they return home to self-quarantine or will they likely require hospitalisation? These are crucial questions for hospitals trying to efficiently and effectively allocate finite medical resources," Yan said.

The findings, according to the researchers, suggest that loss of smell may be predictive of a milder clinical course of COVID-19.

"What's notable in the new findings is that it appears that loss of smell may be a predictor that a SARS-CoV-2 infection will not be as severe, and less likely to require hospitalisation," Yan said.

"If an infected person loses that sense, it seems more likely they will experience milder symptoms, barring other underlying risk factors," she added.

Risk factors for COVID-19 previously reported by other studies include age, and underlying medical conditions, such as chronic lung disease, serious heart conditions, diabetes, and obesity.

In the current study, the scientists made a retrospective analysis between March 3 and April 8 including 169 patients who tested positive for COVID-19 at UC San Diego Health.

They assessed olfactory and gustatory data for 128 of the 169 patients, 26 of whom required hospitalisation.

According to the researchers, patients who were hospitalised for COVID-19 treatment were significantly less likely to report anosmia or loss of smell -- 26.9 per cent compared to 66.7 per cent for COVID-19-infected persons treated as outpatients.

Similar percentages were found for loss of taste, known as dysgeusia, they said.

"Patients who reported loss of smell were 10 times less likely to be admitted for COVID-19 compared to those without loss of smell," said study co-author Adam S. DeConde.

"Moreover, anosmia was not associated with any other measures typically related to the decision to admit, suggesting that it's truly an independent factor and may serve as a marker for milder manifestations of Covid-19," DeConde said.

The researchers suspect that the findings hint at some of the physiological characteristics of the infection.

"The site and dosage of the initial viral burden, along with the effectiveness of the host immune response, are all potentially important variables in determining the spread of the virus within a person and, ultimately, the clinical course of the infection," DeConde said.

If the SARS-CoV-2 virus initially concentrates in the nose and upper airway, where it impacts olfactory function, that may result in an infection that is less severe and sudden in onset, decreasing the risk of overwhelming the host immune response, respiratory failure, and hospitalisation, the scientists added.

"This is a hypothesis, but it's also similar to the concept underlying live vaccinations," DeConde explained.

"At low dosage and at a distant site of inoculation, the host can generate an immune response without severe infection," he added.

Loss of smell, according to the study, might also indicate a robust immune response which has been localised to the nasal passages, limiting effects elsewhere in the body.

Citing the limitations of the study, the scientists said they relied upon self-reporting of anosmia from participants, which posed a greater chance of recall bias among patients once they had been diagnosed with COVID-19.

They added that patients with more severe respiratory disease requiring hospitalisation may not be as likely to recognise or recall the loss of smell.

So the researchers said more expansive studies are needed for validating the results.