The role of built environments in preventing contamination and reducing the spread of Covid-19 for future pandemics

‘The built environment contributes to the spread and contamination of the virus, as people spend more than 90% of their time indoors and even more during lockdown and community quarantine. During the current pandemic, healthy and asymptotic individuals are staying in their houses, and many people that are affected by the virus are now in hospitals and in healthcare facilities. These situations might affect the spread and contamination of the virus, as well as individuals’ interactions with each other.

‘To reduce the contamination and spread of the virus in the built environment that might affect healthy individuals – such as health care professionals, office workers – it is important to understand the steps that need to be taken and the policies to be implemented along with the theories underlying them. One of the approaches to be considered in designing effective fresh air supply and air extraction ventilation systems to minimize the concentration of suspended viruses. This is in addition to other essential procedures to understand the movement of viruses in the indoor air and its suspension/resuspension to and from surfaces.’

• Is it safe to reopen theaters during the Covid-19 pandemic?
• What’s in the pipeline? Evidence on the transmission of SARS-CoV-2 via building wastewater plumbing systems
• Ventilation for residential buildings: Critical assessment of standard requirements in the Covid-19 pandemic context
• Ventilation system design and the coronavirus (Covid-19)
• Outdoor airborne transmission of coronavirus among apartments in high-density cities

Read here (Frontiers in Built Environment, as at September 12, 2021)

MOH estimates three undetected Covid-19 cases for every reported infection

‘Malaysia likely has four times more Covid-19 cases than are being officially reported due to limited testing, said Greater Klang Valley Special Task Force (GKVSTF) chief Dr Chong Chee Kheong. Dr Chong said he agreed with views that the real case tally could be undercounted as the government’s policy is to focus on testing symptomatic cases rather than all suspected cases. “On whether it is true that for every Covid-19 case we detect, there are three more undetected cases, that is true,” he told a media briefing today. The Ministry of Health (MOH) reported a record high 20,596 new Covid-19 cases yesterday.’

Read here (Code Blue, Aug 6, 2021)

Mystery of rising Covid-19 cases in Selangor, KL – P Gunasegaram

‘On Tuesday, new Covid-19 infections in Malaysia numbered 7,654, the first time the daily tally crossed the 7,000 mark in a month. The Klang Valley contributed more than 60 of each 100 cases that day. Selangor logged 3,260 cases, while Kuala Lumpur had 1,550, bringing the total in these two areas to 4,819, or 63% of the Tuesday caseload.

‘But, the population of Selangor and KL stands at 8.3 million – 26%, or slightly over a quarter, of the Malaysian population. That works out to this: the area’s contribution to the national Covid-19 rate is some 2½ times its population share. Why? We need to know the answer to that if we are to deal with the latest coronavirus problem.‘

Read here (The Vibes, July 8, 2021)

Pakistan can get the dangerous Indian Covid situation, warns Indian doctor

‘A very important public service message started circulating in WhatsApp groups in Pakistan and India. It highlights that new Indian COVID variant can be as disastrous for Pakistan as it has been for India. It is written by Dr Pradeep Senha from Sassoon General Hospital Maharashtra. He says “COVID19 new mutation is giving false negatives in nasal swaps.”...

‘He writes, “The virus is now hitting straight into the lungs. It is carrying no symptoms like fever or cough. Just body ache, weakness, loss of appetite. Patients go from mild condition to extreme life and death situation within 8 to 10 hours.”

‘Dr Senha reports an alarming situation in India, he writes, “Our colleagues in small towns across India especially North Eastern regions are saying it is a battle we have already lost. It is now damage control and save as many lives as possible. We have seen 400 plus children just in our district die within 10 to 12 hours. Initial period they showed no symptoms and within hours their oxygen levels dropped and deceased.”

‘He says “We have also attended to several patients who traveled into Mumbai from overseas and had received their jabs and ended up contracting the Indian COVID and 17 out of 28 have died. Health services both in public and private hospitals have collapsed. Rich, middle class and poor all are affected and it is spreading fast, very fast. Any further mutation or variants will potentially be a doomsday scenario.”

Read here (Global Village Space, Apr 24, 2021)

Lancet report says Covid-19 is primarily airborne, safety protocol should change urgently

‘A report published in the journal The Lancet has dismissed the predominant scientific view that SARS-CoV-2, the coronavirus that causes Covid-19, is not an airborne pathogen. The authors of the report have listed 10 reasons for their claim that "SARS-CoV-2 is transmitted primarily by the airborne route".

‘The paper, written by six experts from the UK, the US and Canada, argues that there are "insufficient grounds for concluding that a pathogen is not airborne" while "the totality of scientific evidence indicates otherwise". The experts called for urgent modification in the Covid-19 safety protocol.’

Read here (India Today, Apr 16, 2021)

Ten scientific reasons in support of airborne transmission of SARS-CoV-2

Read here (The Lancet, April 15, 2021)

'Covid is taking over': Brazil plunges into deadliest chapter of its epidemic

‘[André] Machado saw several explanations for the torrent of cases he and other doctors are now seeing, including political mismanagement and the slackening of social distancing measures, principally among the young. In recent months such containment efforts have largely collapsed, with schools and businesses reopening and Bolsonaro’s tourism minister even urging citizens to start holidaying again.

‘But the doctor suspected a third, more troubling element was also at work: an enigmatic and apparently more contagious variant called P1 that is thought to have emerged in the Amazon region in late 2020 but is now circulating across Brazil, including in the southern state of Rio Grande do Sul, where Machado works.’

Read here (The Guardian, Mar 13, 2021)

Coronavirus (Covid-19) infection survey: Characteristics of people testing positive for Covid-19 in England, 22 February 2021

‘The UK government published a report on the infection risk associated with various occupations, based on data on COVID-19 cases in England from September 2020-January 2021. The analysis compared the likelihood of testing positive for SARS-CoV-2 during the study period for 25 standardized occupation categories. The occupation-specific risk ranged from 2.1% to 4.8%, with an overall risk of 3.9%. None of the individual occupation groups had a statistically significant difference from the overall average; however, some of the occupations with the highest risk showed a significant increase over those with the lowest risk. 

‘Occupation groups at the upper end include professions such as teachers, law enforcement and prison staff, childcare and home care, and secretarial professions. Occupation categories with lower infection risk include professions such as farmers and gardeners; scientists, engineers, and researchers; legal, social work, and news media; and textiles and printing services.’ (Summary by John Hopkins Centre for Health Security)

Read here (Government of UK, Feb 21, 2021)

Covid-19 - Improve management of mild cases, close contacts: MMA

‘Improvements are urgently needed in the Health Ministry's handling of mild cases of Covid-19 (category 1 and 2) and their close contacts to eliminate confusion and prevent possible flouting of the home quarantine SOPs which can lead to an increase in community transmissions. The Malaysian Medical Association (MMA) once again urges the Health Ministry to revert to its earlier policy of testing all close contacts. The Health Ministry's current policy is to only test symptomatic close contacts.

‘In its preventive measures, only isolating them will not be sufficient. The health status of all close contacts should be established early or there can be a risk of infections spreading among family members in the household and into the community if they breach the quarantine. Screening close contacts will also improve management of early symptoms of Covid-19.

‘MMA had earlier proposed that the government consider roping in the private sector doctors to test close contacts if it is faced with a shortage in manpower.’

Read here (Malaysiakini, Feb 6, 2021)

Viral loads, including in asymptomatic cases, a key factor in transmission

‘The scientific community is still uncovering the full picture of SARS-CoV-2 transmission dynamics. A study published in The Lancet: Infectious Diseases analyzed SARS-CoV-2 transmission among clusters in Catalonia, Spain, to understand the relationship between viral load and transmission risk. The researchers utilized participant data from a previous clinical trial, and they identified 314 COVID-19 patients that met their inclusion criteria. Among those patients, 282 had at least 1 contact (753 total contacts). The index patients infected 125 secondary cases, corresponding to a secondary attack rate of 17%. 

‘The researchers identified a statistically significant association between viral load in the index patients and the subsequent secondary attack rate. Among index patients with the lowest viral load, index patients exhibited a secondary attack rate of 12%, compared to 24% among the highest group. The researchers estimate that the odds of secondary transmission increase 30% for every log(10) increase in viral load. Additionally, the study found increased likelihood that secondary cases would develop COVID-19 symptoms associated with increased viral load in the index patients (aHR of 1.12 per log(10) increase in viral load). While further research is needed to more fully characterize the factors associated with transmission, this study provides evidence that the index patient’s viral load could be a major driver of secondary transmission risk and potentially disease severity in secondary cases.’ (Source: Updates on the COVID-19 pandemic from the Johns Hopkins Center for Health Security.)

Transmission of COVID-19 in 282 clusters in Catalonia, Spain: a cohort study

Read original here (The Lancet, Feb 2, 2021)

The mystery of India's plummeting Covid-19 cases

‘Last September, India was confirming nearly 100,000 new coronavirus cases a day. It was on track to overtake the United States to become the country with the highest reported COVID-19 caseload in the world. Hospitals were full. The Indian economy nosedived into an unprecedented recession.

‘But four months later, India's coronavirus numbers have plummeted. Late last month, on Jan. 26, the country's Health Ministry confirmed a record low of about 9,100 new daily cases — in a country of nearly 1.4 billion people. It was India's lowest daily tally in eight months. On Monday, India confirmed about 11,000 cases.

"It's not that India is testing less or things are going underreported," says Jishnu Das, a health economist at Georgetown University. "It's been rising, rising — and now suddenly, it's vanished! I mean, hospital ICU utilization has gone down. Every indicator says the numbers are down." Scientists say it's a mystery. They're probing why India's coronavirus numbers have declined so dramatically — and so suddenly, in September and October, months before any vaccinations began.

‘They're trying to figure out what Indians may be doing right and how to mimic that in other countries that are still suffering.’

Read here (NPR, Feb 1, 2021)

Covid-19 rarely spreads through surfaces. So why are we still deep cleaning?

‘Armed with a year’s worth of data about coronavirus cases, researchers say one fact is clear. It’s people, not surfaces, that should be the main cause for concern. Evidence from superspreading events, where numerous people are infected at once, usually in a crowded indoor space, clearly point to airborne transmission, says Marr. “You have to make up some really convoluted scenarios in order to explain superspreading events with contaminated surfaces,” she says.

‘Hand washing is crucial, says Marr, because surface transmission can’t be ruled out. But it’s more important to improve ventilation systems or to install air purifiers than to sterilize surfaces, she says. “If we’ve already paid attention to the air and we have some extra time and resources, then yes, wiping down those high-touch surfaces could be helpful,” she says.

‘Households can also ease up, says Pickering. Quarantining groceries or disinfecting every surface is going too far. “That’s a lot of work and it also is probably not reducing your exposure that much,” she says. Instead, reasonable hand hygiene, as well as wearing a mask and social distancing to reduce exposure from close contacts is a better place to focus efforts.’

Read here (Nature, Jan 29, 2021)

Vaccines need not completely stop Covid transmission to curb the pandemic

‘Influenza may provide the best blueprint of what to expect going forward. The most common flu vaccine—the inactivated virus—is not “truly sterilizing because it doesn’t generate local immune response in the respiratory tract,” Crowcroft says. This fact, coupled with low immunization rates (often shy of 50 percent among adults) and the influenza virus’s ability to infect and move between multiple species, enables it to constantly change in ways that make it hard for our immune system to recognize. Still, depending on the year, flu vaccines have been shown to reduce hospitalizations among older adults by an estimated 40 percent and intensive care admissions of all adults by as much as 82 percent.

‘Research on seasonal coronaviruses suggests that SARS-CoV-2 could similarly evolve to evade our immune systems and vaccination efforts, though probably at a slower pace. And data remain mixed on the relationship between symptoms, viral load and infectiousness. But ample precedent points to vaccines driving successful containment of infectious diseases even when they do not provide perfectly sterilizing immunity. “Measles, diphtheria, pertussis, polio, hepatitis B—these are all epidemic-prone diseases,” Crowcroft says. “They show that we don’t need 100 percent effectiveness at reducing transmission, or 100 percent coverage or 100 percent effectiveness against disease to triumph over infectious diseases.”

Read here (Scientific American, Jan 18, 2021)

The mutated virus is a ticking time bomb

‘There is much we don’t know about the new COVID-19 variant—but everything we know so far suggests a huge danger.

‘A more transmissible variant of COVID-19 is a potential catastrophe in and of itself. If anything, given the stage in the pandemic we are at, a more transmissible variant is in some ways much more dangerous than a more severe variant. That’s because higher transmissibility subjects us to a more contagious virus spreading with exponential growth, whereas the risk from increased severity would have increased in a linear manner, affecting only those infected.’

Read here (The Atlantic, Jan 1, 2021) 

Malaysia's Top Glove fired whistleblower before virus outbreak

‘Afraid of losing his job if he complained directly to management, Khadka, 27, sent the photos to a workers’ rights campaigner in his native Nepal who sent them on to the company and the Malaysian government, without identifying who took them.

‘On Sept. 23, Top Glove sent Khadka a letter terminating his employment for sharing the photos. In the letter, seen by Reuters, the company said it identified him as the originator of the photos from CCTV coverage of workers entering the factory.

‘Fast-forward almost three months, Top Glove’s complex of factories and dormitories in Klang, 40 km (25 miles) west of Kuala Lumpur, has become Malaysia’s biggest coronavirus cluster with more than 5,000 infections, about 94% of them foreigners, the country’s health ministry said in a statement on Dec. 1.’

Read here (Reuters, Dec 13, 2020)

Infected after 5 minutes, from 20 feet away: South Korea study shows COVID-19's spread indoors

‘KJ Seung, an infectious disease expert and chief of strategy and policy for the nonprofit Partners in Health’s Massachusetts COVID response, said the study was a reminder of the risk of indoor transmission as many nations hunker down for the winter. The official definition of a “close contact” — 15 minutes, within 6 feet — isn’t foolproof.

‘Lee and his team recreated the conditions in the restaurant... “Incredibly, despite sitting a far distance away, the airflow came down the wall and created a valley of wind. People who were along that line were infected,” Lee said. “We concluded this was a droplet transmission, and beyond two meters.”

“Eating indoors at a restaurant is one of the riskiest things you can do in a pandemic,” she [Linsey Marr, a civil and environmental engineering professor at Virginia Tech who studies the transmission of viruses in the air] said. “Even if there is distancing, as this shows and other studies show, the distancing is not enough.”

Read here (LA Times, Dec 12, 2020)

IHME projects 5,000 daily Covid-19 cases in Malaysia end-Feb

‘Malaysia is projected to experience a continuous rise in Covid-19 cases until mid-March 2021, hitting over 5,000 infections daily on February 25, according to US-based Institute for Health Metrics and Evaluation (IHME).

‘The IHME model, which is also used by the Trump administration, predicted 2,987 new coronavirus cases in Malaysia on January 1, increasing to 4,176 Covid-19 infections on February 1, and 5,130 cases on March 1. The trend is projected to rise until March 21 with 5,379 infections that day, and then declining to 5,301 cases on April 1.’

Read here (Code Blue, Dec 11, 2020)

Stanford study suggests indoor dining presents huge Covid-19 infection risk

‘According to the New York Times, the study followed the movement of 98 million people to and from indoor public spaces, then calculated traffic to each spot visited as well as how long people stay and each venue’s square footage. Using the area’s infection rate, they then used “standard infectious disease assumptions” to determine how the illness spread across cities.

‘Stanford computer scientist Jure Leskovec, the senior author of the report, tells the Times that “restaurants were by far the riskiest places” for new infections, “about four times riskier than gyms and coffee shops, followed by hotels,” he says. It’s news that jibes with another recent study from the Centers for Disease Control and Prevention (CDC), which said in September that a study of adults across 11 U.S. cities who tested positive for the novel coronavirus were twice as likely to have dined out within the last two weeks than those who tested negative.’

Read here (Eater San Francisco, Nov 11, 2020)

US Covid-19 cases are skyrocketing, but deaths are flat—so far. These 5 charts explain why

 ‘In just the last two weeks, the global daily tally for new COVID-19 cases has jumped more than 30%, according to TIME’s coronavirus tracker, which compiles data from Johns Hopkins University. The steep upward trend is driven by viral waves in Europe and the United States that started in August and mid-September, respectively. On Oct. 23, the daily case count in the U.S. reached a new record high, suggesting that this wave will be worse than the one that swept the country over the summer.

‘But despite this rapid uptick in cases, the daily death count in the U.S. is not yet rising at the same rate, and remains at lower levels than in April. At face value, a lower case-to-fatality rate suggests that fewer people who test positive for the virus are dying from it. But the virus hasn’t necessarily become less lethal; it isn’t mutating quickly enough for that to be the case.

‘What’s happening now is not a result of how the virus treats humans, but rather how humans are treating the virus—that is, how we test for it, how we avoid it and how we combat it. The following five charts explain how human-driven factors are, at least for the moment, keeping deaths from spiking as high as they did early in the pandemic, even as cases rise dramatically...’

Read here (Time, Oct 26, 2020)

Stop wiping down groceries and focus on bigger risks, say experts on coronavirus transmission

“To the best of my knowledge, in real life, scientists like me — an epidemiologist and a physician — and virologists basically don’t worry too much about these things,” said David Morens, a senior adviser to the director of the National Institute of Allergy and Infectious Diseases, Anthony S. Fauci... 

‘But public confusion about the coronavirus and surfaces is understandable, said Angela Rasmussen, a virologist at the Center for Infection and Immunity at Columbia University’s Mailman School of Public Health. “Scientists really haven't really done a very good job of explaining how you get evidence for different types of transmission or different transmission routes.” Finally, she said, it’s important to remember that “viruses have to have a host and they can’t replicate without one. So … the main place that’s going to be the source of virus in anybody’s household is going to be the people in it and not the surfaces or the physical environment.” “Even if there’s virus kicking around on certain things,” she said, “that risk can really be mitigated practically by washing your hands.”

Read here (Washington Post via MSN, Oct 23, 2020)

Why is coronavirus so deadly?

1. Master of deception: ‘In the early stages of an infection the virus is able to deceive the body. Coronavirus can be running rampant in our lungs and airways and yet our immune system thinks everything is a-ok.’
2. It behaves like a 'hit and run' killer: ‘The amount of virus in our body begins to peak the day before we begin to get sick. But it takes at least a week before Covid progresses to the point where people need hospital treatment.’ 
3. It's new, so our bodies are unprepared: ‘This lack of prior-protection is comparable to when Europeans took smallpox with them to the New World, with deadly consequences.’
4. It does peculiar and unexpected things to the body: ‘Covid starts off as a lung disease (even there it does strange and unusual things) and can affect the whole body.’ Like “corrupting” lung cells, clotting blood and causing runaway inflammation.
5. And we're fatter than we should be: ‘Covid is worse if you are obese, as a generous waistline increases the risk of needing intensive care, or death.’

Read here (BBC, Oct 23, 2020)