How contagious is Delta? How long are you infectious? Is it more deadly? A quick guide to the latest science

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Lara Herrero, Griffith UniversityDelta was recognised as a SARS-CoV-2 variant of concern in May 2021 and has proved extremely difficult to control in unvaccinated populations.

Delta has managed to out-compete other variants, including Alpha. Variants are classified as “of concern” because they’re either more contagious than the original, cause more hospitalisations and deaths, or are better at evading vaccines and therapies. Or all of the above.

So how does Delta fare on these measures? And what have we learnt since Delta was first listed as a variant of concern?

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Read more:
Is Delta defeating us? Here’s why the variant makes contact tracing so much harder

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How contagious is Delta?

The R0 tells us how many other people, on average, one infected person will pass the virus on to.

Delta has an R0 of 5-8, meaning one infected person passes it onto five to eight others, on average.

This compares with an R0 of 1.5-3 for the original strain.

So Delta is twice to five times as contagious as the virus that circulated in 2020.

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What happens when you’re exposed to Delta?

SARS-CoV-2 is the virus that causes COVID-19. SARS-CoV-2 is transmitted through droplets an infected person releases when they breathe, cough or sneeze.

In some circumstances, transmission also occurs when a person touches a contaminated object, then touches their face.

One person infected with Delta infects, on average, five to eight others.
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Once SARS-CoV-2 enters your body – usually through your nose or mouth – it starts to replicate.

The period from exposure to the virus being detectable by a PCR test is called the latent period. For Delta, one study suggests this is an average of four days (with a range of three to five days).

That’s two days faster than the original strain, which took roughly six days (with a range of five to eight days).

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The virus then continues to replicate. Although often there are no symptoms yet, the person has become infectious.

People with COVID-19 appear to be most infectious two days before to three days after symptoms start, though it’s unclear whether this differs with Delta.

The time from virus exposure to symptoms is called the incubation period. But there is often a gap between when a person becomes infectious to others to when they show symptoms.

As the virus replicates, the viral load increases. For Delta, the viral load is up to roughly 1,200 times higher than the original strain.

With faster replication and higher viral loads it is easy to see why Delta is challenging contact tracers and spreading so rapidly.

What are the possible complications?

Like the original strain, the Delta variant can affect many of the body’s organs including the lungs, heart and kidneys.

Complications include blood clots, which at their most severe can result in strokes or heart attacks.

Around 10-30% of people with COVID-19 will experience prolonged symptoms, known as long COVID, which can last for months and cause significant impairment, including in people who were previously well.

Even previously well people can get long COVID.
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Longer-lasting symptoms can include fatigue, shortness of breath, chest pain, heart palpitations, headaches, brain fog, muscle aches, sleep disturbance, depression and the loss of smell and taste.

Is it more deadly?

Evidence the Delta variant makes people sicker than the original virus is growing.

Preliminary studies from Canada and Singapore found people infected with Delta were more likely to require hospitalisation and were at greater risk of dying than those with the original virus.

In the Canadian study, Delta resulted in a 6.1% chance of hospitalisation and a 1.6% chance of ICU admission. This compared with other variants of concern which landed 5.4% of people in hospital and 1.2% in intensive care.

In the Singapore study, patients with Delta had a 49% chance of developing pneumonia and a 28% chance of needing extra oxygen. This compared with a 38% chance of developing pneumonia and 11% needing oxygen with the original strain.

Similarly, a published study from Scotland found Delta doubled the risk of hospitalisation compared to the Alpha variant.

Emerging evidence suggests Delta is more likely to cause severe disease than the original strain.
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How do the vaccines stack up against Delta?

So far, the data show a complete course of the Pfizer, AstraZeneca or Moderna vaccine reduces your chance of severe disease (requiring hospitalisation) by more than 85%.

While protection is lower for Delta than the original strain, studies show good coverage for all vaccines after two doses.

Can you still get COVID after being vaccinated?

Yes. Breakthrough infection occurs when a vaccinated person tests positive for SARS-Cov-2, regardless of whether they have symptoms.

Breakthrough infection appears more common with Delta than the original strains.

Most symptoms of breakthrough infection are mild and don’t last as long.

It’s also possible to get COVID twice, though this isn’t common.

How likely are you to die from COVID-19?

In Australia, over the life of the pandemic, 1.4% of people with COVID-19 have died from it, compared with 1.6% in the United States and 1.8% in the United Kingdom.

Data from the United States shows people who were vaccinated were ten times less likely than those who weren’t to die from the virus.

The Delta variant is currently proving to be a challenge to control on a global scale, but with full vaccination and maintaining our social distancing practices, we reduce the spread.

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Read more:
Why is Delta such a worry? It’s more infectious, probably causes more severe disease, and challenges our vaccines

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Lara Herrero, Research Leader in Virology and Infectious Disease, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Achieving COVID-19 herd immunity through infection is dangerous, deadly and might not even work

Under relaxed public health restrictions, deaths will spike far before herd immunity is achieved.
AP Photo/Mark Lennihan

Steven Albert, University of Pittsburgh

White House advisers have made the case recently for a “natural” approach to herd immunity as a way to reduce the need for public health measures to control the SARS-CoV-2 pandemic while still keeping people safe. This idea is summed up in something called the Great Barrington Declaration, a proposal put out by the American Institute for Economic Research, a libertarian think tank.

The basic idea behind this proposal is to let low-risk people in the U.S. socialize and naturally become infected with the coronavirus, while vulnerable people would maintain social distancing and continue to shelter in place. Proponents of this strategy claim so-called “natural herd immunity” will emerge and minimize harm from SARS-CoV-2 while protecting the economy.

Another way to get to herd immunity is through mass vaccinations, as we have done with measles, smallpox and largely with polio.

A population has achieved herd immunity when a large enough percentage of individuals become immune to a disease. When this happens, infected people are no longer able to transmit the disease, and the epidemic will burn out.

As a professor of behavioral and community health sciences, I am acutely aware that mental, social and economic health are important for a person to thrive, and that public health measures such as social distancing have imposed severe restrictions on daily life. But based on all the research and science available, the leadership at the University of Pittsburgh Graduate School of Public Health and I believe this infection-based approach would almost certainly fail.

Dropping social distancing and mask wearing, reopening restaurants and allowing large gatherings will result in overwhelmed hospital systems and skyrocketing mortality. Furthermore, according to recent research, this reckless approach is unlikely to even produce the herd immunity that’s the whole point of such a plan.

Vaccination, in comparison, offers a much safer and likely more effective approach.

When enough of a population is immune to a virus, the immune people protect the vulnerable.
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An uncertain path to herd immunity

Herd immunity is an effective way to limit a deadly epidemic, but it requires a huge number of people to be immune.

The proportion of the population required for herd immunity depends on how infectious a virus is. This is measured by the basic reproduction number, R0, how many people a single contagious person would infect in a susceptible population. For SARS-CoV-2, R0 is between 2 and 3.2. At that level of infectiousness, between 50% and 67% of the population would need to develop immunity through exposure or vaccination to contain the pandemic.

The Great Barrington Declaration suggests the U.S. should aim for this immune threshold through infection rather than vaccination.

To get to 60% immunity in the U.S., about 198 million individuals would need to be infected, survive and develop resistance to the coronavirus. The demand on hospital care from infections would be overwhelming. And according to the WHO estimated infection fatality rate of 0.5%, that would mean nearly a million deaths if the country were to open up fully.

The Great Barrington Declaration hinges on the idea that you can effectively keep healthy, infected people away from those who are at higher risk. According to this plan, if only healthy people are exposed to the virus, then the U.S. could get to herd immunity and avoid mass deaths. This may sound reasonable, but in the real world with this particular virus, such a plan is simply not possible and ignores the risks to vulnerable people, young and old.

You can’t fully isolate high-risk populations

The Great Barrington Declaration calls for “allowing those who are at minimal risk of death to live their lives normally … while protecting those who are at highest risk.” Yet healthy people can get sick, and asymptomatic transmission, inadequate testing and difficulty isolating vulnerable people pose severe challenges to a neat separation based on risk.

First, the plan wrongly assumes that all healthy people can survive a coronavirus infection. Though at-risk groups do worse, young healthy people are also dying and facing long-term issues from the illness.

Grocery stores have been giving older and at-risk shoppers time to shop away from other people, but knowing whether the store employees are infected is not easy.
AP Photo/Sue Ogrocki

Second, not all high-risk people can self-isolate. In some areas, as much as 22% of the population have two or more chronic conditions that put them at higher risk for severe COVID-19. They might live with someone in the low-risk group and they still must shop, work and do the other activities necessary for life. High-risk individuals will come in contact with the low-risk group.

So can you simply guarantee that the low-risk people who interact with the high-risk group are uninfected? People who are infected but not showing symptoms may account for more than 30% of transmission. This asymptomatic spread is hard to detect.

Asymptomatic spread is compounded by shortcomings in the quality of testing. Currently available tests are fairly good, but do not reliably detect the coronavirus during the early phase of infection when viral concentrations can be low.

Accordingly, identifying infection in the low-risk population would be difficult. These people could go on to infect high-risk populations because it is impossible to prevent contact between them.

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Sweden’s herd immunity failure

Without sharp isolation of these two populations, uncontrolled transmission in younger, healthier people risks significant illness and death across vulnerable populations. Both computer models and one real-world experiment back up these fears.

A recent U.K. modeling effort assessed a range of relaxed suppression strategies and showed that none achieved herd immunity while also keeping cases below hospital capacity. This study estimated a fourfold increase in mortality among older people if only older people practice social distancing and the remainder of the population does not.

But epidemiologists don’t have to rely on computer models alone. Sweden tried this approach to infection-based herd immunity. It did not go well. Sweden’s mortality rate is on par with Italy’s and substantially higher than its neighbors. Despite this risky approach, Sweden’s economy still suffered, and on top of that, nowhere near enough Swedes have been infected to get to herd immunity. As of August 2020, only about 7.1% of the country had contracted the virus, with the highest rate of 11.4% in Stockholm. This is far short of the estimated 50%-67% required to achieve herd immunity to the coronavirus.

Vaccines offer a safe pathway to immunity for both the healthy and the vulnerable.
AP Photo/Hans Pennink, File

Exposure versus vaccination

There is one final reason to doubt the efficacy of infection-based herd immunity: Contracting and recovering from the coronavirus might not even give immunity for very long. One CDC report suggests that “people appear to become susceptible to reinfection around 90 days after onset of infection.” The potentially short duration of immunity in some recovered patients would certainly throw a wrench in such a plan. When combined with the fact that the highest estimates for antibody prevalence suggest that less than 10% of the U.S. population has been infected, it would be a long, dangerous and potentially impassable road to infection-based herd immunity.

But there is another way, one that has been done before: mass vaccination. Vaccine-induced herd immunity can end this pandemic the same way it has mostly ended measles, eradicated smallpox and nearly eradicated polio across the globe. Vaccines work.

Until mass SARS-CoV-2 vaccination, social distancing and use of face coverings, with comprehensive case finding, testing, tracing and isolation, are the safest approach. These tried-and-true public health measures will keep viral transmission low enough for people to work and attend school while managing smaller outbreaks as they arise. It isn’t a return to a totally normal life, but these approaches can balance social and economic needs with health. And then, once a vaccine is widely available, the country can move to herd immunity.

Steven Albert, Professor and Chair of Behavioral and Community Health, University of Pittsburgh

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Here’s what you need to know about melioidosis, the deadly infection that can spread after floods

People typically become sick between one and 21 days after being infected.
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Sanjaya Senanayake, Australian National University

The devastating Townsville floods have receded but the clean up is being complicated by the appearance of a serious bacterial infection known as melioidosis. One person has died from melioidosis and nine others have been diagnosed with the disease over the past week.

The bacteria that causes the disease, Burkholderia pseudomallei, is a hardy bug that lives around 30cm deep in clay soil. Events that disturb the soil, such as heavy rains and floods, bring B. pseudomallei to the surface, where it can enter the body through through a small break in the skin (that a person may not even be aware of), or by other means.

Melioidosis may cause an ulcer at that site, and from there, spread to multiple sites in the body via the bloodstream. Alternatively, the bacterium can be inhaled, after which it travels to the lungs, and again may spread via the bloodstream. Less commonly, it’s ingested.

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Melioidosis was first identified in the early 20th century among drug users in Myanmar. These days, cases tend to concentrate in Southeast Asia and the top end of northern Australia.

What are the symptoms?

Melioidosis can cause a variety of symptoms, but often presents as a non-specific flu-like illness with fever, headache, cough, shortness of breath, disorientation, and pain in the stomach, muscles or joints.

People with underlying conditions that impair their immune system – such as diabetes, chronic kidney or lung disease, and alcohol use disorder – are more likely to become sick from the infection.

The majority of healthy people infected by melioidosis won’t have any symptoms, but just because you’re healthy, doesn’t mean you’re immune: around 20% of people who become acutely ill with melioidosis have no identifiable risk factors.

People typically become sick between one and 21 days after being infected. But in a minority of cases, this incubation period can be much longer, with one case occurring after 62 years.

How does it make you sick?

While most people who are sick with melioidosis will have an acute illness, lasting a short time, a small number can have a grumbling infection persisting for months.

One of the most common manifestations of melioidosis is infection of the lungs (pneumonia), which can occur either via infection through the skin, or inhalation of B. pseudomallei.

The challenges in treating this organism, though, arise from its ability to form large pockets of pus (abscesses) in virtually any part of the body. Abscesses can be harder to treat with antibiotics alone and may also require drainage by a surgeon or radiologist.

How is it treated?

Thankfully, a number of antibiotics can kill B. pseudomallei. Those recovering from the infection will need to take antibiotics for at least three months to cure it completely.

If you think you might have melioidosis, seek medical attention immediately. A prompt clinical assessment will determine the level of care you need, and allow antibiotic therapy to be started in a timely manner.

Your blood and any obviously infected body fluids (sputum, pus, and so on) will also be tested for B. pseudomallei or other pathogens that may be causing the illness.

While cleaning up after these floods, make sure you wear gloves and boots to minimise the risk of infection through breaks in the skin. This especially applies to people at highest risk of developing melioidosis, namely those with diabetes, alcohol use disorder, chronic kidney disease, and lung disease.

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Sanjaya Senanayake, Associate Professor of Medicine, Infectious Diseases Physician, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Supreme Court in India Rejects Bail of Orissa Legislator

BJP assemblyman convicted in two murders in 2008 violence says he’s innocent.

NEW DELHI, January 28 (CDN) — India’s Supreme Court on Tuesday (Jan. 25) rejected the bail granted to Hindu nationalist Orissa state legislator Manoj Pradhan following his conviction in the murder of a Christian, Parikhita Nayak.

Pradhan, of the Bharatiya Janata Party (BJP), was convicted on June 29, 2010 of “causing grievous hurt” and “rioting” and sentenced to seven years of prison in the murder of Nayak, of Budedi village, who died on Aug. 27, 2008. In its decision, the Supreme Court ordered the High Court to reconsider its decision to grant him bail.

Pradhan had been granted bail by the High Court on July 6 on grounds having won the April 2009 state assembly election. Contesting the election from jail, he had become a Member of the Legislative Assembly (MLA) representing Kandhamal’s G. Udayagiri constituency. On Sept. 9, 2010 he was convicted in the murder of Bikram Nayak of Budedipada, for which he was sentenced to six years of rigorous imprisonment (see http://www.compassdirect.org, “Court in India Convicts Legislator in Second Murder Case,”
Sept. 10, 2010). He received bail within 40 days of that conviction.

Parikhita Nayak’s widow, Kanaka Rekha Nayak, had challenged the granting of bail before the Supreme Court. She pointed out in her petition that there were seven other murder cases against Pradhan, including the second conviction.

“Being an MLA was not grounds for granting of bail,” she told Compass.

Nayak’s petition also argued that, because of his position, Pradhan intimidated witnesses outside of jail. She told Compass that, after receiving bail in spite of their convictions, Pradhan and an accomplice continued to roam the area, often intimidating her.

In the Supreme Court decision, Justice B. Sudarshan Reddy and Justice S.S. Nijjaron wrote that the High Court should have taken into consideration the findings of the trial court and the alleged involvement of the respondent in more than one case.

“The [bail] order clearly reflects that the High Court was mainly impressed by the fact that the respondent is a sitting MLA,” they wrote. “In the circumstances, we find it difficult to sustain the order.”

Pradhan was accused of stopping Parikhita Nayak and then calling together a large group of persons armed with axes and other weapons, who then hacked Nayak to death; afterward they sought to dispose of the body by burning it.

Pradhan denied all charges against him, telling Compass by telephone that they were “baseless.”

“I have full faith in the judiciary system, and justice will be done,” Pradhan said, adding that he and other “innocent people” have been arrested due to political pressure and that the real culprits are at large.

On his next move, he said he would surrender himself to police custody if necessary and then file another application for bail.

Dr. John Dayal, secretary general of the All India Christian Council, told Compass that he was pleased.

“Pradhan deserves to be behind bars in more than one case, and it was a travesty of justice that he was roaming around terrorizing people,” Dayal said. “He was not involved in every single act of violence, but he was the ring leader. He planned the violence; he led some of the gangs.”

Dibakar Parichha of the Cuttack-Bhubaneswar Catholic Archdiocese told Compass that police records showed that Pradhan was a “field commander of Hindu extremists sent to kill Christians.”

The state government’s standing counsel, Suresh Tripathy, supported this week’s cancellation of bail.

 

Cases against Legislator

Pradhan told Compass that a total of 289 complaints were registered against him in various police stations during the August-September 2008 attacks on Christians in Kandhamal district, Orissa, out of which charge sheets were filed in only 13 cases.

Of the 13, he has been acquitted in seven and convicted in two murder cases, with six more cases pending against him – “Three in Lower Court, two in the High Court and One in the Supreme Court,” Pradhan told Compass.

Of the 13 cases, seven involved murder; of those murder cases, he has been acquitted in three.

Cases have been filed against Pradhan for rioting, rioting with deadly weapons, unlawful assembly, causing disappearance of evidence of offense, murder, wrongfully restraining someone, wrongful confinement, mischief by fire or explosive substance with intent to destroy houses, voluntarily causing grievous hurt and voluntarily causing grievous hurt by dangerous weapons or means.

Pradhan was also accused of setting fire to houses of people belonging to the minority Christian community.

The Times of India reported Pradhan as “one of the close disciples” of Vishwa Hindu Parishad (VHP or World Hindu Council) leader Swami Laxamananda Saraswati, whose assassination on Aug. 23, 2008, touched off the anti-Christian violence in Kandhamal and other parts of Orissa.

 

Status of Trials

Expressing complete dissatisfaction in the trial system, Dayal told Compass that the two Fast Track courts are “meting out injustice at speed.”

“One of the main reasons,” he said, “is lack of police investigation, the inadequacy of the department of projections to find competent public prosecutors, and the inadequacy of the victim community to find a place in the justice process.”

As a result, he said, victims are not appropriately represented and killers are not appropriately prosecuted.

“Therefore, the two courts find enough reason to let people off,” Dayal said.

Complaints filed at a police station in Kandhamal after the violence of 2008 totaled 3,232, and the number of cases registered was 831.

The government of Orissa set up two Fast Track courts to try cases related to the violence that spread to more than a dozen districts of Orissa. The attacks killed more than 100 people and burned 4,640 houses, 252 churches and 13 educational institutions.

The number of violent cases in the Fast Track courts is 231 (non-violent cases numbered 46, with total cases thus reaching 277). Of the violent cases, 128 have resulted in acquittals and 59 in convictions; 44 are pending.

Of the 722 people facing trial, 183 have been convicted, while 639 have been acquitted.

Report from Compass Direct News

Somali militants chase Christians who’ve fled, beat them

After months of evading his pursuers, they finally caught up with him.

Voice of the Martyrs Canada confirms that on August 21, Islamic militants in Addis Ababa, Ethiopia found Mohamed Ali Garas, a prominent Somali church leader and convert from Islam, and beat him severely, reports MNN.

Five years ago, Garas fled his Somali homeland. VOMC’s Greg Musselman says Garas he sought refuge in Ethiopia because "he was involved in church work there as a pastor. Attempts were made on his life. He’s been threatened, he’s been arrested."

On the night he was attacked, he was walking home when he heard two men calling his name. He turned to see what they wanted, and they attacked, fleeing only when a neighbor arrived on the scene. Although the beating was severe, Garas survived.

The attack itself is unsettling, explains Musselman because "they [extremists] are not just leaving it back home; they’re taking it wherever they find these people that have converted to Christ from an Islamic background."

This incident shows that the persecution is not contained within Somalia’s borders. For al Shabaab, they’re ramping up to an all-out war meant to eradicate Christianity.

Shortly before a deadly suicide bombing attack on August 24, an al Shabaab spokesman was quoted as saying: "The operation is meant to eliminate the invading Christians and their apostate government in Somalia. The fighting will continue and, God willing, the mujahideen will prevail."

Somali Christians living in Ethiopia have come under increased attacks from Somali Muslims in recent months. That’s a trend that is likely to continue. Musselman says, "When you understand a little bit of the group like al Shabaab…you’re not surprised that they will go to any length. They’re thinking is that ‘the only kind of a Somali Christian is a dead one.’"

International Christian Concern notes that a Somali pastor in the Ethiopian capital has described this latest attack as "an apparent attempt to scare the Somali Christian community in Addis Ababa who considers Ethiopia a safe haven from religious persecution."

Musselman notes that prayer is a powerful recourse. "Lord, our brothers and sisters in Somalia are such a small group. They’re trying to be faithful. There are other Somalis that have left the country; they’re trying to be faithful, and they continue to suffer attacks, and it’s difficult for them. But we ask You, Lord, to move on the hearts even of the enemies that are persecuting these believers, that they would have the freedom to share the Gospel of Jesus Christ."

Report from the Christian Telegraph