by Adam Lee on May 27, 2020

In the race to contain the coronavirus pandemic, scientists are zeroing in on so-called “superspreader” events, where one sick person infects a large number of others. There’s a pattern that’s been seen in other diseases, known as the 20/80 rule – 20% of sick individuals cause 80% of new cases – and some evidence suggests that it may hold for this virus as well.

This is good news for disease-fighters, because it gives us a big, juicy target to aim at. If we can understand what causes these rare events and clamp down on them, we may be able to resume something like normal life with relatively few other precautions.

So what do the known superspreader events have in common? I read an interesting article examining that question in Quillette (which is a right-wing site, but this specific article doesn’t seem to be problematic).

The article reviews the work of Carl Flügge, a German bacteriologist who studied the exact mechanisms by which a disease spreads from one person to another. Based on his work and others’, we know of three major routes of contagion. First, there are ballistic droplets, the large particles of saliva and mucus ejected by a sneeze or a cough. They quickly fall to the ground and become harmless, unless they land on another person, in which case they can spread the pathogen. Second is aerosols: clouds of much tinier particles, small enough to be suspended in the air, which can transmit disease when someone unknowingly inhales them. The third is fomites: transmission from touching contaminated surfaces, like doorknobs.

We still don’t know for sure which of these routes COVID-19 uses. However, the article catalogues 58 superspreader events in 28 countries (painstakingly assembled by epidemiologists and contact tracers) and finds some intriguing similarities among them.

Namely, most known SSEs happen at parties, large festivals like weddings, or business conferences. In nearly all cases, they occur in crowded indoor settings which feature close contact between people, often involving loud talking, shouting or singing. This supports the ballistic-droplet hypothesis as the primary means of spread.

There’s one more point that jumps out from the list: many of the SSEs are religious events.

Of the 54 SSEs on my list for which the underlying activities were identified, no fewer than nine were linked to religious services or missionary work. This includes massive gatherings such as February’s weeklong Christian Open Door prayer meeting in Mulhouse, France, which has been linked to an astounding 2,500 cases; and a massive Tablighi Jamaat Islamic event in Lahore that attracted a quarter-million people. But it also includes much smaller-scale religious activities, such as proselytizing in rural Punjabi villages and a religious meeting in a Calgary home.

…In the case of religious SSEs, Sikhs, Christians, Jews and Muslims are all represented in the database. The virus makes no distinction according to creed, but does seem to prey on physically intimate congregations that feature some combination of mass participation, folk proselytizing and spontaneous, emotionally charged expressions of devotion. In the case of Islam, it is notable that the same movement, Tablighi Jamaat, has been responsible for massive outbreaks at completely separate events… At Mulhouse, the week’s schedule included Christian “choir performances, collective prayer, singing, sermons from preachers, workshops, and testimony from people who said God had cured their illnesses… Many people came day after day, and spent hours there.” And in Punjab, dozens of Sikhs died thanks to the itinerant rural preaching of a single (now deceased) infamous septuagenarian named Baldev Singh…

One example of an early COVID-19 superspreader event was the outbreak at South Korea’s Shincheonji Church of Jesus, which I wrote about previously. In that isolated and fanatical sect, experts now believe, a single person infected at least 43 others, who in turn spread it onward, resulting in over 5,000 total cases.

Another major outbreak occurred in Iran at the holy site of Qom:

The outbreak appears to have started in Qom, the conservative city of Shiite seminaries run by leading ayatollahs, about two hours from Tehran. It is also home to the Fatima Masumeh shrine โ€” famed for its giant gold dome and intricate blue tilework โ€” which draws pilgrims from all over the world.

…Instead of closing down public sites, a measure that public-health experts have taken in other countries, the head of the shrine in Qom called on pilgrims to keep coming. “We consider this holy shrine to be a place of healing. That means people should come here to heal from spiritual and physical diseases,” Mohammad Saeedi, who is also the representative of Iran’s Supreme Leader in Qom, said in a video. Cases traced back to Iran have been reported in Azerbaijan, Afghanistan, Bahrain, Canada, Georgia, Iraq, Kuwait, Lebanon, Oman, Pakistan, and the United Arab Emirates.

There’s also this church in Canada, especially notable because its members were taking what they thought were adequate precautions:

“I had the opportunity recently to talk to a faith leader whose faith community gathered together in mid-March before many of our public health measures were in place,โ€ Dr Deena Hinshaw said Thursday. “The congregation had a worship service and then gathered together for a celebratory social event. There were only 41 people present, and they were careful to observe two meter distancing and good hand hygiene. They followed all the rules and did nothing wrong.”

Despite that, 24 of the 41 people at the party ended up infected. Two of them died.

In the U.S., there was a CDC report about an outbreak at a church in Arkansas, where 35 of 92 attendees fell sick, with three deaths. This article on Raw Story lists other clusters of cases that have been linked to churches.

To be clear, this isn’t because religion is intrinsically more likely to spread the virus than any other human activity. However, the conditions of many religious services – usually with singing, sometimes with loud preaching or hollering, often with elderly people packed together in crowded buildings – create a near-ideal environment for transmission. This is even more true in the case of fundamentalist churches which believe that God will miraculously heal them or protect them from getting sick. And if they’re proselytizing denominations that send their members far and wide to preach, that’s worst of all.

Unfortunately, the association between COVID-19 and churches is bad news for those of us who want to stop the spread: because religious believers also seem especially likely to dig their heels in and argue that they have a right to gather as they see fit, public-health rules be damned. In a rational world, religious gatherings would be shut down longer than most other kinds of events, but that seems unlikely to happen.

A case in point:

Roman Catholic and Lutheran Church-Missouri Synod congregations across Minnesota plan to resume worship services in defiance of the state’s ban on gatherings of more than 10 people, their leaders said Thursday, the strongest direct challenge to Gov. Tim Walz’s restrictions to slow the spread of the COVID-19 pandemic.

In New York, even Andrew Cuomo originally planned to resume in-person meetings for religious groups – and no one else – as the first stage of lifting lockdowns. This was a blatantly unconstitutional plan that the ACLU quickly shut down, but even so, it shows how politicians’ first instinct is to defer to what churches want. In purple and red states, it’s likely to be even more egregious, and the death toll will be higher for it.

Image credit: Felipe Esquivel Reed via Wikimedia Commons; released under CC BY-SA 4.0 license