OBWOGO: Shhh! If You Want to Reopen Safely, Follow the 4C’s and Stop the Superspreading (Part 8— Think-Like-A-Virus)

I’ve learned from scientists that although human beings claim to be shrewder than all living creatures, they can only remember four things at once, and today, I want to talk about a strategy called the Four C’s— closed spaces, crowds, close contacts and making realistic choices— that some countries are using to stop me from passing on my genes.

Rest assured, I’ll continue defying your predictions until you concede your ignorance.

You see, a lot of the discussion around my spread has concentrated on the average number of new infections caused by each patient. Without preventive measures like social distancing, this basic reproduction number (R0) is about three. However, in reality, some people infect many others and others don’t spread the disease at all.

I don’t need to remind you about that megachurch in South Korea, meatpacking plants in the United States, a wedding in Jordan, or funerals around the world.

In fact, experts agree that most people do not transmit at all and that is why besides R0, some scientists use a value called the dispersion factor (k), which describes how much a disease "clusters". The lower k is, the more transmission comes from a small number of people. I’ll get to this concept in a while.

Okay, to curb an epidemic, R0 (R-naught), the average number of people to whom an infected person passes on a new virus when no measures to contain it, must first drop below one.

But then, you know that most of the people that I infect are penny-pinching stakers with minimal value to my evolutionary ambitions. So, where do the outbreaks that you read about come from?

Shhh! Your secret for mine? It’s suspected that these come from a small number of unstinting humans known as superspreaders and this is why, besides R0, epidemiologists also look at a virus’s dispersion factor, known as “k,” which takes superspreading into consideration.

In other words, the fewer the number of cases of infection responsible for all transmissions, the lower k generally is (this doesn’t render the R0 irrelevant).

Look, evidence is mounting that superspreading is a highly significant factor in the total transmission and scientists estimate that 10 per cent of the people that I infect are responsible for 80 per cent of total transmissions.

Is there any evidence for this? The answer is yes.

Studies have looked at the timeline for when I began to spread my genes in the West and concluded that confirmed coronavirus infections in Europe and the United States, discovered in January, did not ignite the epidemics that followed. Instead, the pandemic was seeded weeks later by a different set of infections implying that most of the people that I infect do not spread and that outbreaks stem from a small number of superspreaders.

Other reports indicate that most chains of infection die out by themselves and that I (SARS-CoV-2) need to be introduced undetected into a new country at least four times to have an even chance of establishing my genes. If you like it, it’s akin to a big fire that sends embers flying around although most of the sparks simply fizzle out.

Oops! That means you can’t compare me to other pathogens that infect humans.

There are valid reasons why our family of coronaviruses prefer “clustering”— attacking groups of tightly connected people while sparing others. One reason is that besides transmitting through droplets, we also spread our genes through fine aerosols that can stay suspended in the air, enabling one person to infect many.

There are other reasons for clustering.

Some people shed more virus and for a longer period of time, than others. A 2019 study of healthy people showed that some people breathe out many more particles than others when they talk. Singing may release more virus than speaking, which could explain the choir outbreaks. Having many social contacts or not washing your hands makes you more likely to pass on the virus.

For now, I need to explain why understanding superspreading is central to controlling my spread.

First, anti-superspreading strategy is premised on predicting where clusters are likely to occur and deploying the 4Cs— making realistic choices to avoid close contact, crowds, confined spaces. 

It goes without saying that a highly contagious person is more likely to spread the infection in a crowd (wedding, a bar, public transport, restaurant, classroom, church, sporting event) than in a small group (within a household), or when contact is extensive or repeated.  

One study in Japan found that the risk of infection indoors was almost 19 times higher than outdoors. Japan built its COVID-19 strategy explicitly around avoiding clusters, advising citizens to avoid closed spaces and crowded conditions.

Another study reported in the New York Times tracing a Covid-19 outbreak in China to a service at a Buddhist temple in Ningbo, in Zhejiang Province, in January best illustrates the effectiveness of the 4C’s strategy.

“Some 300 people were at the service, which lasted two and a half hours and included lunch. It was held outdoors, and most of the worshipers (90 per cent) were not infected. And of the 30 people who were infected (10 per cent), most had traveled on the bus to the temple and back with the first person who became ill, about an hour’s drive each way. On that bus, no one sitting by an open window got sick, with the sole exception of an individual who sat directly next to the infected woman”.

Second, in order to identify the people who could become superspreaders, rigorous testing, contact tracing and isolation of suspects is needed.

By June 2, Hong Kong with a population of about 7.5 million had 1,088 confirmed or probable cases (and four deaths). How did it manage to suppress local outbreaks without a lockdown or mandatory blanket stay-at-home orders? By testing suspects, tracing and quarantining their contacts and isolating confirmed cases in hospital. In addition to outright bans or other restrictions on large social gatherings.

It’s becoming clear that my epidemic spread can be controlled with tactics far less disruptive, socially and economically, than the extended lockdowns or other extreme forms of social distancing that governments enjoy.

However, since I need a human host to spread my genes to the next generation, I’d rather err on the side of these words uttered by a famous French military leader, Napoleon Bonaparte, “Never interrupt your enemy when he is making a mistake”.

Obwogo is a medical doctor, specialist in public health medicine, author and founder of Kienyeji Kenya Farmers’ Network Initiative (KiFaNi).

Email [email protected]

Website WWW.KienyejiKenya.Org