What Is A Super Spreader?

A superspreader is an infected person who transmits an illness to an above-average number of people. Find out today how this happens and what consequences this has in a pandemic. 

The global corona crisis is still shaping our lives and forcing us to understand new terms that can be heard in the media almost every day. PCR tests, R0 number, forecasts and statistics on the current pandemic are important to understand the gravity of the situation and to recognize the progress. Today we’re going to explain another much-cited term: what is a superspreader?

What does this word mean and what role does a super spreader play? If you know more about it, you can also better understand the spread of the new coronavirus SARS-CoV-2. Read on, we will explain interesting aspects to you about this topic.

What is a super spreader?

A super spreader is a person infected with an illness who infects an above-average number of people with the causative virus. An example:

• According to information from the World Health Organization (WHO), the R0 value (base reproduction number) of the SARS-CoV-2 fluctuates between 1.4 and 2.5. This means that each infected patient, on average, infects more than one other, but fewer than three people.
• The SARS virus had an approximate R0 value of 3. During the outbreak of this disease, superspreaders could be observed which infected up to 36 people. This means that the individual reproduction number was approximately 10 times higher than the average values.
• At the beginning of the COVID-19 pandemic  , superspreaders were also detected in Wuhan (China). A clear example is a nurse who transmitted the illness to at least 16 other employees.
• Superspreaders have also been identified in other parts of the world. For example, a judge in New York infected at least 20 people.

The R0 value represents only an average, but the individual reproduction number can vary from it. This is the case with a super-disseminator, for example. We then take a closer look at the role of the superspreader in a pandemic.

A game of statistics

Mathematical theorems are used to calculate the spread of pandemics. The Pareto principle refers to those statistical phenomena that lead, for example, to a small proportion of the population having an impact on the majority of the population.

We say that 20 percent of infected people are responsible for 80 percent of infections. Of course, this rule does not apply to all super spreaders, but this proportion has also been observed in other epidemics.

Even if rule 20/80 is not fully complied with, one can speak of super-broadeners. But how does an infected person become a super spreader?

Superspreader: Risk Factors

There are various theories that try to explain how a person becomes a super-disseminator and infects an above-average number of people around them. However, the exact causes are not yet known.

• Co-infection with other pathogens:  The coexistence of several pathogens in our organism can be responsible for a higher transferability of one pathogen (or two pathogens) to other people. Studies in HIV patients who also had another disease found that these people developed the additional disease more quickly than those who were not co-infected.

• Weak immune system: A weak immune system is unable to efficiently stop the virus from spreading in the body. Therefore the viral load increases. An above-average viral load in turn leads to a higher transmission capacity.
• Efficient Immune System:  Another option is an exceptionally efficient immune system. Because in this case it can happen that the infected person is not aware of their illness and therefore infects many other people.

A study published in the journal Synapse provides interesting results related to this topic: During the SARS pandemic, superspreaders and normal patients were observed. No differences in clinical symptomatology could be found between the two groups.

Both super-spreaders and normal patients  had similar symptoms for fever and lung damage. The scientists could only tell one difference: the super-disseminators had to spend long periods of time in the hospital to overcome the disease.

Superspreader: a term full of puzzles

Both the identification and the role of super-disseminators are difficult to distinguish during a pandemic. Experts nevertheless emphasize the importance of recognizing super spreaders in order to prevent infection.