# COVID-19/Connectivity

In epidemiology of communicable diseases the contact between infected and suceptible is key for risk mitigation as long as vaccination and/or widely available drugs are not available.
* Nonpharmaceutical interventions, that reduce the connectivity between people and which work non-virus specific.
* Workflow transformations to perfomr the same
Measure like Efficacy of Lockdown, Washing Hands, distancing and avoiding large crowds are elements of risk mitigation, connectivity in your social community.
   "Fasten seat belt" methods for "COVID-19"
Security in vehicle (cars, aeroplanes, ...) is linked e.g. to fasten seat-belt. When you fasten your seat belts in a car or in an aeroplane, you would not think of a potential risk of an accident or crash. You would take that as a standard method for risk mitigation at any time you use a car even if you are never involved in an accident with cars.
Assume, you go to the bathroom in an aeroplane. You will have a period of time in which you are not protected by the seat belt, but it is just a short period of time. You are protected by belt the rest of the time and you are not affraid in general, when you leave you seat.
So security has also a psychological and a temporal dimension.
* You are not affraid in general, about going to the toilet in the aeroplane and you do not feel unprotected and
* time must be considered during which you are not protected by a seat belt.
Intuitively you maximize in general the use of the seat belt whenever it is possible and you will not go to the toilet, when the turbulences are annouced by the crew.

## Learning Tasks

* (Fasten seat belt) Transfer these "Fasten Seat Belts" to epidemiological measures for reduction of connectivity. Same task "Transport from A to B"
** with seatbelts or
** without seatbelt.
    Seatbelts might not be as convenient for the passenger but it increases the safety. What are possible workflow transformations and safety measure that can serve as epidemiogical seatbelts.
* (Connectivity as a Limited Joint Resource) Connectivity as a limited joint resource of the population. High connectivity between many people can create hotspots with many infections (identify examples in your country). If no vaccination or drugs are available for the population to keep the infections below a certain threshold, reduction of connectivity (e.g. social distancing, e-Learning, Videoconferencing) is another option of response. Assume everyone can meet with 20 others on family events to keep the basic replication number below 1. Now a single person is planning an event with 10000 guests, where people meet for 3 hours (e.g. concert in a stadium). The 10000 guest increase their connectivity by factor 500. A large number of other people (that did not join the concert) could reduce their connectivity e.g. to 5 to compensate the higher connectivity of the visitors of the concert. Create a role play with different stakeholders with an
** epidemiological,
** ethical,
** social,
** economical,
** legal,
** political, ....
    background and try to identify solutions for sharing a limited resoures of connectivity.
* (Responsibility) Identifiy responsibilities for the implementation of risk mitigation strategies and who allows the access to the shared resource of connectivity! Negotiate in groups, to identify the benefits, risks and responsibilities for higher connectivity! How can risk mitigation be implemented as joint effort of society, that appreciates responsibilities. Assume
** (A) plans smaller events with less people (even if (A) could plan larger events) and
** (B) plans a larger events with more people.
    (A) has an economic disadvantage in comparison to (B). Are regulatory framesworks (like "fasten seat belts"), taxes, insurance, financial contributions to health system finance or free decision making adequate approaches to handle responsibilites? What are your suggestions? Discuss that topic from different disciplinary angles! Countries go different ways in handling COVID-19 pandemics. What are your consequences and what are the lessons learnt?
* (Nonpharmaceutical Interventions) COVID-19 is a communicable disease with a transmission from humans to humans. Therefore addressing the connectivity between people (e.g. by behavioural change) is a logical option for risk mitigation as long as vaccination or secure, widely available pharmaceutical interventions are not available. Washing hands, distancing, avoiding large events and increasing risk literacy in the population (e.g. by science communication - "podcast" of an epidemiologist Prof. Dr. Christian Drosten) must be assessed in the consequence on COVID-19 and other communicable diseases. Scientific analysis of the impact of such risk mitigation strategies by nonpharmaceutical interventions is addressed in scientific peer-reviewed papers itself, so that future intervention can be based of that scientific results about COVID-19 related nonpharmaceutical interventions as a combination of multiple risk mitigation strategies. Even if those COVID-19 related nonpharmaceutical interventions were implemented for COVID-19 they are not virus-specific like drugs as nucleoside/nucleotide analogue. Therefore you might also expect a positive impact on other communicable diseases that share the same transmission route as COVID-19.
    Can you find scientfic evidence in peer-reviewed journals for the efficacy of nonpharmaceutical interventions and a positive impact on other communicable diseases (e.g. respiratory diseases, influenca, ...)?

## Contact and Contact Rates

"Contact" between humans includes different meanings: First of all we think about:
* meeting people,
* shake hands and
* hug friends.
But it includes also non direct contact:
* a large group of people leave the room and
* a few minutes later a next group will enter the room (aerosol transmission)
So contact is not only dependent on spatial distance but also on means to connect people even if the people do not recognize that they met. The connectivity between those groups is also dependent on where the groups met inside a room or outside and how they protect themselves. If the are singing or just sitting and if they keep spatial distance of 2m between them.

## Logic of Contact Rate and Infection

The number of people that you meet is one indicator for the risk and one element of risk mitigation. Consider the contact rate as the lanes of the highway. High contact rates between humans does not mean that there is immediately a high number of infections but it provides the routes for the virus to enter a community much quicker. Comparing that with the example of traffic:
* if you have many lanes on the highway, then the cars can commute much quicker in and out of the city,
* if you have a narrow curved road with just one lane, traffic flows slowly and it takes longer until a fixed number of cars will reach the city center.

## Lockdowns and Reduced Connectivity

Lockdowns are means to control the connectivity between the population. Lockdown are very wide fundamental impact on our life and activities we are involved in. The lockdowns aim to reduce the connectivity between the population and therefore should slow down the epidemioligical spread of a disease. Now we regards a lockdown in a black and white scenario
* (no lockdown) no restrictions (0.0) and
* (radical lockdown) everyone is isoloated and has no contact to anyone else (1.0).
The truth is currently a shade of grey. Analyze publication of efficacy of lockdown and discuss the requirements and constraints of the lockdown for the health system.

## Respiratory Diseases

Compare other respiratory communicable diseases in countries before COVID-19 and during COVID-19 lockdown! Do you see a significant impact of those non-COVID-19 respiratory communicable diseases? What are your conclusions for the efficacy of lockdown for COVID-19? What are other methods to compare activities to control connectivity? What are scientifically sound approaches? What are the differences between diseases and what are scientifically sound methods to measure and compare the impact of risk mitigation activities?