Many governments, the UK included, focus their policy on physical distancing - which is the most obvious eye catching thing that filled the news about Wuhan. Contact tracing often gets far less attention - yet it is the absolute key to stopping this virus. It is also relatively easy to do. It doesn't need health workers. Other countries are using civil servants, community organizations and volunteers.

Contact tracing is the key to winning. Physical distancing is buying time, like defensive tactics in a game of football. Having bought time in this way we can go into the attack, crush this virus and eliminate it from our country.

This is an article in the British Medical Journal calling on the government to resume contact tracing

On 22 March—when there were 5683 confirmed UK cases—Michael Ryan, executive director of the WHO health emergencies programme, repeated the message on the BBC: “What we really need to focus on is finding those who are sick, those who have the virus, and isolate them, find their contacts and isolate them.”

This is entirely unexceptional. Case finding, contact tracing and testing, and strict quarantine are the classic tools in public health to control infectious diseases. WHO says they have been painstakingly adopted in China, with a high percentage of identified close contacts completing medical observation. In Singapore, Vietnam, and South Korea meticulous contact tracing combined with clinical observation plus testing were vital in containing the disease. This combined with strong measures to enforce isolation for travellers returning from high incidence areas obviated the need for a national lockdown and closure of all schools in Taiwan and Singapore.

The mathematical model used by the UK government clearly shows that rigorous contact tracing and case finding is effective: the prediction of 250 000 deaths was predicated on what would happen without contact tracing.

The reasons why tracing was stopped, against WHO recommendations, have not been published. It seems to be connected to a shift from “contain” to “delay” in the government’s action plan, when contact tracing was replaced rather than supplemented with other control measures.

Covid-19: why is the UK government ignoring WHO’s advice?

Some of this contact tracing is easy to do. First you need to find the contacts in the same household.

From experience in China, 75 - 85% of the infection is in households. Yet, even in households, most do not get it. Only 1 in 10 will be infected by an index case in a household, far less than for flu. Those may go on to infect others in the household over a period of time so the longer a household is kept in close proximity, the more cases you get.

So the top priority is to isolate a new case from their own household in order to stop infection within the household. The WHO recommend isolating all the confirmed mild cases in separate wards, for instance repurposed stadiums, or community homes as the Chinese did. If that's not possible, they can isolate at home, with great care to make sure they are well isolated from other members of the household. Tthey recommend that this is done under supervision of a clinician who inspects the house.

Detailed advice here: Home care for patients with COVID-19 presenting with mild symptoms and management of their contacts

After that, most of the remaining infection is through close or prolonged contact in other locations, for instance at work or visiting other families or friends. That includes close proximity in a cruise ship for a long period of time, a hospital or clinic, an overcrowded prison, or care home.

It is not easy to get infected by COVID-19, compared with the flu. However, it makes up for that by being infectious for a very long time. It is infectious from several days BEFORE symptoms start through to up to two weeks AFTER symptoms disappear.

So - after isolating the patient from their household as top priority, the next priority to do is to find people they were in close or prolonged contact with, for the previous several days.

The virus that causes COVID-19 is only transmitted through the larger droplets of coughs, sneezes and talking or singing - NOT though the aerosol of fine droplets when you breathe. So far the WHO have found no reported confirmed cases of airborne transmission (you get occasional studies that claim to establish this but then are withdrawn). With SARS there were multiple clear cases of airborne transmission early on.

This is why contact tracing is so effective for COVID-19. The contacts you can identify relatively quickly by talking to the patient are the ones that are most important to isolate.

Almost anyone can do this. With millions under lock down, this is an ideal time to recruit a workforce of a milllion volunteers to trace contacts.

Also during lock down the number of contacts is greatly reduced, from maybe 10 or 20 to maybe 5 or 10. Because it is not airborne, you don't have to trace everyone who was shopping for food at the same time as the case, say, or who they walked past in the street without interacting with them - infection this way is very rare. This all makes contact tracing so much easier, if the countries would but just do it.

This graphic shows how contact tracing works and helps to explain why it is so effective.

The Director General of the WHO explained that we have to work as a team. We need solidarity for this winning strategy - no country can fight this virus alone. The Director General told the G20 countries that we have to:

  1. Fight to stop the virus with every resource we have at our disposal
  2. Unite to confront the virus. No country can fight this virus alone. We can only fight it together.
  3. Ignite the industrial might and innovation of the G20 to make the tools we need to save lives and distribute those tools to the people who need them.

With the current strategy in the UK, using physical distancing alone, the spread of this virus only stops as a result of half or more already being infected. It might not stop even then as there is no guarantee yet that the antibodies of someone with COVID-19 actually do protect them against reinfection by the same virus.

With contact tracing then countries typically stop it at a few tenths of a percent of the country infected.

This is another article I'm writing to support people we help in the Facebook Doomsday Debunked group, that find us because they get scared, sometimes to the point of feeling suicidal about it, by such stories.

Please share this widely and especially, let's try to get the attention of decision makers in the UK, also journalists and any experts who may have the ear of politicians.



The WHO publish a series of technical documents to guide governments. See Country & Technical Guidance - Coronavirus disease (COVID-19).

The WHO currently recommends quarantining all contacts, whether or not they show symptoms, to catch them in the presymptomatic stages. If they develop symptoms they are then tested and if needs be, isolated as new cases and the process starts again

Any contacts need to be put in 14 days quarantine from the last time they were exposed to the patient.

They count as exposed if they did any of these, from 2 days before and up to 14 days after the onset of symptoms in the patient:


You can totally crush COVID19. China, South Korea have shown how. Spain and Italy are doing it now too. The WHO say this with every press briefing but the media almost never report this. To do this you test, isolate and care for cases, trace contacts and quarantine the contacts.

You don’t have to find everyone.

If you stop 75% of the transmissions you change a transmission that goes

100 cases → 200 cases → 400 cases

to one that goes

100 cases → 50 cases → 25 cases

and it soon stops.

Even if you have a million cases, you can achieve a ten fold reduction per fortnight with rigorous contact tracing. It can go down as fast as it went up.


With all the lock downs, we have a precious second window to find the confirmed cases and isolate them and quarantine all their contacts.

As Maria van Kerkhove put it, in the WHO press conference on 30th March:

Maria van Kerkhove: In some senses transmission has been taken off the streets and pushed back into family units. Now we need to go and look in families to find those people who may be sick and remove them and isolate them in a safe and dignified manner so that's what I was saying previously; the transition from movement restrictions and shut-downs and stay-at-home orders can only be made if we have in place the means to be able to detect suspect cases, isolate confirmed cases, track contacts and follow up on the contacts' health at all times and then isolate any of those people who become sick themselves.

COVID-19-virtual press conference -30 March 2020

That is possible. If we do that then the cases per day will go down rapidly. This is a golden opportunity to do this. We have far fewer contacts during a lock down which makes contact tracing easier.

The isolation has to be for long enough - and isolated from others in the same household, not isolated together with others who don't have it yet.

You can isolate a confirmed case in a household but very much as a last resort. If you do, the WHO advise that both carer and patient should wear masks and they should be advised by a clinician who inspects the premises to check they are suitable and advise them how to do it.

The Director General said this in his famous “test test test” speech, where the UK only reported the need to do lots of tests and left out the part about needing to isolate the confirmed cases

Director General: We have a simple message for all countries: test, test, test.

Test every suspected case. [point 2]

Caring for infected people at home may put others in the same household at risk, so it’s critical that care-givers follow WHO’s guidance on how to provide care as safely as possible.

For example, both the patient and their care-giver should wear a medical mask when they are together in the same room. [point 3]

People infected with COVID-19 can still infect others after they stop feeling sick, so these measures should continue for at least two weeks after symptoms disappear. [point 4]

Visitors should not be allowed until the end of this period.
WHO Director-General's opening remarks at the media briefing on COVID-19 - 16 March 2020

Detailed advice here: Home care for patients with COVID-19 presenting with mild symptoms and management of their contacts


The UK is not doing this. We have to do the whole package not just the lock down and the testing, if we want to succeed in the way other countries have done. Not only China and South Korea - other countries too are succeeding with these measures.

The Chinese isolated most of the mild cases in community centers and gymnasiums, stadiums etc set up to accommodate vast numbers of mild cases to isolate them from society and from their own households and families.

Do this and our numbers will start falling as has been shown in multiple countries now.

It is possible that we get the start of a second wave. This is just a hypothesis and so far there hasn’t been any sign of a second wave in any of the countries that have succeeded in controlling COVID-19. It can happen with some diseases but they don’t know yet if COVID-19 is such a disease.

If we do get a second wave - then we just do the same again but we catch it much faster at an earlier stage.

When we turn the peak and the cases per day start going down the message is to keep up our efforts and push it all the way down to zero. Then keep alert and keep it at zero if it resurges.

This is not possible with flu but COVID-19 is a very unusual respiratory disease, different also from SARS which was airborne, and COVID-19 can be stopped in this way.

From that same press conference:

Mike Ryan: The question is how do you go down and going down isn't just about a lock down and let go. To get down from the numbers, not just stabilize, requires a redoubling of public health efforts to push down. It won't go down by itself. It will bepushed down and that's what we need countries to focus on. What is the strategy now to put in place, the public health measures that will push down the virus after those measures may be released and then how do we take care of people better in a clinical environment to save more lives

Maria van Kerkhove: These physical distancing measures, these stay-at-home measures have bought us a little bit of time, a little window of time and that short window has to be used appropriately so that we get systems in place to look for this virus aggressively through testing, through isolation, through finding contacts, through quarantining those contacts, through caring for further patients because we will still see patients and many patients are going to still require need, to support other countries that are going to go through thus.

So, focusing on what we do now is absolutely critical to make sure we use that time wisely, we use that time effectively so that once we do reach that peak we continue to push and suppress that virus down as quickly as possible but still be ready to find additional cases should they show up. What we've seen in a number of countries in Asia where they brought this virus down, they brought this transmission down; they're now seeing repeat introductions from outside of their countries. They have not let their guard down, they're still aggressively looking for those cases as they come in and suppressing them so that it doesn't start again.

So we need to focus on the now, we need to use our time wisely and that is to aggressively find this virus and care for our patients

COVID-19-virtual press conference -30 March 2020

The video of that press conference is here.

The WHO have been saying this with every press briefing for weeks now.

This is so important and yet so many countries do not seem to understand its importance.

See my


The UK policy is based on a simulated flu disease that has not been updated to match most of the real world data for COVID-19. In their list of assumptions for this model they assume

  • A third of the transmission is to random strangers in the community at a physical distance of up to 2 meters
  • A third is through schools or workplaces
  • Only a third is in households
  • Nearly everyone in the household gets the disease if one of them gets it
  • Patients are infectious from 12 hours before through to 7 days after infection.

They also assume that a third of all the spreading in all those situations is through asymptomatic spreaders who infect others without knowing they have the disease. For COVID-19 a few percent are pre-symptomatic spreaders. There are almost no truly asymptomatic spreaders - though there are asymptomatic infected people they tend to only be infectees and not infectors. For instance most school children have little by way of symptoms, especially the younger ones, and they don't seem to infect adults. This is not well understood.

All these assumptions make it impossible to model the contact tracing for COVID-19 in the models, since most of the people who are infected could not be tracked short of some app that detects everyone who was within 2 meters of you. They have not yet attempted to model this AFAIK. So the decision to drop contact tracing in the UK was done without any attempt to model what its effect is.

Though Singapore did develop a blue-tooth app to detect people you were close to, you do not need this for the basic contact tracing. The UK did this tracing before it moved to the delay stage without any app. It can easily do it again with lots of volunteers just asking people who they have had close or prolonged contact with.

I summarize some of the main differences between the Imperial college study and the real world data as used by the WHO in this graphic:

For details with quotes see The Imperial college London study and Recommendations based on this fictional flu hypothesis in my previous article COVID-19 Does Not Transmit Like Simulated Flu- UK's Policy Fact Checked Against WHO Recommendations And Scientific Evidence

The UK policy is also based on the idea that if you get antibodies to COVID-19 that this protects you from reinfection. Although this is true for influenza, this is not established for COVID-19.

Dengue is an example of a disease where the first infection is mild but the second infection by the same identical virus (no mutation) can trigger a response where low levels of antibodies actually make the disease far more severe and even life threatening. One theory is that the antibodies, unable to overcome the virus, actually usher it towards cells rather than protect them.

SARS also had a similar perverse immune response. In early trials of vaccines, the antibodies triggered by a vaccine could actually make the disease more severe than if the patients weren't vaccinated. The key to a successful vaccine for SARS was to be sure to trigger the right antibodies that didn't have this effect. With this background, and given the similarity of the viruses that cause COVID-19 and SARS, then caution is needed about any statements about long term effects of antibodies to the virus that causes COVID-19.

The experts say that so far we don't know if antibodies to COVID-19 protect you against reinfection, or for how long, and that it's not impossible that a second infection by the virus could lead to a more serious disease.

It is natural for modelers to have great confidence in their models. In normal scientific dialog then these models are compared with the results of other modeling teams and tested against the real world data. Over several months or years, as it becomes clear that the data does not match the model, the models are changed.

This was a question about another mathematical model that Dr Mike Ryan of the WHO answered:

Jamie (Associated Press):: "Dr Mark Lipsitch, an epidemiologist at Harvard, was quoted in The New Yorker yesterday saying that as many as 40 to 70percentof the world’s five billion adults could at some point contract coronavirus. I guess I just wanted to know, is it really that dire, in your perspective? ..."

Dr Mike Ryan (WHO):: ".... We will listen to all good science. Having said that, there are obvious real things happening in the real world that contradict that. If we look at China, today, 20 provinces in China have today downgraded their public health emergency risk level. That’s 20 of 31 have actually gone in the reverse.

They’ve gone from red to yellow, or from yellow to green. Now that’s flying in the face of that prediction.

I’m not saying which one is correct. What I’m telling you, in the real world today, China is moving back towards the green. 11 provinces in China today moved to green, which is their lowest level of risk.

They’ve five levels of risk. On the 29th January, all provinces in China were at level one risk, the highest possible risk. Red, red, the whole of China was red.

So there’s hope in that. In the last 24 hours, only four cases of confirmed COVID-19 infection outside Hubei, were actually from China. Most cases outside Hubei, in China yesterday, came from other countries.

So when I look at that, which is happening in the real world, and then I look at predictions, I need to look, and we need to look at both of those.We need to see what’s happening in Singapore. And the DG has said in his speech, this is not a drill. We need to fight. We need to fight now. Because our predictions will come true if we do nothing. So we have choices today. Some countries are stepping forward and turning to face the fire. And we need all countries to do that right now.

WHO press briefing, 5th March 2020

When you have models say one thing and the real world says another thing - then you need to look at both.

The problem here is not the model or the modelers. If their model needs to be updated, then eventualy they will do so. But we don't have time for that.

The problem is rather the way that one group of theoretical modelers have been connected directly to a governments national health policy with no moderating interaction with the experimentalists.

Not only that, they have not been required to explain their actions and the difference between their policy and the WHO's recommendations. In the urgency of the moment, these academic abstract modelers are guiding our national health policy directly and their reasons for their decisions are not published, and have no independent scrutiny.

To me they remind me of theorists who work on supersymmetry. Their attention is all on the details of the modeling. The premises of the model, and the experimental data are of much lesser concern to such theorists. They rely on experimentalists to respond to their papers, over a long period of time, to tell them they are wrong. But we don't have the time for this here.


Meanwhile you can do a lot to protect yourself with simple effective measures. If you are in the UK and aren’t doing these yet, I recommend starting on them right away. Our government hasn't explained this clearly enough - at least most that I talk to via private messaging in the UK who contact me scared of COVID-19 do not fully understand the importance of this when they first contact me. They think that they are bound to get COVID-19 eventually and all they can do with physical distancing is to help delay the infection to a time when the health service is under less pressure.

This is NOT TRUE. This virus is transmitted via large droplets that people expel when they cough, sneeze or talk. They fall to the ground in seconds. You can only be infected if these droplets land in your eyes, nose or mouth, or if you touch a surface they fell on and then touch your eyes nose or mouth. It is not a contact virus and can only get into your body that way.

See WHO tweet here

For techy details: Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations

See my The coronavirus COVID-19 is NOT AIRBORNE

Follow the advice on distancing and washing your hands thoroughly before touching your eyes, nose and mouth, and this virus can’t get into your body.

It is a bit like people not bothering to wear seat belts in cars before "Clunk click Every Trip".

Do you do these four things?

  1. Wash hands thoroughly
  2. Stay 1-2 meters from anyone coughing.
  3. Wash your hands before you touch your eyes, nose or mouth [try to get out of the habit of touching your face in the day]
  4. Cough or sneeze into your elbow OR cough or sneeze into a tissue and put it into a bin immediately. [this is to protect others]

Do this as thoroughly as the experts, and you can say:

"I don't have COVID-19 - I am very low risk".

Dr Bruce Aylward said that immediately after he returned from Wuhan. He knew he was safe because he did those things.

He did also wear a mask, because that was Chinese policy - but that was to protect others. It doesn't protect you, for instance droplets can still enter through your eyes if you are too close to someone with the virus. He didn’t speak directly to patients or contacts - but anyone he met there could have had COVID-19 and he protected himself with these measures of careful physical distancing and hygiene.

The WHO stress that these simple measures save lives. They are not hard to do if you make them into a habit. More details here:

We all need to carefully follow the instructions to protect ourselves and your loved ones and tell everyone else about what they need to do to stay safe. These instructions work. You also help others too, every time you do this you are also helping to break the transmission chain to others.



See also my


I hope that by writing this article I have helped to communicate findings of the experts on COVID-19 and help spread awareness of why it is that the WHO say this can be controlled, and the basics of contact tracing, which is the key to the process according to them.

Do share with others you know including experts and politicians. This needs to be discussed widely and openly in the larger scientific community and in our political establishments.

Also please say if you spot any mistakes in this article however minor and I will fix them. Especially if anyone reading this is an expert on any of this and notices anything I got wrong here, or have anything to add or correct please contact me, or say in comments.

Everyone, do share your thoughts on this. Thanks!