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expert reaction to new quarantine measures for travellers from Spain and whether there is second wave of COVID-19 occurring there

There have been reports of new quarantine measures for travellers returning to the UK from Spain, and also as to whether Spain is entering a second wave of COVID-19 infections. 


Prof Jose Vazquez-Boland, Chair of Infectious Diseases, Edinburgh Medical School (Biomedical Sciences), University of Edinburgh, said:

“Restriction to people’s movements, and specifically on travel to high-incidence areas, is a priori a sensible measure. But such decisions must be carefully balanced and based on solid factual evidence given their very significant implications.

“Spain has been singled out due to the recent increase in reported cases —8,207 in the last week vs 5,292 the previous one— without taking into account that these are mostly due to localised spikes in the North-eastern part of the country (particularly Catalonia) and mainly involve positive PCRs of asymptomatic people.

“However, as yet the number of covid-19 deaths has not dramatically increased in Spain, with 10 reported in each of the last two weeks and a total of 228 since May 10th.

“In comparison, covid-19 deaths for England and Wales in the two last weeks from which data are available have been 532 and 366 for a total of 3,869 and 3,693 cases (positive tests), respectively. On Sunday 26th alone reports indicate there have been 14 deaths and 747 confirmed cases in the UK.

“The strikingly different ratios of covid-19 confirmed cases vs deaths between Spain and the UK call for a more careful consideration of the epidemiological data. For a meaningful analysis, the incidence data must be normalized by the number of tests performed.

“The quarantine imposed on Spain, with an important impact for UK holidaymakers and the holiday travel industry, may be the ironic consequence of Spain’s ramped up efforts in covid-19 testing and carrier tracing.”


Prof Paul Hunter, Professor in Medicine, University of East Anglia (UEA), said:

“The re-imposition of quarantine for visitors returning from Spain was almost inevitable. From a low of only 280 cases per day (averaged over 7 days) in early June, the number of cases reported from Spain has increased, gradually at first but much more rapidly over the last two weeks to 1,738 on 21st July. This is equivalent to 37 new cases per 1 million population each day. By contrast the UK is reporting only about 10 per 1 million population each day.

“We are indeed entering uncertain times at present with reported case numbers increasing in several European countries, including in the UK. Whether these resurgences are called second waves or spikes or continuation of the first waves is just semantics with little relevance to the control of the pandemic. A spike would tend to be a duration short peak as would be seen after a superspreading event.

“Against this background we cannot exclude having to re-impose quarantine on people returning from other counties or them imposing quarantine requirements on people coming from the UK. As we have seen this week-end, there is unlikely to be much notice of the intention to impose quarantine requirements when they do happen.  For an infection that can potentially double the number of cases every few days delays can lead to substantially larger outbreaks. Governments have to react as soon as the data show an increase is real and looks like being sustained.”


Prof Rowland Kao, Professor of Veterinary Epidemiology and Data Science, University of Edinburgh, said:

“The early period of COVID-19 spread at the beginning of 2020 shows just how rapidly cases of infection can spread in the absence of strict controls and thus it is sensible to consider risks of infection beyond the immediate area where the known cases are high. Spain currently has over 2x as many cases per capita compared to the UK – while it can be difficult to compare numbers directly without a detailed look at testing and the ability to detect infection, it does suggest that travel from Spain carry risk above that from domestic cases, especially when COVID-19 cases in Spain are currently rising. The evaluation of areas of risk should be associated with what is known about patterns of travel across the regions to which any quarantine would apply. In the absence of sufficient information to make an informed decision, it is sensible to make those restrictions cautious (i.e. broader, rather than narrower). The is made more important by the evidence that the test and trace system has not achieved high coverage of contacts in many areas of England, which would suggest that multiple introductions would have the capacity to substantially increase the burden on the systems we have in place.”


Prof Keith Neal, Emeritus Professor in the Epidemiology of Infectious Diseases, University of Nottingham, said:

The move to isolate people returning from countries with high rates of COVID-19 is sensible.  These decisions need to be taken rapidly as situations develop.  The inclusion of the Spanish Islands where infections are low may well not be warranted.  Cases appear to be spreading in bars and night clubs, likely venues for many tourists.  Beaches have also been closed but the degree of risk on a beach with social distancing is difficult to determine.   

“COVID-19 was probably largely introduced into the UK by travellers returning from North Italy and Spain in mid-February.  As many infections may be asymptomatic or only mildly symptomatic, along with 1 in 4 cases refusing to answer the contact tracing service, relying on case identification and tracing will not be enough to stop further significant numbers of transmission chains in the UK arising from returning holiday makers. Returning travellers need to get tested if they show any COVID symptoms such as fever and cough.

“There are more holiday makers in the summer and COVID-19 rates are higher than mid-February.

“Some people have criticised the lack of notice but with cases rising any delay would only increase cases in the UK.  In a few weeks time Spain may have controlled their local outbreaks so waiting for two weeks could have resulted in quarantining travellers when no longer required and not quarantining those most at risk of having acquired infections.”


Prof Stephen Evans, Professor of Pharmacoepidemiology, London School of Hygiene & Tropical Medicine (LSHTM), said:

“As far as I know there are no agreed definitions about “second waves” or “spikes”, and if there were I suspect it would not be easy to distinguish them until several weeks have elapsed. Much of the thinking about second waves is derived from previous influenza epidemics and pandemics, and the patterns may not be the same for Covid-19- SARS Cov-2 is a very different virus to the different influenza viruses.

“If the rate of incidence of a disease caused by a virus (in very general terms not necessarily specific to SARAs Cov 2) is changing, it seems fundamentally dependent on three things:

“1. The virus itself, which can mutate and change its ability to be spread, and having infected someone, to cause disease.

“2. The amount of the virus in the community- as it changes so the rate of infection will change

“3. The characteristics of the population are changing.

“As far as we know, although there have been many thousands of genetic mutations of SARS Cov-2, we do not know if these have led to changes in its ability to spread or in its ability to cause severe or mild disease, but it is possible that has happened.

“The virus is still present in many places around the world and even those places where they think it has been eradicated can either be mistaken or have the virus re-introduced, but in many places there is less than there was two or three months ago.

“Under 3, there will be a serious of factors that can affect spread: a) the number of susceptible people – those not infected or (if we had an effective vaccine) those vaccinated- and in spite of many infections the evidence we have is that the majority of the population everywhere is still susceptible to infection. We have no strong evidence yet of any proven re-infections but that does not mean it has not happened or will not happen; b) the behaviours of people in terms of their risk of infection, such as distancing, handwashing, avoiding indoor crowded places, mask wearing, “lockdown” etc; it is clear that there have been behaviours to reduce risk of transmission in many countries, but it is also apparent that these behaviours are reverting in many places which will lead to increased risks of infection where the virus is still present in the community.

“Where the behaviours reduce risk of transmission no longer occur, it is automatically the case that incidence of infections will increase if the virus is still present. This is shown clearly by mathematical models, but it is obvious without the need for a model- a model will predict the magnitude of such increases in rates of infection.

““Spikes” and more gradual increases (and the dramatic or gradual falls) will each happen with varying effects dependent on the conditions in the specific place and at a specific time according to the local effects of the three things noted above.

“It is then clear, that in a place where there is none or an extremely small amount of the virus present then easing the restrictive measures will have little effect, but where the virus is present (or is imported) then the easing is likely to lead to increases in infection.”


Prof Adam Finn, Professor of Paediatrics, University of Bristol, said:

“Detected cases (but not yet deaths) are going back up in Spain – but probably more localised in particular areas than the first wave – same as in other countries, mostly Catalonia and Aragon as well as Madrid.

“One begins to wonder whether imposing quarantine by whole-country is, like universal lockdown, a blunt tool but maybe the only way anyone has yet figured out to reduce importations and the UK epidemic in March mostly came in the noses of UK nationals returning from France Italy and Spain – so once bitten twice shy, even though we now have our very own supply of virus circulating inside the UK as well.”



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