The COVID Conundrum: Had COVID? Expect issues returning to work.

As the roll out of the COVID-19 vaccinations continues, the world is beginning to plan to return to a sense of normality, which includes a return to work and travel. However, Dr Graham Fry, Tropical Medicine, Trinity College Dublin, Tropical Medical Bureau (Ireland) and Nomad Travel (UK), envisages problems in this return to normality for those who have had COVID-19. Why? The COVID-19 PCR test is too sensitive.

PCR has been used for decades and is still internationally regarded as the ‘gold standard’ for identifying various viral infections. PCR testing produces a binary result of either ‘positive’ or ‘negative’ and in this type of testing, a positive detected result is reported when any level of the genetic material is identified during the PCR process.

It is well recognised that in most cases, an individual who has contracted COVID-19 and is in good general health will not be infectious to others after about 10-14 days. However, these individuals can remain rt-PCT ‘positive’ for many weeks, which consequently affects their ability to return to work or to travel.

For the purposes of post-Covid testing, the simple binary ‘detected’ / ‘not-detected’ reporting system needs to be updated to reflect the differences in Ct rates (this is the amplification needed during analysis to identify Covid-19 genetic material. The more the analyser needs to ‘amplify’ the sample the less genetic material is present).

Binary reporting does not separate out those who are currently infected (low Ct, e.g. 18) from those who had the virus weeks or months ago (high Ct, e.g. >38), where viral fragments remain and where the person has no symptoms and is not infectious.

Dr Graham Fry explains, “We now have the ability to test these individuals and to confirm whether or not they have sufficient circulating antibodies to support the clinically accepted view that they are not infectious”. The triad of a confirmed earlier diagnosis coupled with a clinical assessment and the presence of suitable circulating antibodies should become the new benchmarks to allow these individuals return to work or to undertake international travel without unnecessary restrictions.

According to Johns Hopkins University, 235,444 cases of COVID-19 have been recorded in Ireland, equating to approximately 5% of the country’s population. However, due to limitations in COVID-19 testing in Ireland, the actual figure is likely to be much higher.


For comments / interview opportunities, please contact Niamh Waters,, +353 860492394

Dr Graham Fry – Founder and Group Medical Director

The Tropical Medical Bureau was founded in 1986 by Dr Graham Fry. As the leading Tropical Medical Consultant in the country, Dr Fry plays a pivotal role in the organisation, whether consulting with patients, lecturing to medical students in Trinity College or dealing with media focussed tropical issues on radio and television. His enormous medical experience and expertise in technology have combined to ensure that the TMB occupies national pride of place in tropical medical care.

About Tropical Medical Bureau Group

The Tropical Medical Bureau Group (encompassing Nomad Travel in the UK) is the leading travel medicine clinic group in Ireland, specialists in providing the best information and medical care available for the international traveller. Collectively, the TMB Group sees approximately 60,000 patients on an annual basis, ranging from the private holiday maker to employees of commercial companies, and overseas volunteers to NGO’s and Government departments, all of whom benefit from the expertise of our highly experienced clinic staff.

Since it was founded in 1988, TMB has undergone major growth and expansion to currently encompass 30 clinics, 20 clinics in Ireland (four base clinics and 16 associate clinics). In 2016, TMB acquired Nomad Travel Clinics in the UK. Nomad Travel Clinics has 25 years’ experience in travel health, pharmacy & retail, throughout 10 clinics across the UK.

What distinguishes TMB is our vast experience and expertise, as well as our superb patient aftercare. All our patients have a detailed consultation with one of our specialised healthcare staff. This covers everything from food and water risks, mosquito avoidance, malaria and thrombosis, as well as risks associated from altitude exposure, and also Zika and COVID-19 risks, which may be associated with your trip. Following a detailed consultation, we then decide on which travel vaccines and malaria tablets are appropriate. Our specialised travel medicine software is constantly being updated with travel news, so if anything is happening in your destination that you need to be aware of, we’ll make sure you are.