CompletedObservational

Multi-centre European study of major infectious disease syndromes (MERMAIDS) – Acute respiratory infections

Acute respiratory infections affect the nose, throat, airways, or lungs. While some people recover quickly, others become dangerously ill. Right now, doctors cannot easily predict who will become very unwell, meaning most patients receive standard care rather than treatments tailored to them. Led by the University of Oxford, this observational European study aims to understand how our bodies fight these illnesses. Researchers are studying adults who visit their GP or are admitted to hospital with a sudden chest or throat bug. Taking part involves giving three blood samples and nose or throat swabs over a short period. No experimental medicines are tested, and standard NHS care continues as normal. By studying biological samples and gene responses, researchers hope to uncover why infections hit some people harder, helping doctors design better, tailored treatments to prevent severe illness and hospital stays in the future.

At a glance

Status

Completed

Sponsor

University of Oxford (UK)

Enrolment target

2,000

Start

01 Oct 2015

Estimated completion

30 Apr 2019

Acute respiratory infections

What is this study about?

An acute respiratory infection is a sudden illness affecting the breathing passages, such as the throat, airways, or lungs. Common bugs like the flu or chest infections can cause mild discomfort in some people, but severe, life-threatening breathing problems in others. While older adults or people with existing health conditions are at higher risk, even young and previously healthy individuals can sometimes become critically unwell. Doctors currently cannot predict who will cope well and who will develop complications, which makes it hard to personalise treatment.

This research project, called the MERMAIDS study, is designed to solve that mystery. Researchers want to see how individual immune systems and genes respond when fighting off a sudden respiratory illness. By comparing samples from people with mild symptoms to those who need hospital care, scientists hope to discover the biological clues that explain why severe illness develops.

Because this is an observational study, it does not test any new drugs or alter your normal medical care. Instead, it carefully tracks what happens naturally during your illness. The knowledge gained could help doctors in the UK and across Europe identify vulnerable patients earlier in future outbreaks, ensuring they get the right care quickly to prevent hospitalisation.

Key takeaways

The MERMAIDS study investigates why respiratory infections cause mild illness in some adults but severe illness in others.
It is an observational study, meaning it does not test any new medications or change your treatment.
Participation involves giving three blood samples and nose or throat swabs over a few days.
Open to adults aged 18 and over who developed fever and breathing symptoms in the past week.
Taking part will not directly cure your infection, but it could help improve care for future patients.

Who may be eligible?

You may be able to take part if you are aged 18 or older and have developed a sudden chest, throat, or airway infection within the last seven days. To qualify, you must have a high temperature or fever, alongside at least one breathing symptom (like a cough, sore throat, or blocked nose) and at least one general symptom (such as muscle aches, a headache, extreme tiredness, or chills). The study includes both people seeing their GP for mild symptoms and people admitted to hospital with a more severe infection.

You cannot take part if you are unable to give informed consent, or if you are already taking part in a clinical trial that tests a new medicine. GP patients who need immediate transfer to hospital for admission are also excluded from the primary care group, as are hospital patients who have been transferred from another hospital.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 18 or older.
My breathing symptoms started within the last 7 days.
I have had a sudden high temperature, fever, or chills.
I have a cough, sore throat, or runny/blocked nose.
I have general symptoms like a headache, muscle aches, or extreme tiredness.
I am not currently taking part in another clinical trial testing a new drug.

Answer every question to see your result.

What does participation involve?

If you join the study, you will have biological samples taken three times: when you first enter the study, on day two, and when you are discharged from hospital (or at an equivalent follow-up visit if you joined through your GP). These samples include routine blood tests and gentle swabs taken from your nose or throat.

No experimental drugs or extra therapies are given, and your usual NHS medical treatment will not change in any way. For hospital patients, sample collection is planned alongside regular daily blood tests so you do not need extra needle pricks. If you joined through your GP surgery, you will attend two brief follow-up visits to provide your samples. Your total active participation lasts only a few days until you recover or leave hospital.

Potential risks and benefits

Taking part will not directly improve your health or change the treatment you receive for this illness, but it will help doctors better understand and treat respiratory bugs in the future. Because this is an observational study, the physical risks are very low. Having blood taken can cause brief pain, mild bruising, or rarely a minor infection at the needle site, while swabs may feel briefly ticklish or uncomfortable. Experienced clinical staff carry out all procedures to keep discomfort to a minimum. You can leave the study at any point without giving a reason, and choosing to withdraw will never affect your usual NHS care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Oxfordshire Primary Care Trust
City only
-, England

Common questions

Will taking part change my current medical treatment?

No. Your doctors will continue to treat your infection in the normal way. The study only collects samples to observe your illness.

Does this study test any new or experimental drugs?

No. This is purely an observational study, meaning researchers only study blood and swab samples to see how your immune system responds naturally.

Will I have to pay anything or travel far?

No. Hospital patients are seen on their ward, and GP patients are seen at their local practice or clinic. There are no costs to you.

How many extra needle pricks will I need if I am in hospital?

Very few, if any. The research team aims to collect study blood at the exact same time as your routine NHS morning blood tests.

Can I leave the study if I change my mind?

Yes, absolutely. You can stop participating at any time. It will not affect your standard medical care or your relationship with your healthcare team.

How to find out more

Study Team

mermaids-ari@ndm.ox.ac.uk +44 (0) 1865 612979 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.