Salmonella Outbreak Symptoms and Testing in Wimbledon

By Dr Umer Malik, GP, Wimbledon

On 18 August 2026, the UK Health Security Agency formally declared a national outbreak of Salmonella Enteritidis. There are 207 confirmed cases so far, and London has recorded the highest number of any English region. As a GP working across NHS 111, out of hours, and in hours general practice, I regularly assess patients with diarrhoea, vomiting, and suspected food poisoning. This outbreak is worth paying attention to, especially here in Wimbledon, because it has been more serious than people might expect from a stomach bug.

Public health experts, including from the London School of Hygiene & Tropical Medicine, have described this as a significant outbreak. Part of the concern is the hospitalisation rate. Around 38% of confirmed cases have needed hospital treatment, compared with under 10% typically seen with Salmonella. Two people developed bloodstream infections, and sadly there has been one death. Cases range from babies to people in their 90s, with a median age of just 30.

If you have had a stomach bug recently, or eaten out and are now feeling unwell, it is worth reading this rather than assuming it is just a passing bug.

What I want people in Wimbledon to know

Symptoms usually include diarrhoea, stomach cramps, and sometimes vomiting or fever. They typically start within a day or so of eating contaminated food. Most people recover on their own within a few days with rest and fluids, but this outbreak has not always followed the usual pattern.

Another important point is that confirmed cases are likely only a fraction of the true total. Many people recover from milder Salmonella infections without ever being tested, so it is possible to have been affected without knowing for certain.

The strongest lead so far points to eggs and egg based dishes eaten outside the home. Investigations have highlighted eggs and egg based products such as mayonnaise, from multiple supply sources including imports, used in dishes at food businesses. This is not currently linked to travel in most cases, and it is not the same as saying eggs bought and cooked at home are the main issue. In fact, 97% of those affected had not been abroad, and there is currently no identified link to UK produced eggs or poultry.

Red flags and who should seek help sooner

If you are unwell, the first priority is hydration. Small, frequent sips of water or an oral rehydration solution often work better than trying to drink a large amount at once if you are also feeling sick.

I would be more concerned if you notice blood in your stool, a high fever, severe or worsening abdominal pain, or signs of dehydration such as dark urine, dizziness, a dry mouth, or not needing to pass urine for many hours. Feeling confused, very weak, or short of breath are also red flags that mean it is time to seek help rather than wait it out.

If you are pregnant, caring for a young child, over 65, or have a condition that affects your immune system, it is worth getting checked earlier rather than later even before red flags develop. Young children, pregnant women, adults over 65, and anyone who is immunocompromised are most likely to become seriously unwell and should prioritise assessment if symptomatic. That said, this outbreak has also affected many otherwise healthy adults in their 20s and 30s, so the warning signs matter for everyone in Wimbledon, not only those in higher risk groups.

Common myths I am hearing

One common assumption is that this kind of outbreak only matters if you have travelled abroad. In this case, that is not true. The vast majority of those affected had not left the UK.

Another myth is that this is only about whole eggs cooked at home. The concern raised by experts is broader than that, particularly egg based products such as mayonnaise and dishes eaten at food businesses supplied by imported eggs. At present, there is no link to UK produced eggs.

I also hear people assume that if they are young and generally healthy, food poisoning is unpleasant but not something to take seriously. This outbreak has caused hospital admissions at nearly four times the usual rate, across a wide age range, with a median age of 30, so age alone is not a reason to ignore symptoms.

When testing may help

If symptoms have not started improving after 3 to 4 days, or you want to confirm what is causing them, a stool sample sent for testing can identify the specific infection. At Mayfield Clinic in Wimbledon, this is something we can arrange directly, with same day appointments if needed. You can also read more about our Wimbledon clinic, our private GP service in Wimbledon, and our blood tests in Wimbledon.

If you would like to book an appointment in Wimbledon, we can assess your symptoms and arrange testing where appropriate.

The figures in this article come from the UK Health Security Agency Health Protection Report, volume 20, issue 8, published 18 August 2026, and rapid reaction commentary from the London School of Hygiene & Tropical Medicine, including expert comments from Dr Kathleen O'Reilly, Dr Damien Tully and Professor Brendan Wren.