The ‘most contagious diseases' revealed – and the one in first place could be about to surge in the UK

Scottish Sun

6 hours ago

Plus, everything you need to know to protect yourself from the "most contagious disease"
VIRAL THREAT The 'most contagious diseases' revealed – and the one in first place could be about to surge in the UK
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WE'RE all familiar with the contagious nature of illnesses like the common cold and flu.
If someone infected with one of these viruses sneezes, cough, sings, or talks nearby you, the likelihood of you catching what they've got is pretty high.
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We all know how contagious the common cold and flu are - but they're not the most contagious illnesses
Credit: Getty
But there are more contagious illnesses in existence definitely worth knowing about.
The one that takes the top spot for being most contagious is measles.
According to Dan Baumgardt, senior lecturer at the School of Physiology, Pharmacology and Neuroscience, University of Bristol, it's all based on R0 - a measure of how many other people are likely to become infected from another.
He said: "The R0 measure indicates how an infection will spread in a population.
"If it's greater than one, the outcome is disease spread.
"An R0 of one means the level of people being infected will remain stable, and if it's less than one, the disease will often die out with time."
Measles has made a resurgence globally in recent years, including in the UK - and its R0 is considered high.
While several factors are said to contribute to this, the primary cause is a decline in childhood vaccination rates.
Writing for The Conversation, Baumgardt said this drop has been driven by disruptions such as the Covid pandemic and global conflict, as well as the spread of misinformation about vaccine safety.
He continued: "The R0 number for measles is between 12 and 18. If you do the maths, two cycles of transmission from that first infected person could lead to 342 people catching the illness.
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"That's a staggering number from just one patient – but luckily, the protective power of vaccination helps reduce the actual spread by lowering the number of people susceptible to infection.
Measles is extraordinarily virulent...it's so infectious that an unvaccinated person can catch the virus just by entering a room where an infected person was present two hours earlier.
"People can also be infectious and spread the virus before they develop symptoms or have any reason to isolate."
Just last week, health officials from the UK Health Security Agency (UKHSA) voiced fears that another surge of measles cases could be on the way.
Since January 1, there have been 674 laboratory confirmed measles cases reported in England, with 48 per cent of these cases in London, 16 per cent in the North West, and 10 per cent in the East of England.
And holiday travel and international visits to see family this summer could lead to rising measles cases in England when the new school term begins, the UKHSA warned.
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Measles cases have been on the rise across Europe
Credit: Getty
The main symptoms of measles
MEASLES is highly contagious and can cause serious problems in some people.
The infection usually starts with cold-like symptoms, followed by a rash a few days later.
The first signs include: A high temperature
A runny or blocked nose
Sneezing
A cough
Red, sore, watery eyes
Small white spots may then appear inside the cheeks and on the back of the lips.
A rash tends to come next. This usually starts on the face and behind the ears before spreading to the rest of the body.
The spots are sometimes raised and join together to form blotchy patches. They are not normally itchy.
The rash looks brown or red on white skin. It may be harder to see on darker skin.
Complications are rare, but measles can lead to pneumonia, meningitis, blindness, seizures, and sometimes death.
Source: NHS
As Baumgardt mentioned, one of the best ways to protect yourself from measles is to get vaccinated.
The first measles mumps and rubella (MMR) vaccine is offered to infants when they turn one year old and the second dose to pre-school children when they are around three years and four months old.
Around 99 per cent of those who have two doses will be protected against measles and rubella.
Other infectious diseases
Other infectious diseases with high R0 values, said Baumgardt, include pertussis/whooping cough (12 to 17), chickenpox (ten to 12), and Covid, which varies by subtype but generally falls between eight and 12.
He said: "While many patients recover fully from these conditions, they can still lead to serious complications, including pneumonia, seizures, meningitis, blindness, and, in some cases, death."
But be wary of those with a lower infectivity rate - as it doesn't necessarily mean it's less dangerous, said Baumgardt.
For example, tuberculosis (TB) has an R0 ranging from less than one up to four.
But the danger lies in how difficult it is to treat.
Baumgardt warned: "Once established, it requires a combination of four antibiotics taken over a minimum of six months. Standard antibiotics like penicillin are ineffective, and the infection can spread beyond the lungs to other parts of the body, including the brain, bones, liver and joints.
"What's more, cases of drug-resistant TB are on the rise, where the bacteria no longer respond to one or more of the antibiotics used in treatment."