Half of all suspected chickenpox cases could be ‘other nasty viruses’ parents warned

HALF of cases diagnosed as chickenpox could in fact be caused by other nasty viruses, scientists have warned.

A study testing samples from people suspected of having the common illness found that almost half had bugs like enterovirus or the herpes simplex virus instead.

Causing a telltale itchy, blistery rash, the affliction is so common in the UK that it’s estimated that 90 per cent of children will get it before they turn 15.

Considered fairly harmless, the illness – caused by the varicella-zoster virus – can cause complications in some, such as brain inflammation or serious bacterial infections.

Vaccination against chickenpox is currently only available on the NHS for people who haven’t had the illness before but are in regular or close contact with someone who’s at risk of getting seriously ill if they get chickenpox.

But the Joint Committee on Vaccination and Immunisation recently recommended that two doses of the varicella jab be offered to  to children aged 12 and 18 months.

The Government advisers said the jab will help reduce “tragic, more serious cases” of the common illness if given final approval by the Department of Health and Social Care.

Chickenpox vaccines are routine in many countries, including the US and Australia.

In the US, there were an estimated 4 million cases of chickenpox each year up until the early 1990s, resulting in hundreds of deaths from the common and highly infectious illness.

In response, health authorities launched wide-ranging vaccination campaign in 1995, making sure children were given two doses of the jab.

As the result, chickenpox cases fell by a whopping 97 per cent, according to the Centers of Disease Control and Prevention (CDC).

The disease is now so rare in the US that doctors misdiagnose it half the time, a new report from the Minnesota Department of Health has claimed.

Despite high vaccination rates, it’s possible for people who have been jabbed to get chickenpox.

Signs of the illness tend to differ with breakthrough cases, posing “diagnostic challenges” to doctors in the US.

Patients tend to develop fewer or no blisters – just red spots – as well as a milder fever. These breakthrough cases were more common in people who’d only received on dose of the varicella vaccine, instead of two.

The Minnesota Department of Health Department (MDH) ramped up testing for chickenpox in 2016, providing free tests to people suspected of having the illness after being diagnosed with chickpenpox in medical clinics or at school.

Health authorities also made free at-home testing kits available to families.

MDH tested 420 samples provided by people suspected of having chickenpox between 2016 and 2023.

Nearly half (46 per cent) tested negative for varicella-zoster, the virus that causes chickenpox.

Instead, tests identified enterovirus in 47 cases (11 per cent) and the herpes simplex virus (HSV-1) in 20 people (5 per cent).

Enteroviruses are a group of bugs causing infectious illnesses that are usually mild.

Meanwhile, HSV-1 is the main cause of oral herpes.

Varicella-zoster was only found to have causes illness in 37 per cent of the samples – 20 per cent were breakthrough cases, as patients had received at least one dose of the chickenpox vaccine.

“These findings suggest that the clinical diagnosis of varicella can be unreliable, especially in vaccinated patients, and underscore the importance of laboratory confirmation of varicella,” the report concluded.

It suggested doctors might brush up their chickenpox diagnosis practices.