British parents are being urged to check their child’s polio vaccination status after the UK Health Authority declared a national emergency over a suspected outbreak.
The UK Healthy Security Agency (UKHSA) sounded the alarm yesterday (22 June) after routine sewage inspections in London between February and June found traces of the virus, which had been extinct in Britain until now.
While between one and three cases of polio are detected in UK sewage each year, the UKHSA says these were all isolated, unrelated cases.
The latest samples are genetically related, raising fears the virus is being transmitted in the north-east London communities served by London’s Beckton Sewage Treatment Works, where the samples were found.
Despite efforts to eradicate the virus through vaccination, polio remains endemic in two countries worldwide, putting other countries at risk of importing cases.
British parents have now been urged to ensure their children are fully vaccinated against the potentially deadly and debilitating disease.
NationalWorld has compiled the figures to find out which countries are home to polio, where there have been recent outbreaks and how many children in the UK and around the world are still unvaccinated.
How common is polio – and are cases increasing?
Polio (also known as poliomyelitis or paralytic polio) is caused by the poliovirus. Most people infected with the poliovirus have no symptoms, but some develop poliomyelitis, which can cause muscle weakness, paralysis, and sometimes death.
According to figures from Our World in Data, sourced from the World Health Organization (WHO), the number of cases of paralytic polio worldwide has declined sharply since the 1980s.
The WHO launched a concerted plan in 1988 to eradicate polio by the year 2000.
The number of reported cases of paralytic polio is thought to be an underestimate because people with acute flaccid paralysis — an inflammation of the spinal cord that leads to arm and leg weakness that polio can cause — may not be recognized or responded to Virus to be tested.
For this reason, Our World in Data publishes both the number of reported cases and estimates of the true number, including undetected ones.
Between 1980 and 2021, the number of reported cases of paralytic polio worldwide fell from 52,630 to just 649, while the number of estimated cases fell from 368,410 to 1,872 in 2020.
However, there has been an upswing in recent years.
In 2016, there were just 42 reported cases — 49 if estimates of undetected cases are included.
But the following year, both numbers almost tripled to 118 and 131, respectively.
Cases peaked in 2020 with 1,253 reported and 1,872 estimated cases. The number of reported cases fell to 649 in 2021, although there is still no estimate of the actual number this year.
Which countries have the most cases?
Nigeria was the polio hotspot in 2021 with 415 reported cases – 64% of the global total and up from just eight in the previous year.
It was followed by Afghanistan with 47 cases and Tajikistan with 32 cases.
Afghanistan had the most confirmed cases in 2020 with 364, followed by Pakistan with 219 and Chad with 101.
Those three nations also had the highest number of cases when estimates of undetected infections are included, with 404 in Afghanistan, 243 in Pakistan and 202 in Chad.
Historically, India has been the hardest-hit country since 1980, with 293,708 confirmed cases and 1.96 million estimated – more than half of the world total.
While polio remains rare in Europe, there has been a significant spike in the past year with 34 confirmed cases. In the previous year there was only one case, before that in four consecutive years zero cases.
Ukraine had the most cases on the continent but still only confirmed two infections.
Polio is endemic—continuously present and transmitted—only in Afghanistan and Pakistan, according to the Global Polio Eradication Initiative, which warns that until transmission is stopped in those countries, all countries risk importing cases.
In recent months, both Malawi and Mozambique have reported outbreaks of wild-type poliovirus, the most common type of polio.
How common was polio in the UK – and when was it eradicated?
According to Our World in Data, the last confirmed case of polio in the UK was in 1993 – one case was reported that year, while the estimated true number was seven.
But the last case of British polio actually transmitted within the UK was in 1984, according to Health Protection Scotland, with all cases between then and 1993 being acquired outside the UK and re-imported.
Britain was officially declared polio-free in 2003.
Are children vaccinated in the UK?
Analysis of the latest statistics on child immunization coverage released by the NHS reveals large geographical disparities in the proportion of children vaccinated against polio.
The vaccine comes in a “six-in-one” dose that provides protection against polio, as well as other diseases such as hepatitis B and tetanus.
A basic course is conducted in the first few months of a child’s life, with a booster vaccination required three years after the completion of the basic course.
Vaccination coverage in the UK was 92.6% in 2020/21 – 2.4 percentage points below the World Health Organization target of 95% to ensure herd immunity.
This is the proportion of infants who are vaccinated before their first birthday.
London has the lowest vaccination rate of any UK nation or region, having vaccinated 86.7% of children before their first birthday in 2020-21. The North West was the second worst region with 91.7% vaccination. The North East is the only English region above the WHO target of having 95.5% of children vaccinated.
The vaccination rate across England is 92.0%.
Northern Ireland was also below target with 94.5% of children vaccinated before their first birthday.
Scotland and Wales were the only two nations to meet the target with vaccination rates of 96.5% and 95.6% respectively.
How many children have been vaccinated worldwide?
Polio mainly affects children under the age of five, so early vaccination is essential to prevent transmission.
In 2020, 83% of infants around the world received three doses of polio vaccine, according to the World Health Organization.
However, vaccination coverage can vary greatly from country to country. Only about two in five countries (41%) had immunization rates of 95% or more in 2019, according to figures compiled by Our World in Data. More than a quarter (31%) had a take-up rate of less than 85%.
Papua New Guinea had the lowest immunization coverage, with only 42% of one-year-olds vaccinated against polio. 27 countries had vaccinated 99% of the one-year-olds, including China, Iran and Turkey.
https://www.nationalworld.com/health/where-polio-world-countries-virus-endemic-recent-outbreaks-3742961 Where is polio in the world? Countries where the virus is still endemic – and current outbreaks