There are just 1,186 fully qualified school nurses who are charged with supporting the needs of England's 8.4 million pupils.
The figures have led to a stark warning from the Royal College of Nursing (RCN), which fears that depleted school nursing services will damage attempts to tackle national priorities, such as obesity and mental and emotional health.
The latest workforce statistics come from the Health and Social Care Information Centre and are for May 2015. As well as the 1,186 fully qualified school nurses, there are another 1,867 health professionals working in school nursing roles – although this still only brings the total number of professionals to 3,053.
Meanwhile, the latest pupil census figures from January show that there are 8,403,607 pupils in the school system.
This includes 4.51 million primary pupils and 3.19 million secondary pupils in state schools in England, 20,500 in alternative provision and 101,000 in special schools.
There has also been a 1.3 per cent growth in the number of pupils since January 2014 and pupil numbers are expected to grow further in the coming years.
The RCN is worried that school nursing services are at further risk of depletion following £200 million government cuts to public health budgets in England. There is already a 24 per cent vacancy rate for school nurses, according to Health Education England.
The RCN claims that local authorities in London, Staffordshire, Middlesbrough and Derbyshire are "already considering" cuts to school nurse funding to plug gaps in other areas of public health.
It came as the RCN held a conference late last month to discuss the challenges facing the school nursing sector.
The warnings have been echoed by the National Association of Head Teachers, which is worried about the lack of school nurses at a time when schools face having to manage many complex medical conditions.
New legislation has given schools a legal obligation to support children with long-term health conditions, such as diabetes, epilepsy and asthma.
General secretary Russell Hobby said: "Schools are increasingly dealing with children with complex medical needs and in order to do so effectively it's important that they have the right support.
"Teachers are not nurses, and anyone being asked to administer medication should be appropriately trained, or this should be done by a school nurse to ensure the safety of pupils.
"However, many of our members struggle to access this vital service, with little or no school nurse service for many schools. This makes it incredibly difficult to ensure that children with medical conditions receive the high levels of care they deserve.
"The government needs to make sure that this service is receiving appropriate funding to ensure that pupils with medical conditions are not disadvantaged when it comes to their education."
The RCN points out that one-in-three children in the UK is now overweight and one-in-five is obese.
Meanwhile, one-in-10 suffers from a mental disorder, 15 per cent of pupils in England's schools have an identified SEN (1.3 million pupils) and six per cent have a disability.
An RCN statement said: "School nurses are essential in educating children and their families about these issues, while providing support and care for those in need. However, without sufficient time and funding, they are unable to fulfil their ability to improve these escalating problems."
Previously, school nursing services were commissioned by the NHS but this responsibility has now been passed to local authorities – this has heightened fears that services will be hit as budget cuts take effect.
Caroline Voogd, editor of the British Journal of School Nursing – Headteacher Update's sister title – fears that the new system will lead to a decrease in the already low numbers of fully qualified school nurses.
She said: "Qualified school nurses have a crucial public health role and while numbers are already too low to be able to deliver on all aspects of this role, current commissioning of the service is likely to compound the problem and further deplete the workforce."
She continued: "Some areas are planning to have non-nursing staff deliver public health and are severely cutting school nursing staff numbers to save costs."
Fiona Smith, the RCN's professional lead for children and young people's nursing, added: "School nurses play a critical role in the health of our children yet their work is so often overlooked – and undervalued.
"The conference illustrated the wide range of issues school nurses tackle on a daily basis, from conditions such as epilepsy to behavioural disorders like ADHD. They are talented, multi-skilled nursing staff who deserve immense recognition.
"Unlike any other health professional, school nurses work with children and education staff on a daily basis. However, investment is fundamental if we are to begin solving this crisis in children's health and build a healthy and prosperous future population."
- Pete Henshaw is the editor of Headteacher Update.