Child health services were originally designed to find or prevent physical illness by regular inspections. In the UK these were carried out by clinical medical officers (CMOs) working in infant welfare clinics (later, child health clinics) set up to fill the gap between general practice and hospital care. The services expanded greatly from the mid 1970s; ‘inspections’ have evolved into a regular screening and surveillance system by general practitioners and health visitors, while CMOs have mostly been replaced by consultant paediatricians in community child health (CPCCH).

Screening begins at birth, when every baby is examined for congenital conditions such as dislocated hips, heart malformations, cataract and undescended testicles. Blood is taken to find those babies with potentially serious conditions such as HYPOTHYROIDISM, and a number of other rare inherited metabolic disorders. Screening is also in place for CYSTIC FIBROSIS and hearing impairment. Children from ethnic groups at risk of inherited abnormalities of HAEMOGLOBIN (sickle cell disease; thalassaemia – see under ANAEMIA) have blood tested at some time between birth and six months of age.

At two months, GPs screen babies again for these abnormalities and start the process of primary IMMUNISATION. The routine immunisation programme has been dramatically successful in preventing illness, handicap and deaths: as such it is the cornerstone of the public health aspect of child health, with more potential vaccines being made available every year. Currently, infants are immunised against pertussis (WHOOPING-COUGH), DIPHTHERIA, TETANUS, POLIOMYELITIS, Haemophilus influenza type b (a cause of MENINGITIS, SEPTICAEMIA, ARTHRITIS and epiglottitis), MENINGOCOCCUS B & C (SEPTICAEMIA and meningitis – see NEISSERIACEAE), PNEUMOCOCCUS (SEPTICAEMIA, MENINGITIS, PNEUMONIA) and Rotavirus (a cause of gastroenteritis) at two, three and four months. Selected children from high-risk groups are offered BCG VACCINE against tuberculosis and hepatitis vaccine. At about 12 months all are offered boosters of the vaccines designed to protect against septicaemia and meningitis and a first dose of MMR VACCINE (measles, mumps and rubella); there are pre-school entry ‘boosters’ of diphtheria, tetanus, polio and MMR. From age 2–6, yearly influenza vaccine is offered. Girls aged 12–13 are recommended to have HUMAN PAPILLOMAVIRUS IMMUNISATION and both sexes are given a further booster of DTP and a combined meningococcal A,C,W and Y vaccine at 14.

The US schedule differs somewhat in that hepatitis B is offered to all babies as is chicken- pox vaccine and hepatitis A from 12 months, with minor differences in scheduling the other vaccines.

Throughout the UK, parents are given their child's personal health record to retain. It contains advice on health promotion, including immunisation, developmental milestones (when did he or she first smile, sit up, walk and so on), and graphs – called centile charts – on which to record height, weight and head circumference. There is space for midwives, doctors, practice nurses, health visitors and parents to make notes about the child.

Throughout at least the first year of life, both parents and health-care providers set great store by regular weighing, designed to pick up children who are ‘failing to thrive’. Measuring length is not quite so easy, but height measurements are recommended from about two or three years of age in order to detect children with disorders such as growth-hormone deficiency, malabsorption (e.g. COELIAC DISEASE) and psychosocial dwarfism (see below).

All babies have their head circumference measured at birth, and again at the eight-week check. A too rapidly growing head implies that the infant might have HYDROCEPHALUS – excess fluid in the hollow spaces within the brain. A head that is growing too slowly (MICROCEPHALY) may mean failure of brain growth, which may go hand in hand with physically or intellectually delayed development.

At about eight months, babies receive a surveillance examination, usually by a health visitor. Parents are asked if they have any concerns about their child's hearing, vision or physical ability. The examiner conducts a screening test for hearing impairment – the so-called distraction test; he or she stands behind the infant, who is on the mother's lap, and activates a standardised sound at a set distance from each ear, noting whether or not the child turns his or her head or eyes towards the sound. If the child shows no reaction, the test is repeated a few weeks later; if still negative then referral is made to an audiologist for more formal testing.

The doctor or health visitor will also go through the child's developmental progress (see above) noting any significant deviation from normal which merits more detailed examination. Doctors are also recommended to examine infants developmentally at some time between 18 and 24 months. At this time they will be looking particularly for late walking or failure to develop appropriate language skills.

Screening and surveillance uncover problems which then need careful attention. Most NHS districts have a CDT to carry out this task – working from child development centres – usually separate from hospitals. Various therapists, as well as consultant paediatricians in community child health, contribute to the work of the team. They include physiotherapists, occupational therapists, speech therapists, psychologists, health visitors and, in some centres, pre-school teachers or educational advisers and social workers. Their aims are to diagnose the child's problems, identify his or her therapy needs and make recommendations to the local health and educational authorities on how these should be met. A member of the team will usually be appointed as the family's ‘key worker’, who liaises with other members of the team and coordinates the child's management. Regular review meetings are held, generally with parents sharing in the decisions made. Most children seen by CDTs are under five years old, the school health service and educational authorities assuming responsibility thereafter.

The Children Act 1989, Education Acts 1981, 1986 and 1993, and the Chronically Sick and Disabled Persons Legislation 1979 impose various statutory duties to identify and provide assistance for children with special needs. They include the chronically ill as well as those with impaired development or disabilities such as CEREBRAL PALSY, or hearing, visual or intellectual impairment. Many CDTs keep a register of such children so that services can be efficiently planned and evaluated. Parents of disabled children often feel isolated and neglected by society, and are frequently frustrated by the lack of resources available to help them cope with the sheer hard work involved. The CDT, through its key workers, does its best to absorb anger and divert frustration into constructive actions.

There are other groups of children who come to the attention of child health services. Community paediatricians act as advisers to adoption and fostering agencies, vital since many children needing alternative homes have special medical or educational needs or have behavioural or psychiatric problems. Many see a role in acting as advocates, not just for those with impairments but also for socially disadvantaged children, including those ‘looked after’ in children's homes and those of travellers, asylum seekers, refugees and the homeless.

Regrettably, some children come to the attention of child health specialists because they have been beaten, neglected, emotionally or nutritionally starved or sexually assaulted by their parents or carers. Responsibility for the investigation of these children is that of local-authority social-services departments. However, child health professionals have a vital role in diagnosis, obtaining forensic evidence, advising courts, supervising the medical aspects of follow-up and teaching doctors, therapists and other professionals in training. (See CHILD ABUSE.)

Once children have reached school age, the emphasis changes. The prime need becomes identifying those with problems that may interfere with learning – including those with special needs as defined above, but also those with behavioural problems. Teachers and parents are advised on how to manage these problems, while health promotion and health education are directed at children. Special problems, especially as children reach secondary school (aged 11–18) include accidents, substance abuse, psychosexual adjustment, antisocial behaviour, eating disorders and physical conditions which loom large in the minds of adolescents in particular, such as ACNE, short stature and delayed puberty.

The community dental service whose role is to monitor the whole child population's dental health, provide preventive programmes for all, and dental treatment for those who have difficulty using general dental services – for example, children with complex disability. All children in state-funded schools are dentally screened at ages five and 15.

Since the inception of the NHS, hospital services for children have had enormous success: neonatal and infant mortality rates have fallen by two-thirds; deaths from PNEUMONIA have fallen from 600 per million children to a handful; and deaths from MENINGITIS have fallen to one-fifth of the previous level. Much of this has been due to the revolution in the management of pregnancy and labour, the invention of neonatal resuscitation and neonatal intensive care, and the provision of powerful antibiotics.

At the same time, some children acquire HIV infection and AIDS from their affected mothers; the prevalence of atopic (see ATOPY) diseases (ASTHMA, ECZEMA, HAY FEVER) is rising; more children attend hospital clinics with chronic CONSTIPATION; and little can be done for most viral diseases.

Community child health services can also boast of successes. The routine immunisation programme has wiped out SMALLPOX, DIPHTHERIA and POLIOMYELITIS, and almost wiped out haemophilus, pneumococcal and meningococcal C meningitis, measles and congenital RUBELLA syndrome. WHOOPING-COUGH outbreaks continue, but the death and chronic disability rates have been greatly reduced. Services for severely and multiply disabled children have improved with the closure of long-stay institutions, many of which were distinctly child-unfriendly. Nonetheless, scarce resources mean that families still carry heavy burdens. The incidence of SUDDEN UNEXPECTED DEATH IN INFANCY (cot death) has more than halved as a result of an educational programme based on firm scientific evidence that the risk can be reduced by putting babies to sleep on their backs, avoidance of parental smoking, not overheating, breast feeding and seeking medical attention early for illness.

Children now have fewer accidents and better teeth, but new problems have arisen: children throughout the developed world have become fatter. A UK survey in 2014 found that over 30% of children are overweight or obese. Lack of exercise, the easy availability of food at all times and in all places, together with the rise of ‘snacking’, are likely to provoke significant health problems as these children grow into adult life. Adolescents are at greater risk than ever of ill-health through substance abuse and unplanned pregnancy. Child health services are facing new challenges in the 21st century.