By Lisabel Ting

Children of different ages usually suffer from different types of illness, according to Dr Ang Ai Tin, consultant paediatrician, Thomson Paediatric Clinic, Thomson Medical Centre.

'It is during infancy that a child is the most vulnerable, his immune system is least mature. The first three months are especially important as even a mild infection can become serious,' she said.

During this period, great care must be take to avoid serious infections such as septicaemia (blood infection), meningitis (infection of the brain coverings) and pneumonia, as such infections are potentially life threatening.

After six months of age, common infections will be upper respiratory tract infections, bronchiolitis, pneumonia, gastroenteritis (diarrhoea and vomiting) and urinary tract infections, said Dr Ang.

Infections of the respiratory tract are usually transmitted to the child by older siblings or a caretaker who is unwell.

Gastroenteritis can be due to poor hygiene and food contamination, while urinary tract infections are usually accompanied by a high fever.

When children start to attend pre-school groups or playgroups at around the age of five or six, they are likely to face another potential set of infections.

This is because they are likely to pass germs around, said Dr Ang.

Aside from the common upper respiratory tract infections and gastroenteritis, other common childhood viral infections in this age group, and even among older children, include hand, foot and mouth disease, chickenpox and mumps.

So, what can be done to reduce the likelihood of infection?

Some studies have shown that a healthy microflora may help to decrease respiratory tract and gastrointestinal infections, said Dr Lee Chien Yee, consultant paediatrician and neonatologist, Kinder Clinic, Mount Alvernia Medical Centre.

Both probiotics and prebiotics are important in the development of a healthy microflora in the gut.

Probiotics are dietary supplements that contain healthy bacteria or yeast that can help to restore the body's natural balance, said Dr Lee.

Prebiotics, on the other hand, are indigestible food components that resist the digestion and absorption in the stomach reaching the small and large intestines unmodified. They stimulate the growth of the body's healthy bacteria.

This article was first published in Mind Your Body, The Straits Times on June 18, 2008.