People suffering from chicken pox, especially children, should be hospitalised as soon as possible to avoid unexpected and serious complications during its peak season this month, doctors have warned.

The warning came after a two-year-old boy was hospitalised in Ho Chi Minh City 's Paediatrics Hospital No1 and diagnosed with septicaemia having contracted chicken pox two weeks before. A two-day-old new-born, who caught the disease from her mother, is also under intensive care.

Doctor Nguyen Tien Dung, head of the Bach Mai Hospital's Children Ward, said that the hospital received about 200 patients each day on average, ranging from between one and five years old.

Dung said the number of patients was less than the previous year, but that of those who were in a critical condition and at risk of complications such as pneumonia and meningitis was higher.

"These patients mistook the disease for an allergic reaction and didn't treat it correctly," he said.

From five to six patients are being hospitalised for treatment each day on average in the National Hospital for Contagious and Tropical Diseases in Hanoi .

Doctor Nguyen Tien Lam from the hospital said there had been an increasing number of adults admitted with chicken-pox in recent days, and many were displaying serious symptoms.

"They might not have been vaccinated or their immune systems were weak," he said, adding that late treatment could lead to many complications, such as deep scarring and hearing problems.

Doctor Truong Huu Khanh, director of the Paediatrics Hospital No1's Infectious Ward, said children over 12 months old and pregnant women should be vaccinated to avoid contracting the disease.

Infected people should be kept isolated to avoid transmitting the disease to others, he said.

Chickenpox is caused by the varicella zoster virus and characterised by skin eruptions. People are at the highest risk of catching chicken-pox in Vietnam during March./.