LONDON (Reuters Health) - British public health authorities have warned that more children risk catching measles, mumps and rubella as uptake of the triple MMR vaccine continues to fall.

The Health Protection Agency said on Monday its latest figures showed that MMR uptake among two-year olds fell to 78.9 percent in the first three months of the year -- a drop of 2.1 percent on the previous quarter. This followed a similar decrease from 83 to 81 percent in the quarter before.

There were 151 cases of measles, 441 cases of mumps, and four cases of rubella in the first quarter of 2003. Only six of the children who contracted measles had been vaccinated, including one child who received a single measles jab rather than MMR.

Uptake of the triple vaccine has been falling in the UK for several years after researchers at London's Royal Free Hospital suggested a possible link with autism. The link has been denied by most researchers who have examined the evidence.

Commenting on the latest figures, the agency's Natasha Crowcroft said in a statement: "We are concerned because as coverage falls more children are left susceptible to measles, mumps and rubella. We would like to reassure parents that MMR is the safest and most effective way to protect our children."

Crowcroft said research showed that the majority of parents were still confused about the safety of MMR.

"They perceive that medical science gives equal weight to both sides of the argument when in fact the balance of scientific evidence is overwhelmingly in favour of the vaccine being safe."