According to the federal home ministry, 10,012 people have died since the December 26 tsunamis devastated regions in south-eastern coastal India and the Andaman and Nicobar Islands in the Bay of Bengal.

Southern Tamil Nadu state reported the most deaths at 7,941. At least 5,624 people are still missing, with 5,531 untraced in the Andamans archipelago alone.

As Indian armed forces continued to look for the missing, the biggest challenge was to keep more than 380,000 people living in 614 overcrowded relief camps free from disease.

For a week starting January 2, UNICEF has been helping the state governments of Tamil Nadu and Kerala in a measles and Vitamin A immunization campaign targeting 115,000 children.

But “sporadic” cases of measles and chicken pox were “spread over several camps” in Tamil Nadu and the Andamans, health ministry official P.K. Hota said.

“Measles is a deadly threat to children living in crowded camps,” said Marzio Babille, UNICEF’s chief of health in India. “It spreads quickly, killing children, or severely weakens their immune systems.”

The children are then too weak to fight off other diseases, and this leads to more deaths.

Hota said the government was on high alert and doctors would work in the tsunami-hit areas for at least two months to prevent any major outbreak, the Times of India newspaper reported.

Unicef teams were also travelling across Tamil Nadu installing water storage tanks and distributing packets of oral rehydration salts to prevent outbreaks of diarrhoea.

Volunteers used animation to explain how diarrhoea can spread rapidly in crowded and unsanitary conditions, advised people on the importance of washing their hands with soap and water, and taught them how to prepare the life-saving salt solution.

Help in tackling Tamil Nadu’s water shortage has come cross-country from the north-western desert state of Rajasthan, the Telegraph newspaper reported.

A defence ministry mobile laboratory from parched Jodhpur city in Rajasthan used reverse osmosis to purify water in several Tamil Nadu villages.

The “nuclear, biological and chemical water purification system” is fitted to an army truck and was created to provide potable water during defence operations, the report said.

It has a suction capacity of 7,000 litres and takes an hour to convert 3,000 litres of raw water into water that is fit to drink.

More aid has come from an unlikely source in Rajasthan. The 700 inmates of a jail in Udaipur city have decided to eat only one meal a day for 10 days and will skip breakfast for a month. They said the groceries - wheat flour, pulses, oil and sugar - saved would be sent to relief camps, the Hindustan Times newspaper reported.

Tens of thousands of Indians have started taking the first steps towards rebuilding their lives. Some of the survivors, who say they will never forget the morning of December 26, also want future generations to feel their pain.

Tharayil Kadavu village in Kerala state’s Alapuzha district has been renamed Tsunami Junction. Residents said the name would remind generations to come of the immense sufferings of the village.