When Hong Kong medical doctor and former lawmaker Lo Wing-Lok visited the Tamil Nadu in India with Oxfam Hong Kong just a day after the massive December 26 tsunami struck, like other doctors assessing the damage, he found that many villages' drinking water had been contaminated by last week's huge tsunami waves.

He also said the damage was such in the remote Tamil Nadu region that volunteer medical professionals would be useless in the field if they were not backed up by a self-sufficient mobile hospital unit.

"The situation in the most severe area is still rather chaotic… the medical relief there requires a military type of operation," Lo said. "There are very few personnel who can operate as a well formed unit. If doctors and nurses just volunteer and they have little training [they] may not be able to help," he added.

Lo also said that not all aid agencies are equally equipped to deliver aid. "Some are faring a little bit better if they have long established relationship with a local partner," he said. Lo said that Oxfam Hong Kong is able to help in Tamil Nadu because of pre-existing ties to a local charity. That group, he said, is able to find trained medical volunteers within India.

Lo said that aside from the devastation, deaths, and high numbers of injured, he witnessed uncontrollable crying and emotional distress in one village. He said aid workers can play a role in engaging villagers in the reconstruction of homes and infrastructure. "It may help the villagers to start talking to each other… repairing of damage to the village and damage to the minds of the people," he said.

Lo saw no immediate evidence of disease outbreaks in Tamil Nadu but believed the threat remained high.

As world leaders met in the Indonesian capital of Jakarta Thursday (January 6) pledging further support, the World Health Organization (WHO) warned that disease in the Tsunami's aftermath could cause the death toll to spike to 300,000. The UN agency said $66 million is needed simply to prevent the spread of sickness among the 1–2 million people displaced people across affected areas.

Disease surveillance is poor and even nonexistent in many parts of the affected areas. WHO Director General Lee Jong Wook said his agency estimates 150,000 people are in immediate risk of disease. He did not mention, however, how surveillance systems—the key to stopping an outbreak in its tracks—could be improved in far-flung areas. Waterborne disease like cholera and mosquito-borne diseases such as dengue fever and malaria posed the biggest threat, said WHO.

Dengue fever in Indonesia has been a seasonal problem for decades. Last year, the country reported an unusually high number—more than 58,000 of cases and 600 deaths from the illness, which peaked in March.

The US Centers for Disease Control and Prevention (CDC) has said, however, that dead bodies left in the wake of the tsunami do not pose a great threat to health. Corpses can only transmit disease, such as hepatitis or salmonella, if they are handled improperly, according to the CDC website. The center warned against the indiscriminate burial of unidentified human remains.