MANILA, Philippines -- The Department of Health is still determining the exact source of the contaminated water blamed for the outbreak of typhoid fever in Calamba, Laguna.

Dr. Yolanda Oliveros, director of the DoH-National Center for Disease Prevention and Control (NCDPC), told reporters on Friday that the DoH is conducting “sanitary surveys” to determine which portion of Calamba’s water distribution system is contaminated.

“We want to trace which portion of the distribution system is contaminated so we can investigate and stop water distribution from that source,” said Oliveros.

The typhoid fever outbreak has downed more than 1,000 residents of Calamba, Laguna and killed one.

Water samples taken from the Bukal Pumping Station of the Calamba Water District showed bacteriological content that caused the typhoid fever outbreak in the area.

Although the DoH findings are already definitive, Calamba Water District officials disputed the claims, saying their water sources are clean.

Oliveros said the DoH saw the need to investigate the pipes because it was also possible that the main water sources from the Bukal Pumping Station are clean, but that some of the pipes in the distribution system may have some contaminated and leaking pipes.

She said that even if contamination is limited to only a portion of the distribution system, it is still within the responsibility of the Calamba Water District as water providers in the area.

But lawyer Emilio Capulong, CWD director, said the DoH report that the water coming from the CWD was contaminated based on its water quality tests has no basis.

Capulong said the DoH tests were conducted without the presence of their representatives and most water samples came from selected places that were not covered by the CWD.

“There was no joint testing between DoH and CWD, only recently when we requested after the DoH conclusion on Monday,” Capulong said.

CWD provides water to 150,353 households in 39 out of 54 villages in Calamba.

CWD officials suspected that the outbreak could be caused by food intake, sanitation, or infected groundwater and aquifer.

“We are assuring that the water here is safe, clean and potable. And, nothing to be worried about,” Capulong said.

Latest data from the DoH show that hospital admissions for typhoid fever in Calamba went up to 902 in the March 8-11 period from 590 cases in the preceding weeks.

Community-based patients reached 1,534 cases in the same period. These are patients who have shown symptoms of typhoid fever and have gone to the village health centers or were only treated at home. With a report from Niña Catherine Calleja, Inquirer Southern Luzon