Hanoi officials discovered a group of over a thousand blood-sucking bugs carrying parasites on Monday.
The bugs were found under a wood pile owned by a family in Tu Liem District. The cluster represents the biggest group of the bugs ever found in Hanoi.
Experts collected around 600 samples of grown and young bugs, as well as the eggs, from the group for further study.
Truong Xuan Lam, an entomologist at the Institute of Ecology and Biological Resources said they dissected seven bugs all of which contained human blood and parasites.
Lam said the parasites have spread to white mice at his laboratory.
"There needs to be researches to see if these parasites can spread diseases to human," he said.
The expert said they have not figured out how dangerous the parasites could be to human populations.
In Vietnam, the blood-sucking bugs were first found in Hanoi and then provinces in the central region.
Scientists first suspected the bugs were the same insects (Trypanosoma Cruzi) that transmit the Chagas disease specific to Latin America.
Later, scientists said the bugs found in Vietnam are "assassin bugs" that are fairly harmless.
Still, they have pledged to conduct further research into the matter.