According to the Preventive Health and Environment Department under the Ministry of Health, some 75 percent of people infected with the cholera bacteria don’t show any signs of infection but are still infectious.

It also said some 3-5 percent of recovered patients still carry the bacteria for a month or even longer if they are not treated properly.

In related news, six people suspected of contracting the A H1N1 virus by the Hanoi International Health Quarantine Center late last week have tested negative, the National Institute of Infectious and Tropical Diseases said Sunday.

Reported by Nam Son