Cleaning a nursery classroom (photo: TTXVN)

Seven children and one care taker at Tuoi Ngoc Kindergarten were sick with chickenpox on January 1, and In February, ten students at Nguyen Du Primary School were found with chickenpox. The disease was found at two other primary schools in March.

Students at Hoa Mi and Son Ca kindergartens were infected with hand-foot-mouth disease, while many students at Tran Quoc Toan Primary School had mumps.

The Centre for Preventive Medicine in HCM City immediately carried out measures to clean classrooms and put schools under monitoring in order to prevent further infection. 

Dr. Nguyen Tri Dung, director of HCM City Centre for Preventive Medicine, said hot weather was an ideal environment for the spread of viruses.

In the first three months, the city had 1,155 hand-foot-mouth cases. The city's hospitals also reported 3,000 dengue fever cases, an increase of 43 percent compared to the same period last year -- two people have died.

The health sector has put contagious respiratory diseases under close monitoring and is carrying out more preventive measures to maintain healthy living environments, especially as many people move around the country during the six-day holiday of Liberation Day on April 30 and May Day on May 1.