By Tan Ee Lyn
HONG KONG (Reuters) - Hong Kong closed a kindergarten for a week on Tuesday after initial tests showed that a second child may have died of scarlet fever and experts warned that the epidemic sweeping through Hong Kong, Macao and parts of China may worsen.
The five-year-old boy, who died on Tuesday morning, went to a kindergarten with 400 other children. While authorities have not detected any other scarlet fever cases at the school, it was advised to shut for a week.
"We will be monitoring the situation very closely," Thomas Tsang, a medical doctor and controller of Hong Kong's Center for Health Protection (CHP), told a news conference.
The disease, caused by group A streptococcus bacteria and spread by contaminated respiratory secretions, killed a seven-year-old Hong Kong girl at the end of last month and has made hundreds of other children sick in China, Hong Kong and Macao.
Scientists in Hong Kong who isolated the bacteria in a six-year-old patient found a slight change in its genetic structure which may have enhanced its ability to spread.
"If the genetic mutation is responsible for the increased transmissibility of the bacteria, the outbreak may be sustained for some time," Tsang said.
Scientists at the University of Hong Kong will analyze bacteria samples from other patients to see if they can shed more light on the epidemic, Tsang said.
While scarlet fever happens every year in this region, its incidence has shot up this year.
"Mainland China and Macau are also suffering from unusually high numbers of scarlet fever cases and we believe it may be a regional phenomenon," a spokeswoman for the Health Department in Hong Kong said earlier on Tuesday.
"The outbreak hasn't shown signs of slowing down and we may continue to see more cases this summer."
Scarlet fever affects mostly children under 10. They develop fever, a sore throat and break out in a red rash on their trunk, neck and limbs. It can be treated with antibiotics but complications can result in shock, heart and kidney illnesses.
Hong Kong has had more than 419 cases of scarlet fever this year, by far the highest number in years. Clusters of cases were found in kindergartens, primary schools and childcare centers.
Cases in Hong Kong were up 4.5 fold compared with the same period last year. As well as the seven-year-old girl who died in late May, two boys, aged 6 and 11, developed complications but are now in stable condition.
Cases in China and Macau were up 2.6 and 4.7 fold respectively, according to CHP.
Half of group A streptococcus bacteria in Hong Kong are resistant to the antibiotics erythromycin and clindamycin, but they are all susceptible to penicillin, according to the CHP.
(Editing by Alex Richardson)