Fears grow that genetic change in the scarlet fever germ is behind outbreak as the new strain is being found in Hong Kong patients, with the number of cases hitting 526. Mutated bacteria have been found in dozens of patients suffering from scarlet fever as the Hong Kong Hospital Authority held an emergency meeting to try to stop the spread of the deadly disease.
University of Hong Kong microbiologist Yuen Kwok-yung said the same mutation detected in samples taken from the seven-year-old girl who died in Queen Mary Hospital on May 29 had been found in “dozens more” patients. The finding supports the theory that a genetic change within the group A Streptococcus bacteria is the cause of the outbreak, said Yuen.
At yesterday’s meeting, the Hospital Authority decided to step up surveillance by testing more patients for group A Streptococcus, which can cause other diseases such as meningitis and tonsillitis.
Dr. Dominic Tsang Ngai-chong, the authority’s chief infection control officer, said that from today all public hospitals would start taking samples from patients with an infection of the skin, throat or soft tissues, which could also be caused by group A Streptococcus. “Such surveillance can help us to know how widespread the bacteria actually are, and how many of them also have the genetic mutation,” he said.
Two children have died of scarlet fever in the past three weeks. Symptoms include a rash over the body, a bright red strawberry-like tongue, fever and a sore throat. The number of infections continues to climb every day. Among the new cases was an 18-year-old man, which doctors said was unusual as the disease normally affects children aged three to 10.
The University of Hong Kong microbiology department last week discovered the genetic mutation in the group A Streptococcus bacteria in a girl recovering from scarlet fever. The bacteria have a new genome fragment which comes from other bacteria found in the mouth.
The Centre for Health Protection confirmed last night it had found two different strains of group A Streptococcus in the two fatal cases – the “emm12” strain in the seven-year-old girl but an “emm1” strain in the five-year-old boy who died on Tuesday at Princess Margaret Hospital. Another microbiologist at the University of Hong Kong, Dr. Ho Pak-leung, said it was normal to find more than one strain of the bacteria because both emm12 and emm1 strains were common in Hong Kong.
The authority last night reminded doctors to be on the alert for children with chickenpox. If a child has wounds on his or her skin, group A Streptococcus can get into the bloodstream easier and cause fatal toxin shock – as happened in the case of the five-year-old victim.
Doctors were advised to prescribe penicillin to any children with skin infections caused by chickenpox. Starting from 24 June, public hospitals have to report all severe cases of scarlet fever requiring intensive care.
Source: South China Morning Post