Hong Kong parents are being warned to stay vigilant against scarlet fever amid a surge this year in cases of the potentially deadly disease. Nearly 2,000 cases were reported in the city in the first 11 months of the year, up nearly 60 per cent from the 1,244 recorded for the same period in 2016, according to the Department of Health. Scarlet fever is a bacterial infection that mostly affects children under 10 years old. The increase in cases could be the result of a bacterial mutation as well as an unusually strong flu season weakening children’s immunity, doctors say. Hong Kong Medical Association vice-president Dr Alvin Chan Yee-shing predicted additional local reports of the disease. “The number of cases are picking up rapidly, and we expect the trend to continue in the coming weeks and months,” he said. Scarlet fever claimed many thousands of lives in the 19th century and made a comeback in Hong Kong in 2011. That year, the number of cases soared to 1,526 from just 128 in 2010. Countries from the mainland to Britain have recorded similar trends, although what is causing the worldwide resurgence in the centuries-old disease remains unknown. Girl infected with drug-resistant tuberculosis held in quarantine at Hong Kong hospital Chan believed global warming and air pollution were possible factors. In Hong Kong, two children died from scarlet fever in 2011. They had previously been infected with chickenpox. With late treatment and insufficient rest, scarlet fever could lead to death Dr Alvin Chan, Medical Association Scarlet fever can give rise to complications such as rheumatic heart disease and acute nephritis, which can cause heart disease and kidney failure later in life. Symptoms include fever, sore throat and a sandpaper-textured rash spreading from the neck and upper torso to the whole body. A patient’s tongue may also appear red and bumpy, a phenomenon known as “strawberry tongue”. But a spokesman for the department said it had no evidence that a gene mutation in the bacterium was responsible for the uptick. While scarlet fever is curable with antibiotics such as penicillin, no vaccine is yet available. The consequences of late treatment are grave, Chan noted, especially when children are also afflicted with the flu or chickenpox. Children infected by chickenpox have very weak immunity,” he said. “Coupled with late treatment and insufficient rest, scarlet fever could lead to death.” Doctors advised parents and children to be alert to personal hygiene, urging them to wash their hands after touching their mouth, nose and eyes. They are also advised to maintain good indoor ventilation and stay away from crowds. The bacteria can be transmitted through either respiratory droplets, such as those produced by coughing and sneezing, or direct contact with respiratory secretions. The peak season for scarlet fever runs from November to March and from June to July, the department said.