A 12-year-old boy in Hong Kong has come down with chikungunya fever – the first case reported in the city in six years.

The patient is being treated at Princess Margaret Hospital after returning from the Chinese mainland on Wednesday. He went to a private doctor in Kwun Tong before being transferred to United Christian Hospital, Albert Au Ka-wing, head of the Communicable Disease Branch of the Centre for Health Protection of the Department of Health, told a press conference on Saturday.

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The Food and Environmental Hygiene Department has carried out investigations and mosquito control measures. Within a 250-meter radius around the patient’s home, at the hospital and places he had visited, efforts to exterminate mosquitoes have been strengthened, along with regular patrols.

Jacky Chan Man-chun, medical director of the Hospital Authority’s Infectious Disease Centre, said the patient’s fever had subsided on Saturday morning, and the pain at the joints had diminished.

He said most patients of chikungunya fever – a mosquito-borne viral disease – can recover on their own although some symptoms, such as pain at the joints, may persist for an extended period.

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Au said most patients with chikungunya fever have mild symptoms, and the disease cannot be transmitted from person to person. However, the virus can remain dormant in mosquitoes for about nine days before spreading again. The authorities have stepped up mosquito-eradication efforts.

Au urged doctors to check patients’ travel history if the symptoms appear.

The current outbreak began in Foshan, Guangdong province, last month, mostly concentrated in the Shunde district.

Au said there has been no evidence of a large-scale transmission of the disease, and Hong Kong residents should not be unduly alarmed. The authorities will introduce chikungunya fever reagents in quantities sufficient to meet the needs of residents, and there’s no need to carry out citywide tests at the moment, he said.

READ MORE: Guangdong moves swiftly to combat Chikungunya

Healthcare authorities in Guangdong, Hong Kong and Macao launched a joint campaign against chikungunya fever last month following an outbreak of the disease.

Contact the writer at atlasshao@chinadailyhk.com