Hong Kong has recorded its first locally acquired case of chikungunya fever, involving an 82-year-old woman who did not have any travel history within the incubation period.
The woman, who lives at Fung Tak Estate, Wong Tai Sin, tested positive for the mosquito-borne virus when she attended the Accident and Emergency Department at Kwong Wah Hospital last Thursday.
She had previously developed a swollen and painful left ankle on October 18, which escalated into a fever and joint pain four days later. She then sought medical attention from a private doctor.
Investigations revealed that she had visited Qingyuan in Guangdong, China, in late August but had no travel history during the incubation period, which is around two to 12 days prior to onset.
The case was therefore classified as local, according to a statement by the Department of Health’s Centre for Health Protection (CHP) on Sunday.
Chikungunya fever
The city had recorded a total of 46 confirmed cases of chikungunya fever as of 5pm on Saturday, all of which were imported. None of the other patients had been near the location of the local case.
According to the CHP website, symptoms of the mosquito-borne virus include fever and joint pain, with other common signs such as muscle pain, headache, nausea, fatigue and rash. There is no antiviral drug treatment available – preventative measures, such as using repellent, are best.
“Given that the activity areas of the 82-year-old patient are primarily within the estate, the CHP cannot rule out the possibility that unidentified infected patient(s) in the area may have transmitted the virus to mosquitoes in the estate, leading to her infection,” the statement said.
The CHP, together with the Food and Environmental Hygiene Department (FEHD), have inspected locations near Fung Tak Estate, as well as conducted vector investigations and mosquito control operations to minimise the risk of transmission.
The CHP will issue letters to doctors, hospitals, schools and institutions, providing the latest information on chikungunya fever.
In addition, the CHP has been hosting a health consultation booth at Fung Tak Shopping Centre as of Sunday, where residents with relevant symptoms can seek help. An inquiry hotline will also be se tup.
The mosquito infestation indices this year are lower than in previous years, according to the FEHD.
The mosquito infestation index in September stood at 2.5 per cent – a decrease from 9.5 per cent in June. The Gravidtrap index indicates that the distribution of mosquitoes in the local case’s area was not extensive in October, albeit a slight increase from September. Gravitraps are devices which attract and trap adult female mosquitoes.
Last Thursday, the city recorded its first fatal case of chikungunya fever after a 77-year-old man with a chronic illness died the day before.
The man developed a fever and joint pain after returning to Hong Kong from a trip to Guangzhou in China’s Guangdong province. His condition subsequently deteriorated and he eventually died of the mosquito-borne virus, complicated by multi-organ failure.
