Hong Kong enters two-week watch for Zika virus
Woman who became city’s first case of Zika infection leaves hospital fully recovered, but experts say the next two to three weeks will be critical to avoid outbreak
Hong Kong has entered a critical two-week period under the threat of the dreaded Zika virus spreading locally, after confirming the city’s first case on Thursday night.
The infected patient, an expatriate woman who travelled recently to the Caribbean, left hospital fully recovered yesterday, but health authorities are taking no chances as the virus could still spread through mosquitoes that may have bitten her in the city.
There is also the added concern that around 1,500 people, including 38 local athletes, are returning from the Olympic Games in Rio de Janeiro, Brazil, where the disease surfaced last year. And China’s winning athletes from Rio are also starting a three-day visit to the city today.
The 38-year-old who became Hong Kong’s first imported case of Zika was discharged from the United Christian Hospital after a complete recovery. While she was out of danger, it would take two to three weeks to see whether she might have spread the virus during the infection period, an expert said.
Jasper Chan Fuk-woo, a microbiologist at the University of Hong Kong, explained that the virus usually stays in the blood for around two weeks.
“The risk of an outbreak in Hong Kong is not particularly high at the moment, as it is not unexpected that we will have imported cases,” he said. “But it’s more if the city sees its first local case. The coming two to three weeks will be very critical.”
Fresh from Brazil, Hong Kong swimmer Sze Hang-yu admitted that both she and teammate Claudia Lau Yin-yan had been bitten by mosquitoes in Rio, but they were not too worried.
“We don’t feel unwell at all. If anything, I am still a little jet-lagged,” she joked at a welcoming ceremony for the city’s Olympic squad yesterday.
So far, 20 people, including at least one local athlete, have signed up for voluntary screening for the virus at HKU upon returning from Brazil, even though they showed no symptoms of infection. Their test results are pending.
Local cyclist Sarah Lee Wai-sze said she would also take a blood test as a precaution, even though she joked that the mosquito problem in Hong Kong was more serious than in Rio.
The visiting mainland delegation will be given health advice and briefed on protective measures against mosquito bites, a spokesman for the Department of Health said.
HKU microbiologist Ho Pak-leung noted that while 80 per cent of infected people did not show any symptoms of sickness, the Zika virus could still spread to babies through pregnancy.
The symptoms are flu-like, such as mild fever, rash, joint pain and red eyes. But Zika causes microcephaly, a serious birth defect which manifests in an underdeveloped brain and head.
Ho advised women not to plan for pregnancy for at least two months after travelling to any Zika-hit area, and men to use condoms for six months.
Health authorities are unable to say whether the city’s first Zika infection is an isolated case or may be more widespread.
Mosquito exterminators were out in force yesterday at Lohas Park in Tseung Kwan O, where she lives, and the International Finance Centre in Central where she works. The woman was said to have visited other places such as Wo Mei Hung Min Road in Sai Kung and Lockhart Road in Wan Chai during the infection period.
She had travelled to the Caribbean island of Saint-Barthelemy from August 6 to August 20, before returning to Hong Kong on August 22. She fell ill last Saturday and sought help at Matilda Medical Centre in Central on Tuesday, where she left blood and urine samples for testing.
She was placed in United Christian Hospital’s isolation ward when she tested positive on Thursday.
Three family members she had travelled with showed no symptoms.