Thursday, May 04, 2017

Hong Kong CHP Reports A Late Season Flu Surge

Credit HK CHP Flu Express


Hong Kong often sees a biphasic or `double peaked’  flu season, with their heaviest activity usually from February–April and (a less severe) season in June through August, as was described in the 2008 PLoS One research paper Seasonality of Influenza A(H3N2) Virus: A Hong Kong Perspective (1997–2006).
This winter's flu HK season began earlier than usual (see last December's Hong Kong: Early Flu Surge Puts Pressure On Local Hospitals), and appeared to have run its course by the middle of April with their Flu Express Week 15 reporting a `low level' of flu activity.
Today, somewhat unexpectedly, Hong Kong's CHP is reporting a recent surge in influenza activity, and is reinstating their enhanced surveillance for severe seasonal influenza.

A letter has been sent to local physicians alerting them, a public notice has been posted, and today's Flu Express provides additional details

Flu Express is a weekly report produced by the Respiratory Disease Office of the Centre for Health Protection. It monitors and summarizes the latest local and global influenza activities.
Local Situation of Influenza Activity (as of May 3, 2017)

Reporting period: Apr 23 – 29, 2017 (Week 17)

  • According to the latest surveillance data, the local influenza activity has increased in the past few weeks.
  • From May 5, 2017 onwards, the Centre for Health Protection (CHP) will collaborate with the Hospital Authority (HA) and private hospitals to reactivate the enhanced surveillance for severe seasonal influenza cases (i.e. influenza-associated admissions to intensive care unit or deaths) among patients aged 18 or above in order to monitor the severity of influenza infection. Besides, the CHP continues to routinely monitor severe paediatric influenza-associated complications or deaths among people aged below 18 years.
  • Apart from adopting personal, hand and environmental hygiene practices against respiratory illnesses, those members of the public who have not received influenza vaccine are urged to get vaccinated as soon as possible for personal protection.
  • Influenza can cause serious illnesses in high-risk individuals and even healthy persons. Given that seasonal influenza vaccines are safe and effective, all persons aged 6 months or above except those with known contraindications are recommended to receive influenza vaccine for personal protection.
  • The Vaccination Subsidy Scheme (VSS) 2016/17 was launched on Oct 20, 2016. Subsidised vaccination has been provided for children aged 6 months to under 12 years, elderly aged 65 years or above, pregnant women, persons with intellectual disabilities and persons receiving Disability Allowance (DA). In addition, starting from Nov 3, 2016, the eligibility of free vaccination under the Government Vaccination Programme has been expanded to include children aged 6 years to under 12 years from families receiving Comprehensive Social Security Assistance or holding valid Medical Waiver Certificates as well as persons receiving DA who are existing clients of public clinics and hospitals. Please refer to the webpages (
                 (Continue. . . .)

From the public notice, we also learn that while this year has been predominantly an H3N2 season, the number of H1N1 cases is increasing. Schools are instructed to conduct daily temperature checks of all students, and are required to notify the CHP of any unusual number of respiratory illnesses and/or absenteeism.

     The Centre for Health Protection (CHP) of the Department of Health today (May 4) urged the public, particularly young children, the elderly and chronic disease patients, to observe strict hand, personal and environmental hygiene against influenza amid the increased activity of local seasonal influenza in the past two weeks.
     According to the latest surveillance data of the CHP, the positive percentage of seasonal influenza viruses among respiratory specimens received increased from 8.44 per cent to 10.08 per cent from the week of April 16 to that of April 23. While most detections were influenza A(H3) (5.65 per cent in the week of April 23), the percentage of influenza A(H1) detections had increased from 1.70 per cent in the week of April 16 to 3.19 per cent in that of April 23.
     In the same period, the number of institutional outbreaks of influenza-like illness (ILI) increased from one (affecting four persons) to four (21 persons). The average ILI consultation rate among sentinel private doctors rose from 31.6 to 49.9 cases per 1 000 consultations in the same period, while that of General Out-patient Clinics increased from 3.6 to 4.0.
     "Our data show that the local seasonal influenza activity has increased. Starting from tomorrow (May 5), we will collaborate with the Hospital Authority and private hospitals to reactivate the enhanced surveillance for severe seasonal influenza, i.e. influenza-associated admission to the Intensive Care Unit or death in adults aged 18 or above, to better monitor the severity of illness," a spokesman for the CHP said.
     In children aged under 18, routine surveillance of severe influenza-associated complications or deaths is ongoing.
     The CHP has issued letters to doctors, hospitals, institutions and schools to appeal for heightened vigilance.
     Schools should check the body temperature of all students every day when they arrive at school to identify those with fever. To prevent outbreaks, those with fever (oral temperature over 37.5 degrees Celsius or ear temperature over 38 degrees C), with or without respiratory symptoms, should not be allowed to attend school. Schools should advise them to seek medical advice and avoid school till two days after fever subsides.
     In addition, staff should check their temperature before work every day and those with fever or respiratory illnesses should refrain from work.
     "Schools should promptly report to the CHP in case of an increase in respiratory illnesses or absentees for immediate epidemiological investigations and outbreak control. We will issue letters to kindergartens and child care centres as well as primary and secondary schools on the above measure," the spokesman said.

Ends/Thursday, May 4, 2017

Issued at HKT 19:08

While all of this may seem like much to do about nothing, Hong Kong - as both an international city, and sitting adjacent to the `flu factory' that is Mainland China -  is uniquely positioned to be the first see any changes to the seasonal flu virus.
Having experienced the first human outbreak of H5N1 in 1997, followed six years later by the devastating SARS epidemic (see SARS And Remembrance), Hong Kong's CHP takes their vulnerability to infectious disease outbreaks very seriously. 
This surge in flu activity in Hong Kong may be a short-lived blip of little consequence. But should it prove otherwise, we couldn't ask for a more proactive or better equipped health department to deal with it.

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