The Centre for Health Protection (CHP) of the Department of Health today (July 21) confirmed the first local case of Japanese encephalitis (JE) transmitted by blood transfusion in hospital.

     The Controller of the CHP, Dr Wong Ka-hing, said, "Following investigations into the case reported yesterday (July 20), experts in epidemiology, public health, infection control and microbiology of the CHP and the Hospital Authority have been working closely and held meetings on public health assessment and necessary follow-up to be conducted by parties concerned."

     Investigations revealed that the male patient aged 52 had received a number of blood transfusions during hospitalisation.

     Residual samples of the blood transfused to the patient in the incubation period were retrieved for laboratory investigations. Upon the CHP's testing, one blood sample from Queen Mary Hospital (QMH) and one from the Hong Kong Red Cross Blood Transfusion Service tested positive for JE virus, both originating from the same donation which was transfused to the patient on June 22. Of note, the genetic sequence of the virus from the positive sample from QMH was identical to that of the patient. Samples from three other donations transfused to the patient on different dates tested negative.

     The CHP has swiftly conducted source tracing and identified the 46-year-old male blood donor concerned who gave blood on May 29. He has been asymptomatic all along.

     Contact tracing has identified two other patients who had received the donor's blood products. One is a discharged patient of QMH who received transfusion on June 2 and QMH is contacting the patient for clinical assessment and blood testing. The other is a patient of Queen Elizabeth Hospital who died of chronic illness on July 4 after surgery, during which the patient received transfusion on June 20. Relatives will be contacted.

     Epidemiologically, the donor had no travel history to JE-endemic areas and his home contact has remained asymptomatic. He lives in Kingswood Villas, Tin Shui Wai and recalled no mosquito bites.

     "The CHP will proceed standard public health actions as a precautionary measure. The Food and Environmental Hygiene Department (FEHD) and the Agriculture, Fisheries and Conservation Department have been informed for necessary follow-up," Dr Wong said.

     Officers of the CHP will conduct site visit and field investigations by questionnaire surveys at the donor's residence for active case finding and arranging blood tests. A health talk will be held at 9.30am tomorrow (July 22) with the FEHD to deliver health advice to residents and the public.

     In addition, site visit has been conducted at Grantham Hospital and a health talk was held this afternoon.

     The CHP's JE hotline (2125 1122) will operate from 9am to 5.45pm this weekend and next week.

     The Guangdong and Macau health authorities have been informed of the case and the CHP will issue letters to doctors and hospitals to alert them to the latest situation.

     While JE is principally mosquito-borne, overseas scientific literature show that, based on nature of similar flaviviruses, blood transfusion and organ transplant are considered to be potential modes of transmission of JE virus.

Ends/Friday, July 21, 2017
Issued at HKT 21:53

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