CHP announces investigation progress on Legionnaires' disease case
The Centre for Health Protection (CHP) of the Department of Health (DH) previously announced a Legionnaires' disease (LD) case involving a 45-year-old female. Based on further investigation findings, the CHP today (December 17) announced that the possibility of a nosocomial infection cannot be ruled out. The CHP has instructed the hospital concerned, St Paul's Hospital, to thoroughly disinfect the water system on the relevant floor. No other patients who stayed on the same floor developed symptoms of LD so far.
The female patient concerned had underlying illness and was immunosuppressed. She was admitted to a private room at St Paul's Hospital on November 19 for treatment of her underlying illness and was discharged on November 26. She was readmitted to the same hospital on November 28 for the same underlying illness. After re-admission, she developed a fever and her chest X-ray showed symptoms of pneumonia. Her respiratory specimen collected on December 2 tested positive for Legionella pneumophila serogroup 1. The patient's condition subsequently deteriorated and she succumbed on December 6 due to her underlying illness.
As the patient had stayed in the community and hospitalised at St Paul's Hospital during the incubation period, the CHP conducted environmental investigations at her residence and the hospital to investigate the source of infection. On December 5, the CHP and the Electrical and Mechanical Services Department collected water and environmental samples at the hospital. A total of 24 water samples were collected from wards of the floor where the patient was admitted between November 19 to 26. Upon laboratory testing by the Public Health Laboratory Services Branch of the CHP, 16 samples tested positive for Legionella pneumophila serogroup 1 at levels ranging from 0.9 to 7.3 colony-forming units per millilitre (cfu/ml), exceeding the action level for water supply systems in high-risk areas of hospitals (i.e. 0.1 cfu/ml or above). All 12 environmental samples tested negative.
The CHP also collected water and environmental samples from the patient's residence. Relevant laboratory testing is ongoing.
Taking into account the length of the patient's hospital stay, onset date and preliminary test results, the possibility of a nosocomial infection cannot be ruled out at this stage.
The patient had no household contacts. The CHP placed 28 patients admitted to the same floor concerned since mid-November under medical surveillance. No additional LD cases have been identified among the patients so far. All have been discharged.
St Paul's Hospital has closed and suspended use of the wards on the floor concerned and will thoroughly disinfect the water supply system on that floor as instructed by the CHP. Investigation is ongoing. The CHP has provided health advice and medical surveillance recommendations to the hospital, and will continue to closely monitor the implementation of the measures and conduct epidemiological investigations.
Legionellae are found in various environmental settings and grow well in warm water (20 to 45 degrees Celsius). They can be found in aqueous environments such as water tanks, hot and cold water systems, cooling towers, whirlpool spas, water fountains, humidifiers and home respiratory devices that support breathing. People may become infected when they breathe in contaminated droplets (aerosols) and mist generated by artificial water systems, or when handling garden soil, compost and potting mixes.
The public may visit the CHP'sLD page, theCode of Practice for Prevention of LDand theHousekeeping Guidelines for Cold and Hot Water Systems for Building Managementof the Prevention of LD Committee, and the CHP'srisk-based strategyfor prevention and control of LD.
Source: AI-found images
Local pig samples test positive for African Swine Fever virus
The Agriculture, Fisheries and Conservation Department (AFCD) today (December 17) announced that samples taken from a licensed pig farm in Yuen Long had tested positive for the African Swine Fever (ASF) virus.
An AFCD spokesman said, "Four pig samples were taken from a licensed pig farm in Lau Fau Shan, Yuen Long, yesterday (December 16). Upon testing by AFCD staff, all the samples were found positive for the ASF virus. The AFCD has immediately suspended transportation of any pigs from the farm concerned until further notice according to the contingency plan on ASF. The AFCD is arranging culling of pigs, for the sake of prudence."
He further said, "Positive cases should be seriously and promptly handled as the effect of ASF is very lethal to pigs. If the spread is not contained, a large number of pigs will die, hence seriously impacting pig farmers and the pig rearing industry. AFCD staff immediately notified all local pig farmers of this incident and reminded them to alert the AFCD immediately if abnormal health conditions are observed in pigs. In addition, the AFCD is arranging staff to inspect the one operating pig farm within 3 kilometres of the index farm and collect pig samples for ASF testing. For the sake of prudence, the AFCD has suspended movements of pigs on this pig farm until further notice. No reports of abnormalities from pig farms outside the 3km zone have been received so far. AFCD staff are continuing close surveillance to detect pigs with abnormalities and if a farm is infected as early as possible. Surveillance of the activities of nearby wild pigs of the index farm will also be stepped up. Moreover, the AFCD is maintaining close contact with pig farmers via text message groups, keeping them informed of the latest situation of ASF and ways to prevent the infection of pigs."
The spokesman stressed that ASF is not a zoonotic disease and will not infect humans; hence, it does not cause any human health and food safety risks. Regardless of whether the pigs are infected with ASF, pork cooked thoroughly is safe for consumption. Members of the public do not need to be concerned. The AFCD held a seminar for pig farmers on specific preventive measures and biosecurity advice against ASF last month, with a view to enhancing vigilance of the industry in prevention of ASF. Meanwhile, in order to strengthen the knowledge of local pig farmers of the clinical signs of ASF for early detection and reporting of abnormalities of pigs, the AFCD has launched the Guidelines for Reporting Cases of African Swine Fever to assist pig farmers in identifying suspected cases for early reporting and appropriate follow-up.
The present case does not affect the operation of local slaughterhouses nor the overall supply of live pigs. Since June 2019, a daily clearance arrangement whereby live pigs will be slaughtered within 24 hours upon admittance has been imposed in Sheung Shui and Tsuen Wan slaughterhouses. Under the arrangement, lairages in different areas of the slaughterhouses will be cleared out and undergo thorough cleaning and disinfection every day to further enhance biosecurity and minimise the risk of infection among pigs in the slaughterhouses.
The Food and Environmental Hygiene Department and the AFCD will continue to stringently conduct cleaning and disinfection of Mainland live pig transportation vehicles and their counterparts for local pigs at slaughterhouses to minimise the risk of cross-infection of ASF. Mainland live pig vehicles and local ones should be thoroughly cleaned and disinfected every time they leave the Sheung Shui Slaughterhouse (SSSH), and the respective designated positions for their cleaning and disinfection are separated. Manpower and equipment of the SSSH have been strengthened immediately for cleaning and disinfection of the vehicles. In light of these stepped-up measures, the slaughterhouses need not be closed and other pigs need not be culled.
As culling operation takes time, the AFCD will release updated operation information every day later on the departmental webpage,www.afcd.gov.hk, for the public.
Source: AI-found images
