CHP appeals for heightened vigilance against melioidosis infection; Sai Kung resident infected

^{Burkholderia pseudomallei bacteria under the microscope}

The Centre for Health Protection (CHP) of the Department of Health (DH) yesterday (12/10) appealed to members of the public for heightened vigilance against melioidosis and urged them to maintain personal and environmental hygiene.

The CHP received reports from the Hospital Authority (HA) Kowloon West Cluster that 15 melioidosis cases have been recorded from August to October. According to information from the HA, a total of 29 melioidosis cases have been recorded in Hong Kong this year as of today, involving 21 males and eight females, aged from 42 to 93 years, 20 of them live in Sham Shui Po and the other patients live in Kwun Tong, Wong Tai Sin, Sai Kung, Kwai Tsing, Eastern District and Yau Tsim Mong. Nineteen patients have been discharged, four patients are still hospitalised and six patients passed away, which involved four males and two females aged from 54 to 93 years, and five of them were with underlying diseases.

Melioidosis, which is prevalent in Southeast Asia and Northern Australia, is a disease caused by the bacterium Burkholderia pseudomallei. Melioidosis cases have been recorded in Hong Kong each year. According to the records of the HA, the number of melioidosis cases recorded in Hong Kong from 2017 to 2021 were 12, six, three, 12 and 17 respectively.

For the 15 cases reported by the Kowloon West Cluster, initial epidemiological investigations of the CHP revealed that most patients are with underlying diseases and immunocompromised, and they had not visited any places in common. As the relevant patients all live in Sham Shui Po, the CHP has conducted investigations and collected relevant environmental samples in the area, and all samples tested negative for melioidosis.

According to overseas literature and local data, melioidosis bacteria survives in the environment. Infection cases are more common after typhoons or storms. The bacterium Burkholderia pseudomallei of melioidosis in the soil and muddy water may expose to the ground after typhoons or storms, and the bacteria would spread easier with strong wind and storms. As such, the number of melioidosis cases may increase.

A spokesman for the CHP said that no vaccine is currently available for melioidosis. The CHP reminded members of the public, especially high risk groups such as persons with underlying diseases, to avoid contact with soil or muddy water after storms and heavy rain to prevent melioidosis infection.

The spokesman said that the bacterium Burkholderia pseudomallei is widespread in soils and muddy water, particularly common in moist clay soils. Humans can become infected through contact with contaminated soil and surface waters (especially through skin abrasions/wounds); inhalation of contaminated dust/water droplets; and ingestion of contaminated water. Person-to-person transmission is rare but may occur through contact with the blood or body fluids of an infected person. Depending on the site of infection, common symptoms of melioidosis include fever, headache, localised pain or swelling, ulceration, chest pain, cough, haemoptysis, and swelling of regional lymph nodes. Members of the public should seek medical advice promptly if they develop symptoms. They should take the following preventive measures against infection:

• Avoid contact with contaminated soil;
• Wear appropriate protective clothing or footwear when participating in activities with possible contact with soil or water, e.g. use gloves and wear boots;
• Wash or shower after exposure to contaminated water or soil;
• Always clean any wounds as soon as possible and cover any cuts or grazes with waterproof dressings;
• Wash hands with liquid soap and water after handling with soils or gardening;
• Observe food hygiene and avoid drinking raw water; and
• Travellers can contract the disease through outdoor water sports. Risk of infection can be minimised by avoiding exposure to water sources (such as rivers, ponds or lakes) that might be contaminated.

For more information on melioidosis, please visit the website of the CHP www.chp.gov.hk/en/healthtopics/content/24/101110.html.