The Centre for Health Protection today appealed to the public for heightened vigilance against melioidosis and urged people to maintain personal and environmental hygiene.

The centre received reports from the Hospital Authority Kowloon West Cluster, stating that 15 melioidosis cases have been recorded from August to October.

Initial epidemiological investigations revealed that most of the patients have underlying diseases and are immunocompromised, and they had not visited any places in common.

As all the patients live in Sham Shui Po, the centre conducted investigations and collected environmental samples in the district. All samples tested negative for melioidosis.

According to the authority's information, 29 melioidosis cases have been recorded in Hong Kong so far this year, involving 21 men and eight women aged 42 to 93. Twenty of them live in Sham Shui Po, while others live in Kwun Tong, Wong Tai Sin, Sai Kung, Kwai Tsing, Eastern and Yau Tsim Mong districts.

Among the cases, 19 patients have been discharged from hospitals, four are still hospitalised and six passed away. Five of the deceased had underlying diseases.

The centre pointed out that melioidosis is prevalent in Southeast Asia and Northern Australia and is a disease caused by the bacterium Burkholderia pseudomallei. Cases have been recorded in Hong Kong each year, with a total of 50 cases from 2017 to 2021.

The melioidosis bacteria is widespread in soil and muddy water, particularly common in moist clay soil. It may expose to the ground after typhoons or storms and would spread easier with strong wind and storms, leading to a possible increase in the number of melioidosis cases.

Humans can be infected through contact with contaminated soil and surface waters, inhalation of contaminated dust or water droplets, and ingestion of contaminated water. Person-to-person transmission is rare but may occur through contact with infected patients' blood or body fluids.

Common symptoms of melioidosis include fever, headache, localised pain or swelling, ulceration, chest pain, cough, haemoptysis and swelling of regional lymph nodes.

Noting that no vaccine is currently available for melioidosis, the centre reminded the public, especially people in high-risk groups such as those with underlying diseases, to avoid contact with soil or muddy water after storms and heavy rain in order to prevent infection.