Epidemiological characteristics and clinical treatment of melioidosis: a 11-year retrospective cohort study in Hainan.

Background: Melioidosis is a tropical infectious disease caused by Burkholderia pseudomallei, characterised by a high case fatality rate.

Objectives: We summarized the cases of melioidosis at Sanya People's Hospital in Hainan over the past eleven years. This information served as a reference for the epidemiological study, diagnosis, treatment, and prevention of melioidosis in China.

Methods: A retrospective study was conducted to compile clinical data from 138 melioidosis patients treated at Sanya People's Hospital in Hainan Province between 2012 and 2023. By comparing these data with domestic and international clinical case studies, the study aimed to summarise the epidemiological characteristics, clinical manifestations, and therapeutic regimens of melioidosis in Hainan Island.

Results: This study revealed that 84.1% of melioidosis cases were observed in males (116/138). The predominant age group affected was 40 to 60 years, constituting 58.0% (80/138) of the total cases. Farmers and fishermen represented the primary demographic, accounting for 63.8% (88/138). The peak incidence of melioidosis in Hainan was observed in the wet season (summer and autumn months), representing 79.0% of cases (109/138). The most prevalent comorbidity in melioidosis cases was diabetes mellitus (77.5%). Bacteremic melioidosis was the predominant infection type (81.9%). Compared with the non-bacteremic group, the bacteremic group exhibited significantly higher incidences of complications, disseminated infections, and abnormal chest CT findings (p < 0.001, respectively). Further analysis indicated that patients with melioidosis and abnormal chest CT findings had an increased likelihood of concurrent bacteremia (OR = 7.289, 95%CI 1.608-33.039, p = 0.010). During the acute phase of anti-infective treatment, 37.7% (52/138) of the patients underwent intravenous anti-infective drug therapy for at least 2 weeks. Additionally, 56.5% (78/138) of the patients received carbapenems (Meropenem or Imipenem, MEPN or IPM) as part of their anti-infective therapy. In the eradication phase of treatment, 66.0% (66/100) of the patients completed the recommended treatment duration of at least 12 weeks. Furthermore, the majority (90/100, 90.0%) received monotherapy with trimethoprim-sulfamethoxazole (TMP-SMX).

Conclusion: In Hainan Island, the prevalence of melioidosis is notably high among middle-aged male outdoor workers, exhibiting a distinct seasonal pattern with most cases occurring during the summer and autumn months. Bacteremia represents the most common form of melioidosis infection, and abnormal chest CT findings in melioidosis patients serve as a significant hint of bacteremia. Currently, the selection of antimicrobial agents for melioidosis treatment in Hainan Province generally adheres to international guidelines; however, the process requires further standardisation.