A Case Report of Unusual Diagnosis of Melioidosis in a Non-Traveler: Implications for Transmission and Diagnosis

Abstract

Melioidosis is prevalent in Southeast Asia, acquired via breathing or skin contact with water or soil contaminated by Burkholderia pseudomallei. This article reports a 42-year-old male melioidosis patient without underlying diseases or travel history to epidemic areas, discussing its significance for epidemiology, diagnosis and treatment in non-epidemic areas. The patient's clinical manifestations, disease progression, previous treatment, admission examination, diagnostic process, treatment and follow-up results were retrospectively analyzed. tNGS, microbial culture and WGS were used for sample and pathogen identification and genetic analysis. The patient had recurrent fever with erythema nodosum on the left lower limb. Misdiagnosed and treated ineffectively in other hospitals, he was diagnosed with melioidosis in the Second Affiliated Hospital of Jiaxing University. The strain was identified as Burkholderia pseudomallei, type ST46. Appropriate antibiotic treatment was selected based on drug sensitivity test results. After 6 months of follow-up, most lesions were absorbed, laboratory indicators normalized and the clinical effect was good. Epidemiological investigations suggested ST46 might be transmitted via non-traditional routes related to the fact that 15 days before the onset of the disease, the patient had purchased live turtles and the soil for raising them online which were sourced from Yunnan, indicating the possibility of geographical transmission. This case enriches understanding of melioidosis' non-traditional transmission, strain transmission, clinical diagnosis and treatment, highlighting the importance of considering the disease in non-endemic areas' differential diagnosis and the need for further epidemiological surveillance and research.

Keywords: melioidosis; non-endemic areas; non-traditional transmission; targeted next-generation sequencing.

Figure 1

The timeline shows the entire diagnosis and treatment process of this case.

Figure 2

(A) The chest CT image before treatment. (B) The histological pathology image stained to visualize tissue structures. (C) The growth of B. pseudomallei on blood agar and (D) MacConkey agar.

Figure 3

(A) The brain MRI image before treatment and (B) the PET-CT images.

Figure 4

(A) The follow-up chest CT image and (B) the brain MRI image. (C) The follow-up appearance of the same area.

Figure 5

The phylogenetic tree. The red-boxed area highlights samples mainly from China and Vietnam. The XXL represents isolated strain (ST46 type) as shown in red text.