Melioidosis in Timor-Leste: First Case Description and Phylogenetic Analysis

Abstract

Burkholderia pseudomallei, the causative agent of melioidosis, has not yet been reported in Timor-Leste, a sovereign state northwest of Australia. In the context of improved access to diagnostic resources and expanding clinical networks in the Australasian region, we report the first 3 cases of culture-confirmed melioidosis in Timor-Leste. These cases describe a broad range of typical presentations, including sepsis, pneumonia, multifocal abscesses, and cutaneous infection. Phylogenetic analysis revealed that the Timor-Leste isolates belong to the Australasian clade of B. pseudomallei, rather than the Asian clade, consistent with the phylogeographic separation across the Wallace Line. This study underscores an urgent need to increase awareness of this pathogen in Timor-Leste and establish diagnostic laboratories with improved culture capacity in regional hospitals. Clinical suspicion should prompt appropriate sampling and communication with laboratory staff to target diagnostic testing. Local antimicrobial guidelines have recently been revised to include recommendations for empiric treatment of severe sepsis.

Keywords: Burkholderia pseudomallei; Timor-Leste; melioidosis; phylogeny.

Figure 1.

A (left), Clinically apparent abdominal distension. B (right), Computerized tomography demonstrated large, multiloculated hepatic abscess.

Figure 2.

A (left), Chest x-ray demonstrating left lower lobar consolidation. B (middle), Skin and soft tissue infection over the left popliteal fossa. C (right), Healing and scar formation 3 months after commencement of therapy.

Figure 3.

Phylogenetic tree of B. pseudomallei isolates. The scale bar indicates substitutions per site. Bootstrap support (based on 1000 replicates) for branches below 80% is shown.

Figure 4.

Timor-Leste in relation to the ecological boundary of Wallace's line.