Multistate Outbreak of Melioidosis Associated with Imported Aromatherapy Spray

Abstract

Melioidosis, caused by the bacterium Burkholderia pseudomallei, is an uncommon infection that is typically associated with exposure to soil and water in tropical and subtropical environments. It is rarely diagnosed in the continental United States. Patients with melioidosis in the United States commonly report travel to regions where melioidosis is endemic. We report a cluster of four non-travel-associated cases of melioidosis in Georgia, Kansas, Minnesota, and Texas. These cases were caused by the same strain of B. pseudomallei that was linked to an aromatherapy spray product imported from a melioidosis-endemic area.

Figure 1.. Timeline of Four Cases of Melioidosis between March and July 2021.

Shown are the dates of symptom onset, hospital admission, positive cultures (the collection date and the date of initial identification by automated systems that resulted in consideration of melioidosis), and the patient’s death, if applicable. The date of symptom onset is not necessarily specific to a diagnosis of melioidosis because Patients 1, 2, and 4 had coinfections. The date of symptom onset in Patient 3 was estimated on the basis of a family report noted in the medical record and was not necessarily specific to a diagnosis of melioidosis.

Figure 2.. Coinfection Detected on Immunohistochemical Analysis of Tissues at Autopsy in Patient 4.

Panel A shows extensive immunolabeling of Burkholderia pseudomallei in the pneumonic lung, and Panel B shows extensive immunolabeling of B. pseudomallei within and around microabscesses in the brain. Panel C shows scattered immunolabeling of severe acute respiratory syndrome coronavirus 2 within intraalveolar cells in the lung.

Figure 3.. Phylogenomic Comparisons of B. pseudomallei Genomes with Isolates Obtained from the Four Patients and from a Contaminated Aromatherapy Spray Bottle.

The isolates obtained from the four patients (KS2021a, TX2021a, MN2021a, and GA2021a) and an isolate obtained from a contaminated aromatherapy spray bottle (GA2021_Spray_1A) contained strain ATS2021. Panel A shows the core single-nucleotide polymorphism phylogeny of 1696 genomes in which the new isolates were initially placed. Geographic origins were selected from the BioSample database of the National Center for Biotechnology Information, and the specific geographic regions listed were based on definitions from the 2021 World Factbook of the Central Intelligence Agency (https://www.cia.gov/the-world-factbook/). Samples of unknown geographic origin are white. The red branch inside the dashed red square denotes the outbreak strains, surrounded by isolates predominantly from South Asia. Panel B shows the high-resolution clade with the closest isolates to the outbreak strain from maximum-likelihood analysis in Parsnp (Harvest, version 1.3) rendered with the use of MEGA X software (https://www.megasoftware.net/).