Cluster of Non-Travel Associated Burkholderia pseudomallei Cases Linked to Contaminated Room Spray
MDHHS-Bureau of Laboratories
Burkholderia pseudomallei, a tier one select agent and the causative agent of melioidosis (also known as Whitmore’s Disease), is known as the “great mimicker”. Clinical presentation is often misdiagnosed as tuberculosis or pneumonia due to wide ranging symptoms. Cases within the United States are rare and typically associated with travel to endemic areas of the world (southeast Asia, northern Australia, Indian subcontinent, southern China, Hong Kong, and Taiwan).1 Non-travel associated cases, such as the recent cluster of four cases, are extremely rare. The cluster of cases spanned March to July of 2021 and included four states: Texas, Georgia, Kansas, and Minnesota.
Transmission mainly occurs through direct contact with contaminated soil and water through cuts or abrasions, inhalation of contaminated soil dust, or ingestion of contaminated water. Human to human and animal to human transmission is extremely rare. Incubation can range from 1-21 days with only 5% of cases being activated after latent infection. Activations can happen many years after initial infection with one case of reactivation occurring 62 years after the initial exposure.2
To investigate the recent four state cluster whole genome sequencing was performed. Genetic analysis indicated that all 4 cases were related, and the cluster was eventually linked to Better Homes & Gardens Aromatherapy Room Spray Lavender & Chamomile scent with gemstones. The product was manufactured in India and sold through Walmart from February to October 21, 2021, when the recall took effect. An additional five scents were also removed as an abundance of caution. B. pseudomallei isolated from the contaminated room spray was found to match the isolates from all four cases.3 To date, no additional cases have been identified.
While rare, this incident emphasizes the global nature of both travel and product importation and importance of being vigilant for select agents. Sentinel Laboratories play a crucial role to recognize, rule-out, or refer utilizing the Sentinel Laboratory Procedures.4 It is important to rule-out select agents prior to loading onto commercial identification systems to prevent potential laboratory exposures. Automated systems may fail to correctly identify B. pseudomallei and may mis-identify as B. thailandensis, B. cepacia, and other members of the Burkholderia genera, Chromobacterium violaceum, Ochorobactrum anthropic, and possibly Pseudomonas spp., Acinetobacter spp., and Aeromonas spp., B. cepacia can closely mimic B. pseudomallei. The ASM sentinel guidelines recommend confirming identification of B. cepacia particularly if recovered from blood or tissue from a non-cystic fibrosis patient. The most notable characteristic to assess is amoxicillin clavulanate resistance. B. cepacia will be resistant while 99% of B. pseudomallei isolates are susceptible.
For more information on select agents, or to schedule a Biothreat Agent training contact the Bioterrorism Training Coordinator, Jason Wholehan wholehanj@michigan.gov
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