Assessing the potential for Burkholderia pseudomallei in the southeastern United States

Melioidosis is an underreported zoonosis in many countries where environmental conditions are favorable for growth of Burkholderia pseudomallei, the causative agent.1,2 The disease is most often detected in tropical areas such as Southeast Asia and northern Australia, where the case fatality rate in humans is estimated to be as high as 50%.1 Diagnosis is difficult owing to a lack of specific clinical signs and limitations of currently available diagnostic tests. Cases of melioidosis involving animals are sporadically reported, and the global extent of B pseudomallei in the environment is not well understood.3 Burkholderia pseudomallei has been proposed for inclusion on the USDA’s National List of Reportable Animal Diseases4 and has been classified as a category B bioterrorism agent by the US Department of Health and Human Services. Burkholderia pseudomallei is also designated as a tier-1 select agent under the Federal Select Agent Program because it is among “the biological agents and toxins that present the greatest risk of deliberate misuse with significant potential for mass casualties or devastating effect to the economy, critical infrastructure, or public conficonfidence and poses a severe threat to public health and safety.”5 Burkholderia pseudomallei is not known to be present in the continental United States, other than in select research laboratories, but is now considered endemic in Puerto Rico.6 In addition, the number of human cases diagnosed in the United States has increased in recent years, and not all cases can be attributed to travel outside the United States.7,8 The present report describes the epidemiology of B pseudomallei infection in domestic animals and assesses the potential for establishment of the organism in the southeastern United States. To minimize the consequences of environmental contamination and the possibility that the organism will become endemic, veterinarians should be aware of the signs of melioidosis in domestic animals and of procedures for diagnosing and reporting the condition.