Public health officials are urging extra precautions after an investigation into residents of a high-risk area on Mississippi’s Gulf Coast found deadly bacteria living in soil around the homes of two people who fell ill.
The investigation began after two unrelated residents – one this year and the other in 2020 – contracted melioidosis in the area. Both are believed to have contracted melioidosis, known as Whitmore’s disease, after being exposed to a rare strain of bacteria called Burkholderia pseudomallei, found only in tropical countries.
While the bacteria was found in Puerto Rico, Wednesday’s announcement marks the first time the bacteria has been found in soil in a US state.
Both people have since recovered, a Mississippi Department of Health spokesperson said in an email. The CDC said in a health alert that patients were hospitalized with sepsis and treated with antibiotics to fight the bacteria.
According to the CDC, patients are usually diagnosed an average of one week after contact with contaminated soil or puddles and the bacteria develop.
Nicknamed “The Great Imitator,” this disease can be difficult for doctors to diagnose because of the variety of symptoms it can cause.
Symptoms may include fever, swelling, cough, joint pain, or seizures, depending on where the infection is located. Bacteria can also infect the brain.
Only a fraction of exposure to the bacteria—one study estimated 1 in 4,600—causes disease. However, the mortality rate for melioidosis can range from 10% in Australia to 35% in Thailand.
Laboratories can also struggle to accurately identify Burkholderia pseudomallei in patient samples. The recent case in Texas was initially misdiagnosed by scientists using an automated algorithm to investigate the pattern.
According to the CDC, an average of 12 cases are diagnosed nationwide each year, usually in people who have recently traveled to a tropical country abroad where the bacteria has spread into the environment.
“Because these bacteria have been identified on the Mississippi Gulf Coast, people living on the Gulf Coast who are at high risk of severe infection should take the recommended precautions,” said Mississippi State Epidemiologist. Paul Byers said in a statement.
The bacteria has been present in the area since at least 2020 and poses a “very low” risk to the general public, according to the CDC. Many healthy people who encounter the bacteria in the environment never end up with melioidosis.
However, the two agencies say some residents are at high risk of becoming seriously ill and should take precautions.
These extra steps include avoiding mud, especially after heavy rain, and wearing gloves and boots to avoid contact with soil contaminated with Burkholderia pseudomallei.
“The most common underlying conditions that make a person sick or die from melioidosis include diabetes, excessive alcohol use, chronic lung disease, chronic kidney disease, and immunosuppressive conditions,” the CDC said.
Until this year, previous hunts by public health officials had found no evidence of Burkholderia pseudomallei living on U.S. soil outside of Puerto Rico. Scientists there have previously reported that the bacteria are “rare but ecologically sound.”
However, there have been cases reported by state health departments in the past, raising concerns that the bacteria could spread widely on US soil.
In 2018, one case was reported in Texas in a person who had not been outside the country in decades. Investigators have not been able to identify the source of the infection, which genomic sequencing may have linked to an earlier case from the same county that was proposed 15 years ago.
In last year’s epidemic, four people were infected, two of them died. The CDC linked these infections to contaminated aromatherapy sprays sold by Walmart.
The agency said it is continuing to investigate the potential spread of the virus with state health departments, which will require “extensive environmental sampling.”
Wednesday’s announcement added the continental United States to the list of countries with endemic melioidosis, but federal scientists believe the disease’s prevalence and numbers may be underreported worldwide.
Earlier this year, the Council of State and Territorial Epidemiologists voted to add the disease to the CDC’s list of nationally notifiable diseases for state health departments.
Although bacteria cannot be removed from tissue, the agency says, “public health efforts should primarily focus on improving disease identification for appropriate treatment.”