# UC Davis: melioidosis antibodies persist for years after infection, complicating tests as bacterium spreads in the U.S.

- Published: 2026-11-10 12:44 UTC
- Section: Life & Health › Medicine
- Tags: melioidosis, Burkholderia pseudomallei, melioidosis antibody tests, soil bacterium, melioidosis in Mississippi, infection surveillance, antibody persistence, UC Davis School of Medicine, Mahidol University, The Lancet Microbe
- URL: https://realtech.media/news/rt-d63ac464a491772e6ec3a6d5_uc_davis_melioidosis/

**A Thai cohort study in The Lancet Microbe found antibodies to Burkholderia pseudomallei persist for years, so a positive test may reflect past infection. This matters for surveillance in new regions.**

![UC Davis: melioidosis antibodies persist for years after infection, complicating tests as bacterium spreads in the U.S.](https://realtech.media/media/2026/11/6cf9fce9cb10eced.jpg)
*NASA Johnson Space Center, Wikimedia Commons, Public domain*

Researchers from the UC Davis School of Medicine and Mahidol University in Thailand have published a study in The Lancet Microbe on how antibodies change over time after melioidosis infection, according to a release on newswise.com. [1] The work looks at how blood tests for this disease should be read in diagnosis and surveillance. [1]

Melioidosis is caused by the soil-dwelling bacterium *Burkholderia pseudomallei*, found in tropical and subtropical soil and surface water. [1] It is treated with antibiotics, and its fatality rate is 10% to 50%. [1] People and animals can be infected through contact with contaminated soil, dust or water. [1] Symptoms include fever, stomach pain and seizures, and the disease can resemble pneumonia, tuberculosis or cancer, which is why it is sometimes called "the great mimicker". [1]

## Antibody persistence in the Thai cohort

The researchers followed people in Thailand after confirmed melioidosis infections to measure how long antibodies against the bacterium remain detectable. [1] They examined antibody responses to two promising diagnostic targets. [1] Antibody levels can persist for years after infection, so a positive result may reflect past infection rather than recent disease. [1]

According to Kristen Aiemjoy, assistant professor at the UC Davis Department of Public Health Sciences and co-senior author, antibody tests may be especially useful where the disease is rare or newly emerging, since few people have been previously exposed. [1] Where the disease has circulated for decades, earlier infections make results harder to interpret. [1]

## Range of the bacterium

Melioidosis is endemic in northern Australia and Southeast Asia, particularly northeast Thailand. [1] Recent evidence suggests that its range is expanding. [1] In 2022, researchers from the Centers for Disease Control and Prevention linked multiple human infections to soil and water in Mississippi, in a paper published in the New England Journal of Medicine. [1] That finding provided some of the strongest evidence that the bacterium has become established in the continental United States. [1] Reports of the disease are also increasing in South Asia and Africa. [1]

Scientists have warned that climate change could enlarge the areas where the bacterium can survive. [1] Aiemjoy noted that once the organism is established in soil and water, it can persist and replicate for long periods, creating an ongoing risk of exposure. [1] The study is published in The Lancet Microbe, article 101450. [1]

## Sources

1. [newswise.com](https://www.newswise.com/articles/public-healthnovember-6-2026-potentially-deadly-soil-bacterium-gaining-foothold-in-new-regions-including-u-s)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-d63ac464a491772e6ec3a6d5_uc_davis_melioidosis/