A small pilot study has found that nearly half of a group of people diagnosed with chronic fatigue syndrome tested positive for infections caused by two types of microscopic parasites and bacteria.
The findings raise new questions about whether hidden infections could contribute to the illness, which is also known as myalgic encephalomyelitis, or ME/CFS.
Researchers analyzed blood samples from 50 participants who had been experiencing severe fatigue for at least six months along with neurological symptoms such as memory problems, confusion, sleep difficulties, headaches, anxiety, or tremors.
Using advanced genetic testing techniques, they looked for evidence of two groups of pathogens: Bartonella and Babesia.
The study, published in the journal Pathogens, detected at least one of these infections in 23 of the 50 participants.
Bartonella is a group of bacteria usually spread by insects such as fleas, lice, and possibly ticks, as well as through animals that carry the bacteria in their blood.
One well-known species causes cat scratch disease, which was once thought to be a short-term infection but is now known to sometimes lead to long-lasting symptoms. Scientists have identified dozens of Bartonella species, many of which can infect humans.
Babesia is a different type of organism that infects red blood cells and is typically transmitted through tick bites.
In rare cases, it can also spread through blood transfusions, organ transplants, or from mother to baby during pregnancy. Both Bartonella and Babesia infections have been linked to chronic illness in some patients and are sometimes found alongside Lyme disease.
To detect these infections, the researchers used a method called quantitative polymerase chain reaction, which identifies tiny amounts of genetic material from pathogens in blood samples. The tests confirmed Bartonella infection in 11 participants, Babesia infection in 10, and both infections in two individuals.
Although the study group was small and cannot represent all people with ME/CFS, the researchers say the results are notable because current diagnoses of chronic fatigue syndrome rely mainly on symptoms and general biological markers rather than identifying specific causes. Finding evidence of infections suggests that, at least for some patients, underlying pathogens might be involved.
Experts caution that the findings do not prove these infections cause chronic fatigue syndrome, but they highlight a possible link that deserves further investigation. Larger studies will be needed to determine how common these infections are among patients and whether treating them could improve symptoms.
Chronic fatigue syndrome remains a complex and poorly understood condition that can severely affect daily life. People with the illness often struggle with extreme exhaustion, cognitive difficulties, and other health problems that do not improve with rest.
By exploring possible infectious triggers, researchers hope to uncover new clues about why the condition develops and how it might be treated.
The study’s authors say the unexpectedly high rate of infections in their sample provides a starting point for future research that could lead to better diagnosis and care for people living with this challenging disorder.
