ABSTRACT.
Background: No confirmed cases of Lyme disease have been reported in Australia. However, for more than 30 years an increasing number of Australians have experienced chronic and debilitating symptoms associated with tick bites. The Australian Department of Health has chosen to designate these cases as Debilitating Symptom Complexes Attributed to Ticks (DSCATT). Nevertheless, peripheral blood smear (PBS) microscopy, the test of choice for diagnosing babesiosis and capable of confirming active Bartonella and other hemopathogen infections, is not used.
Objective: To evaluate the presence of persistent hemopathogens in Australian patients with syndromic diagnoses of ME/CFS, Long COVID, and DSCATT using optical microscopy of PBS.
Methods: Observational case series study. 28 PBS from patients meeting the inclusion criteria (primary diagnosis of ME/CFS or Long COVID, and residence in Australia) were analyzed. The review was performed by a veterinarian with more than 30 years of experience in PBS microscopy.
Results: In 27 of the 28 cases (96.4%), at least one pathogen was identified. The most frequent were the parasite Babesia (75.0%, n= 21) and the bacterium Bartonella (64.3%, n= 18). Coinfections were frequent (71.4%, 20/28 cases), with the Babesia + Bartonella combination being the most common (46.4%, 13/28). Borrelia was confirmed in one case (3.6%). Details of a case with 40 years of symptoms and physical limitation under the diagnosis of ME/CFS are included.
Conclusion: This study provides evidence that persistent infections by Babesia and Bartonella, detected through PBS microscopy, are frequent and underdiagnosed causes of ME/CFS, Long COVID, and DSCATT in Australia. The results are consistent with more than 500 previously reported cases and align with the official reports of the Australian Senate and Government. In addition, the first autochthonous case of persistent Borrelia infection in Australia is documented, confirmed by direct visualization through microscopy with digital magnification and artificial intelligence analysis. These findings support the need to incorporate PBS microscopy as a first-line diagnostic tool in clinical practice.
Keywords: Babesiosis, Bartonella, Borrelia, ME/CFS, Long COVID, DSCATT, Mycoplasma, Microsporidia, tick-borne disease, blood smear, hemopathogens, One Health
Publication Date: 2026-06-14