An article describes a severe case of chikungunya virus infection in a 64-year-old Australian traveler who returned from Sri Lanka in 2025. The patient presented with fever, acute confusion, headache, neck stiffness, myalgias, and progressive neurological deterioration shortly after returning to Australia. The infection was confirmed by RT-PCR in serum, urine, and cerebrospinal fluid, and genomic sequencing showed that the virus belonged to the Indian Ocean lineage, associated with the chikungunya outbreak in Sri Lanka during 2024–2025.
The course was complicated, with probable meningoencephalitis, cognitive impairment, extrapyramidal symptoms, transient visual loss, severe thrombocytopenia, anemia, rhabdomyolysis, hyperferritinemia, and a spontaneous retroperitoneal hematoma requiring transfusions. Although the patient was not immunocompromised, he presented with cardiovascular comorbidities, habitual alcohol consumption, and undiagnosed pre-existing cognitive impairment—factors that may have reduced his physiological reserve and contributed to a more severe course of the disease.
This case underscores that, while chikungunya typically causes fever with arthralgia and is rarely fatal, it can lead to serious neurological and hematological complications, especially in older adults or those with underlying health conditions. The authors emphasize that, unlike other infections such as dengue or malaria, there are no well-established criteria for defining or predicting severe chikungunya. In conclusion, the article warns of the risk of severe chikungunya in travelers returning from areas with active outbreaks, particularly in the Indian Ocean and Sri Lanka.
Given the lack of specific antiviral treatment, prevention remains crucial: protection against mosquito bites, epidemiological surveillance, early consideration of the diagnosis in febrile travelers, and, in the future, the potential role of chikungunya vaccines.
