The babesia incubation period can be much longer than expected—as this unusual case demonstrates. A 19-year-old man developed symptoms 10 weeks after traveling to New York, showing why Babesia can be missed when doctors focus only on recent tick exposure.
The case was published in Cureus by Patel and colleagues.
The Case: A 10-Week Babesia Incubation Period
Ten weeks after travelling to New York, the patient was diagnosed with Babesia. Initially, he presented with a 4-day history of fever, generalized weakness, and flu-like symptoms.
His fever was 104.8°F. His hemoglobin dropped from 9.3 g/dL to 6.7 g/dL within 5 hours. He was diagnosed with hemolysis and transfused with 2 units of packed red blood cells. A peripheral blood smear revealed a Maltese cross typically seen in Babesia.
Why This Patient Was at Higher Risk
Babesia is more likely to be symptomatic in individuals with a history of a splenectomy. This young man had a splenectomy for hereditary spherocytosis when he was 3 years old—putting him at risk for severe disease.
Babesia is more likely to be contracted in the Northeastern region of the United States. This young man had returned from a trip to New York. The disease is less likely to be contracted in Florida where he presented to an emergency room—which may have contributed to diagnostic delay.
Diagnosis and Treatment
Early in the disease, Babesia is more likely to be diagnosed with a thick blood smear under the microscope. But later in the course of the disease, a PCR or antibody test can confirm the infection.
The patient was prescribed quinine, but it was stopped due to headache, tinnitus, and blurred vision. Instead, he was successfully treated with atovaquone, clindamycin, and azithromycin.
Other Cases of Extended Babesia Incubation Period
During their third trimester, two mothers were treated for Lyme disease with amoxicillin. Both babies were born and discharged home. But several weeks later, the babies became ill with Babesia.
This pattern of congenital babesia with delayed presentation further supports that the babesia incubation period can extend well beyond what clinicians expect.
Why the Babesia Incubation Period Matters
This case illustrates two critical points:
- The incubation period can extend 10 weeks or more—far beyond typical expectations
- Babesia can present outside endemic areas when patients have traveled
- Patients without a spleen are at higher risk for severe disease
- A thorough travel history is essential for diagnosis
When symptoms don’t appear until weeks after exposure, Lyme treatment may have already concluded—leaving Babesia undiagnosed and untreated.
Frequently Asked Questions
How long is the babesia incubation period?
The babesia incubation period typically ranges from 1-4 weeks but can extend to 10 weeks or more, as this case demonstrates. Patients may not connect symptoms to tick exposure months earlier.
Why was this patient diagnosed in Florida?
He had traveled to New York—an endemic area—10 weeks before symptoms appeared. Babesia is rare in Florida, which may have delayed diagnosis.
Why did the patient have severe symptoms?
He had a splenectomy as a child. Without a spleen, the body cannot filter infected red blood cells effectively, leading to more severe disease.
What is a Maltese cross?
A Maltese cross is a distinctive pattern seen on blood smear when four Babesia parasites form inside a red blood cell. It’s a diagnostic hallmark of the infection.
Can babies get Babesia with a delayed onset?
Yes. Two newborns contracted Babesia from their mothers during pregnancy but didn’t show symptoms until weeks after being discharged from the hospital.
References
- Patel JK, Tirumalasetty K, Zeidan B Jr, Desai P, Frunzi J. A Case Report of Babesiosis Seen Outside of its Endemic Area and Incubation Period. Cureus. 2020;12(12):e11926.
- Saetre K, Godhwani N, Maria M, et al. Congenital Babesiosis After Maternal Infection With Borrelia burgdorferi and Babesia microti. J Pediatric Infect Dis Soc. 2018;7(1):e1-e5.
When I was 59, I was diagnosed with only Babesia after a screening for lyme and co-infections. I was treated for Lyme with doxi at least twice prior, my tests show I had Lyme in the past. After initial treatment of Atovaquone and azithromycin I was told I was cured without ever getting a second test taken. I did not have any have of the classic fevers with babesia – but I had night sweats and air hunger for many years. I was taking cingular for the air hunger for years before the diagnosis. I now am working with a herbal acupuncturist for chronic Lyme and I am off the cingular.
My main symptoms are fatigue, I have a window of hours when I’m feeling ok, then wham a blanket of fatigue covers me and I have get horizontal. I do have body aches and pain, but that is manageable. I never know when the blanket will hit. With the treatment, my window of feeling ok is increasing.
Question: can babesia hang around and flare up like Lyme? If I am not careful in the heat & humidity my air hunger returns. The night sweats have never gone away, but during a flare, the sweat smells sickly. Sometimes I have to change my clothes 5 times a night. This can happen maybe 2-4 times a year.
Thank you
I have patients in my practice whose long term illness does well with empiric treatment for Babesia. Some of them have sweats and air hunger.