# Missed Until Critical: Unravelling the Mystery of Persistent Hemolysis With a Definitive Diagnosis of Babesiosis

**Authors:** Paris D Slagle, Shirley Ann T Tomdio, Lauren A Waldorf, Eric A Williams, Habeeb Agbabiaka, Gashaw Hassen, Vaughn E Powell, Jada Harris

PMC · DOI: 10.7759/cureus.86381 · 2025-06-19

## TL;DR

A 54-year-old woman was initially misdiagnosed with malaria but later found to have babesiosis, highlighting the importance of accurate diagnosis and treatment for tick-borne diseases.

## Contribution

The paper presents a clinical case emphasizing the diagnostic challenges between babesiosis and malaria and the need for confirmatory testing.

## Key findings

- The patient was initially misdiagnosed with malaria but later confirmed to have babesiosis.
- Persistent hemolysis and septic shock occurred despite initial treatment, underscoring the severity of babesiosis.
- The case highlights the importance of geographical awareness and confirmatory testing for tick-borne diseases.

## Abstract

Babesiosis is a parasitic protozoan infection caused primarily by Babesia microti in the United States. Its presentation can imitate that of malaria, which often leads to misdiagnosis. We present here a case of a 54-year-old female with multiple comorbidities, such as hypertension and hyperlipidemia, who was initially diagnosed with malaria but, with further investigation, was found to have babesiosis. The patient initially presented with anemia and thrombocytopenia, prompting an extensive and meticulous workup including a peripheral blood smear and autoimmune studies. From these tests, we were able to diagnose her with a malarial infection that was treated with quinine and doxycycline, then atovaquone/proguanil following worsening infection. Despite the appropriate treatment, she developed septic shock and respiratory failure, prompting a higher level of care in the intensive care unit. With persistent parasitemia, a sample was sent to the department of health for speciation, which determined that she was infected with Babesia. Clinically, she improved after the transition to atovaquone and azithromycin, but unfortunately, she was readmitted due to persistent hemolysis and pneumonia requiring extended antibiotic therapy and supportive care. This case highlights the challenges posed by the similarities of babesia and malaria infection and emphasizes the importance of geographical location and confirmatory testing in differentiating these two infections. It raises awareness among clinicians regarding tick-borne illnesses in endemic regions, as in this case, to minimize delays in diagnosis and treatment. This case also shows how early recognition and treatment are crucial to prevent severe complications of babesiosis, including septic shock, especially in the immunocompromised and elderly population.

## Linked entities

- **Chemicals:** quinine (PubChem CID 441073), doxycycline (PubChem CID 54671203), atovaquone (PubChem CID 74989), proguanil (PubChem CID 4923), azithromycin (PubChem CID 447043)
- **Diseases:** Babesiosis (MONDO:0005661), malaria (MONDO:0005136), hyperlipidemia (MONDO:0021187), respiratory failure (MONDO:0021113), pneumonia (MONDO:0005249)
- **Species:** Babesia microti (taxon 5868)

## Full-text entities

- **Diseases:** infected (MESH:D007239), parasitemia (MESH:D018512), septic shock (MESH:D012772), Hemolysis (MESH:D006461), respiratory failure (MESH:D012131), hypertension (MESH:D006973), malaria (MESH:D008288), pneumonia (MESH:D011014), hyperlipidemia (MESH:D006949), thrombocytopenia (MESH:D013921), protozoan infection (MESH:D011528), Babesiosis (MESH:D001404), tick-borne illnesses (MESH:D017282), autoimmune (MESH:D001327), anemia (MESH:D000740)
- **Chemicals:** quinine (MESH:D011803), azithromycin (MESH:D017963), doxycycline (MESH:D004318), atovaquone/proguanil (MESH:C109496), atovaquone (MESH:D053626)
- **Species:** Homo sapiens (human, species) [taxon 9606], Babesia microti (species) [taxon 5868]

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Source: https://tomesphere.com/paper/PMC12276050