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Published on: December 19, 2020
Human Granulocytic Anaplasmosis as a COVID-19 Mimicker
Deeksha Ramanujam1, Adeel Nasrullah2, Marshall Bahr1
1Department of Medicine, Allegheny Health Network, Pittsburgh, Pennsylvania, USA.
Introduction:
Human granulocytic anaplasmosis (HGA) is a tick-borne illness caused by the bacterium Anaplasma phagocytophilum. HGA has a widely variable clinical presentation and can be life-threatening.
Case Description:
A 77-year-old man was transferred from an outside facility with altered mental status, a fever of up to 40.5°C, and shortness of breath. Laboratory analysis revealed a progressively worsening pro-inflammatory state and abnormalities in the patient's coagulation studies. With clinical and laboratory evidence concerning for potential COVID-19 infection, the patient was placed in isolation as a precaution. The results of two COVID-19 tests, given approximately 24 hours apart, were negative. The patient's spouse confirmed a bug bite to his upper extremity while working outdoors. His symptoms resolved completely after a 10-day course of empiric doxycycline.
Discussion:
The diverse clinical presentations of HGA necessitate a broad differential diagnosis, including viral, bacterial and non-infectious aetiologies. In severe cases, a cytokine-mediated immune cascade can occur (namely, cytokine storm) leading to devastating downstream effects. This cytokine storm can be seen in many other diseases, but most recently it has been demonstrated in the novel coronavirus disease 2019 (COVID-19).
Conclusion:
Here we present a case of HGA in which diagnosis was delayed due to mimicry of COVID-19 infection. This case highlights the importance of taking clinical and social histories, seasonality and geography into account during diagnosis, and maintaining a broad differential with non-specific symptoms. Despite the current COVID-19 pandemic, we recommend that HGA remains in the differential diagnosis of a pro-inflammatory state with an atypical respiratory presentation.
Learning Points:
Human granulocytic anaplasmosis (HGA) has a widely variable clinical presentation and can be life-threatening.When presented with non-specific symptoms, it is critical to consider clinical and social histories, seasonality and geography while maintaining a broad differential.Cytokine storm can be seen in HGA and other diseases, but most recently it has been observed in the novel COVID-19. However, despite the prevalence of COVID-19, we recommend that HGA remain in the differential diagnosis of a pro-inflammatory state with an atypical respiratory presentation.
Insights
Human granulocytic anaplasmosis (HGA), a tick-borne illness, can mimic COVID-19 symptoms like fever and respiratory distress. Early diagnosis considering patient history and geography is crucial for effective doxycycline treatment.
Area of Science:
- Infectious Diseases
- Tick-borne Illnesses
- Bacteriology
Background:
- Human granulocytic anaplasmosis (HGA) is a severe tick-borne disease caused by *Anaplasma phagocytophilum*.
- HGA presents with highly variable symptoms, posing diagnostic challenges.
- The condition can lead to life-threatening complications.
Purpose of the Study:
- To report a case of HGA misdiagnosed as COVID-19 due to overlapping symptoms.
- To emphasize the importance of a broad differential diagnosis in patients with non-specific symptoms.
- To highlight HGA as a critical consideration in pro-inflammatory states, even during the COVID-19 pandemic.
Main Methods:
- Case report of a 77-year-old male with altered mental status, fever, and shortness of breath.
- Initial workup included tests for COVID-19, which were negative.
- Diagnosis was confirmed after considering patient history of a tick bite and response to doxycycline.
Main Results:
- The patient presented with symptoms mimicking COVID-19, including fever and respiratory issues.
- Laboratory findings indicated a pro-inflammatory state and coagulation abnormalities.
- Symptoms resolved completely following a 10-day course of doxycycline.
Conclusions:
- HGA's diverse clinical manifestations necessitate a broad differential diagnosis, including viral, bacterial, and non-infectious causes.
- Severe HGA can trigger a cytokine storm, similar to COVID-19.
- Clinical and social histories, seasonality, and geography are vital for diagnosing HGA, especially when symptoms overlap with other conditions.
