Human Granulocytic Anaplasmosis as a COVID-19 Mimicker

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.

Human granulocytic anaplasmosis combined with rhabdomyolysis: a case report

Background Human granulocytic anaplasmosis (HGA) is a systemic inflammatory response caused by the rickettsial bacterium Anaplasma phagocytophilum. Rhabdomyolysis and acute kidney injury (AKI) are rare complications of HGA. Here, we report a case of HGA concurrent with rhabdomyolysis and AKI in an elderly patient. Case presentation An 84-year old woman with a medical history of hypertension was hospitalised after two days of fever, dizziness, whole body pain, and general weakness. Laboratory investigations showed severe thrombocytopenia, leukopenia, impaired renal function, and elevated cardiac enzyme and myoglobin levels. On the day after admission, peripheral blood smear revealed morula inclusions in neutrophils, a suggestive finding of HGA. Real-time polymerase chain reaction (PCR) results indicated the presence of A. phagocytophilum. Antibiotics were de-escalated to doxycycline monotherapy. After 10 days of antibiotic treatment, laboratory tests showed complete recovery from HGA complicated with rhabdomyolysis and AKI. Conclusions HGA can lead to serious complications in patients with associated risk factors. Therefore, in patients with HGA accompanied by rhabdomyolysis, management with antibiotics and hydration should be initiated immediately, and not delayed until diagnostic confirmation.

Anchoring on COVID-19: A Case Report of Human Granulocytic Anaplasmosis Masquerading as COVID-19

Introduction: Human granulocytic anaplasmosis (HGA) is caused by Anaplasma phagocytophilum and transmitted through the deer tick. Most cases are mild and can be managed as an outpatient, but rare cases can produce severe symptoms. Case Report: A 43-year-old male presented with severe respiratory distress mimicking coronavirus disease 2019 (COVID-19). Labs and imaging were consistent with COVID-19; however, polymerase chain reaction was negative twice. Peripheral smear revealed inclusion bodies consistent with HGA. Conclusion: Human granulocytic anaplasmosis is an uncommon diagnosis and rarely causes severe disease. Recognition of unique presentations can aid in quicker diagnosis, especially when mimicking presentations frequently seen during the COVID-19 pandemic.

Human granulocytic anaplasmosis in a Single University Hospital in the Republic of Korea

To date, only a few studies have analyzed the clinical characteristics and genetic features of human granulocytic anaplasmosis (HGA) in South Korea. Thus, in this study, we investigated the clinical characteristics of HGA and methods used for clinical diagnosis. The clinical characteristics of patients with HGA were studied retrospectively. We reviewed the medical charts of 21 confirmed patients with HGA admitted to the Chosun University Hospital, located in Gwangju, South Korea. Twenty-one HGA patients visited the hospital 2–30 days (median 7 days) after the onset of symptoms. Fourteen patients (66.7%) had fever, which was alleviated 2 h (range 0–12.75 h) after starting treatment with doxycycline. Of the 18 patients who underwent peripheral blood (PB) smear test, only one (5.6%) had morulae. Additionally, only 4/17 patients (23.5%) had morulae in the PB smear reconducted after the confirmation of anaplasmosis. All 21 patients recovered without significant complications. As per results of the blood tests conducted at the time of admission, 7/21 (33.3%) and 5/21 (23.8%) patients showed at least 1:16 and 1:80 of IgM and IgG titers, respectively. Most HGA patients in Korea recovered without significant complications. The indirect immunofluorescence antibody diagnosis or morulae identification for HGA in this study had low sensitivity in the early stage of the disease.

A Traumatic Tick Bite: A Case Report

Introduction: Human granulocytic anaplasmosis is a tick-borne disease with an increasing incidence associated with morbidity and mortality. Uncertainty remains whether a prophylactic dose of doxycycline is effective in prevention. Case Report: We present a case of an 80-year-old female with syncope, resultant facial trauma, and fever two weeks after a tick bite for which she received prophylaxis. Workup revealed anaplasmosis, and treatment led to symptomatic improvement. Conclusion: We review the presenting symptoms, laboratory findings, and treatment of anaplasmosis, as well as give caution about the limitations in prescribing a prophylactic dose of doxycycline following a tick bite.

Incompetence of the Asian Longhorned Tick (Acari: Ixodidae) in Transmitting the Agent of Human Granulocytic Anaplasmosis in the United States

The Asian longhorned tick, Haemaphysalis longicornis Neumann (Acari: Ixodidae), was recently introduced into the United States and is now established in at least 15 states. Considering its ability for parthenogenetic propagation and propensity for creating high-density populations, there is concern that this tick may become involved in transmission cycles of endemic tick-borne human pathogens. Human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum is one of the more common tick-borne diseases in the United States, especially in the northeastern and midwestern states. There is considerable geographical overlap between HGA cases and the currently known distribution of H. longicornis, which creates a potential for this tick to encounter A. phagocytophilum while feeding on naturally infected vertebrate hosts. Therefore, we evaluated the ability of H. longicornis to acquire and transmit the agent of HGA under laboratory conditions and compared it to the vector competence of I. scapularis. Haemaphysalis longicornis nymphs acquired the pathogen with the bloodmeal while feeding on infected domestic goats, but transstadial transmission was inefficient and PCR-positive adult ticks were unable to transmit the pathogen to naïve goats. Results of this study indicate that the Asian longhorned tick is not likely to play a significant role in the epidemiology of HGA in the United States.