Splenic rupture from babesiosis, an emerging concern? A systematic review of current literature

Human granulocytotropic anaplasmosis-A systematic review and analysis of the literature

Human granulocytotropic anaplasmosis (HGA) is a zoonotic tick-borne bacterial infection caused by Anaplasma phagocytophilum. While most cases are reported from North America, HGA has been recognized as an emerging disease in several regions of the world in recent decades. Most available data comes from case reports, case series and retrospective studies, while prospective studies and clinical trials are largely lacking. To obtain a clearer picture of the currently known epidemiologic distribution, clinical and paraclinical presentation, diagnostic aspects, complications, therapeutic aspects, and outcomes of HGA, we systematically reviewed the literature and analyzed and summarized the data. Cases of HGA are reported from all continents except from Antarctica. HGA primarily presents as an unspecific febrile illness (88.5% of the cases) often accompanied by thrombocytopenia (71.8% of the cases), abnormal liver injury tests (66.7% of the cases), and leukopenia (49.8% of the cases). Although we found complications reported in a total of 40.5% of the reviewed cases and severe and even life-threatening complications are not infrequent (e.g. acute renal failure 9.8%, multi organ failure 7.5%, ARDS 6.3%, a.o.), sequelae are rare (2.1% of the cases) and lethality is low (3.0% of the cases). Treatment with doxycycline shows a rapid response, with the fever subsiding in the majority of patients within one day of starting treatment. Unlike in human monocytotropic ehrlichiosis (HME), reports of opportunistic infections complicating HGA are rare. HGA during pregnancy does not appear to be associated with unfavorable outcomes. In addition, our analysis provides some evidence that HGA may differ in clinical aspects and laboratory characteristics in different regions of the world. Overall, the data analyzed indicates a non-negligible bias in reporting/publication, so a certain degree of caution is required when generalizing the data.

Babesiosis Presenting as Splenic Rupture in the Midwest: A Case Report

Babesia microti is a parasite that invades erythrocytes inducing hemolysis. It presents with a variety of non-specific symptoms that can be mistaken for other illnesses. A rare manifestation of babesiosis is splenic rupture, generally seen in a younger, healthier population with low parasitemia, which can be treated conservatively depending on the grade and clinical condition. This case describes an elderly male with multiple comorbidities who is an avid hiker in the Northern Ohio and Western Pennsylvania areas presenting with a spontaneous American Association for the Surgery of Trauma (AAST) grade V splenic rupture requiring emergent splenectomy. Subsequent re-admission was required to diagnose babesiosis, which was managed with pharmacotherapy and plasmapheresis. In lieu of other identifiable etiologies, patients with atraumatic splenic rupture in an endemic area should be screened for possible parasitic infections.

Pathogenesis of Anemia in Canine Babesiosis: Possible Contribution of Pro-Inflammatory Cytokines and Chemokines-A Review

Canine babesiosis is a tick-borne protozoan disease caused by intraerythrocytic parasites of the genus Babesia. The infection may lead to anemia in infected dogs. However, anemia is not directly caused by the pathogen. The parasite's developmental stages only have a marginal role in contributing to a decreased red blood cell (RBC) count. The main cause of anemia in affected dogs is the immune response to the infection. This response includes antibody production, erythrophagocytosis, oxidative damage of RBCs, complement activation, and antibody-dependent cellular cytotoxicity. Moreover, both infected and uninfected erythrocytes are retained in the spleen and sequestered in micro-vessels. All these actions are driven by pro-inflammatory cytokines and chemokines, especially IFN-γ, TNF-α, IL-6, and IL-8. Additionally, imbalance between the actions of pro- and anti-inflammatory cytokines plays a role in patho-mechanisms leading to anemia in canine babesiosis. This article is a review of the studies on the pathogenesis of anemia in canine babesiosis and related diseases, such as bovine or murine babesiosis and human or murine malaria, and the role of pro-inflammatory cytokines and chemokines in the mechanisms leading to anemia in infected dogs.

Human Babesiosis

Babesiosis is caused by intraerythrocytic parasites that are transmitted primarily by ticks, infrequently through blood transfusion, and rarely through transplacental transmission or organ transplantation. Human babesiosis is found throughout the world, but the incidence is highest in the Northeast and upper Midwestern United States. Babesiosis has clinical features that resemble malaria and can be fatal in immunocompromised and older patients. Diagnosis is confirmed by identification of Babesia parasites on blood smear or Babesia DNA with polymerase chain reaction. Standard treatment consists of atovaquone and azithromycin or clindamycin and quinine for 7 to 10 days.

Splenic artery embolization for spontaneous splenic rupture due to Babesiosis: a case report

Babesiosis incidence in the United States has been increasing with an 11% rise between 2018 and 2019 based on the latest CDC annual summary, reaching its highest ever reported incidence. This primarily tick-borne disease is particularly prevalent in New England. Despite predominantly nonspecific and at times subtle symptoms, life-threatening complications do occur. One such complication is splenic rupture which has been suggested to be more common in younger and otherwise healthy individuals. This is a report on a successful splenic artery embolization in a 65-year-old male from upstate New York who, unlike most prior studies, showed splenic rupture after he was discharged with negative parasitemia and general improvement following several days of targeted antibiotic therapy. Increased incidence and various presentations of Babesiosis call for an attempt to promote clinical awareness for radiologists among other specialties.

Cross-sectional imaging findings of splenic infections: is differential diagnosis possible?

The spleen plays an important role in the immunological homeostasis of the body. Several neoplastic and non-neoplastic diseases may affect this organ, and imaging is of fundamental importance for diagnosis. Infectious diseases of the spleen can be encountered in daily radiology practice, and differential diagnosis may sometimes be challenging. Infectious involvement of the spleen can be primary or secondary to a different source outside the spleen. Despite the fact that different infectious diseases may cause similar imaging findings, we believe that differential diagnosis between different causes may also be possible in certain patients with imaging. Early diagnosis may potentially enhance patients’ treatment and outcome. In this review, we aimed to increase imaging specialists’ awareness of splenic infections by describing the multimodality imaging features of common and atypical infections of the spleen with their differential diagnoses.

Lessons Learned for Pathogenesis, Immunology, and Disease of Erythrocytic Parasites: Plasmodium and Babesia

Malaria caused by Plasmodium species and transmitted by Anopheles mosquitoes affects large human populations, while Ixodes ticks transmit Babesia species and cause babesiosis. Babesiosis in animals has been known as an economic drain, and human disease has also emerged as a serious healthcare problem in the last 20–30 years. There is limited literature available regarding pathogenesis, immunity, and disease caused by Babesia spp. with their genomes sequenced only in the last decade. Therefore, using previous studies on Plasmodium as the foundation, we have compared similarities and differences in the pathogenesis of Babesia and host immune responses. Sexual life cycles of these two hemoparasites in their respective vectors are quite similar. An adult Anopheles female can take blood meal several times in its life such that it can both acquire and transmit Plasmodia to hosts. Since each tick stage takes blood meal only once, transstadial horizontal transmission from larva to nymph or nymph to adult is essential for the release of Babesia into the host. The initiation of the asexual cycle of these parasites is different because Plasmodium sporozoites need to infect hepatocytes before egressed merozoites can infect erythrocytes, while Babesia sporozoites are known to enter the erythrocytic cycle directly. Plasmodium metabolism, as determined by its two- to threefold larger genome than different Babesia, is more complex. Plasmodium replication occurs in parasitophorous vacuole (PV) within the host cells, and a relatively large number of merozoites are released from each infected RBC after schizogony. The Babesia erythrocytic cycle lacks both PV and schizogony. Cytoadherence that allows the sequestration of Plasmodia, primarily P. falciparum in different organs facilitated by prominent adhesins, has not been documented for Babesia yet. Inflammatory immune responses contribute to the severity of malaria and babesiosis. Antibodies appear to play only a minor role in the resolution of these diseases; however, cellular and innate immunity are critical for the clearance of both pathogens. Inflammatory immune responses affect the severity of both diseases. Macrophages facilitate the resolution of both infections and also offer cross-protection against related protozoa. Although the immunosuppression of adaptive immune responses by these parasites does not seem to affect their own clearance, it significantly exacerbates diseases caused by coinfecting bacteria during coinfections.

Post-traumatic intrathoracic splenosis and role of Tc-99m Sulfur colloid scintigraphy in confirmation

Splenosis is acquired ectopic splenic tissue, usually a sequela of trauma. Its imaging appearance is can be deceiving, and at unusual locations may be mistaken for an alternate cause mass lesion. We present one such unusual case of splenosis in a 53 year-old man with history of heart failure involving the thoracic cavity identified as splenosis on nuclear medicine imaging and suspicion was raised given the remote history splenectomy after splenic rupture during trauma. We will discuss the imaging appearances of splenosis on CT, MRI and nuclear medicine studies, with emphasis on using nuclear medicine as a modality of choice to avoid biopsy. We will also go on to include a brief review of literature on this topic in this article. The key facts are role of detailed clinical history and requirement of high index of suspicion to avoid unnecessary intervention in the case of splenosis.

Babesiosis: Appreciating the Pathophysiology and Diverse Sequela of the Infection

Babesiosis is a blood-borne disease found mainly in the United States caused by a parasitic piroplasm. While most infections are mild to moderate in immunocompetent hosts, life-threatening complications can occur in those with significant comorbidities like congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD). There is sparse literature discussing the complications of Babesia microti infection or the pathophysiology and management thereof. A literature review was conducted to consolidate the current knowledge about the disease, pathophysiology, and proposed management of all potential complications based on risk factors and other clinical information. A MeSH cross-references strategy was employed in PubMed using the search terms “babesia” and “babesiosis” and the established associated conditions, and the search expanded to increase capture. Only papers written in the English language and discussing human subjects in the North American patient population were included. The initial search yielded 315 papers and, after applying the inclusion/exclusion criteria, a final number of 18 was reviewed. The various complications and pathophysiology thereof are then discussed according to organ system. Babesia is a subversive parasite associated with a variety of conditions. We hope a better appreciation of all potential presentations and complications will help clinicians manage this increasingly common zoonosis and reduce adverse effects. More research is recommended into the pathophysiology and prevention of complications following this and other tick-borne illnesses.

Tick-Borne-Associated Illnesses in the Pediatric Intensive Care Unit

When unrecognized and antibiotic delay occurs, Lyme disease, Rocky Mountain–spotted fever, babesiosis, and human ehrlichiosis and anaplasmosis can result in multiorgan system dysfunction and potentially death. This review focuses on the early recognition, evaluation, and stabilization of the rare life-threatening sequelae seen in tick-borne illnesses that require admission in the pediatric intensive care unit.

Splenic Complications of Babesia microti Infection in Humans: A Systematic Review

Splenic complications of acute Babesia microti infection include splenomegaly, splenic infarct, and splenic rupture. These complications are relatively rarely reported, and the aim of this research was to synthetize data on this topic according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the PubMed database. In this review, we find that unlike other severe complications of babesiosis, splenic infarct and rupture occur in younger and immunocompetent patients, and they do not correlate with parasitemia level. Furthermore, admission hemoglobin of 10 mg/dl or less, platelet count of 50 × 10⁹/L or less, presence of hemodynamic instability, and splenic rupture were associated independently with an increased risk of requiring splenectomy. As babesiosis is an emerging tick-borne zoonosis, we hope that this review will help to raise awareness among clinicians regarding this rare but potentially life-threatening complication.

Intrahepatic splenosis demonstrated by diffusion weighted MRI with histologic confirmation

Acquired ectopic splenic tissue is called splenosis, which is common after the history of trauma or surgical exploration. We present a rare case of intrahepatic splenosis in 36-year-old male patient mimicking a liver neoplasm on imaging however presented with left flank pain for 5 months and had remote history of splenectomy after splenic rupture from trauma. We discuss various imaging modalities and the role of various magnetic resonance imaging sequences and nuclear medicine examination. We also discuss the differentiating features to be kept to make the correct diagnosis along with a brief review of literature. We mentioned signal intensities of splenic lesions and normal signal intensity of spleen in different magnetic resonance imaging sequences and with high suspicion how we can diagnose splenosis and avoid unnecessary biopsy and its result related stress.

Splenic findings in patients with acute babesiosis

PURPOSE

To identify the imaging manifestations of splenic involvement in babesiosis, a potentially fatal tick-borne zoonosis with multi-organ involvement.

METHODS

In our single center HIPAA compliant IRB-approved study, we performed a retrospective search of the electronic medical record at our institution to identify all patients with known or suspected acute babesiosis from 2000 to 2017. We then reviewed all abdominal imaging of patients with confirmed disease to identify incidence and characteristics of splenic involvement. Splenomegaly was determined using a height- and gender-adjusted reference.

RESULTS

After exclusions, 63 patients with a confirmed diagnosis of babesiosis and contemporaneous imaging of the spleen were included in the final cohort. Within this cohort, 56 (89%) had splenomegaly at a minimum and 13 had splenic infarcts. Splenic rupture was present in eight patients with three having a pseudoaneurysm. In 14 patients with follow-up imaging, the spleen subsequently diminished in size. One additional patient with ruptured spleen underwent emergency splenectomy prior to imaging.

CONCLUSION

Although the literature suggests splenic involvement is a rare finding, acute parasitemia with babesiosis commonly affects the spleen. Recognition of this association can aid radiologists diagnosing splenic involvement in babesiosis and can lead to appropriate intervention in the minority with splenic hemorrhage.