Severe Babesiosis Research Articles

Atraumatic splenic rupture from Babesia: A disease of the otherwise healthy patient

Babesiosis, an infection caused by the protozoan Babesia microti and transmitted by the Ixodes scapularis tick, is commonly described in the literature with an approximate incidence of 1000 cases per year (Herwaldt et al., 2012). Infections in North America occur most frequently during the spring and summer months in the Northeastern and Midwestern United States. Babesia can cause a wide spectrum of clinical manifestations ranging from a self-limited febrile illness or mild anemia to severe illness causing acute respiratory distress syndrome (ARDS), disseminated intravascular coagulopathy (DIC) and multisystem organ failure. Severe illness most commonly occurs in elderly, immunocompromised, or asplenic patients (Vannier and Krause, 2012). Splenic rupture has been generally described as a complication of severe illness secondary to babesiosis. We describe a case of spontaneous splenic rupture in an otherwise healthy woman that required emergent splenectomy. Recent case reports suggest that splenic rupture occurs in people without known risk factors for severe babesiosis. Physicians should be aware of this acute presentation in otherwise healthy individuals.

Babesia in a Nonsplenectomized Patient Requiring Exchange Transfusion.

Babesiosis is a tick born zoonosis caused by red blood cell parasites of the genus Babesia. It is caused predominantly by B. microti and B. divergens, microti being more common in the US. The parasites are transmitted by Ixodes tick to their host but infection can also spread by blood transfusion and perinatally. Clinical manifestations vary from subclinical infection to fulminating disease depending upon the immune status of the patient. About half of patients, hospitalized with babesiosis, develop complication with fatality rates of 6 to 9% which increase up to 21% among those with immunosuppression. A case of 58-year-old previously healthy man, infected by B. microti, was reported on 2000 who presented with severe disease characterized by severe anemia, DIC, and renal and respiratory failure. First case of overwhelming septic shock without respiratory involvement due to babesiosis in a healthy patient with an intact spleen was published in a case report on 2011. Since our patient here is an immunocompetent healthy male with intact spleen presenting with severe babesiosis requiring exchange transfusion, this presentation of Babesia is rare and warrants further study.

Severe Babesiosis in Immunocompetent Man, Spain, 2011

his work was funded by grants from Ministerio de Economia y Competitividad (AGL2010-21774) and Instituto de Salud Carlos III (MPY1411/09) from Spain to E.M. Work in the laboratory of C.A.L. is funded by the NIH (HL105694).

Genetic diversity of merozoite surface antigens in Babesia bovis detected from Sri Lankan cattle

Babesia bovis, the causative agent of severe bovine babesiosis, is endemic in Sri Lanka. The live attenuated vaccine (K-strain), which was introduced in the early 1990s, has been used to immunize cattle populations in endemic areas of the country. The present study was undertaken to determine the genetic diversity of merozoite surface antigens (MSAs) in B. bovis isolates from Sri Lankan cattle, and to compare the gene sequences obtained from such isolates against those of the K-strain. Forty-four bovine blood samples isolated from different geographical regions of Sri Lanka and judged to be B. bovis-positive by PCR screening were used to amplify MSAs (MSA-1, MSA-2c, MSA-2a1, MSA-2a2, and MSA-2b), AMA-1, and 12D3 genes from parasite DNA. Although the AMA-1 and 12D3 gene sequences were highly conserved among the Sri Lankan isolates, the MSA gene sequences from the same isolates were highly diverse. Sri Lankan MSA-1, MSA-2c, MSA-2a1, MSA-2a2, and MSA-2b sequences clustered within 5, 2, 4, 1, and 9 different clades in the gene phylograms, respectively, while the minimum similarity values among the deduced amino acid sequences of these genes were 36.8%, 68.7%, 80.3%, 100%, and 68.3%, respectively. In the phylograms, none of the Sri Lankan sequences fell within clades containing the respective K-strain sequences. Additionally, the similarity values for MSA-1 and MSA-2c were 40–61.8% and 90.9–93.2% between the Sri Lankan isolates and the K-strain, respectively, while the K-strain MSA-2a/b sequence shared 64.5–69.8%, 69.3%, and 70.5–80.3% similarities with the Sri Lankan MSA-2a1, MSA-2a2, and MSA-2b sequences, respectively. The present study has shown that genetic diversity among MSAs of Sri Lankan B. bovis isolates is very high, and that the sequences of field isolates diverged genetically from the K-strain.

Babesiosis-Induced Acute Kidney Injury With Prominent Urinary Macrophages

Babesia is an obligate intracellular erythrocyte parasite that can infect humans. Severe symptomatic disease from massive hemolysis and multiorgan system failure, including acute kidney injury (AKI), occurs. Acute tubular injury from a combination of volume depletion and heme pigment toxicity from profound hemolysis is the most common cause of AKI. We present a case of severe babesiosis complicated by dialysis-requiring AKI with the unique finding of large macrophages containing engulfed erythrocyte fragments in urine sediment. This urinary finding raised the possibility of another diagnosis distinct from acute tubular injury. Subsequent kidney biopsy demonstrated infection-associated acute interstitial nephritis.

Senna-Containing Laxatives Induce Severe Dermatitis in Toddlers: Status Epilepticus Associated with Long-acting Methylphenidate in a Child: Severe Hyperthermia after Administration of Methylphenidate: Panniculitis and Arthralgia in Melanoma Patients Treated with BRAF Inhibitors: Severe Babesiosis Associated with Tumor Necrosis Factor α Antagonist: Catatonia and Encephalopathy Associated with Paliperidone Palmitate: Pulmonary Toxicity after Bortezomib Treatment

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Severe Babesiosis in a Patient Treated With a Tumor Necrosis Factor Antagonist

Severe Babesiosis in a Patient Treated With a Tumor Necrosis Factor Antagonist

Babesiasp. EU1 Infection in a Forest Reindeer, the Netherlands

<i>Babesia</i>sp. EU1 Infection in a Forest Reindeer, the Netherlands

ABDOMINAL ULTRASONOGRAPHIC FINDINGS IN DOGS NATURALLY INFECTED WITH BABESIOSIS

Canine babesiosis is a tick-borne disease with a worldwide distribution that can involve multiple organs and result in a wide variety of clinical manifestations. Our goal was to describe the sonographic changes occurring in 72 dogs naturally infected with babesiosis. Seven healthy Beagle dogs were used as a control group. The most common finding in all dogs was splenomegaly with a diffuse heterogenic parenchyma and generally reduced echogenicity. Diffuse hypoechoic hepatomegaly and bilaterally increased cortical echogenicity of the renal parenchyma were found more frequently in severe uncomplicated and complicated babesiosis groups. Mean renal resistive index and pulsatility index (PI) values were 0.66/1.35, 0.73/1.91, and 0.71/1.73 for mild uncomplicated, severe uncomplicated, and complicated babesiosis groups, respectively. A markedly increased PI for complicated and severe uncomplicated groups correlated with anemia and severity of renal damage. Ultrasonography can be an adjunct for diagnosis and monitoring canine babesiosis and its systemic complications. The detection of diffuse heterogeneous splenomegaly can support the diagnosis of Babesia infection, because of the high prevalence of this lesion in these patients.

Red cell exchange transfusion for babesiosis in Rhode Island

We report four cases of clinically severe tick borne babesiosis treated with chemotherapy and adjunctive red cell exchange (RCE) at two Rhode Island hospitals from 2004 to 2007. All RCE procedures were performed using a Cobe Spectra device and were well tolerated without complications. The volume of allogeneic red cells used in the exchange was determined using the algorithm in the apheresis device with the input variables of preprocedure hematocrit, weight, height, an assumed allogeneic red cell hematocrit of 55 and a desired post procedure hematocrit of 27. The preprocedure level of parasitemia varied between 2.4% and 24% and the postprocedure level of parasitemia between 0.4 and 5.5% with an average overall percent reduction in parasitemia of 74%. Retrospectively, application of a new formula to calculate red cell mass appeared to correlate better with the percent reduction in parasitemia. Previous reports of RCE in babesiosis were reviewed. The reported reduction in parasitemia varied from 50% to >90%. Although a preprocedure level of parasitemia of 10% is sometimes used as a threshold for RCE in clinically severe babesiosis, this threshold does not have a firm empirical basis. No postprocedure desired level of parasitemia is indicated nor the mass of allogeneic red cells needed to achieve such a level. We conclude that current estimates of the dose of allogeneic red cells used in RCE are probably inaccurate, advocate a new formula to estimate this dose and suggest that a 90% reduction in parasitemia should be the minimally desired target of RCE in babesiosis.

Can tumor necrosis factor α blockade predispose to severe babesiosis?

Can tumor necrosis factor α blockade predispose to severe babesiosis?

The South African form of severe and complicated canine babesiosis: Clinical advances 1994–2004

Babesia ( canis) rossi infection is common in dogs in South Africa, and frequently causes severe, life-threatening disease. Acidemia, persistent hyperlactatemia, hemoconcentration, elevated creatinine, cerebral babesiosis, pulmonary edema and pancreatitis are all associated with mortality rates above 30%, compared with overall mortality of 12% in admitted cases. Although half the admitted cases are severely anemic, hemoconcentration is associated with far higher mortality. Cerebral babesiosis is uncommon, but carries a poor prognosis. The pathological mechanism has been suggested to be endothelial cell damage and necrosis, followed by segmental microvascular necrosis with perivascular edema and hemorrhage. Renal involvement in babesiosis resembles the functional renal failure of sepsis. Hypotension is common, and other cardiovascular disturbances have been documented. Cerebellar ataxia, rhabdomyolysis and pancreatitis are recently identified complications. While the previous categorization into “severe” (life-threatening anemia) and “complicated” (complications not directly attributable to anemia) disease has proved useful, the distinction is artificial and probably unnecessary. An updated approach to classification is suggested, aimed at grouping animals by severity and prognosis, and using simple measures, such as clinical collapse and abnormal breathing, as much as possible. Although inflammatory mechanisms are undoubtedly important in the pathophysiology of babesiosis, there can be little doubt that tissue hypoxia plays a major role in the disease process.

クリンダマイシンによる&lt;I&gt;Babesia gibsoni&lt;/I&gt;感染犬の治療

The efficacy of intramuscular clindamycin administration was evaluated at a dose of 50mg/kg b. w. b.i. d. for seven days in combination with a hepatic therapy, against severe cases infected withBabesia gibsoni. In the treated group, anemia and parasitemia were improved compaved with those in the control group. In addition, side effects such as damage at the injection site and clinical abnormality were not observed in the treated group. Based on these findings, we conclude that this treatment is useful for severe canine babesiosis cases.

Antigenic variation by protozoan parasites: insights from Babesia bovis

Antigenic variation of surface membrane proteins by protozoan parasites enables these pathogenic organisms to avoid host immune responses and thus perpetuate long-term infections. Babesia bovis, the causative agent of severe babesiosis in cattle, was previously shown to undergo antigenic variation through modifications to its primary surface antigen, a protein called VESA1. In this issue, Al-Khedery and Allred provide a detailed description of the genes that encode VESA1 and present convincing evidence for progressive, segmental gene conversion in the generation of variant forms of this surface antigen.

Possible mechanisms underlying age‐related resistance to bovine babesiosis

Calves infected with the tick-borne parasites Babesia spp. do not develop severe clinical babesiosis. Instead they display persistent low parasitaemias without any apparent ill-effects. This age-related resistance not only benefits the host, but also furthers parasite transmission. Both calves and adult animals respond with a Th I immune response to primary infection. Here we hypothesize that the difference in the outcome of infection may at least partly be explained by the localization and timing of the inflammatory response: in calves NO production occurs early and appears to be concentrated in the spleen. On the other hand, there is evidence that a delayed and systemic inflammatory response occurs in adult animals that is ineffectual and probably contributes to the pathogenesis. An improved understanding of the possible mechanisms that underlie this phenomenon may lead to new approaches for the treatment and immune prophylaxis of the disease.

Glucose, lactate, and pyruvate concentrations in dogs with babesiosis

To document changes in glucose, lactate, and pyruvate concentrations in dogs with severe or complicated babesiosis; assess relationships among glucose, lactate, and pyruvate concentrations in those dogs; and compare clinical and laboratory variables in dogs with and without hypoglycemia and hyperlactatemia. 20 dogs with naturally developing severe or complicated babesiosis. Samples and measurements were obtained before treatment was initiated. Babesiosis was diagnosed by examination of blood smears. Arterial blood pressure measurement, parasite quantification, CBC count, serum biochemical analysis, urinalysis, venous blood gas analysis, and acid-base determination were performed. Glucose, lactate, and pyruvate concentrations were measured in samples of venous blood. We detected a significant negative correlation between glucose and lactate concentrations. Glucose, lactate, and pyruvate concentrations all differed significantly between dogs that died and those that survived. Three of 5 dogs that died had concurrent hypoglycemia, hyperlactatemia, and hyperpyruvatemia. Hypoglycemic dogs differed significantly from normoglycemic dogs with regard to lactate, urea, and bicarbonate concentrations; lactate-to-pyruvate ratio; percentage parasitemia; and PCO2. Dogs with hyperlactatemia differed significantly from normolactatemic dogs with regard to clinical collapse; alanine transaminase activity; concentrations of bilirubin, urea, creatinine, and bicarbonate; percentage parasitemia; and PCO2. Abnormal carbohydrate metabolism is commonly evident in dogs with severe or complicated babesiosis and is often associated with changes in other clinical and laboratory variables. Significant differences were found between survivors and nonsurvivors. Hypoglycemia should be assessed and aggressively treated in dogs with babesiosis. Lactate concentration can be used as an indicator of disease severity.

Prognostic Value of Blood Lactate, Blood Glucose, and Hematocrit in Canine Babesiosis

Canine babesiosis typically causes hemolytic anemia but also can result in multiple organ dysfunction. Human patients with severe disease often have persistent hyperlactatemia, and blood lactate concentration is correlated with survival rate. In dogs, blood lactate concentration has been shown to be of prognostic value in patients with gastric dilatation‐volvulus and in dogs admitted to intensive care units. Serial blood lactate and glucose concentrations and hematocrit on admission were determined in 90 dogs with naturally occurring, severe or complicated canine babesiosis. Forty‐five dogs (50%) had hyperlactatemia (blood lactate concentration &gt;22.5 mg/dL) and 20 (22.2%) had hypoglycemia (blood glucose concentration &lt; 59.4 mg/dL) at presentation. Measurements significantly associated with mortality were hypoglycemia on admission, blood lactate concentration 45 mg/dL on admission, blood lactate concentration &gt;22.5 mg/dL at 8, 16, and 24 hours after admission, and increase or &lt; 50% decrease in blood lactate concentration within 8 and 16 hours after admission. Blood lactate concentration persistently 40 mg/dL indicated a very poor prognosis. We conclude that serial blood lactate measurements are useful in predicting survival in dogs with severe and complicated canine babesiosis.

Babesia divergens (Phylum Apicomplexa) in vitro growth in the presence of calf serum

Resistance to severe babesiosis in young calves has frequently been ascribed to an unknown serum factor(s) which inhibits growth of Babesia bovis in vitro. Our experiments show that young calf sera are as suitable as adult bovine sera for the in vitro culture of Babesia divergens, indicating that in this species at least inverse age resistance is due to alternative mechanisms. The suitability of commercial foetal calf sera for B. divergens cultures seems highly variable.

Babesia divergens (Phylum Apicomplexa) in vitro growth in the presence of calf serum

Resistance to severe babesiosis in young calves has frequently been ascribed to an unknown serum factor(s) which inhibits growth of Babesia bovis in vitro. Our experiments show that young calf sera are as suitable as adult bovine sera for the in vitro culture of Babesia divergens , indicating that in this species at least inverse age resistance is due to alternative mechanisms. The suitability of commercial foetal calf sera for B. divergens cultures seems highly variable.

Cardiac Troponins in Canine Babesiosis

This study compared the sensitivity of ECG and cardiac troponins to predict cardiac histopathological changes, clinical severity, and survival in canine babesiosis. One control group (n = 9) and 4 groups of dogs with mild uncomplicated babesiosis (n = 8), severe uncomplicated babesiosis (n = 9), complicated babesiosis (n = 8), and babesiosis and concurrent immune‐mediated he‐molytic anemia (IMHA) (n = 9) were studied. A 1‐minute lead II ECG was recorded, and cardiac troponin I (cTnl) and T (cTnT) concentrations in plasma were measured. cTnl concentrations were significantly higher in the complicated (mean, 9.9; SE, ±5.76) and concurrent IMHA (mean, 6.53; SE, ±4.32) groups and in the 3 dogs that died of the disease (mean, 22.17; SE, ±12.85) than in the control dogs (concentration below detection limit of test, —0.3 ng/mL). The 3 nonsurvivors had the most severe cardiac histopathological changes, but no arrhythmia and minimal other ECG changes. Dogs with babesiosis developed a variety of ECG abnormalities, but the abnormalities were not associated with disease severity, outcome, or plasma cardiac troponin concentrations. The exception was the presence of ventricular premature complexes (VPCs), which were associated with high cardiac troponin concentrations. This study showed an association between cTnl concentration and histological changes, clinical severity, and survival and no correlation between ECG abnormalities and histological changes or biochemical evidence of myocardial damage as reflected by cTnl concentrations. From this study, it was concluded that the analysis of plasma cTnl is a feasible and sensitive test and is superior to cTnT in diagnosing cardiac involvement in dogs with babesiosis.