Method Development for the Prediction of Melt Quality in the Extrusion Process.

Simulation models are used to design extruders in the polymer processing industry. This eliminates the need for prototypes and reduces development time for extruders and, in particular, extrusion screws. These programs simulate, among other process parameters, the temperature and pressure curves in the extruder. At present, it is not possible to predict the resulting melt quality from these results. This paper presents a simulation model for predicting the melt quality in the extrusion process. Previous work has shown correlations between material and thermal homogeneity and the screw performance index. As a result, the screw performance index can be used as a target value for the model to be developed. The results of the simulations were used as input variables, and with the help of artificial intelligence-more precisely, machine learning-a linear regression model was built. Finally, the correlation between the process parameters and the melt quality was determined, and the quality of the model was evaluated.

Tafenoquine for Relapsing Babesiosis: A Case Series.

BACKGROUND: Relapsing babesiosis often occurs in highly immunocompromised patients and has been attributed to the acquisition of resistance against drugs commonly used for treatment such as atovaquone, azithromycin, and clindamycin. Tafenoquine, which is approved for malaria prophylaxis and presumptive antirelapse treatment of Plasmodium vivax malaria, has shown activity against Babesia microti in several animal models of acute infection and in a single human case of relapsing babesiosis. Here, we report 5 cases of relapsing babesiosis treated with tafenoquine, including the previous case, and begin to define the conditions for optimal use of tafenoquine in relapsing babesiosis. METHODS: A definitive diagnosis of babesiosis was made by microscopic examination of Giemsa-stained thin blood smears or a real-time polymerase chain reaction (PCR) that targets the parasite 18S rRNA gene. Clearance of B. microti infection was ascertained by use of blood smear and real-time PCR. RESULTS: Tafenoquine was initiated with a loading dose of 600 mg. A weekly maintenance dose consisted of 200 mg or 300 mg; the lower dose was associated with a delayed clearance of B. microti. In 2 cases, all antimicrobial agents but tafenoquine were discontinued prior to clearance of infection. In 2 other cases, clearance was achieved while tafenoquine was administered along with other antimicrobial agents. In 3 of these 4 cases, tafenoquine was used in combination with atovaquone-proguanil. Other agents included atovaquone, azithromycin, and/or clindamycin. In 1 case, tafenoquine was administered alone and failed to prevent relapse. CONCLUSIONS: Tafenoquine can be a useful adjunct for the treatment of highly immunocompromised patients experiencing relapsing babesiosis caused by B. microti.

Absence of Anti-Babesia microti antibody in commercial intravenous immunoglobulin (IVIG).

BACKGROUND: Babesiosis is a worldwide emerging protozoan infection that is associated with a spectrum of disease severity from asymptomatic infection to severe organ damage and death. While effective treatment strategies are available, some immunocompromised patients experience severe acute and prolonged/relapsing illness due in part to an impaired host antibody response. Intravenous immunoglobulin (IVIG) has been used as an adjunctive therapy in some immunocompromised babesiosis patients, but its therapeutic effect is uncertain. We evaluated the presence of Babesia microti antibodies in commercial samples of IVIG. METHODS/PRINCIPLE FINDINGS: The presence of B. microti antibodies in commercial samples of IVIG were tested using an immunofluorescence assay. A subset of samples was then tested for B. microti antibodies using an enzyme linked immunosorbent assay. Out of 57 commercial IVIG samples tested using IFA, and 52 samples tested using ELISA, none were positive for B. microti antibodies. CONCLUSIONS: Commercially available IVIG may not be of therapeutic benefit for babesiosis patients. Additional sampling of IVIG for B. microti antibody and a clinical trial of babesiosis patients given IVIG compared with controls would provide further insight into the use of IVIG for the treatment of babesiosis.

Immune Control in Repeated Babesia microti Infection in a Patient With B-Cell Deficiency.

The immunology of human babesiosis is poorly investigated. We present a comprehensive investigation of a 75-year-old man with B-cell deficiency who experienced 3 episodes of babesiosis over a 6-year period. Slowly evolving clinical immunity was observed, as evidenced by milder clinical symptoms and lower peak parasite burden after each subsequent babesiosis episode. The patient exhibited several striking immunologic findings. First, the patient had exceptionally high Babesia microti-specific antibodies despite very few circulating B cells, which predominantly coexpressed CD27 (memory marker) and CD95 (death receptor). Second, we demonstrated the presence of long-lasting NK cells and expansion of T memory stem cells. Third, levels of the IP-10 cytokine directly correlated with parasite burden. These results raise fundamental questions on the priming, maintenance, and location of a B-cell population that produces high antibody levels in the face of severe B-cell deficiency. Our results should invoke interest among researchers to study the immunology and pathogenesis of human babesiosis.

Disparities Associated With Total Joint Arthroplasty Transfusion Rates.

BACKGROUND: Infections, readmissions, and mortalities after total joint arthroplasty (TJA) are serious complications, and transfusions have been associated with increased complication rates following TJA. Certain populations, including women, Black patients, patients who have public insurance and older adults have higher risks of transfusion. Recently, there has been a decline in transfusion rates and a greater emphasis on equity in medicine. This study examined whether disparities in transfusion rates still exist and what variables influence rates over time. METHODS: We used a health care system database to identify 5,435 total knee arthroplasty (TKA) and 2,105 total hip arthroplasty (THA) patients from 2013 to 2021. Transfusion rates were 2.9 and 3.1% in the TKA and THA arthroplasty groups, respectively. White race represented 67.1 and 69.8% of the TKA and THA groups, respectively. Fisher exact and Wilcoxon rank sum tests were used to compare categorical and continuous variables. Multivariable logistic regressions were performed to predict transfusion rates within 5 days of surgery and adjust for potential confounders. RESULTS: Transfusion rates declined over time. However, Black patients had a higher rate of transfusion than White patients despite similar hemoglobin levels, 5.1 versus 1.8% (P < .001) in the TKA group and 4.1 versus 2.7% (P = .103) in the THA group. Following adjustment, the biggest factor associated with a higher transfusion risk in the TKA group was being Black (adjusted odds ratio = 2.2, 95% confidence interval = 1.55 to 3.13). CONCLUSIONS: Transfusion rates for TJA patients are declining; however, Black patients continued to receive transfusions at higher rates in patients receiving TKA.

Transfusion-transmitted Babesia spp.: a changing landscape of epidemiology, regulation, and risk mitigation.

Babesia spp. are tick-borne parasites with a global distribution and diversity of vertebrate hosts. Over the next several decades, climate change is expected to impact humans, vectors, and vertebrate hosts and change the epidemiology of Babesia. Although humans are dead-end hosts for tick-transmitted Babesia, human-to-human transmission of Babesia spp. from transfusion of red blood cells and whole blood-derived platelet concentrates has been reported. In most patients, transfusion-transmitted Babesia (TTB) results in a moderate-to-severe illness. Currently, in North America, most cases of TTB have been described in the United States. TTB cases outside North America are rare, but case numbers may change over time with increased recognition of babesiosis and as the epidemiology of Babesia is impacted by climate change. Therefore, TTB is a concern of microbiologists working in blood operator settings, as well as in clinical settings where transfusion occurs. Microbiologists play an important role in deploying blood donor screening assays in Babesia endemic regions, identifying changing risks for Babesia in non-endemic areas, investigating recipients of blood products for TTB, and drafting TTB policies and guidelines. In this review, we provide an overview of the clinical presentation and epidemiology of TTB. We identify approaches and technologies to reduce the risk of collecting blood products from Babesia-infected donors and describe how investigations of TTB are undertaken. We also describe how microbiologists in Babesia non-endemic regions can assess for changing risks of TTB and decide when to focus on laboratory-test-based approaches or pathogen reduction to reduce TTB risk.

Severity of Chronic Venous Insufficiency on Primary Total Knee Arthroplasty Outcomes.

BACKGROUND: More than 700,000 people in the United States undergo total knee arthroplasty (TKA) each year. Chronic venous insufficiency (CVI) affects 5% to 30% of adults, sometimes resulting in leg ulceration. These CVI cases in TKAs have been associated with worse outcomes; however, we found no study differentiating CVI severity. METHODS: This retrospective study analyzed TKA outcomes at one institution from 2011 to 2021 using patient-specific codes. Analyses included short-term complications (< 90 days postoperative), long-term complications (< 2 years), and CVI status (yes/no; simple/complex/unclassified). Complex CVI consisted of pain, ulceration, inflammation, and/or other complications. Revisions within 2 years and readmissions within 90 days post-TKA were assessed. Composite complications included short-term and long-term complications, revisions, and readmissions. Multivariable logistic regressions predicted complication (any/long/short) as a function of CVI status (yes/no; simple/complex) and potential confounding variables. Of 7,665 patients, 741 (9.7%) had CVI. Among CVI patients, 247 (33.3%) had simple CVI, 233 (31.4%) had complex CVI, and 261 (35.2%) had unclassified CVI. RESULTS: There was no difference in CVI versus control in composite complications (P = .722), short-term complications (P = .786), long-term complications (P = .15), revisions (P = .964), or readmissions (P = .438) postadjustment. Composite complication rates were 14.0% without CVI, 16.7% with complex CVI, and 9.3% with simple CVI. Complication rates differed between simple and complex CVI (P = .035). CONCLUSION: Overall, CVI did not affect postoperative complications versus control. Patients who have complex CVI are at higher risk for post-TKA complications compared to those who have simple CVI.

How do surgeons decide when to treat proximal humerus fractures with operative versus nonoperative management?

PURPOSE: The objective of this study was to determine the underlying factors that drive the decision for surgeons to pursue operative versus nonoperative management for proximal humerus fractures (PHF) and if fellowship training had an impact on these decisions. METHODS: An electronic survey was distributed to members of the Orthopaedic Trauma Association and the American Shoulder and Elbow Surgeons Society to assess differences in patient selection for operative versus nonoperative management of PHF. Descriptive statistics were reported for all respondents. RESULTS: A total of 250 fellowship trained Orthopaedic Surgeons responded to the online survey. A greater proportion of trauma surgeons preferred nonoperative management for displaced PHF fractures in patients over the age of 70. Operative management was preferred for older patients with fracture dislocations (98%), limited humeral head bone subchondral bone (78%), and intraarticular head split (79%). Similar proportions of trauma surgeons and shoulder surgeons cited that acquiring a CT was crucial to distinguish between operative and nonoperative management. CONCLUSION: We found that surgeons base their decisions on when to operate primarily on patient's comorbidities, age, and the amount of fracture displacement when treating younger patients. Further, we found a greater proportion of trauma surgeons elected to proceed with nonoperative management in patients older than the age of 70 years old as compared to shoulder surgeons.

Reducing face touching through haptic feedback: A treatment evaluation against fomite-mediated self-infection.

Fomite-mediated self-infection via face touching is an understudied transmission pathway for infectious diseases. We evaluated the effect of computer-mediated vibrotactile cues (presented through experimental bracelets located on one or both hands of the participant) on the frequency of face touching among eight healthy adults in the community. We conducted a treatment evaluation totaling over 25,000 min of video observation. The treatment was evaluated through a multiple-treatment design and hierarchical linear modeling. The one-bracelet intervention did not produce significantly lower levels of face touching across both hands, whereas the two-bracelet intervention did result in significantly lower face touching. The effect increased over repeated presentations of the two-bracelet intervention, with the second implementation producing, on average, 31 fewer face-touching percentual points relative to baseline levels. Dependent on the dynamics of fomite-mediated self-infection via face touching, treatment effects could be of public health significance. The implications for research and practice are discussed.

Neurologic Complications of Babesiosis, United States, 2011-2021.

Babesiosis is a globally distributed parasitic infection caused by intraerythrocytic protozoa. The full spectrum of neurologic symptoms, the underlying neuropathophysiology, and neurologic risk factors are poorly understood. Our study sought to describe the type and frequency of neurologic complications of babesiosis in a group of hospitalized patients and assess risk factors that might predispose patients to neurologic complications. We reviewed medical records of adult patients who were admitted to Yale-New Haven Hospital, New Haven, Connecticut, USA, during January 2011-October 2021 with laboratory-confirmed babesiosis. More than half of the 163 patients experienced >1 neurologic symptoms during their hospital admissions. The most frequent symptoms were headache, confusion/delirium, and impaired consciousness. Neurologic symptoms were associated with high-grade parasitemia, renal failure, and history of diabetes mellitus. Clinicians working in endemic areas should recognize the range of symptoms associated with babesiosis, including neurologic.

Human Borrelia miyamotoi Infection in North America.

Borrelia miyamotoi is an emerging pathogen that causes a febrile illness and is transmitted by the same hard-bodied (ixodid) ticks that transmit several other pathogens, including Borrelia species that cause Lyme disease. B. miyamotoi was discovered in 1994 in Ixodes persulcatus ticks in Japan. It was first reported in humans in 2011 in Russia. It has subsequently been reported in North America, Europe, and Asia. B. miyamotoi infection is widespread in Ixodes ticks in the northeastern, northern Midwestern, and far western United States and in Canada. In endemic areas, human B. miyamotoi seroprevalence averages from 1 to 3% of the population, compared with 15 to 20% for B. burgdorferi. The most common clinical manifestations of B. miyamotoi infection are fever, fatigue, headache, chills, myalgia, arthralgia, and nausea. Complications include relapsing fever and rarely, meningoencephalitis. Because clinical manifestations are nonspecific, diagnosis requires laboratory confirmation by PCR or blood smear examination. Antibiotics are effective in clearing infection and are the same as those used for Lyme disease, including doxycycline, tetracycline, erythromycin, penicillin, and ceftriaxone. Preventive measures include avoiding areas where B. miyamotoi-infected ticks are found, landscape management, and personal protective strategies such as protective clothing, use of acaricides, and tick checks with rapid removal of embedded ticks.

Disparities in Elective and Nonelective Total Hip Arthroplasty.

BACKGROUND: Prior studies have shown disparities in utilization of primary and revision total hip arthroplasty (THA). However, little is known about patient population differences associated with elective and nonelective surgery. Therefore, the aim of this study was to explore factors that influence primary utilization and revision risk of THA based on surgery indication. METHODS: Data were obtained from 7,543 patients who had a primary THA from 2014 to 2020 in a database, which consists of multiple health partner systems in Louisiana and Texas. Of these patients, 602 patients (8%) underwent nonelective THA. THA was classified as "elective" or "nonelective" if the patient had a diagnosis of hip osteoarthritis or femoral neck fracture, respectively. RESULTS: After multivariable logistic regression, nonelective THA was associated with alcohol dependence, lower body mass index (BMI), women, and increased age and number of comorbid conditions. No racial or ethnic differences were observed for the utilization of primary THA. Of the 262 patients who underwent revision surgery, patients who underwent THA for nonelective etiologies had an increased odds of revision within 3 years of primary THA (odds ratio (OR) = 1.66, 95% Confidence Interval (CI) = 1.06-2.58, P-value = .025). After multivariable logistic regression, patients who had tobacco usage (adjusted odds ratio (aOR) = 1.36, 95% CI = 1.04-1.78, P-value = .024), alcohol dependence (aOR = 2.46, 95% CI = 1.45-4.15, P-value = .001), and public insurance (OR = 2.08, 95% CI = 1.18-3.70, P-value = .026) had an increased risk of reoperation. CONCLUSION: Demographic and social factors impact the utilization of elective and nonelective primary THA and subsequent revision surgery. Orthopaedic surgeons should focus on preoperative counseling for tobacco and alcohol cessation as these are modifiable risk factors to directly decrease reoperation risk.

The impact of ABO and RhD blood types on Babesia microti infection.

BACKGROUND: Babesiosis is an emerging infectious disease caused by intraerythrocytic Babesia parasites that can cause severe disease and death. While blood type is known to affect the mortality of Plasmodium falciparum malaria patients, associations between red blood cell (RBC) antigens and Babesia microti infection and disease severity are lacking. METHODS: We evaluated RhD and ABO blood types of Babesia-infected (18S rRNA reactive) blood donors in 10 endemic states in the Northeastern and northern Midwestern United States. We also assessed possible associations between RhD and ABO blood types and disease severity among hospitalized babesiosis patients in Connecticut. RESULTS: A total of 768 Babesia-infected blood donors were analyzed, of which 750 (97.7%) had detectable B. microti-specific antibodies. B. microti-infected blood donors were more likely to be RhD- (OR of 1.22, p-value 0.024) than RhD+ donors. Hospitalized RhD- babesiosis patients were more likely than RhD+ patients to have high peak parasitemia (p-value 0.017), which is a marker for disease severity. No differences in RhD+ blood type were noted between residents of the Northeast (OR of 0.82, p-value 0.033) and the Midwest (OR of 0.74, p-value 0.23). Overall, ABO blood type was not associated with blood donor B. microti infection, however, B. microti-infected donors in Maine and New Jersey were more likely to be blood type B compared to non-type B (OR 2.49 [p = 0.008] and 2.07 [p = 0.009], respectively), while infected donors from Pennsylvania were less likely to be type B compared to non-type B (OR 0.32 [p = 0.02]). CONCLUSIONS: People expressing RhD antigen may have a decreased risk of B. microti infection and babesiosis severity. The association of B antigen with B. microti infection is less clear because the antigen appeared to be less prevalent in infected Pennsylvania blood donors but more prevalent in Maine and New Jersey infected donors. Future studies should quantify associations between B. microti genotypes, RBC antigens, and the frequency and severity of B. microti infection to increase our understanding of human Babesia pathogenesis and improve antibody, vaccine, and RBC exchange transfusion strategies.

Lack of Demographic Information in Total Hip Arthroplasty/Total Knee Arthroplasty Randomized Controlled Trial Publications.

BACKGROUND: The impact of social determinants of health (SDOH) has been documented in orthopaedic literature. However, there is a lack of data on the inclusion of these variables in orthopaedic studies. Our aim was to investigate how many total hip arthroplasties and total knee arthroplasties randomized controlled trials report SDOH variables such as race, ethnicity, insurance, income, and education within the manuscript. METHODS: A systematic review was conducted on a PubMed search for randomized controlled trials published from 2017 to 2019 in the Journal of Bone and Joint Surgery, Journal of Arthroplasty, Clinical Orthopaedics and Related Research, and Osteoarthritis and Cartilage. Data collected included publication year, type of surgery, and the inclusion of race, ethnicity, insurance, income, and education. RESULTS: Of the 72 manuscripts included in the study, 5.6% of the manuscripts mentioned race, 4.2% included race within the demographic table, and 1.4% included ethnicity in the demographic table. Overall, only 5 studies discussed any one of the variables studied and none included any SDOH variables in their multivariable regressions. There were no statistically significant differences on inclusion across journal year (P value = .78), journal name (P value = 1.00), or surgery type (P value = .555). CONCLUSION: Our findings identify a major shortcoming in the inclusion of SDOH variables in total knee arthroplasty/total hip arthroplasty publications. Their exclusion may be indirectly perpetuating disparities if research that does not use representative patient samples is used in creating health policies and national standards. LEVEL OF EVIDENCE: Level V.

Animal models of the immunology and pathogenesis of human babesiosis.

Animal models of human babesiosis have provided a basic understanding of the immunological mechanisms that clear, or occasionally exacerbate, Babesia infection and those pathological processes that cause disease complications. Human Babesia infection can cause asymptomatic infection, mild to moderate disease, or severe disease resulting in organ dysfunction and death. More than 100 Babesia species infect a wide array of wild and domestic animals, and many of the immunologic and pathologic responses to Babesia infection are similar in animals and humans. In this review, we summarize the knowledge gained from animal studies, their limitations, and how animal models or alternative approaches can be further leveraged to improve our understanding of human babesiosis.

Broad Antimicrobial Resistance in a Case of Relapsing Babesiosis Successfully Treated With Tafenoquine.

We describe a case of relapsing babesiosis in an immunocompromised patient. A point mutation in the Babesia microti 23S rRNA gene predicted resistance to azithromycin and clindamycin, whereas an amino acid change in the parasite cytochrome b predicted resistance to atovaquone. Following initiation of tafenoquine, symptoms and parasitemia resolved.

Risk of Infection Following Gunshot Wound Fractures to the Foot and Ankle: A Multicenter Retrospective Study.

The purpose of this multicenter retrospective chart review was to describe demographics, fracture and wound characteristics, and treatments for foot and/or ankle fractures caused by gunshot wounds (GSWs) and identify factors that increase risk of infection in adults treated at 5 urban level 1 trauma centers in South and Midwest regions of the United States. A total of 244 patients sustained GSW-related fractures of the foot/ankle during 2007-2017, of whom 179 had ≥30 days of follow-up data after the initial injury. Most patients were male (95.1%; 232/244) with an average age of 31.2 years. On average, patients sustained 1.3 GSWs (range 1-5) to the foot/ankle. Most GSWs were categorized as low energy (85.1%; 171/201) and the majority (58.2%; 142/244) had retained bullet fragments. Antibiotics were administered at initial presentation to 78.7% (192/244) of patients and 41.8% (102/244) were managed operatively at the time of initial injury. Nerve injury, vascular injury, and infection were documented in, respectively, 8.6% (21/243), 6.6% (16/243), and 17.2% (42/244) of all cases. Multivariable analysis revealed that high-energy injuries and retained bullet fragments increased the risk of infection by 3-fold (odds ratio 3.09, 95% confidence interval 1.16-8.27, p = .025) and 3.5-fold (OR 3.48, 95% CI1.40-8.67; p = .008), respectively. Side of injury, primary injury region, and vascular injury were not significant predictors of infection risk. Further research should examine whether retained bullet fragments are directly associated with infection risk and support the development of guidelines regarding the management of patients with GSW-related fractures to the ankle/foot.

Cardiac Complications of Human Babesiosis.

BACKGROUND: Human babesiosis is a worldwide emerging tick-borne disease caused by intraerythrocytic protozoa. Most patients experience mild to moderate illness, but life-threatening complications can occur. Although cardiac complications are common, the full spectrum of cardiac disease and the frequency, risk factors, and outcomes in patients experiencing cardiac complications are unclear. Accordingly, we carried out a record review of cardiac complications among patients with babesiosis admitted to Yale-New Haven Hospital over the last decade to better characterize cardiac complications of babesiosis. METHODS: We reviewed the medical records of all adult patients with babesiosis admitted to Yale-New Haven Hospital from January 2011 to October 2021, confirmed by identification of Babesia parasites on thin blood smear and/or by polymerase chain reaction. The presence of Lyme disease and other tick-borne disease coinfections were recorded. RESULTS: Of 163 enrolled patients, 32 (19.6%) had ≥1 cardiac complication during hospitalization. The most common cardiac complications were atrial fibrillation (9.4%), heart failure (8.6%), corrected QT interval prolongation (8.0%), and cardiac ischemia (6.8%). Neither cardiovascular disease risk factors nor preexisting cardiac conditions were significantly associated with the development of cardiac complications. The cardiac complication group had a greater prevalence of high-grade parasitemia (>10%) (P < .001), longer median length of both hospital (P < .001) and intensive care unit stay (P < .001), and a higher mortality rate (P = .02) than the group without cardiac complications. CONCLUSIONS: Cardiac complications of acute babesiosis are common and occurred in approximately one-fifth of this inpatient sample. Further investigation is needed to elucidate the relationship between babesiosis severity and cardiac outcomes.

Comparing the Epidemiology and Health Burden of Lyme Disease and Babesiosis Hospitalizations in the United States.

Background: Lyme disease (LD) and babesiosis are increasing in the United States. We sought to characterize and compare their epidemiology and health burden using a nationally representative sample of hospitalizations. Methods: Data were extracted from the National Inpatient Sample (NIS) pertaining to LD and babesiosis for 2018 and 2019. The NIS is a comprehensive database of all-payer inpatient hospitalizations, representing a stratified systematic random sample of discharges from US hospitals. Patient demographics, clinical outcomes, and admission costs were evaluated, in addition to hospital-level variables (eg, location/teaching status and census division). Annual incidence of hospitalizations was calculated using US Census Bureau data. Results: The annual incidence of hospitalizations of LD-related and babesiosis-related hospitalizations were 6.98 and 2.03 per 1 000 000 persons/year. Of the 4585 LD hospitalizations in 2018-2019, 60.9% were among male patients, 85.3% were White, and 39.0% were ≥60 years. Of the 1330 babesiosis hospitalizations in 2018-2019, 72.2% were among male patients, 78.9% were White, and 74.1% were ≥60 years; 70.0% of LD and 91.7% of babesiosis hospitalizations occurred in Middle Atlantic or New England. Lower disease severity was noted in 81.8% of LD hospitalizations compared with 49.3% of babesiosis hospitalizations, whereas those suffering from high severity were 2.3% and 6.0%, respectively. The mean hospital charges for LD and babesiosis hospitalizations were $33 440.8 and $40 689.8, respectively. Conclusions: Despite overlap between the 2 diseases, LD has a broader geographic range and a greater number of hospital admissions, whereas babesiosis is more severe, incurring longer hospital stays, higher inpatient costs, and deaths.

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.