Parasite burden and red blood cell exchange transfusion for babesiosis.

BACKGROUND: The association between parasite burden and end-organ dysfunction in subjects with Babesia microti infection has not been extensively studied, nor has the optimal role of red blood cell exchange (RCE) transfusion in babesiosis treatment. This retrospective chart review evaluates the associations between parasitemia, end-organ dysfunction, and outcomes in babesiosis patients treated with antimicrobial agents and RCE compared to those treated with antimicrobial agents alone. MATERIALS AND METHODS: We evaluated adults (≥18 years of age) with laboratory-confirmed babesiosis who were admitted between 2011 and 2017 to Yale New Haven Hospital, located in a Babesia-endemic region of the Northeastern United States. Patient demographics, parasitemia levels, clinical and laboratory indicators of end-organ dysfunction, and outcomes were examined. RESULTS: Ninety-one subjects (mean age 65.1 years, 69.2% male) were studied. Subjects were stratified according to peak parasitemia: <1% (n = 34), 1-5% (n = 24), 5-10% (n = 15), and >10% (n = 18). Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels. Median length of hospital stay increased with each successive peak parasitemia level (P < .001). These results indicate a strong association between peak parasitemia level and disease severity. Nineteen subjects underwent RCE, all with peak parasitemia ≥9% and some degree of end-organ dysfunction. CONCLUSIONS: Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia. Our data suggest that the use of parasitemia >10%, coupled with clinical status, is a reasonable indicator for RCE in babesiosis patients.

Associations between monthly rainfall and mortality in cattle due to East Coast fever, anaplasmosis and babesiosis.

Weather conditions can impact infectious disease transmission, causing mortalities in humans, wild and domestic animals. Although rainfall in dry tropical regions is highly variable over the year, rainfall is thought to play an important role in the transmission of tick-borne diseases. Whether variation in rainfall affects disease-induced mortalities, is, however, poorly understood. Here, we use long-term data on monthly rainfall and Boran cattle mortality (1998-2017) to investigate associations between within-year variation in rainfall and cattle mortalities due to East Coast fever (ECF), anaplasmosis and babesiosis in Laikipia, Kenya, using ARIMAX modelling. Results show a negative correlation between monthly rainfall and cattle mortality for ECF and anaplasmosis, with a lag effect of 2 and 6 months, respectively. There was no association between babesiosis-induced mortalities and monthly rainfall. The results of this study suggest that control of the tick-borne diseases ECF and anaplasmosis to reduce mortalities should be intensified during rainy periods after the respective estimated time lags following dry periods.

Transfusion transmitted babesiosis: A systematic review of reported cases.

BACKGROUND: Transfusion transmitted babesiosis (TTB) has a high mortality rate but may go unrecognized, particularly in non-endemic areas. We therefore conducted a systematic review to better characterize clinical aspects of TTB. METHODS: A literature search was conducted in PubMed and CINAHL databases, from which 25 eligible articles describing 60 TTB patients met criteria for data extraction. RESULTS: Symptom evaluation was provided for 25 implicated donors: 18/25 (72%) were asymptomatic while 7/25 (28%) had mild flu-like symptoms but were asymptomatic at time of donation. It was common for a single donor or donation to infect multiple patients. Where reported, species included B. microti - 54/60 (90%), B. duncani - 3/60 (5%), and B. divergens-like/MO-1 - 1/60 (2%). Most TTB patients (44/60, 73%) resided in endemic states, while most TTB deaths 6/9 (67%) occurred in non-endemic states. Severity of hemolysis was proportional to degree of parasitemia. Mortality in our series was 9/60 (15%); most deaths occurred at extremes of the age spectrum: 6/9 non-survivors were aged >55 years, 2/9 were <1 year, only 1/9 was 2-54 years. Number of comorbidities was higher among non-survivors (median = 4) compared to survivors (median = 1). CONCLUSIONS: All implicated donors (for which symptoms data were reported) resulting in TTB infections were asymptomatic at the time of donation, and it was common for a single donor or donation to infect multiple patients. Mortality of TTB appeared highest among those with more comorbidities and in non-endemic states. Heightened awareness of this diagnosis is key in its recognition.

Spatiotemporal cluster and incidence analysis of cattle mortality caused by bovine babesiosis in Styria, Austria, between 1998 and 2016.

Reported fatal cases of bovine babesiosis (syn.: piroplasmosis, red water fever) in cattle were analyzed to identify spatial and temporal clusters of their incidence in the Austrian province of Styria. Data were collected within a governmental babesiosis compensation program. Diagnosis was performed using a standardized necropsy protocol. Between 1998 and 2016, a total of 1257 cases of fatal babesiosis were registered and compensated. Within the study interval, annual numbers of fatal babesiosis differed significantly among municipalities. Spatiotemporal analysis covering the entire study period revealed one high-risk cluster in the western and central northern region of Styria and a low-risk cluster in the southeastern part of Styria. Annual temporal analysis demonstrated that cases accumulated in June. Annual spatial analysis revealed consistently that cases mainly occurred in the western and central northern regions, whereas they occurred rarely in the southeastern regions. These results should increase awareness and facilitate protective actions against ticks during certain time periods and geographic areas.

A clinical and pathological description of 320 cases of naturally acquired Babesia rossi infection in dogs.

Babesia rossi causes the most severe clinical disease in dogs of all the babesia parasites. We included 320 naturally-infected dogs that presented for care at the Onderstepoort Veterinary Academic Hospital between 2006 and 2016. All dogs had mono-infections confirmed by multiplex PCR. The data allowed more accurate clinical classification of the disease and identified parameters that were associated with disease severity and death. Odds ratios for dying were significant (P < 0.05) for increased band neutrophil count, collapse at presentation; presence of cerebral signs; hypoglycaemia; hyperlactatemia; high urea, high creatinine; hyperbilirubinaemia; hypercortisolaemia; and hypothyroxinaemia. Joint component analysis confirmed that the variables with significant odds ratios grouped together with death. Yet, multivariate logistic regression was unable to identify a group of significant independent predictors of death. Receiver Operator Characteristic curves indicated that low total thyroid hormone, high bilirubin, high serum urea and high cortisol concentrations were the variables with the highest sensitivity and specificity for death. These data provide both the clinician and researcher with a set of easily-measured laboratory and clinical assessments to classify cases into those that are uncomplicated and those that are complicated. The disease is complex and multisystemic and probably involves mechanisms more proximal in the pathogenesis than those that have been evaluated.

The impact of Babesia microti blood donation screening.

BACKGROUND: Babesia microti, an intraerythrocytic parasite endemic in the Northeast and upper Midwest United States, is responsible for over 200 reported cases of transfusion-transmitted babesiosis (TTB). The American Red Cross has prospectively screened donations in endemic areas for B. microti since 2012. METHODS: Blood donation samples from Massachusetts, Connecticut, Minnesota, and Wisconsin were tested by arrayed fluorescence immunoassay and real-time polymerase chain reaction. Donors with reactive results by any test were deferred and invited to participate in a follow-up study. RESULTS: Screening of 506,540 donations (June 2012-May 2018) yielded 1299 reactives, 177 of which were DNA and antibody positive and 25 DNA positive only. During the same time, 23 unscreened RBC units collected in Connecticut and Massachusetts were involved in TTB cases, making the risk of transmitting the infection from an unscreened donation in these two states 15.6-times greater than from a Babesia-negative unit. B. microti screening in Connecticut and Massachusetts has been associated with a reduction in TTB cases; none reported from blood donors residing in Connecticut since 2016. The positive donor rate has also decreased in Connecticut from 0.67% in 2013 to 0.23% in 2017. Ongoing follow-up testing has shown that only 10% of antibody-positive donors serorevert within 1 year, while 94% of polymerase chain reacton-positive donors become negative within 12 months. CONCLUSIONS: Blood donation screening for B. microti in endemic areas effectively mitigates TTB risk. Screening should be considered for all areas demonstrating ongoing risk defined as clinical cases or positive blood donors including those associated with TTB cases.

Babesiosis as a cause of acute respiratory distress syndrome: a series of eight cases.

OBJECTIVES: The characteristics of patients with Acute Respiratory Distress Syndrome (ARDS) as a complication of Babesia microti infection have not been systematically described. METHODS: Adult patients admitted to the medical intensive care unit (MICU) of a tertiary care hospital in the Lower Hudson Valley of New York from 1/1/2008 to 8/1/2016 were evaluated for ARDS complicating babesiosis. RESULTS: Of 22 patients with babesiosis in the MICU, eight (36.4%; 95% CI: 19.7-57.0%) had ARDS. Six patients (75%) developed ARDS following initiation of anti-babesia drug therapy; however, the mean duration of symptoms in these patients exceeded that of patients who developed ARDS prior to initiation of treatment (7.50 ± 3.83d vs. 4.50 ± 0.71d, p = 0.34). Three patients (37.5%; 95% CI: 13.7-69.4%) expired without recovery from ARDS. In comparison, the mortality rate for the 14 MICU babesiosis patients without ARDS was 14.3% (p = 0.31). There was a trend toward younger age in survivors relative to non-survivors (mean age 54.6 ± 13.8y vs. 74.0 ± 6.24y, p = 0.07). Three of the five survivors did not require mechanical ventilation. The mean sequential organ failure assessment score of non-survivors was significantly higher than that of survivors (12.3 ± 1.15 vs. 6.0 ± 1.4, p = 0.0006). CONCLUSION: Among 22 critically ill adult patients with B. microti infection, ARDS developed in eight (35.4%), and three (37.5%) expired without resolution of the ARDS. ARDS often followed the initiation of anti-babesia drug therapy, raising the question of whether the death of the parasite per se contributed to its development. However, this observation was confounded by the longer duration of symptoms preceding initiation of drug therapy.

Haemoparasitic agents associated with ovine babesiosis: A possible negative interaction between Babesia ovis and Theileria ovis.

Babesiosis, theileriosis, and anaplasmosis are the most common tick-borne diseases in sheep. The majority of anaplasmosis and theileriosis are subclinical; however, babesiosis causes severe infections in small ruminants. Although there are many reports of co-infections with the agents of these diseases, their clinical severity compared with either of the infections alone is unknown. Within the host, interactions between co-infecting species may cause variations in clinical presentation and response to therapy. The aim of this study was to determine the tick-borne agents in sheep located at sites where fatal disease outbreaks caused by babesiosis have commonly been reported. Two hundred and nine sheep with clinical signs suggestive of ovine babesiosis were included in the study. The initial diagnosis of haemoparasites was based on clinical symptoms and microscopy and was confirmed using PCR assays. The blood samples were examined for the presence of Babesia ovis (B. ovis), Anaplasma ovis (A. ovis), A. phagocytophilum, and Theileria ovis (T. ovis). The results showed 86.12% of the animals were infected with one or more pathogens. B. ovis was the dominant pathogen. Overall, the infection rate of B. ovis, A. ovis, T. ovis, and A. phagocytophilum was 70.81%, 56.94%, 21.05%, and 2.39%, respectively. The infection rate of B. ovis alone (31.11%) was higher than A. ovis (9.44%) or T. ovis (1.67%) alone. Co-infections were found at a higher percentage (57.78%) than single infections (42.22%). A. ovis was detected in the blood of a high percentage (98.07%) of co-infected animals. Coexistence of B. ovis and A. ovis (34.45%) was more common than other combinations of species. There was a noticeably low level of co-occurrence between B. ovis and T. ovis (1.11%). During the study, 11 sick animals did not survive despite treatment. Seven were infected with B. ovis alone, three had a dual infection with B. ovis and A. ovis, and one had B. ovis, A. ovis, and T. ovis.

Occurrence of tick-borne haemoparasites in cattle in the Mungwi District, Northern Province, Zambia.

Little is known about the occurrence of haemoparasites in cattle in communal grazing areas of Mungwi District of Northern Province, Zambia. Clinical signs and post mortem lesions are pathognomonic of mixed tick-borne infections especially babesiosis, anaplasmosis and East Coast fever. The main objective of this study was to screen selected communal herds of cattle for tick-borne haemoparasites, and identify the tick vectors associated with the high cattle mortalities due to suspected tick-borne diseases in the local breeds of cattle grazing along the banks of the Chambeshi River in Mungwi District, Northern Province, Zambia. A total of 299 cattle blood samples were collected from July to September 2010 from Kapamba (n = 50), Chifulo (n = 102), Chisanga (n = 38), Kowa (n = 95) and Mungwi central (n = 14) in the Mungwi District. A total of 5288 ticks were also collected from the sampled cattle from April to July 2011. DNA was extracted from the cattle blood and the hypervariable region of the parasite small subunit rRNA gene was amplified and subjected to the reverse line blot (RLB) hybridization assay. The results of the RLB assay revealed the presence of tick-borne haemoparasites in 259 (86.6%) cattle blood samples occurring either as single (11.0%) or mixed (75.6%) infections. The most prevalent species present were the benign Theileria mutans (54.5%) and T. velifera (51.5%). Anaplasma marginale (25.7%), Babesia bovis (7.7%) and B. bigemina (3.3%) DNA were also detected in the samples. Only one sample (from Kapamba) tested positive for the presence of T. parva. This was an unexpected finding; also because the tick vector, Rhipicephalus appendiculatus, was identified on animals from Kowa (14.0%), Chisanga (8.5%), Chifulo (6.0%) and Kapamba (1.4%). One sample (from Kapamba) tested positive for the presence of Ehrlichia ruminantium even though Amblyomma variegatum ticks were identified from 52.9% of the sampled animals from all study areas. There was significant positive association between T. mutans and T. velifera (p < 0.001) infections, and between A. marginale and B. bovis (p = 0.005). The presence of R. microplus tick vectors on cattle was significantly associated with B. bovis (odds ratio, OR = 28.4, p < 0.001) and A. marginale (OR = 42.0, p < 0.001) infections, while A. variegatum presence was significantly associated with T. mutans (OR = 213.0, p < 0.001) and T. velifera (OR = 459.0, p < 0.001) infections. Rhipicephalus decoloratus was significantly associated with B. bigemina (OR = 21.6, p = 0.004) and A. marginale (OR = 28.5, p < 0.001). Multivariable analysis showed a significant association between location and tick-borne pathogen status for A. marginale (p < 0.001), T. mutans (p = 0.004), T. velifera (p = 0.003) and T. taurotragi (p = 0.005). The results of our study suggest that the cause of cattle mortalities in Mungwi during the winter outbreaks is mainly due to A. marginale, B. bovis and B. bigemina infections. This was confirmed by the clinical manifestation of the disease in the affected cattle and the tick species identified on the animals. The relatively low prevalence of T. parva, B. bigemina, B. bovis and E. ruminantium could indicate the existence of endemic instability with a pool of susceptible cattle and the occurrence of disease outbreaks.

Babesia odocoilei as a cause of mortality in captive cervids in Canada.

Nine cases of fatal infection with Babesia odocoilei were confirmed in reindeer (Rangifer tarandus tarandus) and elk (Cervus canadensis) housed in zoological institutions located in southern Quebec, Ontario, and Manitoba, Canada between 2013 and 2016. All animals died of a hemolytic crisis. Frequent postmortem findings were extensive hemorrhage, pigmenturia, and intrahepatic cholestasis. The described ante- and postmortem signs are consistent with those of previously reported cases in the United States. Diagnosis was confirmed in all cases by polymerase chain reaction performed on DNA extracted from whole blood or frozen spleen. We propose that babesiosis is an emerging disease of cervids in multiple Canadian provinces, most likely as a result of climate change and the northward range expansion of Ixodes scapularis, the primary tick vector for B. odocoilei. The role of captive animals as sentinels for wildlife health is also highlighted.

Babesia odocoilei,une cause de la mortalité chez les cervidés captifs au Canada. Entre 2013 à 2016, neuf cas d'infection fatale par Babesia odocoilei ont été détectés chez des caribous (Rangifer tarandus tarandus) et des wapitis (Cervus canadensis) gardés dans des établissements zoologiques situés dans le sud du Québec, de l'Ontario et du Manitoba, Canada. Les animaux sont morts suite à une crise hémolytique. Hémorragies, pigmenturie et cholestase intrahépatique ont fréquemment été identifiées à l'examen postmortem. Les signes ante- et postmortem décrits correspondent avec ceux des cas précédemment signalés aux États-Unis. Le diagnostic de babésiose fut confirmé par réaction en chaîne par polymérase sur l'ADN extrait d'échantillons de sang ou de rate congelée. Nous proposons que la babésiose des cervidés est une maladie émergente au Canada, et ce probablement en conséquence du réchauffement climatique et du mouvement vers le nord de la tique Ixodes scapularis, le principal vecteur de B. odocoilei. La valeur des animaux captifs comme sentinelles pour la santé de la faune est également discutée.(Traduit par les auteurs).

Relation of antioxidant status at admission and disease severity and outcome in dogs naturally infected with Babesia canis canis.

BACKGROUND: Canine babesiosis is caused by species of the Babesia genus and has become an emerging disease worldwide. To the authors' knowledge there are no reports in which antioxidants have been analyzed in different presentations of canine babesiosis or in which the prognostic value of antioxidants has been studied. The aim of this study was to evaluate whether oxidative stress could be related to the severity and outcome of canine babesiosis. For this purpose a profile consisting of four antioxidant biomarkers (superoxide dismutase - SOD, glutathione peroxidase - GPx, catalase, total antioxidant status - TAS) and malondialdehyde - MDA as an oxidant biomarker (previously evaluated, here studied for comparative purposes) were evaluated in dogs with canine babesiosis of different clinical severity and outcomes. RESULTS: The study was conducted with a sample of 40 dogs suffering from babesiosis (further divided into uncomplicated, one complication and multiple organ dysfunction syndrome - MODS group) and 30 healthy dogs (control group). Additionally, the babesiosis group was divided according to the anaemia into non-anaemic, mildly anaemic, moderately anaemic and severely anaemic dogs. The results of our study showed significantly decreased SOD, catalase and TAS values in diseased dogs compared to controls, while there were no significant differences in GPx between these groups. Dogs that developed MODS showed lower activities of SOD and GPx and higher MDA values compared to dogs with uncomplicated babesiosis as well as with dogs that developed one complication. Superoxide dismutase, catalase and GPx were negatively correlated whereas MDA was positively correlated with the lethal outcome of the disease. Furthermore, this study detected more pronounced decrease in antioxidant biomarkers (SOD, GPx and catalase) in dogs with moderate anaemia compared to those with mild anaemia. CONCLUSIONS: The results of this study showed changes in biomarkers related to the antioxidant status of dogs naturally infected with B. canis canis. These biomarkers could be used as indicators of disease severity and outcome in dogs suffering from babesiosis.

Mortality in virulent canine babesiosis is associated with a consumptive coagulopathy.

The inflammatory response to infection can activate the coagulation system via complex interactions. If uncontrolled, this may lead to a consumptive coagulopathy, a major risk factor for a poor clinical outcome. This prospective observational study was conducted to determine whether consumptive coagulopathy in dogs with Babesia rossi infection is related to mortality. Seventy-two client-owned dogs diagnosed with canine babesiosis were included. Diagnosis was confirmed by polymerase chain reaction and reverse line blot and dogs co-infected with Babesia vogeli or Ehrlichia canis were excluded. Blood samples were collected at admission. Coagulation factor-, antithrombin (AT)-, and protein C (PC)-activity, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer concentrations were measured. The mortality rate was 18% (13/72 dogs) and the median activities of all the coagulation factors were significantly lower in the non-survivors compared to the survivors. Median PT and aPTT were significantly longer in the non-survivors compared to the survivors. Median AT activity was not significantly different but median PC activity was significantly decreased in the non-survivors. Median D-dimer concentrations were significantly higher in non-survivors compared to survivors. This study showed that dogs that died from B. rossi infection had a more severe consumptive coagulopathy compared to survivors, characterized by procoagulant activation, inhibitor consumption, and increased fibrinolytic activity.

Outbreak of equine piroplasmosis in Florida.

CASE DESCRIPTION: A 7-year-old Quarter Horse gelding was hospitalized in Ocala, Fla, because of lethargy, fever, anorexia, and swelling of distal aspects of the limbs. A tentative diagnosis of equine piroplasmosis (EP) was made on the basis of examination of a blood smear. The case was reported to the Florida State Veterinarian, and infection with Babesia equi was confirmed. The subsequent investigation included quarantine and testing of potentially exposed horses for B equi and Babesia caballi infections, tick surveillance, and owner-agent interviews. CLINICAL FINDINGS: 210 horses on 25 premises were tested for infection with EP pathogens. Twenty B equi-infected horses on 7 premises were identified; no horses tested positive for B caballi. Seven horses, including the index case, had clinical findings consistent with EP Dermacentor variabilis was considered the only potential tick vector for B equi collected, and all D variabilis specimens tested negative for Babesia organisms via PCR assay. Results of the epidemiological investigation suggested that B equi was spread by use of shared needles and possibly blood transfusions. All horses that tested positive were involved in nonsanctioned Quarter Horse racing, and management practices were thought to pose substantial risk of transmission of blood-borne pathogens. TREATMENT AND OUTCOME: Final outcome of B equi-infected horses was euthanasia, death from undetermined causes, or shipment to a US federal research facility. CLINICAL RELEVANCE: This investigation highlights the importance of collaboration between private veterinary practitioners, state veterinary diagnostic laboratories, and regulatory officials in the recognition, containment, and eradication of foreign animal disease.

Macrophages are critical for cross-protective immunity conferred by Babesia microti against Babesia rodhaini infection in mice.

Although primary infection of mice with Babesia microti has been shown to protect mice against subsequent lethal infection by Babesia rodhaini, the mechanism behind the cross-protection is unknown. To unravel this mechanism, we investigated the influence of primary infection of mice with nonlethal B. microti using different time courses on the outcome of subsequent lethal B. rodhaini infection. Simultaneous infections of mice with these parasites resulted in rapid increases in parasitemia, with 100% mortality in BALB/c mice, as observed with control mice infected with B. rodhaini alone. In contrast, mice with acute, resolving, and chronic-phase B. microti infections were completely protected against B. rodhaini, resulting in low parasitemia and no mortalities. Mice immunized with dead B. microti were not protected from B. rodhaini infection, although high antibody responses were induced. Interestingly, the protected mice had significantly decreased levels of antibody response, cytokines (including gamma interferon [IFN-γ], interleukin-2 [IL-2], IL-8, IL-10, and IL-12), and nitric oxide levels after infection with B. rodhaini. SCID mice and IFN-γ-deficient mice with chronic B. microti infections demonstrated protective responses comparable to those of immunocompetent mice. Likewise, in vivo NK cell depletion did not significantly impair the protective responses. Conversely, macrophage depletion resulted in increased susceptibility to B. rodhaini infection associated with changes in their antibody and cytokines profiles, indicating that macrophages contribute to the protection against this challenge infection. We conclude that future development of vaccines against Babesia should include a strategy that enhances the appropriate activation of macrophages.

Transfusion-transmitted Babesia spp.: bull's-eye on Babesia microti.

Babesia spp. are intraerythrocytic protozoan parasites of animals and humans that cause babesiosis, a zoonotic disease transmitted primarily by tick vectors. Although a variety of species or types of Babesia have been described in the literature as causing infection in humans, the rodent parasite Babesia microti has emerged as the focal point of human disease, especially in the United States. Not only has B. microti become established as a public health concern, this agent is increasingly being transmitted by blood transfusion: estimates suggest that between 70 and 100 cases of transfusion-transmitted Babesia (TTB) have occurred over the last 30 years. A recent upsurge in TTB cases attributable to B. microti, coupled with at least 12 fatalities in transfusion recipients diagnosed with babesiosis, has elevated TTB to a key policy issue in transfusion medicine. Despite clarity on a need to mitigate transmission risk, few options are currently available to prevent the transmission of B. microti by blood transfusion. Future mitigation efforts may stress serological screening of blood donors in regionalized areas of endemicity, with adjunct nucleic acid testing during the summer months, when acute infections are prevalent. However, several hurdles remain, including the absence of a licensed blood screening assay and a thorough cost-benefit analysis of proposed interventions. Despite current obstacles, continued discussion of TTB without proactive intervention is no longer a viable alternative.

Feline babesiosis.

OBJECTIVE: To review and summarize current information regarding the etiology, clinical presentation, diagnosis, treatment, and prognosis of feline babesiosis, especially with regard to features distinct from canine babesiosis. ETIOLOGY: Babesiosis is caused by hemoprotozoa of the genus Babesia. Numerous species of Babesia exist worldwide. The babesial organism spends the majority of its life cycle within the erythrocyte of the definitive host, resulting in hemolysis, with or without systemic complications. DIAGNOSIS: Definitive diagnosis depends on direct visualization of the organism on blood smear or a positive polymerase chain reaction. Positive serologic tests indicate only exposure, with or without active infection. THERAPY: Antiprotozoal drugs and supportive care are the mainstays of therapy. Primaquine phosphate is considered the treatment of choice in cats. PROGNOSIS: Prognosis depends on the severity of disease, which in turn depends on both organism and host factors. Mortality rates of 15-20% are reported.

C-reactive protein in canine babesiosis caused by Babesia rossi and its association with outcome.

C-reactive protein (CRP) is a positive major acute-phase protein in dogs and can be used as a predictive marker for risk of disease and to monitor the response to treatment. Increased concentrations in certain diseases are associated with poor outcome. This cross-sectional, observational study of 75 dogs naturally infected with Babesia rossi was designed to examine the relationship between outcome and CRP concentration at admission and the magnitude of CRP change 24 hours after admission. Diagnosis was confirmed by polymerase chain reaction (PCR) and reverse line blot. CRP concentrations were determined by an automated human CRP Turbidometric Immunoassay, previously validated for use in dogs. There was no significant difference in mean CRP concentration between survivors (n = 57), 107.5 +/- 49.5 mg/l and non-survivors (n = 11), 122.1 +/- 64.6 mg/l at admission and using the exact logistic regression, adjusting for age and sex, there was no association with outcome (P = 0.53). Multiple regression analysis failed to show a significant relationship between admission CRP concentration and number of days of hospitalisation in the survivors, adjusting for age and sex (P = 0.65). Similarly, no significance was found in the relationship between the magnitude of change in CRP concentration 24 hours after admission, and the number of days of hospitalisation in survivors, (P = 0.34). It is concluded that CRP concentration, as a measure of the acute phase response, is not associated with outcome in canine babesiosis, and inflammation is unlikely to be the only cause of severity of disease.

Influence of zinc deficiency to the rats infected with Babesia rodhaini.

Zinc deficiency induces a wide range of disorders including immunodeficiency. It is known that microbial infections occur with a high frequency in the zinc-deficient hosts, but the study on the correlation between parasitic infection and zinc status in hosts is scarcely performed. We observed that the influence of zinc deficiency to the rats infected with Babesia rodhaini. Experiments of B. rodhaini infection were conducted using zinc-deficient (ZD; eat ad libitum or 10 g/day on the ZD diet), zinc-adequate (ZA; eat ad libitum on the ZA diet), and diet-restricted (DR; eat 7 g/day on the ZA diet) rats. The findings in this study suggested that the zinc deficiency had deleterious effects on the hemodynamics and mortality of the rats infected with B. rodhaini.

Transfusion-transmitted Babesia microti identified through hemovigilance.

BACKGROUND: Babesia microti, the primary cause of human babesiosis in the United States, is an intraerythrocytic parasite endemic to the Northeast and upper Midwest. Published studies indicate that B. microti increasingly poses a blood safety risk. The American Red Cross Hemovigilance Program herein describes the donor and recipient characteristics of suspected transfusion-transmitted B. microti cases reported between 2005 and 2007. STUDY DESIGN AND METHODS: Suspected transfusion-transmitted Babesia infections were reported by transfusion services or were discovered through recipient-tracing investigations of prior donations from donors with a positive test for B. microti in a serologic study. Follow-up samples from involved donors were tested by Babesia-specific immunofluorescence assay, Western blot, and/or real-time polymerase chain reaction analysis. RESULTS: Eighteen definite or probable B. microti infections, including five fatalities, were identified in transfusion recipients, 16 from hospital-reported cases and two through serologic lookback studies. Thirteen recipients were 61 to 84 years old and two were 2 years old or younger. Two recipients had sickle cell disease and four were known to be asplenic, including one with sickle cell disease. Seventeen antibody-positive donors were implicated; 11 (65%) were residents in Babesia-endemic areas, while four (24%) nonresident donors had a history of travel to endemic areas. CONCLUSIONS: Transfusion-transmitted B. microti can be a significant cause of transfusion-related morbidity and mortality, especially in infant, elderly, and asplenic blood recipients. These data demonstrate the need for interventions, in both endemic and nonendemic areas of the United States, to reduce patient risk.

Septic shock in canine babesiosis.

The records of all canine patients (86) that had been diagnosed with babesiosis and that were admitted to the Clinic for Internal Diseases, Faculty of Veterinary Medicine, Zagreb from January 2007 to December 2007 were reviewed retrospectively. All dogs that had been diagnosed with canine babesiosis and that had systemic inflammatory response syndrome (SIRS) followed by multiple organ dysfunction syndrome (MODS), and refractory hypotension, were included in this study. Of 86 patients diagnosed with canine babesiosis that were admitted during the study period, 10 had evidence of septic shock and were included in this study. Seven of the 10 dogs had a level of parasitaemia above 1%, with the highest level being 20.2%, seven of the 10 dogs were anaemic and three of the 10 dogs were leucopoenic. Thrombocytopenia was present in nine dogs. Hypoglycaemia was noted in two dogs, and bilirubinaemia in nine dogs. Four patients had involvement of two organs, five had involvement of three organs, and one had involvement of four organs. The organ that was most frequently involved was the kidney (nine cases). Central nervous system dysfunction was the rarest complication noted (one case). The mortality rate in non-septic shock canine babesiosis was 2.6%. All dogs that developed septic shock died between the first and the fourth day after admission. The 100% mortality rate that is reported here reflects the fact that in cases in which progression of the inflammatory response leads to the development of septic shock, an unfavourable outcome should be expected.