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Current Opinion in Hematology Nov 2020As human babesiosis caused by apicomplexan parasites of the Babesia genus is associated with transfusion-transmitted illness and relapsing disease in immunosuppressed... (Review)
Review
PURPOSE OF REVIEW
As human babesiosis caused by apicomplexan parasites of the Babesia genus is associated with transfusion-transmitted illness and relapsing disease in immunosuppressed populations, it is important to report novel findings relating to parasite biology that may be responsible for such pathology. Blood screening tools recently licensed by the FDA are also described to allow understanding of their impact on keeping the blood supply well tolerated.
RECENT FINDINGS
Reports of tick-borne cases within new geographical regions such as the Pacific Northwest of the USA, through Eastern Europe and into China are also on the rise. Novel features of the parasite lifecycle that underlie the basis of parasite persistence have recently been characterized. These merit consideration in deployment of both detection, treatment and mitigation tools such as pathogen inactivation technology. The impact of new blood donor screening tests in reducing transfusion transmitted babesiosis is discussed.
SUMMARY
New Babesia species have been identified globally, suggesting that the epidemiology of this disease is rapidly changing, making it clear that human babesiosis is a serious public health concern that requires close monitoring and effective intervention measures. Unlike other erythrocytic parasites, Babesia exploits unconventional lifecycle strategies that permit host cycles of different lengths to ensure survival in hostile environments. With the licensure of new blood screening tests, incidence of transfusion transmission babesiosis has decreased.
Topics: Animals; Babesia; Babesiosis; Blood Safety; Blood Transfusion; Erythrocytes; Host-Parasite Interactions; Humans; Life Cycle Stages; Public Health
PubMed: 32889826
DOI: 10.1097/MOH.0000000000000606 -
Pathogens and Global Health Jun 2022Human babesiosis is an emerging tick-borne protozoan zoonosis caused by parasites of the genus and transmitted by ixodid ticks. It was thought to be a public health... (Meta-Analysis)
Meta-Analysis
Human babesiosis is an emerging tick-borne protozoan zoonosis caused by parasites of the genus and transmitted by ixodid ticks. It was thought to be a public health problem mainly for the immunocompromised, however the increasing numbers of documented cases among immunocompetent individuals is a call for concern. In this systematic review and meta-analysis, we reported from 22 countries and 69 studies, an overall pooled estimate (PE) of 2.23% (95% CI: 1.46-3.39) for infections in humans. PEs for all sub-groups varied significantly (p < 0.05) with a continental range of 1.54% (95% CI: 0.89-2.65) in North America to 4.17% (95% CI: 2.11-8.06) in Europe. PEs for country income levels, methods of diagnosis, study period, sample sizes, species and targeted population ranged between 0.43% (95% CI: 0.41-0.44) and 7.41% (95% CI: 0.53-54.48). recorded the widest geographic distribution and was the predominant specie reported in North America while was predominantly reported in Europe. Eight species; -like, and were reported in humans from different parts of the world with the highest prevalence in Europe, lower middle income countries and among individuals with history of tick bite and other tick-borne diseases. To control the increasing trend of this emerging public health threat, tick control in human settlements, the use of protective clothing by occupationally exposed people and the screening of transfusion blood in endemic countries are recommended. AJOL: African Journals OnLine, CI: Confidence interval, CIL: Country income level, df: Degree of freedom, HIC: Higher-income countries, HQ: High quality, : Inverse variance index, IFAT: Indirect fluorescent antibody test, ITBTBD: Individuals with tick-bite and tick-borne diseases, JBI: Joanna Briggs Institute, LIC: Lower-income countries, LMIC: Lower middle-income countries, MQ: Medium quality, NA: Not applicable, N/America: North America, OEI: Occupational exposed individuals, OR: Odds ratio, PE: Pooled estimates, PCR: Polymerase chain reaction, Prev: Prevalence, PRISMA: Preferred Reporting System for Systematic Reviews and Meta-Analyses, Q: Cochran's heterogeneity statistic, QA: Quality assessment, Q-p: Cochran's p-value, qPCR: Quantitative polymerase chain reaction, S/America: South America, Seq: Sequencing, UMIC: Upper middle-income countries, USA: United States of America.
Topics: Animals; Babesia; Babesiosis; Humans; Prevalence; Tick-Borne Diseases; Zoonoses
PubMed: 34788196
DOI: 10.1080/20477724.2021.1989185 -
Frontiers in Cellular and Infection... 2022Apicomplexan parasites transmitted by vectors, including spp. and spp., cause severe disease in both humans and animals. These parasites have a complex life cycle... (Review)
Review
Apicomplexan parasites transmitted by vectors, including spp. and spp., cause severe disease in both humans and animals. These parasites have a complex life cycle during which they migrate, invade, and replicate in contrasting hosts such as the mammal and the invertebrate vector. The interaction of parasites with the host cell is mediated by adhesive proteins which play a key role in the different cellular processes regarding successful progression of the life cycle. Thrombospondin related anonymous protein (TRAP) is a superfamily of adhesins that are involved in motility, invasion and egress of the parasite. These proteins are stored and released from apical organelles and have either one or two types of adhesive domains, namely thrombospondin type 1 repeat and von Willebrand factor type A, that upon secretion are located in the extracellular portion of the molecule. Proteins from the TRAP superfamily have been intensively studied in species and to a lesser extent in spp., where they have proven to be functionally relevant throughout the entire parasite's journey both in the arthropod vector and in the mammalian host. In recent years new findings provided answers to the role of TRAP proteins and in some cases the function of these adhesins during the parasite's life cycle was redefined. In this review we will discuss the current knowledge of the diverse roles of the TRAP superfamily in vector-borne parasites from Class Aconoidasida. We will focus on the varied approaches that allowed the understanding of protein function and the relevance of TRAP- superfamily throughout the entire parasite's cell cycle.
Topics: Animals; Babesia; Mammals; Parasites; Plasmodium; Protozoan Proteins; Thrombospondins
PubMed: 35463644
DOI: 10.3389/fcimb.2022.831592 -
International Journal For Parasitology Feb 2019The global impact of bovine babesiosis caused by the tick-borne apicomplexan parasites Babesia bovis, Babesia bigemina and Babesia divergens is vastly underappreciated.... (Review)
Review
The global impact of bovine babesiosis caused by the tick-borne apicomplexan parasites Babesia bovis, Babesia bigemina and Babesia divergens is vastly underappreciated. These parasites invade and multiply asexually in bovine red blood cells (RBCs), undergo sexual reproduction in their tick vectors (Rhipicephalus spp. for B. bovis and B. bigemina, and Ixodes ricinus for B. divergens) and have a trans-ovarial mode of transmission. Babesia parasites can cause acute and persistent infections to adult naïve cattle that can occur without evident clinical signs, but infections caused by B. bovis are associated with more severe disease and increased mortality, and are considered to be the most virulent agent of bovine babesiosis. In addition, babesiosis caused by B. divergens has an important zoonotic potential. The disease caused by B. bovis and B. bigemina can be controlled, at least in part, using therapeutic agents or vaccines comprising live-attenuated parasites, but these methods are limited in terms of their safety, ease of deployability and long-term efficacy, and improved control measures are urgently needed. In addition, expansion of tick habitats due to climate change and other rapidly changing environmental factors complicate efficient control of these parasites. While the ability to cause persistent infections facilitates transmission and persistence of the parasite in endemic regions, it also highlights their capacity to evade the host immune responses. Currently, the mechanisms of immune responses used by infected bovines to survive acute and chronic infections remain poorly understood, warranting further research. Similarly, molecular details on the processes leading to sexual reproduction and the development of tick-stage parasites are lacking, and such tick-specific molecules can be targets for control using alternative transmission blocking vaccines. In this review, we identify and examine key phases in the life-cycle of Babesia parasites, including dependence on a tick vector for transmission, sexual reproduction of the parasite in the midgut of the tick, parasite-dependent invasion and egression of bovine RBCs, the role of the spleen in the clearance of infected RBCs (IRBCs), and age-related disease resistance in cattle, as opportunities for developing improved control measures. The availability of integrated novel research approaches including "omics" (such as genomics, transcriptomics, and proteomics), gene modification, cytoadhesion assays, RBC invasion assays and methods for in vitro induction of sexual-stage parasites will accelerate our understanding of parasite vulnerabilities. Further, producing new knowledge on these vulnerabilities, as well as taking full advantage of existing knowledge, by filling important research gaps should result in the development of next-generation vaccines to control acute disease and parasite transmission. Creative and effective use of current and future technical and computational resources are needed, in the face of the numerous challenges imposed by these highly evolved parasites, for improving the control of this disease. Overall, bovine babesiosis is recognised as a global disease that imposes a serious burden on livestock production and human livelihood, but it largely remains a poorly controlled disease in many areas of the world. Recently, important progress has been made in our understanding of the basic biology and host-parasite interactions of Babesia parasites, yet a good deal of basic and translational research is still needed to achieve effective control of this important disease and to improve animal and human health.
Topics: Animals; Babesia; Babesiosis; Blood Cells; Cattle; Cattle Diseases; Host-Pathogen Interactions; Ticks
PubMed: 30690089
DOI: 10.1016/j.ijpara.2018.11.002 -
Parasites & Vectors Jul 2021Lyme borreliosis (LB) is the most common vector-borne disease in Europe. Monitoring changes in the prevalence of different Borrelia species in ticks may be an important...
BACKGROUND
Lyme borreliosis (LB) is the most common vector-borne disease in Europe. Monitoring changes in the prevalence of different Borrelia species in ticks may be an important indicator of risk assessment and of differences in pathogenicity in humans. The objective of our study was to assess the prevalence, co-infection and distribution of Borrelia and Babesia species in ticks removed from humans in a large sample collected during a study period of 4 years.
METHODS
The ticks were collected throughout Poland from March to November over 4-year period from 2016 to 2019. All ticks (n = 1953) were morphologically identified in terms of species and developmental stage. Molecular screening for Borrelia and Babesia by amplification of the flagellin gene (flaB) or 18S rRNA marker was performed. Pathogen identity was confirmed by Sanger sequencing or PCR-restriction fragment length polymorphism analysis.
RESULTS
The ticks removed from humans in Poland during this study belonged to two species: Ixodes ricinus (97%) and Dermacentor reticulatus (3%). High Borrelia prevalence (25.3%), including B. miyamotoi (8.4%), was confirmed in Ixodes ricinus ticks removed from humans, as was the change in frequency of occurrence of Borrelia species during the 4-year study. Despite Babesia prevalence being relatively low (1.3%), the majority of tested isolates are considered to be pathogenic to humans. Babesia infection was observed more frequently among Borrelia-positive ticks (2.7%) than among ticks uninfected with Borrelia (0.8%). The most frequent dual co-infections were between Borrelia afzelii and Babesia microti. The presence of Borrelia was also confirmed in D. reticulatus (12.7%); however the role of these ticks in spirochete transmission to susceptible hosts is still unclear.
CONCLUSIONS
Although the overall risk of developing LB after a tick bite is low in Europe, knowledge of the prevalence and distribution of Borrelia and Babesia species in ticks might be an important indicator of the risk of both these tick-borne diseases.
Topics: Animals; Babesia; Babesiosis; Borrelia; Coinfection; Female; Humans; Ixodes; Longitudinal Studies; Lyme Disease; Male; Poland; Prevalence; Tick-Borne Diseases
PubMed: 34210355
DOI: 10.1186/s13071-021-04849-5 -
Scientific Reports Nov 2022Canine babesiosis is a tick-borne disease caused by Babesia spp., which infects and destroys healthy erythrocytes, leading to mortality and morbidity in dogs. The...
Canine babesiosis is a tick-borne disease caused by Babesia spp., which infects and destroys healthy erythrocytes, leading to mortality and morbidity in dogs. The diagnosis of babesiosis is tedious and time-consuming, especially in latent and chronic infections. Here, a recombinase polymerase amplification combined with a lateral flow dipstick (RPA-LFD) assay was developed for rapid and accurate detection of Babesia spp. in canine blood specimens based on the 18S rRNA region. The RPA-LFD assay using rpaBab264 gave specificity to Babesia spp. in dogs (B. vogeli and B. gibsoni) without cross-amplification to other parasites (apicomplexans and non-apicomplexans), with detection limit of at least 22.5 copies/μl (0.1 fg/µl) at 40 °C for at least 10 min. The whole process of DNA amplification by RPA and readout by LFD did not exceed 30 min. To determine the performance of the RPA-LFD assay, a total of 30 clinical samples was examined and compared with conventional PCR (cPCR) and multiplex HRM (mHRM). Eight dogs (26.67%) were detected as positive by RPA-LFD, while seven and six were found positive by cPCR and mHRM, respectively. RPA-LFD and cPCR showed high agreement with Babesia spp. detection with kappa > 0.9. We confirmed that the dogs were infected by B. vogeli from sequences of positive PCR results. Our findings suggested that RPA-LFD using the rpaBab264 assay offered a rapid, accurate, cost-effective and simple method for Babesia spp. detection that is feasibly applicable to be rapid kit at a pet hospital or point-of-care testing.
Topics: Dogs; Animals; Recombinases; Babesia; Babesiosis; Nucleotidyltransferases; Polymerase Chain Reaction
PubMed: 36446883
DOI: 10.1038/s41598-022-25165-7 -
Parasites & Vectors Oct 2022The tick Rhipicephalus microplus (Ixodida: Ixodidae, Canestrini, 1888) causes substantial economic and health losses in cattle production and is the main vector of...
BACKGROUND
The tick Rhipicephalus microplus (Ixodida: Ixodidae, Canestrini, 1888) causes substantial economic and health losses in cattle production and is the main vector of Babesia bigemina (Piroplasmidae: Babesidae, Smith & Kilborne, 1893). Babesia bigemina is responsible for a tick-borne disease known as babesiosis that can cause hemolytic anemia, fever and death. In the study reported here, we investigated the relationship between the number of ticks per animal and the number of B. bigemina cytochrome b gene (cbisg) copies in the blood of Brangus and Nellore cattle reared without acaricidal treatment in the Brazilian Cerrado biome over a 1-year period.
METHODS
Ticks on 19 animals (9 Brangus and 10 Nellore cattle) were counted every 18 days, and blood was collected every 36 days for 12 months. Serological samples were analyzed with an indirect enzyme-linked immunosorbent assay, and genomic DNA was analyzed by conventional PCR and quantitative PCR. The PCR products were sequenced by the Sanger method.
RESULTS
The Brangus and Nellore breeds showed similar weight development and no clinical signs of babesiosis. Statistically significant differences (P < 0.05) between the breeds were observed for the number of ticks and the number of B. bigemina cbisg gene copies.
CONCLUSIONS
No correlation between the number of ticks and the number of circulating copies of cbisg was observed, although Nellore cattle presented with fewer ticks than Brangus cattle and the number of cbisg copies was higher for Nellore cattle than for Brangus cattle.
Topics: Cattle; Animals; Babesia; Rhipicephalus; Brazil; Babesiosis; Seasons; Cattle Diseases; Real-Time Polymerase Chain Reaction; Ecosystem
PubMed: 36307861
DOI: 10.1186/s13071-022-05513-2 -
Antimicrobial Agents and Chemotherapy May 2016The present study evaluated the growth-inhibitory effects of clofazimine, currently used for treating leprosy, against Babesia bovis, B. bigemina, B. caballi, and...
The present study evaluated the growth-inhibitory effects of clofazimine, currently used for treating leprosy, against Babesia bovis, B. bigemina, B. caballi, and Theileria equi in in vitro culture and against Babesia microti in mice. The 50% inhibitory concentrations (IC50s) of clofazimine against the in vitro growth of B. bovis, B. bigemina, B. caballi, and T. equi were 4.5, 3, 4.3, and 0.29 μM, respectively. In mice infected with B. microti, treatment with 20 mg/kg of body weight of clofazimine administered orally resulted in a significantly lower peak parasitemia (5.3%) than that in the control group (45.9%), which was comparable to the subcutaneous administration of 25 mg/kg diminazene aceturate, the most widely used treatment for animal piroplasmosis. Although slight anemia was observed in both clofazimine- and diminazene aceturate-treated infected mice, the level and duration of anemia were lower and shorter, respectively, than those in untreated infected mice. Using blood transfusions and PCR, we also examined whether clofazimine completely killed B. microti On day 40 postinfection, when blood analysis was performed, parasites were not found in blood smears; however, the DNA of B. microti was detected in the blood of clofazimine-treated animals and in several tissues of clofazimine- and diminazene aceturate-treated mice by PCR. The growth of parasites was observed in mice after blood transfusions from clofazimine-treated mice. In conclusion, clofazimine showed excellent inhibitory effects against Babesia and Theileria in vitro and in vivo, and further study on clofazimine is required for the future development of a novel chemotherapy with high efficacy and safety against animal piroplasmosis and, possibly, human babesiosis.
Topics: Animals; Antimalarials; Babesia; Clofazimine; Erythrocytes; Female; Mice; Mice, Inbred BALB C; Plasmodium falciparum; Polymerase Chain Reaction; Theileria
PubMed: 26883713
DOI: 10.1128/AAC.01614-15 -
Frontiers in Cellular and Infection... 2022The protozoan parasite spp. invades into tick oocytes and remains in the offspring. The transovarial transmission phenomenon of in ticks has been demonstrated...
The protozoan parasite spp. invades into tick oocytes and remains in the offspring. The transovarial transmission phenomenon of in ticks has been demonstrated experimentally, but the molecular mechanisms remain unclear. invasion into oocytes occurs along with the progression of oogenesis. In the present study, to find the key tick factor(s) for transmission, we focused on molecules involved in yolk protein precursor (vitellogenin, Vg) synthesis and Vg uptake, which are crucial events in tick oogenesis. With a tick- experimental model, the expression profiles of , , , , and , Vg synthesis-related genes, and Vg receptor () and autophagy-related gene 6 (), Vg uptake-related genes, were analyzed using real-time PCR using tissues collected during the preovipositional period in -infected ticks. The expression levels of () and decreased in the fat body of -infected ticks 1 day after engorgement. In the ovary, mRNA expression was significantly higher in -infected ticks than in uninfected ticks 1 and 2 days after engorgement and decreased 3 days after engorgement. expression was significantly lower in -infected ticks than in uninfected ticks 2 and 4 days after engorgement. had a lower gene expression in -infected ticks compared to uninfected ticks 2 days after engorgement. Additionally, western blot analysis using protein extracts from each collected tissue revealed that Vg-2 (HlVg-2) accumulate in the fat body and hemolymph of -infected ticks. These results suggest that Vg uptake from the hemolymph to the ovary was suppressed in the presence of . Moreover, knockdown ticks had a lower detection rate of DNA in the ovary and a significant reduction of DNA in the hemolymph compared with control ticks. Taken together, our results suggest that accumulated HlVg-2 is associated with infection or transmission in the tick body. These findings, besides previous reports on VgR, provide important information to elucidate the transovarial transmission mechanisms of pathogens in tick vectors.
Topics: Animals; Babesia; DNA; Fat Body; Female; Hemolymph; Ixodidae; Vitellogenins
PubMed: 35800383
DOI: 10.3389/fcimb.2022.908142 -
Ticks and Tick-borne Diseases Mar 2022The distribution and population size of the red sheep tick (Haemaphysalis punctata) are increasing in Northern Europe, and in the United Kingdom reports of human biting...
The distribution and population size of the red sheep tick (Haemaphysalis punctata) are increasing in Northern Europe, and in the United Kingdom reports of human biting by this species have increased in recent years. To assess the risk of tick-borne disease (TBD) transmission to humans and livestock by H. punctata, ticks sampled from sites in Southern England were screened using PCR for either Borrelia species or piroplasms over a three year period, 2018-2020. A total of 302 H. punctata were collected from eight locations. From these, two Babesia species associated with TBD infections in livestock, Babesia major and Babesia motasi, and the human pathogen Borrelia miyamotoi were detected, predominantly from a single location in Sussex. Consequently, the range expansion of this tick across Southern England may impact public and livestock health.
Topics: Animals; Babesia; Borrelia; Ixodes; Ixodidae; Sheep; Tick-Borne Diseases
PubMed: 35042078
DOI: 10.1016/j.ttbdis.2022.101902