-
Pathogens (Basel, Switzerland) Sep 2021Parasites from diverse hosts morphologically identified as have previously been shown to belong to a paraphyletic species complex. With a growing number of reports of... (Review)
Review
Parasites from diverse hosts morphologically identified as have previously been shown to belong to a paraphyletic species complex. With a growing number of reports of -like parasites from across the world, this paper seeks to report on the current knowledge of the diversity of this species complex. Phylogenetic analysis of 18S rDNA sequences obtained from GenBank shows that the diversity of the species complex has markedly increased and now encompasses at least five distinct clades. This cryptic diversity calls into question much of our current knowledge of the life cycle of these parasites, as many biological studies were conducted before DNA sequencing technology was available. In many cases, it is uncertain which -like parasite was studied because parasites from different clades may occur sympatrically and even share the same host. Progress can only be made if future studies are conducted with careful attention to parasite identification and PCR primer specificity.
PubMed: 34578201
DOI: 10.3390/pathogens10091168 -
Transfusion Medicine Reviews Jul 2016Because testing of donors for Babesia microti has become available, it is important to determine the kinds of patients who should receive B microti-tested blood. We... (Review)
Review
Because testing of donors for Babesia microti has become available, it is important to determine the kinds of patients who should receive B microti-tested blood. We searched PubMed, AABB abstracts, and FDA Web site to identify all cases of transfusion-transmitted babesiosis (TTB). Cases were analyzed for underlying medical condition, age, presence of spleen, and reason for transfusion in relation to 5 classes of recipient outcome severity. Sixty-seven reports included 256 transfusion cases where donor tested positive for B microti, 165 of which resulted in TTB. Sixty recipients did not develop disease or become test positive, and test results were not known for 31 more. The 165 cases of TTB involved hematologic (19%), neonate (10%), cardiovascular (8%), and gastrointestinal (6%) patients. Thirty-two (19%) of the 165 infected patients died with death attributed to babesiosis in 25 of the cases. Nine (5%) were asymptomatic, 27 (16%) were symptomatic but had uncomplicated disease, and 16 (10%) had complicated disease. The severity of disease was mixed among many disease categories. Patients >65 years of age included the largest number of recipients (59/165, 36%) and deaths (11/32, 34%), although deaths occurred in other age groups as well. TTB cases were predominantly due to red cells (133 of 140 specified units), with red blood cell units processed in a variety of ways and at all storage duration. TTB with complicated babesiosis and/or death occurred in patients of all age groups and with a variety of underlying medical conditions.
Topics: Babesia microti; Babesiosis; Blood Donors; Blood Transfusion; Humans
PubMed: 27260107
DOI: 10.1016/j.tmrv.2016.04.002 -
Pathogens (Basel, Switzerland) Jul 2019Persistent infection is a characteristic feature of babesiosis, a worldwide, emerging tick-borne disease caused by members of the genus Persistence of infection in... (Review)
Review
Persistent infection is a characteristic feature of babesiosis, a worldwide, emerging tick-borne disease caused by members of the genus Persistence of infection in reservoir hosts increases the probability of survival and transmission of these pathogens. Laboratory tools to detect in red blood cells include microscopic detection using peripheral blood smears, nucleic acid detection (polymerase chain reaction and transcription mediated amplification), antigen detection, and antibody detection. , the major cause of human babesiosis, can asymptomatically infect immunocompetent individuals for up to two years. Chronically infected blood donors may transmit the pathogen to another person through blood transfusion. Transfusion-transmitted babesiosis causes severe complications and death in about a fifth of cases. Immunocompromised patients, including those with asplenia, HIV/AIDS, malignancy, or on immunosuppressive drugs, often experience severe disease that may relapse up to two years later despite anti- therapy. Persistent infection is promoted by immune evasive strategies and impaired host immune mechanisms. The health burden of persistent and recrudescent babesiosis can be minimized by development of novel therapeutic measures, such as new anti-parasitic drugs or drug combinations, improved anti-parasitic drug duration strategies, or immunoglobulin preparations; and novel preventive approaches, including early detection methods, tick-avoidance, and blood donor screening.
PubMed: 31319461
DOI: 10.3390/pathogens8030102 -
Journal of Clinical Microbiology Oct 2017, a zoonotic intraerythrocytic parasite, is the primary etiological agent of human babesiosis in the United States. Human infections range from subclinical illness to... (Review)
Review
, a zoonotic intraerythrocytic parasite, is the primary etiological agent of human babesiosis in the United States. Human infections range from subclinical illness to severe disease resulting in death, with symptoms being related to host immune status. Despite advances in our understanding and management of , the incidence of infection in the United States has increased. Therefore, research focused on eradicating disease and optimizing clinical management is essential. Here we review this remarkable organism, with emphasis on the clinical, diagnostic, and therapeutic aspects of human disease.
Topics: Animals; Antiparasitic Agents; Babesia microti; Babesiosis; Hemolysis; Humans; Ixodes; Mice; Tick-Borne Diseases; United States
PubMed: 28747374
DOI: 10.1128/JCM.00504-17 -
Zoonoses and Public Health Nov 2022Wild rodents are natural reservoir hosts of various pathogens, including Babesia microti. This study investigated the presence of B. microti in rodents from Erzurum...
Wild rodents are natural reservoir hosts of various pathogens, including Babesia microti. This study investigated the presence of B. microti in rodents from Erzurum province in Turkey. A total of 498 rodents and 21 rodent-fed ticks were analysed using the polymerase chain reaction (PCR) technique to test for the presence of B. microti. Babesia spp. were detected in three (0.6%) of the 498 rodent spleen samples. The Babesia-positive rodent species were identified as Microtus socialis by means of molecular analysis. The rodent-fed ticks comprised 15 Ixodes laguri and 6 Rhipicephalus sanguineus, none of which tested positive for Babesia spp. A sequence analysis of the 18S PCR amplicons confirmed the three Babesia-positive samples to be B. microti. The Erzurum isolates were 100% identical to the zoonotic Jena strain. The results of this study indicate the existence of zoonotic B. microti strains that may constitute a potential public health risk in Erzurum province. Future studies should determine the tick vector and other reservoir rodent species of B. microti in Erzurum.
Topics: Animals; Arvicolinae; Babesia microti; Babesiosis; Ixodes; Rodentia; Turkey; Zoonoses
PubMed: 35726555
DOI: 10.1111/zph.12983 -
Parasites & Vectors Nov 2022The Babesia microti-like parasite is an emerging tick-borne piroplasm that has been detected in a range of hosts worldwide. Babesia vulpes, which is found in dogs and...
BACKGROUND
The Babesia microti-like parasite is an emerging tick-borne piroplasm that has been detected in a range of hosts worldwide. Babesia vulpes, which is found in dogs and foxes, has been reclassified from B. microti-like parasites. The relationships among these B. microti-like parasites and B. vulpes with respect to host range and geographical origin have not been elucidated.
METHODS
Blood samples were collected from 27 raccoon dogs in South Korea and used to screen for B. microti-like parasites based on a PCR assay targeting the 18S rRNA gene of Babesia. For comparative purposes, in addition to 18S rRNA sequences from nine raccoon dogs, we also analyzed 18S rRNA sequences from B. microti-like parasites infecting hosts in different geographical regions worldwide obtained from the GenBank database, giving 123 sequences in total. The genetic variation and evolutionary relationships among these sequences were examined based on analyses using DnaSP, MEGA, Arlequine, and BEAST software.
RESULTS
Babesia microti-like parasites were identified in nine raccoon dogs and found to be related to B. vulpes obtained from Spanish dogs. Among the 123 sequences from 14 countries and various hosts, we identified 43 haplotypes with high genetic variance. Based on the genetic variance and phylogenetic analyses, we established that the B. microti-like parasites isolated in different geographical regions and from hosts belonging to five orders showed higher among-population variation than within-population variation. Babesia vulpes parasites infecting carnivore hosts, including raccoon dogs, foxes, skunks and dogs, appear to be genetically distinct from B. microti-like parasites infecting hosts belonging to the other orders.
CONCLUSIONS
Our study demonstrated the genetic variation and evolutionary relationships among 18S rRNA sequences obtained from blood samples collected from various hosts and different geographical regions. Babesia vulpes was identified from raccoon dogs in South Korea. In addition, higher genetic variations were observed among populations of different hosts and geographical origins and, in particular, low connectivity was observed among host populations in the order Carnivora and those in other orders. These results suggest the B. vulpes, a piroplasmid species pathogenic in domestic dogs and wild canines, is genetically and evolutionarily different from B. microti-like parasites.
Topics: Animals; Babesia; Babesia microti; Parasites; Babesiosis; RNA, Ribosomal, 18S; Foxes; Phylogeny; Raccoon Dogs
PubMed: 36329533
DOI: 10.1186/s13071-022-05528-9 -
CMAJ : Canadian Medical Association... Aug 2021
Topics: Aged; Anemia; Anti-Infective Agents; Atovaquone; Azithromycin; Babesia microti; Babesiosis; Canada; Humans; Male; Thrombocytopenia; Treatment Outcome
PubMed: 34373269
DOI: 10.1503/cmaj.201983 -
Tropical Animal Health and Production Feb 2023Babesia microti (Apicomplexa: Piroplasmida) causes a medically important tick-borne zoonotic protozoan disease. Egyptian camels are susceptible to Babesia infection;...
Babesia microti (Apicomplexa: Piroplasmida) causes a medically important tick-borne zoonotic protozoan disease. Egyptian camels are susceptible to Babesia infection; however, just a few cases have been documented. This study aimed to identify Babesia species, specifically Babesia microti, and their genetic diversity in dromedary camels in Egypt and associated hard ticks. Blood and hard tick samples were taken from 133 infested dromedary camels slaughtered in Cairo and Giza abattoirs. The study was conducted from February to November 2021. The 18S rRNA gene was amplified by polymerase chain reaction (PCR) to identify Babesia species. Nested PCR targeting the β-tubulin gene was used to identify B. microti. The PCR results were confirmed by DNA sequencing. Phylogenetic analysis based on the ß-tubulin gene was used to detect and genotype B. microti. Three tick genera were identified in infested camels (Hyalomma, Rhipicephalus, and Amblyomma). Babesia species were detected in 3 out of 133 blood samples (2.3%), while Babesia spp. were not detected in hard ticks by using the 18S rRNA gene. B. microti was identified in 9 out of 133 blood samples (6.8%) and isolated from Rhipicephalus annulatus and Amblyomma cohaerens by the β-tubulin gene. The phylogenetic analysis of the β-tubulin gene revealed that USA-type B. microti was prevalent in Egyptian camels. The results of this study suggested that the Egyptian camels may be infected with Babesia spp. and the zoonotic B. microti strains, which pose a potential risk to public health.
Topics: Animals; Babesia microti; Camelus; Egypt; Phylogeny; Tubulin; Babesia; Babesiosis; Ixodidae; Rhipicephalus; RNA, Ribosomal, 18S
PubMed: 36808565
DOI: 10.1007/s11250-023-03507-5 -
Frontiers in Cellular and Infection... 2020Malaria and babesiosis, the two primary intraerythrocytic protozoan diseases of humans, have been reported in multiple cases of co-infection in endemic regions. As the...
Malaria and babesiosis, the two primary intraerythrocytic protozoan diseases of humans, have been reported in multiple cases of co-infection in endemic regions. As the geographic range and incidence of arthropod-borne infectious diseases is being affected by climate change, co-infection cases with and are likely to increase. The two parasites have been used in experimental settings, where prior infection with has been shown to protect against fatal malarial infections in mice and primates. However, the immunological mechanisms behind such phenomena of cross-protection remain unknown. Here, we investigated the effect of a primary infection on the outcome of a lethal challenge infection using a murine model. Simultaneous infection with both pathogens led to high mortality rates in immunocompetent BALB/c mice, similar to control mice infected with alone. On the other hand, mice with various stages of primary infection were thoroughly immune to a subsequent challenge. Protected mice exhibited decreased levels of serum antibodies and pro-inflammatory cytokines during early stages of challenge infection. Mice repeatedly immunized with dead quickly succumbed to infection, despite induction of high antibody responses. Notably, cross-protection was observed in mice lacking functional B and T lymphocytes. When the role of other innate immune effector cells was examined, NK cell-depleted mice with chronic infection were also found to be protected against . Conversely, macrophage depletion rendered the mice vulnerable to . The above results show that the mechanism of cross-protection conferred by against is innate immunity-based, and suggest that it relies predominantly upon the function of macrophages. Further research is needed for elucidating the malaria-suppressing effects of babesiosis, with a vision toward development of novel tools to control malaria.
Topics: Animals; Babesia microti; Babesiosis; Macrophages; Malaria; Mice; Mice, Inbred BALB C
PubMed: 32411624
DOI: 10.3389/fcimb.2020.00193 -
Clinical Microbiology Reviews Jan 2011Babesia spp. are intraerythrocytic protozoan parasites of animals and humans that cause babesiosis, a zoonotic disease transmitted primarily by tick vectors. Although a... (Review)
Review
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.
Topics: Animals; Babesia microti; Babesiosis; Humans; Iatrogenic Disease; Transfusion Reaction; United States
PubMed: 21233506
DOI: 10.1128/CMR.00022-10