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Infectious Disease Clinics of North... Jun 2015Babesiosis is caused by intraerythrocytic protozoan parasites that are transmitted by ticks, or less commonly through blood transfusion or transplacentally. Human... (Review)
Review
Babesiosis is caused by intraerythrocytic protozoan parasites that are transmitted by ticks, or less commonly through blood transfusion or transplacentally. Human babesiosis was first recognized in a splenectomized patient in Europe but most cases have been reported from the northeastern and upper midwestern United States in people with an intact spleen and no history of immune impairment. Cases are reported in Asia, Africa, Australia, Europe, and South America. Babesiosis shares many clinical features with malaria and can be fatal, particularly in the elderly and the immunocompromised.
Topics: Anti-Bacterial Agents; Babesia; Babesiosis; DNA, Protozoan; Enzyme Inhibitors; Erythrocytes; Humans; Polymerase Chain Reaction
PubMed: 25999229
DOI: 10.1016/j.idc.2015.02.008 -
Clinical Microbiology Reviews Mar 2020Increases in tick-borne disease prevalence and transmission are important public health issues. Efforts to control these emerging diseases are frustrated by the struggle... (Review)
Review
Increases in tick-borne disease prevalence and transmission are important public health issues. Efforts to control these emerging diseases are frustrated by the struggle to control tick populations and to detect and treat infections caused by the pathogens that they transmit. This review covers tick-borne infectious diseases of nonrickettsial bacterial, parasitic, and viral origins. While tick surveillance and tracking inform our understanding of the importance of the spread and ecology of ticks and help identify areas of risk for disease transmission, the vectors are not the focus of this document. Here, we emphasize the most significant pathogens that infect humans as well as the epidemiology, clinical features, diagnosis, and treatment of diseases that they cause. Although detection via molecular or immunological methods has improved, tick-borne diseases continue to remain underdiagnosed, making the scope of the problem difficult to assess. Our current understanding of the incidence of tick-borne diseases is discussed in this review. An awareness of the diseases that can be transmitted by ticks in specific locations is key to detection and selection of appropriate treatment. As tick-transmitted pathogens are discovered and emerge in new geographic regions, our ability to detect, describe, and understand the growing public health threat must also grow to meet the challenge.
Topics: Animals; Clinical Laboratory Techniques; Humans; Tick-Borne Diseases; Ticks
PubMed: 31896541
DOI: 10.1128/CMR.00083-18 -
Pathogens (Basel, Switzerland) Sep 2021are tick-borne intra-erythrocytic parasites and the causative agents of babesiosis. , which are readily transfusion transmissible, gained recognition as a major risk to... (Review)
Review
are tick-borne intra-erythrocytic parasites and the causative agents of babesiosis. , which are readily transfusion transmissible, gained recognition as a major risk to the blood supply, particularly in the United States (US), where is endemic. Many of those infected with remain asymptomatic and parasitemia may persist for months or even years following infection, such that seemingly healthy blood donors are unaware of their infection. By contrast, transfusion recipients are at high risk of severe babesiosis, accounting for the high morbidity and mortality (~19%) observed in transfusion-transmitted babesiosis (TTB). An increase in cases of tick-borne babesiosis and TTB prompted over a decade-long investment in blood donor surveillance, research, and assay development to quantify and contend with TTB. This culminated in the adoption of regional blood donor testing in the US. We describe the evolution of the response to TTB in the US and offer some insight into the risk of TTB in other countries. Not only has this response advanced blood safety, it has accelerated the development of novel serological and molecular assays that may be applied broadly, affording insight into the global epidemiology and immunopathogenesis of human babesiosis.
PubMed: 34578209
DOI: 10.3390/pathogens10091176 -
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 -
Frontiers in Microbiology 2021More than 100 spp. tick-borne parasites are known to infect mammalian and avian hosts. belong to Order Piroplasmid ranked in the Phylum Apicomplexa. Recent... (Review)
Review
More than 100 spp. tick-borne parasites are known to infect mammalian and avian hosts. belong to Order Piroplasmid ranked in the Phylum Apicomplexa. Recent phylogenetic studies have revealed that of the three genera that constitute Piroplasmida, and are polyphyletic while is nested within a clade of . Several spp. and sub-types have been found to cause human disease. , the most common species that infects humans, is endemic in the Northeastern and upper Midwestern United States and is sporadically reported elsewhere in the world. Most infections are transmitted by Ixodid (hard-bodied) ticks, although they occasionally can be spread through blood transfusion and rarely via perinatal transmission and organ transplantation. Babesiosis most often presents as a mild to moderate disease, however infection severity ranges from asymptomatic to lethal. Diagnosis is usually confirmed by blood smear or polymerase chain reaction (PCR). Treatment consists of atovaquone and azithromycin or clindamycin and quinine and usually is effective but may be problematic in immunocompromised hosts. There is no human vaccine. genomics studies have only recently been initiated, however they already have yielded important new insights regarding the pathogen, population structure, and pathogenesis. Continued genomic research holds great promise for improving the diagnosis, management, and prevention of human babesiosis, and in particular, the identification of lineage-specific families of cell-surface proteins with potential roles in cytoadherence, immune evasion and pathogenesis.
PubMed: 34539601
DOI: 10.3389/fmicb.2021.697669 -
Frontiers in Cellular and Infection... 2017Understanding host-pathogen-tick interactions remains a vitally important issue that might be better understood by basic research focused on each of the dyad interplays.... (Review)
Review
Understanding host-pathogen-tick interactions remains a vitally important issue that might be better understood by basic research focused on each of the dyad interplays. Pathogens gain access to either the vector or host during tick feeding when ticks are confronted with strong hemostatic, inflammatory and immune responses. A prominent example of this is the spp.-tick-vertebrate host relationship. spp. are intraerythrocytic apicomplexan organisms spread worldwide, with a complex life cycle. The presence of transovarial transmission in almost all the species is the main difference between their life cycle and that of other piroplasmida. With more than 100 species described so far, are the second most commonly found blood parasite of mammals after trypanosomes. The prevalence of spp. infection is increasing worldwide and is currently classified as an emerging zoonosis. and are the most frequent etiological agents associated with human babesiosis in North America and Europe, respectively. Although the -tick system has been extensively researched, the currently available prophylactic and control methods are not efficient, and chemotherapeutic treatment is limited. Studying the molecular changes induced by the presence of in the vector will not only elucidate the strategies used by the protozoa to overcome mechanical and immune barriers, but will also contribute toward the discovery of important tick molecules that have a role in vector capacity. This review provides an overview of the identified molecules involved in -tick interactions, with an emphasis on the fundamentally important ones for pathogen acquisition and transmission.
Topics: Animals; Antigens; Arthropod Proteins; Babesia; Babesiosis; Calreticulin; Disease Vectors; Glycoproteins; Host-Parasite Interactions; Salivary Glands; Tick-Borne Diseases; Ticks
PubMed: 29034218
DOI: 10.3389/fcimb.2017.00429 -
Pathogens (Basel, Switzerland) Jul 2019The incidence and geographic distribution of human babesiosis is growing in the U.S. Its major causative agent is the protozoan parasite, . is transmitted to humans... (Review)
Review
The incidence and geographic distribution of human babesiosis is growing in the U.S. Its major causative agent is the protozoan parasite, . is transmitted to humans primarily through the bite of ticks, which are vectors for a number of other pathogens. Other routes of transmission are blood transfusion and in rare cases of mother-to-foetus transmission, through the placenta. This review discusses the current literature on mammalian coinfection with and , the causative agent Lyme disease.
PubMed: 31370180
DOI: 10.3390/pathogens8030117 -
Archives of Pathology & Laboratory... Jan 2019Babesiosis is most commonly caused by Babesia microti and is transmitted via the bite of an infected Ixodes spp tick. However, Babesia is also transmitted via blood...
Babesiosis is most commonly caused by Babesia microti and is transmitted via the bite of an infected Ixodes spp tick. However, Babesia is also transmitted via blood transfusion. In the United States, the first case of transfusion-transmitted babesiosis was recognized in 1979, and in recent years, the incidence has rapidly increased. Because most of the infected blood donors do not experience any symptoms, they pose a significant risk to the blood supply. Donor deferral for a history of babesiosis is currently performed but is ineffective. In March 2018, the FDA licensed a DNA PCR and antibody assay that were used in tandem in pivotal trials for screening blood donors for B microti; with other assays still being evaluated under investigational new drug protocols. Blood donation screening is essential to reducing the risk of transfusion-transmitted babesiosis, which is why blood centers collecting in geographic regions of highest risk have been testing since approximately 2010. Investigational NAT assays of higher sensitivity are pending FDA review. Further, in July 2018, the FDA issued a draft guidance for reducing the risk of transfusion-transmitted babesiosis. Release of the final guidance may be postponed until sensitivities and specificities of all current and potential strategies have been properly evaluated.
Topics: Babesiosis; Blood Donors; Cost-Benefit Analysis; Donor Selection; Erythrocytes; Humans; Transfusion Reaction
PubMed: 30376376
DOI: 10.5858/arpa.2017-0250-RS -
Clinical Microbiology Reviews Jul 2000Babesiosis is an emerging, tick-transmitted, zoonotic disease caused by hematotropic parasites of the genus Babesia. Babesial parasites (and those of the closely related... (Review)
Review
Babesiosis is an emerging, tick-transmitted, zoonotic disease caused by hematotropic parasites of the genus Babesia. Babesial parasites (and those of the closely related genus Theileria) are some of the most ubiquitous and widespread blood parasites in the world, second only to the trypanosomes, and consequently have considerable worldwide economic, medical, and veterinary impact. The parasites are intraerythrocytic and are commonly called piroplasms due to the pear-shaped forms found within infected red blood cells. The piroplasms are transmitted by ixodid ticks and are capable of infecting a wide variety of vertebrate hosts which are competent in maintaining the transmission cycle. Studies involving animal hosts other than humans have contributed significantly to our understanding of the disease process, including possible pathogenic mechanisms of the parasite and immunological responses of the host. To date, there are several species of Babesia that can infect humans, Babesia microti being the most prevalent. Infections with Babesia species generally follow regional distributions; cases in the United States are caused primarily by B. microti, whereas cases in Europe are usually caused by Babesia divergens. The spectrum of disease manifestation is broad, ranging from a silent infection to a fulminant, malaria-like disease, resulting in severe hemolysis and occasionally in death. Recent advances have resulted in the development of several diagnostic tests which have increased the level of sensitivity in detection, thereby facilitating diagnosis, expediting appropriate patient management, and resulting in a more accurate epidemiological description.
Topics: Animals; Babesia; Babesiosis; Disease Susceptibility; Humans; Phylogeny; Protozoan Vaccines; Vaccines, Synthetic
PubMed: 10885987
DOI: 10.1128/CMR.13.3.451 -
Pathogens (Basel, Switzerland) Nov 2021The biology of intraerythrocytic parasites presents unique challenges for the diagnosis of human babesiosis. Antibody-based assays are highly sensitive but fail to... (Review)
Review
The biology of intraerythrocytic parasites presents unique challenges for the diagnosis of human babesiosis. Antibody-based assays are highly sensitive but fail to detect early stage infections prior to seroconversion (window period) and cannot distinguish between an active infection and a previously resolved infection. On the other hand, nucleic acid-based tests (NAT) may lack the sensitivity to detect window cases when parasite burden is below detection limits and asymptomatic low-grade infections. Recent technological advances have improved the sensitivity, specificity and high throughput of NAT and the antibody-based detection of . Some of these advances include genomics approaches for the identification of novel high-copy-number targets for NAT and immunodominant antigens for superior antigen and antibody-based assays for . Future advances would also rely on next generation sequencing and CRISPR technology to improve detection. This review article will discuss the historical perspective and current status of technologies for the detection of , the most common species causing human babesiosis in the United States, and their implications for early diagnosis of acute babesiosis, blood safety and surveillance studies to monitor areas of expansion and emergence and spread of species and their genetic variants in the United States and globally.
PubMed: 34959518
DOI: 10.3390/pathogens10121563