Human Granulocytic Anaplasmosis During Pregnancy: Case Series and Literature Review

Human granulocytotropic anaplasmosis-A systematic review and analysis of the literature

Human granulocytotropic anaplasmosis (HGA) is a zoonotic tick-borne bacterial infection caused by Anaplasma phagocytophilum. While most cases are reported from North America, HGA has been recognized as an emerging disease in several regions of the world in recent decades. Most available data comes from case reports, case series and retrospective studies, while prospective studies and clinical trials are largely lacking. To obtain a clearer picture of the currently known epidemiologic distribution, clinical and paraclinical presentation, diagnostic aspects, complications, therapeutic aspects, and outcomes of HGA, we systematically reviewed the literature and analyzed and summarized the data. Cases of HGA are reported from all continents except from Antarctica. HGA primarily presents as an unspecific febrile illness (88.5% of the cases) often accompanied by thrombocytopenia (71.8% of the cases), abnormal liver injury tests (66.7% of the cases), and leukopenia (49.8% of the cases). Although we found complications reported in a total of 40.5% of the reviewed cases and severe and even life-threatening complications are not infrequent (e.g. acute renal failure 9.8%, multi organ failure 7.5%, ARDS 6.3%, a.o.), sequelae are rare (2.1% of the cases) and lethality is low (3.0% of the cases). Treatment with doxycycline shows a rapid response, with the fever subsiding in the majority of patients within one day of starting treatment. Unlike in human monocytotropic ehrlichiosis (HME), reports of opportunistic infections complicating HGA are rare. HGA during pregnancy does not appear to be associated with unfavorable outcomes. In addition, our analysis provides some evidence that HGA may differ in clinical aspects and laboratory characteristics in different regions of the world. Overall, the data analyzed indicates a non-negligible bias in reporting/publication, so a certain degree of caution is required when generalizing the data.

Human Granulocytic Anaplasmosis

Human granulocytic anaplasmosis (HGA) is a bacterial infection caused by Anaplasma phagocytophilum and transmitted by the bite of the black-legged (deer tick) in North America. Its incidence is increasing. HGA can be transmitted after 24 to 48 hours of tick attachment. The incubation period is 5 to 14 days after a tick bite. Symptoms include fever, chills, headache, and myalgia. Complications include shock, organ dysfunction, and death. Mortality is less than 1% with appropriate treatment. Doxycycline is first line treatment for all ages. Start it empirically if symptoms and risk factors suggest HGA. PCR is the confirmatory test of choice.

Human Granulocytic Anaplasmosis-A Systematic Review of Published Cases

Anaplasma phagocytophilum is an emerging, Gram-negative, obligate intracellular pathogen that is transmitted by a tick vector. Human infection ranges from asymptomatic to severe disease that can present with pancytopenia, multiorgan failure, and death. The aim of this systematic review is to analyze case reports and case series reported over the last two decades in peer-reviewed journals indexed in the Medline/PubMed database according to the PRISMA guidelines. We found 110 unique patients from 88 case reports and series. The most common mode of transmission was tick bite (60.9%), followed by blood transfusion (8.2%). Infection was acquired by blood transfusion in nearly half (42%) of the immunocompromised patients. Most patients reported fever (90%), followed by constitutional (59%) and gastrointestinal symptoms (56%). Rash was present in 17% of patients, much higher than in previous studies. Thrombocytopenia was the most common laboratory abnormality (76%) followed by elevated aspartate aminotransferase (AST) (46%). The diagnosis was most commonly established using whole-blood polymerase chain reaction (PCR) in 76% of patients. Coinfection rate was 9.1% and Borrelia burgdorferi was most commonly isolated in seven patients (6.4%). Doxycycline was used to treat 70% of patients but was only used as an empiric treatment in one-third of patients (33.6%). The overall mortality rate was 5.7%, and one patient died from trauma unrelated to HGA. The mortality rates among immunocompetent and immunocompromised patients were 4.2% (n = 4/95) and 18.2% (n = 2/11), respectively. Four of the six patients who died (66.6%) received appropriate antibiotic therapy. Among these, doxycycline was delayed by more than 48 h in two patients.

Less common bacterial, fungal and viral infections: review of management in the pregnant patient

This review is a comprehensive summary of treatment options for pregnant patients with less common bacterial, fungal, and viral infections. It offers guidance to clinicians based on the most recently published evidence-based research and expert recommendations. A search of MEDLINE (inception to March 2021) and the CDC website was performed. Liposomal amphotericin B is the preferred therapy for cryptococcosis, histoplasmosis, oesophageal candidiasis, and coccidioidomycosis, especially during the first trimester due to teratogenic concerns with azole antifungals. For oral candidiasis, clotrimazole troches or miconazole mucoadhesive buccal tablets are recommended. A β-lactam antimicrobial is preferred over doxycycline for various manifestations of Lyme disease and the drug of choice for Pneumocystis pneumonia is trimethoprim/sulfamethoxazole. Acyclovir is the preferred antiviral for varicella zoster virus. Fluoroquinolones, macrolides, and aminoglycosides should be avoided if possible and there are alternate agents available for an effective treatment regimen. There is a scarcity of clinical data in pregnant patients with less common bacterial, fungal and viral infections. This population lacks definitive recommendations in many clinical practice guidelines. The key to optimizing therapy is a comprehensive review of the available evidence and a careful balance of risks and benefits before final treatment decisions.

Ehrlichiosis and anaplasmosis subcommittee report to the Tick-borne Disease Working Group

Ehrlichioses and anaplasmosis have undergone dramatic increases in incidence, and the geographic ranges of their occurrence and vectors have also expanded. There is marked underreporting of these diseases owing to deficient physician awareness and knowledge of the illnesses as well as limited access to appropriate diagnostic tests. Human monocytic ehrlichiosis and anaplasmosis are life threatening diseases with estimated case fatality rates of 2.7 and 0.3%, respectively. However, knowledge of their full range of signs and symptoms is incomplete, and the incidence of subclinical infections is unknown. Currently available laboratory diagnostic methods are poorly utilized, and with the exception of nucleic acid amplification tests are not useful for diagnosis during the acute stage of illness when timely treatment is needed. The Ehrlichiosis and Anaplasmosis Subcommittee of the Tick-Borne Disease Working Group recommended active clinical surveillance to determine the true incidence, full clinical spectrum, and risk factors for severe illness, as well as standardized surveillance of ticks for these pathogens, and enhanced education of primary medical caregivers and the public regarding these diseases. The subcommittee identified the needs to develop sensitive, specific acute stage diagnostic tests for local clinical laboratories and point-of-care testing, to develop approaches for utilizing electronic medical records, data mining, and artificial intelligence for assisting early diagnosis and treatment, and to develop adjunctive therapies for severe disease.

COVID-19 and the Consequences of Anchoring Bias

Suspicion of coronavirus disease in febrile patients might lead to anchoring bias, causing misdiagnosis of other infections for which epidemiologic risks are present. This bias has potentially severe consequences, illustrated by cases of human granulocytic anaplasmosis and Lyme disease in a pregnant woman and human granulocytic anaplasmosis in another person.

Genetic diversity of Anaplasma bacteria: Twenty years later

The genus Anaplasma (family Anaplasmataceae, order Rickettsiales) includes obligate intracellular alphaproteobacteria that multiply within membrane-bound vacuoles and are transmitted by Ixodidae ticks to vertebrate hosts. Since the last reclassification of Anaplasmataceae twenty years ago, two new Anaplasma species have been identified. To date, the genus includes eight Anaplasma species (A. phagocytophilum, A. marginale, A. centrale, A. ovis, A. bovis, A. platys, A. odocoilei, and A. capra) and a large number of unclassified genovariants that cannot be assigned to known species. Members of the genus can cause infection in humans and a wide range of domestic animals with different degrees of severity. Long-term persistence which, in some cases, is manifested as cyclic bacteremia has been demonstrated for several Anaplasma species. Zoonotic potential has been shown for A. phagocytophilum, the agent of human granulocytic anaplasmosis, and for some other Anaplasma spp. that suggests a broader medical relevance of this genus. Genetic diversity of Anaplasma spp. has been intensively studied in recent years, and it has been shown that some Anaplasma spp. can be considered as a complex of genetically distinct lineages differing by geography, vectors, and host tropism. The aim of this review was to summarize the current knowledge concerning the natural history, pathogenic properties, and genetic diversity of Anaplasma spp. and some unclassified genovariants with particular attention to their genetic characteristics. The high genetic variability of Anaplasma spp. prompted us to conduct a detailed phylogenetic analysis for different Anaplasma species and unclassified genovariants, which were included in this review. The genotyping of unclassified genovariants has led to the identification of at least four distinct clades that might be considered in future as new candidate species.

Vector-borne diseases in pregnancy

Vector-borne infections cause a significant proportion of world-wide morbidity and mortality and many are increasing in incidence. This is due to a combination of factors, primarily environmental change, encroachment of human habitats from urban to peri-urban areas and rural to previously uninhabited areas, persistence of poverty, malnutrition and resource limitation in geographical areas where these diseases are endemic. Pregnant women represent the single largest ‘at risk’ group, due to immune-modulation and a unique physiological state. Many of these diseases have not benefitted from the same level of drug development as other infectious and medical domains, a factor attributing to the ‘neglected tropical disease’ title many vector-borne diseases hold. Pregnancy compounds this issue as data for safety and efficacy for many drugs is practically non-existent, precluding exposure in pregnancy to many first-line therapeutic agents for ‘fear of the unknown’ or overstated adverse pregnancy-foetal outcomes. In this review, major vector-borne diseases, their impact on pregnancy outcomes, current treatment, vaccination and short-comings of current medical practice for pregnant women will be discussed.

Status of Anaplasma spp. infection in domestic ruminants from Iran: A systematic review with meta-analysis

Anaplasma species are tick-borne pathogens that are obligatory intracellular of ruminants and other mammalians. In this investigation, we systematically reviewed the distribution of anaplasmosis among domestic ruminants in Iran. Five and four English and Persian databases were studied, respectively, based on keywords and throughout 17 years (2001–2017). Thirty-eight articles were included in this systematic review and meta-analysis. Totally, 5093 cattle, 1958 sheep, and 1232 goats corresponding to prevalence of Anaplasma infection from different areas of Iran were examined. The total prevalence of Anaplasma infection was estimated to be 34% (95% CI 27%, 41%) in domestic ruminants. Based on our data, Khozestan (54%) and Khorasan Razavi (46%) provinces were the most prevalent areas in Iran and Kerman (3%) and Hamedan (1%) provinces are the lowest. The highest prevalence of Anaplasma spp. infection was belonged to A. ovis (44%) and the lowest to A. phagocytophilum (1%) with a significant difference among them (p < .001). In addition, the most common diagnostic tests were PCR (54%), microscopy (35%) and ELISA (7%) assays. The high prevalence of ovine and bovine anaplasmosis in Iran, confirms the stability situations of animal anaplasmosis in the studied regions particularly northeastern and southwestern parts of the country. Our data offer valuable and encouraging information as regards the current situation of anaplasmosis in domestic livestock in Iran, which might be useful for active and passive surveillance and preventing plans.

An Overview of Tickborne Infections in Pregnancy and Outcomes in the Newborn: The Need for Prospective Studies

Tick-borne infections are an ever-increasing issue internationally, many factors contribute to this including a changing climate. Pregnant women represent the single largest vulnerable group in populations due to a relative immune deficiency status. Infections in pregnant women have the added gravity of potential infection in the developing fetus which may have catastrophic consequences including death in-utero or lifelong debilitation. Currently there is a paucity of data surrounding tick-borne infections in pregnancy and long-term outcomes for mother and infant for conditions like Lyme disease and co-infections. At present there are no established international surveillance systems to identify and gain understanding of these infections in pregnancy. Furthermore, the removal of Congenital Lyme Disease from ICD-11 codes hampers dialogue and characterization of borreliosis in pregnancy and stifles future developments of this understudied domain. This review makes the case for further study and re-opening a dialogue of tick-borne infections in pregnancy.

A review on the eco-epidemiology and clinical management of human granulocytic anaplasmosis and its agent in Europe

Anaplasma phagocytophilum is the agent of tick-borne fever, equine, canine and human granulocytic anaplasmosis. The common route of A. phagocytophilum transmission is through a tick bite, the main vector in Europe being Ixodes ricinus. Despite the apparently ubiquitous presence of the pathogen A. phagocytophilum in ticks and various wild and domestic animals from Europe, up to date published clinical cases of human granulocytic anaplasmosis (HGA) remain rare compared to the worldwide status. It is unclear if this reflects the epidemiological dynamics of the human infection in Europe or if the disease is underdiagnosed or underreported. Epidemiologic studies in Europe have suggested an increased occupational risk of infection for forestry workers, hunters, veterinarians, and farmers with a tick-bite history and living in endemic areas. Although the overall genetic diversity of A. phagocytophilum in Europe is higher than in the USA, the strains responsible for the human infections are related on both continents. However, the study of the genetic variability and assessment of the difference of pathogenicity and infectivity between strains to various hosts has been insufficiently explored to date. Most of the European HGA cases presented as a mild infection, common clinical signs being pyrexia, headache, myalgia and arthralgia. The diagnosis of HGA in the USA was recommended to be based on clinical signs and the patient’s history and later confirmed using specialized laboratory tests. However, in Europe since the majority of cases are presenting as mild infection, laboratory tests may be performed before the treatment in order to avoid antibiotic overuse. The drug of choice for HGA is doxycycline and because of potential for serious complication the treatment should be instituted on clinical suspicion alone.

Anaplasma phagocytophilum presenting with orchitis in a renal transplant recipient

Human granulocytic anaplasmosis (HGA), caused by Anaplasma phagocytophilum, is an emerging tick-borne disease. It is spread by the black-legged deer tick Ixodes scapularis that serves as the vector for six human pathogens. HGA is still rarely reported in solid organ transplant recipients. In solid organ transplant recipients, orchitis has been reported secondary to chickenpox, tuberculosis and infections due to Listeria monocytogenes and Nocardia asteroides. Orchitis as a presenting feature of HGA infection has only been reported in animals. We present a unique case of a renal transplant recipient with HGA that presented as orchitis. We also compare the clinical presentation and laboratory findings of our patient with other cases of HGA in transplant recipients. To the best of our knowledge, our patient is one of the first cases of A phagocytophilum mono-infection causing a classical presentation of orchitis in a transplant patient.

Intrauterine Transmission of Anaplasma phagocytophilum in Persistently Infected Lambs

Anaplasma phagocytophilum, which causes the disease tick-borne fever (TBF), is the most important tick-borne pathogen in European animals. TBF may contribute to severe welfare challenges and economic losses in the Norwegian sheep industry. The bacterium causes a persistent infection in sheep and several other animal species. The objective of this study was to investigate whether intrauterine transmission occurs in persistently infected sheep. The study included thirteen 5–6-month-old unmated ewes, of which twelve were experimentally infected with A. phagocytophilum (GenBank acc. no. M73220). Four to six weeks later, all ewes were mated, and nine became pregnant. Blood samples were collected from these ewes and their offspring. If the lamb died, tissue samples were collected. The samples were analyzed with real-time PCR (qPCR) targeting the msp2 gene. PCR-positive samples were further analyzed by semi-nested PCR and 16S rDNA sequencing. A total of 20 lambs were born, of which six died within two days. Six newborn lambs (30%) were PCR-positive (qPCR), of which one was verified by 16S rDNA sequencing. The present study indicates that intrauterine transmission of A. phagocytophilum in persistently infected sheep may occur. The importance of these findings for the epidemiology of A. phagocytophilum needs to be further investigated.

Anaplasmosis in pediatric patients: Case report and review

Human granulocytic anaplasmosis (HGA) is a tick-borne infection, characterized as an acute and sometimes severe febrile illness which may be associated with leukopenia and thrombocytopenia. Most case reports of HGA have been in adults, with only 8 case reports of HGA in children. We add a ninth case of HGA, which occurred in a 5-year-old. The paucity of pediatric HGA case reports maybe because publication bias, or HGA in children is a mild illness and children with HGA are less likely than adults to seek medical care, or the diagnosis of HGA requires a blood draw and adults (versus children) are more likely to get diagnostic testing. The 9 case reports in children suggest that pediatric HGA is usually a mild infection and that doxycycline and rifampin are effective therapies. Like adults, children with HGA frequently present with fever, headache, and malaise; however, children are more likely than adults to have abdominal pain as a prominent complaint.

Human Granulocytic Anaplasmosis as a Cause of Febrile Illness in Korea Since at Least 2006

AbstractHuman granulocytic anaplasmosis (HGA) is a tick-borne rickettsial zoonosis with fever, thrombocytopenia, and leukopenia. HGA has been reported in Korea in 2013 but it is uncertain how long it has existed. A retrospective study was conducted on patients who underwent bone marrow examination due to fever and cytopenia, with no clear hematologic or microbiologic causes, from 2003 through 2012. Laboratory diagnosis was made by detecting 16S rRNA genes of Anaplasma phagocytophilum from the stored blood samples. Among the 70 patients, five (7.1%) HGA cases were found, and the earliest case dated back to 2006. Two cases met the diagnostic criteria of hemophagocytic lymphohistiocytosis (HLH) and were fatal. Although HGA has been prevalent in Korea since at least 2006, it is not always diagnosed and has posed a possible lethal health risk to the people in Korea. HGA should be considered as a cause of fever with cytopenia or HLH.

Congenital Tick Borne Diseases: Is This An Alternative Route of Transmission of Tick-Borne Pathogens In Mammals?

Tick-borne diseases (TBDs) have become a popular topic in many medical journals. Besides the obvious participation of ticks in the transmission of pathogens that cause TBD, little is written about alternative methods of their spread. An important role is played in this process by mammals, which serve as reservoirs. Transplacental transfer also plays important role in the spread of some TBD etiological agents. Reservoir species take part in the spread of pathogens, a phenomenon that has extreme importance in synanthropic environments. Animals that accompany humans and animals migrating from wild lands to urban areas increase the probability of pathogen infections by ticks This article provides an overview of TBDs, such as tick-borne encephalitis virus (TBEV), and TBDs caused by spirochetes, α-proteobacteria, γ-proteobacteria, and Apicomplexa, with particular attention to reports about their potential to cross the maternal placenta. For each disease, the method of propagation, symptoms of acute and chronic phase, and complications of their course in adults, children, and animals are described in detail. Additional information about transplacental transfer of these pathogens, effects of congenital diseases caused by them, and the possible effects of maternal infection to the fetus are also discussed. The problem of vertical transmission of pathogens presents a new challenge for medicine. Transfer of pathogens through the placenta may lead not only to propagation of diseases in the population, but also constitute a direct threat to health and fetal development. For this reason, the problem of vertical transmission requires more attention and an estimation of the impact of placental transfer for each of listed pathogens.

Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis - United States

Tickborne rickettsial diseases continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of low-cost, effective antibacterial therapy. Recognition early in the clinical course is critical because this is the period when antibacterial therapy is most effective. Early signs and symptoms of these illnesses are nonspecific or mimic other illnesses, which can make diagnosis challenging. Previously undescribed tickborne rickettsial diseases continue to be recognized, and since 2004, three additional agents have been described as causes of human disease in the United States: Rickettsia parkeri, Ehrlichia muris-like agent, and Rickettsia species 364D. This report updates the 2006 CDC recommendations on the diagnosis and management of tickborne rickettsial diseases in the United States and includes information on the practical aspects of epidemiology, clinical assessment, treatment, laboratory diagnosis, and prevention of tickborne rickettsial diseases. The CDC Rickettsial Zoonoses Branch, in consultation with external clinical and academic specialists and public health professionals, developed this report to assist health care providers and public health professionals to 1) recognize key epidemiologic features and clinical manifestations of tickborne rickettsial diseases, 2) recognize that doxycycline is the treatment of choice for suspected tickborne rickettsial diseases in adults and children, 3) understand that early empiric antibacterial therapy can prevent severe disease and death, 4) request the appropriate confirmatory diagnostic tests and understand their usefulness and limitations, and 5) report probable and confirmed cases of tickborne rickettsial diseases to public health authorities.

Alpha proteobacteria of genusAnaplasma(Rickettsiales: Anaplasmataceae): Epidemiology and characteristics ofAnaplasmaspecies related to veterinary and public health importance

TheAnaplasmaspecies are important globally distributed tick-transmitted bacteria of veterinary and public health importance. These pathogens, cause anaplasmosis in domestic and wild animal species including humans.Rhipicephalus, Ixodes, DermacentorandAmblyommagenera of ticks are the important vectors ofAnaplasma.Acute anaplasmosis is usually diagnosed upon blood smear examination followed by antibodies and nucleic acid detection. All age groups are susceptible but prevalence increases with age. Serological cross-reactivity is one of the important issues amongAnaplasmaspecies. They co-exist and concurrent infections occur in animals and ticks in same geographic area. These are closely related bacteria and share various common attributes which should be considered while developing vaccines and diagnostic assays. Movement of susceptible animals from non-endemic to endemic regions is the major risk factor of bovine/ovine anaplasmosis and tick-borne fever. Tetracyclines are currently available drugs for clearance of infection and treatment in humans and animals. Worldwide vaccine is not yet available. Identification, elimination of reservoirs, vector control (chemical and biological), endemic stability, habitat modification, rearing of tick resistant breeds, chemotherapy and tick vaccination are major control measures of animal anaplasmosis. Identification of reservoirs and minimizing the high-risk tick exposure activities are important control strategies for human granulocytic anaplasmosis.

Tick-borne Diseases (Borreliosis, Anaplasmosis, Babesiosis) in German and Austrian Dogs: Status quo and Review of Distribution, Transmission, Clinical Findings, Diagnostics and Prophylaxis

Tick-borne diseases (TBD) in dogs have gained in significance in German and Austrian veterinary practices. The widespread European tick species Ixodes ricinus represents an important vector for spirochaetes of the Borrelia burgdorferi sensu lato group and Rickettsiales such as Anaplasma phagocytophilum. The meadow or ornate dog tick (Dermacentor reticulatus) is an important vector for Babesia canis, as is the brown dog tick (Rhipicephalus sanguineus) for Babesia vogeli in the Mediterranean region. The present work covers pathogen transmission by tick vectors, including the mechanisms and the minimum intervals required, in conjunction with possible non-vector-borne transmission routes. It also addresses the incubation periods, pathogenicity and clinical findings associated with each pathogen and genospecies and presents case examples. Current data on prevalence, annual fluctuations and distribution in various pre-selected dog populations (symptomatic versus asymptomatic) in both countries are depicted in maps. Reasons for changes in prevalence (especially of Borrelia) are discussed. Criteria and algorithms for clinical diagnosis and monitoring in dogs, including case history, direct detection (blood smears, molecular detection by species-specific PCR and sequencing) and indirect methods (whole-cell and peptide-based antibody tests), are presented, together with laboratory abnormalities (haematology, clinical chemistry, urine). The role of anti-C6 antibody concentration (ACAC) and its correlation with proteinuria and Lyme nephritis are assessed on the basis of new data. Consideration is also given to the importance of blood smears, PCR and serology in the case of anaplasmosis and babesiosis, and the diagnostic value of combining these methods. The relevance of molecular differentiation of Anaplasma species (A. phagocytophilum versus A. platys) and Babesia spp. (large versus small forms) in cases of serological cross-reaction is emphasized. A summary is given of methods for prophylaxis using acaricide products (collars, spot-on solutions and oral treatments in both countries), vaccination (Borrelia and Babesia vaccines) and imidocarb-based chemoprophylaxis for large Babesia.

Anaplasma marginale and Anaplasma phagocytophilum: Rickettsiales pathogens of veterinary and public health significance

Anaplasma marginale and Anaplasma phagocytophilum are the most important tick-borne bacteria of veterinary and public health significance in the family Anaplasmataceae. The objective of current review is to provide knowledge on ecology and epidemiology of A. phagocytophilum and compare major similarities and differences of A. marginale and A. phagocytophilum. Bovine anaplasmosis is globally distributed tick-borne disease of livestock with great economic importance in cattle industry. A. phagocytophilum, a cosmopolitan zoonotic tick transmitted pathogen of wide mammalian hosts. The infection in domestic animals is generally referred as tick-borne fever. Concurrent infections exist in ticks, domestic and wild animals in same geographic area. All age groups are susceptible, but the prevalence increases with age. Movement of susceptible domestic animals from tick free non-endemic regions to disease endemic regions is the major risk factor of bovine anaplasmosis and tick-borne fever. Recreational activities or any other high-risk tick exposure habits as well as blood transfusion are important risk factors of human granulocytic anaplasmosis. After infection, individuals remain life-long carriers. Clinical anaplasmosis is usually diagnosed upon examination of stained blood smears. Generally, detection of serum antibodies followed by molecular diagnosis is usually recommended. There are problems of sensitivity and cross-reactivity with both the Anaplasma species during serological tests. Tetracyclines are the drugs of choice for treatment and elimination of anaplasmosis in animals and humans. Universal vaccine is not available for either A. marginale or A. phagocytophilum, effective against geographically diverse strains. Major control measures for bovine anaplasmosis and tick-borne fever include rearing of tick-resistant breeds, endemic stability, breeding Anaplasma-free herds, identification of regional vectors, domestic/wild reservoirs and control, habitat modification, biological control, chemotherapy, and vaccinations (anaplasmosis and/or tick vaccination). Minimizing the tick exposure activities, identification and control of reservoirs are important control measures for human granulocytic anaplasmosis.

Arthropod-borne bacterial diseases in pregnancy

Arthropod-borne bacterial diseases affect more than 25,000 Americans every year and thousands more around the world. These infections present a diagnostic dilemma for clinicians because they mimic many other pathologic conditions and are often low on or absent from the differential diagnosis list. Diagnosis is particularly challenging during pregnancy, as these infections may mimic common pregnancy-specific conditions, such as typical and atypical preeclampsia, or symptoms of pregnancy itself. Concerns regarding the safety in pregnancy of some indicated antibiotics add a therapeutic challenge for the prescriber, requiring knowledge of alternative therapeutic options for many arthropod-borne bacterial diseases. Physicians, especially those in endemic areas, must keep this class of infections in mind, particularly when the presentation does not appear classic for more commonly seen conditions. This article discusses presentation, diagnosis, and treatment of the most common of these arthropod-borne bacterial diseases, including Lyme disease, Rocky Mountain spotted fever, tick-borne relapsing fever, typhus, plague, cat-scratch disease, and Carrión disease.

Essential domains of Anaplasma phagocytophilum invasins utilized to infect mammalian host cells

Anaplasma phagocytophilum causes granulocytic anaplasmosis, an emerging disease of humans and domestic animals. The obligate intracellular bacterium uses its invasins OmpA, Asp14, and AipA to infect myeloid and non-phagocytic cells. Identifying the domains of these proteins that mediate binding and entry, and determining the molecular basis of their interactions with host cell receptors would significantly advance understanding of A. phagocytophilum infection. Here, we identified the OmpA binding domain as residues 59 to 74. Polyclonal antibody generated against a peptide spanning OmpA residues 59 to 74 inhibited A. phagocytophilum infection of host cells and binding to its receptor, sialyl Lewis x (sLe^x-capped P-selectin glycoprotein ligand 1. Molecular docking analyses predicted that OmpA residues G61 and K64 interact with the two sLe^x sugars that are important for infection, α2,3-sialic acid and α1,3-fucose. Amino acid substitution analyses demonstrated that K64 was necessary, and G61 was contributory, for recombinant OmpA to bind to host cells and competitively inhibit A. phagocytophilum infection. Adherence of OmpA to RF/6A endothelial cells, which express little to no sLe^x but express the structurally similar glycan, 6-sulfo-sLe^x, required α2,3-sialic acid and α1,3-fucose and was antagonized by 6-sulfo-sLe^x antibody. Binding and uptake of OmpA-coated latex beads by myeloid cells was sensitive to sialidase, fucosidase, and sLe^x antibody. The Asp14 binding domain was also defined, as antibody specific for residues 113 to 124 inhibited infection. Because OmpA, Asp14, and AipA each contribute to the infection process, it was rationalized that the most effective blocking approach would target all three. An antibody cocktail targeting the OmpA, Asp14, and AipA binding domains neutralized A. phagocytophilum binding and infection of host cells. This study dissects OmpA-receptor interactions and demonstrates the effectiveness of binding domain-specific antibodies for blocking A. phagocytophilum infection.

Anaplasma phagocytophilum causes the potentially deadly bacterial disease granulocytic anaplasmosis. The pathogen replicates inside white blood cells and, like all other obligate intracellular organisms, must enter host cells to survive. Multiple A. phagocytophilum surface proteins called invasins cooperatively orchestrate the entry process. Identifying these proteins’ domains that are required for function, and determining the molecular basis of their interaction with host cell receptors would significantly advance understanding of A. phagocytophilum pathogenesis. In this study, the binding domains of two A. phagocytophilum surface proteins, OmpA and Asp14, were identified. The specific OmpA residues that interact with its host cell receptor were also defined. An antibody cocktail generated against the binding domains of OmpA, Asp14, and a third invasin, AipA, blocked the ability of A. phagocytophilum to infect host cells. The data presented within suggest that binding domains of OmpA, Asp14, and AipA could be exploited to develop a vaccine for granulocytic anaplasmosis.

Transfusion-associated Anaplasma phagocytophilum infection in a pregnant patient with thalassemia trait: a case report

BACKGROUND

Human granulocytic anaplasmosis (HGA) is an acute nonspecific febrile illness caused by the bacterium Anaplasma phagocytophilum. Although usually transmitted via tick bite, HGA may rarely also be acquired through transfusion. HGA during pregnancy may pose significant gestational risks due to altered maternal immune status and the potential for perinatal transmission.

CASE REPORT

A pregnant 34-year-old Massachusetts woman with β-thalassemia trait was diagnosed at 32 weeks of gestation with transfusion-associated HGA (TAHGA) after receiving nine leukoreduced red blood cell transfusions. She was successfully treated with rifampin therapy and gave birth to a healthy child who tested negative for HGA after delivery. An implicated blood donor was subsequently identified through physician collaboration with the regional American Red Cross and Massachusetts Department of Public Health.

DISCUSSION

This is the 11th reported case of HGA in pregnancy and is at least the sixth known case in which leukoreduction did not prevent TAHGA. As seen in this case, nonspecific symptomatology of variable onset can impede diagnosis and treatment. This may increase risk of poor outcomes in maternal HGA patients. Cases of TAHGA, although currently uncommon, may increase as the incidence of HGA in certain parts of the country increases.

CONCLUSION

Heightened cross-institutional awareness of the potential risk of TAHGA is warranted. Clinicians need to consider transfusion-associated infections when fever occurs in a transfusion recipient. This case provides additional evidence that leukoreduction does not obviate risk of A. phagocytophilum contamination of donated blood components.

Demonstration of transplacental transmission of a human isolate of Anaplasma phagocytophilum in an experimentally infected sheep

Anaplasma phagocytophilum, first identified as a pathogen of sheep in Europe, more recently has been recognized as an emerging tick-borne pathogen of humans in the U.S. and Europe. Transmission of A. phagocytophilum is reported to be by ticks, primarily of the genus Ixodes. While mechanical and transplacental transmission of the type genus organism, A. marginale, occur in addition to tick transmission, these modes of transmission have not been considered for A. phagocytophilum. Recently, we developed a sheep model for studying host-tick-pathogen interactions of the human NY-18 A. phagocytophilum isolate. Sheep were susceptible to infection with this human isolate and served as a source of infection for I. scapularis ticks, but they did not display clinical signs of disease, and the pathogen was not apparent in stained blood smears. In the course of these experiments, one sheep unexpectedly gave birth to a lamb 5 weeks after being experimentally infected by inoculation with the pathogen propagated in HL-60 cells. The lamb was depressed and not feeding and was subsequently euthanized 18 h after birth. Tissues were collected at necropsy for microscopic examination and PCR to confirm A. phagocytophilum infection. At necropsy, the stomach contained colostrum, the spleen was moderately enlarged and thickened with conspicuous lymphoid follicles, and mesenteric lymph nodes were mildly enlarged and contained moderate infiltrates of eosinophils and neutrophils. Blood, spleen, heart, skin and cervical and mesenteric lymph nodes tested positive for A. phagocytophilum by PCR, and sequence analysis confirmed that the lamb was infected with the NY-18 isolate. Transplacental transmission should therefore be considered as a means of A. phagocytophilum transmission and may likely contribute to the epidemiology of tick-borne fever in sheep and other mammals, including humans.

Non-lyme tick-borne diseases: a neurological perspective

Tick-borne diseases are prevalent throughout the world and present a diagnostic challenge owing to their nonspecific clinical symptoms. Many tick-borne diseases involve the central and peripheral nervous systems. Early diagnosis or at least suspicion of a tick-borne cause is necessary to institute early empiric treatment. After a brief review of tick biology, we present the most common tick-borne diseases. A brief discussion of epidemiology, the transmission route, and pathogenesis is followed by a discussion of the clinical manifestations, diagnosis and treatment options when available. The review emphasizes the infectious causes with a significant neurological manifestation.

Close correlation between development of MODS during the initial 72 h of hospitalization and hospital mortality in severe fever with thrombocytopenia syndrome

An emerging infectious disease was identified as severe fever with thrombocytopenia syndrome (SFTS) in central China since late March 2009. We found the patients with SFTS had severe clinical symptoms, and progressed rapidly to multiple organ dysfunction syndrome (MODS) with high fatality rate of 25%-30%. The aim of this study was to assess the significance of risk factors predicting the development of MODS and death in SFTS patients. Consecutive SFTS admissions between May 2009 and September 2011 were analyzed for parameters of organ function during hospitalization using Marshall scoring system for MODS, and platelet counts were recorded on admission and at 24, 48, 72 h and one week after admission. We investigated the kinetics of organ failures and analyzed the association between age, platelet count and development of MODS or death. A total of 92 SFTS patients were enrolled in this study. Among them, 32 patients with dysfunction of over 4 organs were identified, 45% of them died within 72 h, 72% died within 5 days, and 76% died within 7 days after admission. We also found cumulative Marshall score was significantly higher in death patients (11.76±2.05) than in survival patients (4.22±1.98) (P<0.001). In addition, SFTS patients had older age and lower platelet counts in MODS and death groups. Furthermore, we also observed that there was a close correlation between platelet count on admission and Marshall score (P<0.001). High Marshall score, advanced age and lower platelet counts were the main risk factors for the development of MODS, and those factors could predict mortality in SFTS patients, suggesting prompt treatment and close monitoring of severe complications, especially MODS, are of great importance in saving patients' lives.

Anaplasma phagocytophilum Asp14 is an invasin that interacts with mammalian host cells via its C terminus to facilitate infection

Anaplasma phagocytophilum, a member of the family Anaplasmataceae, is the tick-transmitted obligate intracellular bacterium that causes human granulocytic anaplasmosis. The life cycle of A. phagocytophilum is biphasic, transitioning between the noninfectious reticulate cell (RC) and infectious dense-cored (DC) forms. We analyzed the bacterium's DC surface proteome by selective biotinylation of surface proteins, NeutrAvidin affinity purification, and mass spectrometry. Transcriptional profiling of selected outer membrane protein candidates over the course of infection revealed that aph_0248 (designated asp14 [14-kDa A. phagocytophilum surface protein]) expression was upregulated the most during A. phagocytophilum cellular invasion. asp14 transcription was induced during transmission feeding of A. phagocytophilum-infected ticks on mice and was upregulated when the bacterium engaged its receptor, P-selectin glycoprotein ligand 1. Asp14 localized to the A. phagocytophilum surface and was expressed during in vivo infection. Treating DC organisms with Asp14 antiserum or preincubating mammalian host cells with glutathione S-transferase (GST)-Asp14 significantly inhibited infection of host cells. Moreover, preincubating host cells with GST-tagged forms of both Asp14 and outer membrane protein A, another A. phagocytophilum invasin, pronouncedly reduced infection relative to treatment with either protein alone. The Asp14 domain that is sufficient for cellular adherence and invasion lies within the C-terminal 12 to 24 amino acids and is conserved among other Anaplasma and Ehrlichia species. These results identify Asp14 as an A. phagocytophilum surface protein that is critical for infection, delineate its invasion domain, and demonstrate the potential of targeting Asp14 in concert with OmpA for protecting against infection by A. phagocytophilum and other Anaplasmataceae pathogens.

A case report of human granulocytic anaplasmosis (ehrlichiosis) in pregnancy and a literature review of tick-borne diseases in the United States during pregnancy

There is paucity of data regarding tick-borne diseases during pregnancy. Here, we report a case of human granulocytic anaplasmosis during pregnancy with successful treatment and a favorable neonatal outcome. We also review diagnosis, treatment, and outcomes of published case reports from 1983 to 2010 of human granulocytic anaplasmosis, Lyme disease, babesiosis, and human monocytic ehrlichiosis in the United States.

TARGET AUDIENCE

Obstetricians and Gynecologists and Family Physicians.

LEARNING OBJECTIVES

After the completing the CME activity, physicians should be better able to diagnose tick-born diseases, implement best treatment options during the pregnancy, and assess the neonatal outcomes.

Typical and atypical manifestations of Anaplasma phagocytophilum infection in dogs

Eighteen clinically ill dogs, naturally infected with Anaplasma phagocytophilum, were examined at a veterinary practice in Baxter, Minnesota. A clinical examination, complete blood cell count, enzyme- linked immunosorbent assay (ELISA) for A phagocytophilum, Borrelia burgdorferi, and Ehrlichia canis antibodies and Dirofilaria immitis antigen, and a polymerase chain reaction test for A phagocytophilum DNA were obtained for all dogs. Physical examination findings included fever, arthropathy, lymphadenopathy, epistaxis, acute gastritis, cervical hyperpathia, and central nervous system dysfunction. Complete blood cell count abnormalities included thrombocytopenia, morulae in neutrophils, anemia, leukopenia, eosinopenia, lymphopenia, and monocytosis. Seroreactivity to A phagocytophilum was found in 61%, B burgdorferi antibodies in 17%, and D immitis antigen in 5% of the dogs. Fever, arthropathy, neurologic dysfunction, and epistaxis are clinical syndromes that can be associated with A phagocytophilum infection. Treatment with doxycycline resulted in rapid resolution of clinical signs in all dogs.

The clinical characteristics and outcomes of patients with human granulocytic anaplasmosis in China

OBJECTIVES

The incidence of human granulocytic anaplasmosis (HGA), a tick-borne disease caused by the obligate intracellular bacterium Anaplasma phagocytophilum, has increased across the world. However, information on HGA is lacking in China. The purpose of this study was to investigate the clinical features and outcomes of HGA patients in China.

METHODS

A total of 83 patients with HGA from the provinces of Hubei and Henan in China, who were admitted to Union Hospital between March 2009 and September 2010, were included in this study. We investigated the epidemiology, clinical features, laboratory markers, and therapeutic effects in these patients. We also analyzed life-threatening complications such as systemic inflammatory response syndrome (SIRS)/multiple organ dysfunction syndrome (MODS) following HGA and assessed the risk factors for a poor clinical outcome.

RESULTS

In our study, an HGA outbreak peak was observed for the months May to August. The highest age-specific incidence occurred among the group of patients aged 50-59 years. With regard to patient occupation and pathological origin, we found that 73 of the 83 patients with HGA had a peasant occupation. With respect to symptoms, 45 patients had no complications and 38 patients diagnosed with HGA met SIRS criteria, of whom 25 rapidly developed MODS. The mortality for the entire cohort was 26.5%. The factors predictive of patients developing MODS and an adverse outcome were advanced age, disturbance of consciousness, highly elevated lactate dehydrogenase, creatinine, and aspartate aminotransferase levels, and the presence of SIRS. Moreover, MODS was found to be an independent predictor of death.

CONCLUSIONS

In China, HGA patients had severe clinical symptoms and high rates of complications and mortality. These findings may provide useful information so that physicians will be on the alert for severe complications after a diagnosis of HGA; they will also be useful for optimizing supportive care for HGA-related critical illness. Prompt treatment and close monitoring of severe complications such as SIRS and MODS are of great importance in saving patient lives.

Rickettsial and ehrlichial infections

Rickettsial diseases represent a clinically homogeneous group of infections characterized by fever, headache myalgias, variable presence of a rash, and a broad spectrum of neurological manifestations. Epidemiological information including time of year, geography, history of arthropod exposure, and animal contact gives important clues to the diagnosis, and should be actively elicited. Abnormalities in hematological indices of liver function tests should also increase suspicion for illness. Delay in initiation of doxycycline therapy while awaiting laboratory confirmation of infection has been associated with progressive neurological impairment and death. Clinicians should maintain a low threshold to initiate empiric therapy for rickettsial diseases in any patient with neurological findings and compatible exposures, signs, or laboratories, as these syndromes represent readily treatable causes of neurological dysfunction.

Infections in Pregnancy

Despite advances in peripartum care, maternal morbidity and mortality associated with infections in pregnancy are increasing even in developed countries. Recently published data from the Center for Disease Control's Pregnancy Mortality Surveillance System indicates that although maternal mortality from hemorrhage, embolism, and anesthesia has declined in the United States, the proportion of maternal deaths due to infections has increased. During 1991–7 infection accounted for 13.2% of pregnancy-related deaths overall and 36.3% of abortion-related deaths. The greatest infection risk is found in blacks, older women, women without prenatal care, and women with multiple pregnancy. In the United States pregnancy rates are stable or increasing in these groups. Infection is also a major cause of morbidity and mortality for the fetus and newborn. Many perinatal infections are associated with intra-uterine growth retardation and low birthweight, or cause fetal and neonatal brain injury. Infections, particularly bacterial vaginosis and chorioamnionitis, can result in preterm delivery of live-born infants (delivery before 37 weeks gestation), or stillbirth. A multitude of immunologic, endocrinologic, metabolic, physiologic, and anatomic changes influence the likelihood and course of many infections during pregnancy. Some of these changes are intrinsic, and occur in all normal pregnancies, while others occur to varying degrees in normal and abnormal pregnancies.

Lack of evidence for perinatal transmission of canine granulocytic anaplasmosis from a bitch to her offspring

Granulocytic anaplasmosis is an emerging infectious disease affecting dogs and humans in the United States and other regions of the world. Relatively few cases have been described in pregnant women, and perinatal transmission appears to occur infrequently in humans. Infection in pregnant dogs has not been reported. Diagnosis of infection during pregnancy poses therapeutic challenges, because doxycycline, the treatment of choice, is teratogenic. Also, infection during pregnancy may result in more severe disease. When infection is diagnosed after parturition, knowledge of the risk of perinatal transmission to offspring is important, because prophylactic therapy in neonates is also not without risk. In this report, we describe relatively severe clinical manifestations of Anaplasma phagocytophilum infection in a postpartum bitch and a lack of perinatal transmission to her puppies.

Diagnosis and treatment of tick infestation and tick-borne diseases with cutaneous manifestations

Hard and soft ticks may be associated directly or indirectly with a number of dermatoses, both infectious and inflammatory in origin. Morbidity may occur as a result of tick bites, tick toxicosis, and even infestation. These arthropod vectors may transmit life-threatening protozoan, bacterial, rickettsial, and viral diseases with systemic and cutaneous findings. Additionally, ticks may transmit more than one pathogen with subsequent human coinfection. This article reviews the presentation of tick-borne illnesses and the medical management of these diseases. Among others, diseases such as ehrlichiosis, anaplasmosis, babesiosis, tularemia, borrelioses, tick-borne encephalitides, rickettsial spotted fevers, and tick typhus are discussed in this article. The recognition of skin manifestations associated with these diseases is paramount to early diagnosis and treatment initiation.

Identification of Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato in patients with erythema migrans

Anaplasma phagocytophilum has been first isolated from the blood of two Czech patients simultaneously with a cultivation of Borrelia burgdorferi sensu lato from their erythema migrans lesions. Cultivation of different Borrelia spp. from 12 erythema migrans biopsies, from 2 blood, one liquor and one placenta sample in BSK-H medium was successful. Adapted conventional methods targeting 16S rRNA and OspA genes for real-time polymerase chain reaction (PCR) and partial sequencing of these genes together with microscopical examinations of the blood smears provided a direct detection of the B. afzelii, B. burgdorferi, B. garinii, B. valaisiana and B. bissettii in the skin, B. garinii in the blood, placenta and liquor in 24 (36.3 %) patients, and A. phagocytophilum in 10 (15 %) patients with erythema migrans. Positive indirect IgM immunofluorescence against Anaplasma sp. was obtained in 7 cases, specific IgG antibodies were detected in 12 patients. Three women suffering from erythema migrans in the first trimester had positive PCR for Anaplasma and/or for Borrelia in the blood and two of them, later, in the placenta. Interpretation of laboratory data can bring important contribution to establishing the role of Anaplasma sp. in erythema migrans and forming the principle of precaution with laboratory diagnosis during pregnancy which always should be reflected in the resistance of Anaplasma sp. toward penicillins.

Human granulocytic ehrlichiosis complicating early pregnancy

BACKGROUND

The goal of this case is to review the zoonotic infection, human granulocytic ehrlichiosis, presenting with pyrexia. Case. A 22-year-old multigravid female presented to the emergency department with a painful skin rash, high fever, and severe myalgias. The patient underwent a diagnostic evaluation for zoonotic infections due to her geographical and seasonal risk factors. Treatment of human granulocytic ehrlichiosis was successful though the patient spontaneously aborted presumably due to the severity of the acute illness.

CONCLUSION

Treatment of human granulocytic ehrlichiosis in pregnancy presents unique challenges. Management of pyrexia during pregnancy is limited to external cooling in the setting of thrombocytopenia and elevated aminotransferases. Extensive counseling regarding teratogenic potential of medications allows the patient to weigh the pros and cons of treatment.