Epidemiological, clinical, and laboratory characteristics of human granulocytic anaplasmosis in North India.

Human granulocytic anaplasmosis (HGA) is an emerging, rickettsial tick-borne disease caused by Anaplasma phagocytophilum. Sero-epidemiological data demonstrate that this pathogen has a worldwide distribution. The diagnosis of HGA requires a high index of clinical suspicion, even in endemic areas. In recent years, HGA has increasingly been reported from Asia and described in China, Japan, and Korea. We serologically and molecularly screened 467 patients with clinical suspicion of Anaplasmosis. The present study describes the epidemiology, clinical, and laboratory details of 6 confirmed and 43 probable cases of human granulocytic anaplasmosis. One of the HGA patients developed secondary invasive opportunistic Aspergillus fumigatus and Acinetobacter baumanii infection during the illness, which resulted in a fatal infection. The HGA patients without severe complications had excellent treatment responses to doxycycline. The emergence of this newly recognized tick-borne zoonotic HGA in North India is a significant concern for public health and is likely underdiagnosed, underreported, and untreated. Hence, it is also essential to establish a well-coordinated system for actively conducting tick surveillance, especially in the forested areas of the country.IMPORTANCEThe results of the present study show the clinical and laboratory evidence of autochthonous cases of Anaplasma phagocytophilum in North India. The results suggest the possibility of underdiagnosis of HGA in this geographical area. One of the HGA patients developed secondary invasive opportunistic Aspergillus fumigatus and Acinetobacter baumanii infection during the illness, which resulted in a fatal infection.

Anaplasma bovis-Like Infections in Humans, United States, 2015-2017.

We detected the DNA of an Anaplasma bovis-like bacterium in blood specimens from 4 patients from the United States with suspected tickborne illnesses. Initial molecular characterization of this novel agent reveals identity to A. bovis-like bacteria detected in Dermacentor variabilis ticks collected from multiple US states.

Using Serum Specimens for Real-Time PCR-Based Diagnosis of Human Granulocytic Anaplasmosis, Canada.

Whole blood is the optimal specimen for anaplasmosis diagnosis but might not be available in all cases. We PCR tested serum samples collected in Canada for Anaplasma serology and found 84.8%-95.8% sensitivity and 2.8 average cycle threshold elevation. Serum can be acceptable for detecting Anaplasma spp. when whole blood is unavailable.

Human case of Anaplasma phagocytophilum infection in Eastern Taiwan.

Human granulocytic anaplasmosis (HGA) is a tick-borne infection caused by the bacterium Anaplasma phagocytophilum. In this study, we report an indigenous case of clinically diagnosed HGA. The patient was a 41-year-old man who experienced a tick bite and later developed fever, chills, myalgia, malaise, thrombocytopenia, leukocytosis with a left shift, elevated hepatic transaminase levels, and splenomegaly upon admission to the hospital. Immunofluorescence assays detected seroconversion against A. phagocytophilum, whereas tests for spotted fever group rickettsiae, murine typhus, scrub typhus, Q fever, and ehrlichiosis were negative. ELISA and Western blot analysis using recombinant MSP2 protein confirmed the exposure to A. phagocytophilum. Oral doxycycline and intravenous ceftriaxone were prescribed, and the patient made a full recovery. Our findings indicate the presence of HGA on the main island of Taiwan. Precautions against tick bites should be taken when engaging in outdoor activities, and HGA should be considered by physicians in the differential diagnosis.

Detection and Genotypic Analysis of Anaplasma bovis and A. phagocytophilum in Horse Blood and Lung Tissue.

A clinical case of Anaplasma bovis was reported for the first time in our previous study (2019) in a horse, a nondefinitive host. Although A. bovis is a ruminant and not a zoonotic pathogen, it is responsible for persistent infections in horses. In this follow-up study, the prevalence of Anaplasma spp., including A. bovis, was assessed in horse blood and lung tissue samples to fully understand Anaplasma spp. pathogen distribution and the potential risk factors of infection. Among 1696 samples, including 1433 blood samples from farms nationwide and 263 lung tissue samples from horse abattoirs on Jeju Island, a total of 29 samples (1.7%) tested positive for A. bovis and 31 (1.8%) samples tested positive for A. phagocytophilum, as determined by 16S rRNA nucleotide sequencing and restriction fragment length polymorphism. This study is the first to detect A. bovis infection in horse lung tissue samples. Further studies are needed to clarify the comparison of sample types within cohorts. Although the clinical significance of Anaplasma infection was not evaluated in this study, our results emphasize the need to clarify the host tropism and genetic divergence of Anaplasma to enable the development of effective prevention and control measures through broad epidemiological studies.

Global status of Anaplasma phagocytophilum infections in human population: A 50-year (1970-2020) meta-analysis.

BACKGROUND & OBJECTIVES: Anaplasma phagocytophilum causes human granulocytic anaplasmosis; a febrile tick-borne bacterial zoonosis of increasing public health importance in many parts of the world which is life threatening in undiagnosed, misdiagnosed and untreated cases. In this study we determined and reported the global status of the pathogen in man. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was used to perform a systematic review and meta-analysis of data published in six electronic databases between 1970 and 2020. We pooled data using the random-effects model, performed sensitivity analysis by the single study deletion method and assess across study bias by the funnel plot and its statistical significance by the Egger's regression test. RESULTS: A total of 7018 cases of A. phagocytophilum were reported from 48,619 individuals examined across 22 countries in three continents. Overall pooled estimate was 8.13% (95% CI: 5.70 - 11.47) with a range of 4.64 (95% CI: 1.78 - 11.54) to 12.18% (95% CI: 7.66 - 18.83) across sub-groups. Regional prevalence was highest in North America 11.07% (95% CI: 3.13 - 32.38), while that in relation to study population was highest among occupationally exposed population 11.41% (95% CI: 5.69 - 21.56). INTERPRETATION & CONCLUSION: The study revealed a significant variation in the prevalence of A. phagocytophilum across Asia, Europe and North America, with the highest prevalence in North America and among occupationally exposed population. To curtail the menace of this growing public health crisis, we recommend integrated control programmes involving tick control, the use of appropriate clothing by occupationally exposed population and health education.

Loop-mediated isothermal amplification assay for the rapid detection of Anaplasma marginale in cattle based on major surface protein 5 gene.

BACKGROUND & OBJECTIVES: Timely intervention is needed to minimize the economic losses of vector-borne bovine anaplasmosis which can be possible by the isothermal amplification assay. METHODS: Anaplasma marginale in the cattle of south Gujarat, India was detected in the PCR and LAMP by amplifying the fragment of msp5 gene. The PCR product was digested with EcoRI, and sequenced to confirm its pathogen specific detection. RESULTS: Species specific PCR observed a band of 457 bp of msp5 DNA following 1% agarose gel electrophoresis. Positive LAMP reaction turned into yellow colour while negative sample depicted original pink colour. A detection limit of PCR and LAMP was up to 10-6 and 10-8 of the original genomic DNA of A. marginale, respectively. A single cut site of EcoRI was observed in the PCR product. Current msp5 DNA sequences of A. marginale (MW538962 and MW538961) showed 100% homology with the published sequences. Monophyletic lineage type relationship was observed with high bootstrap proportion among the msp5 DNA sequences of A. marginale in the phylogram. Prevalence rate of A. marginale was significantly higher (p<0.05) in the PCR [43/280 (15.36%)] and LAMP [62/280 (22.14%)] than the microscopic technique [17/280 (6.07%)]. Diagnostic sensitivity, specificity, positive and negative predictive values at 95% CI for LAMP assay with respect to PCR were 93.02%, 90.72%, 64.52% and 98.62%, respectively. INTERPRETATION & CONCLUSION: Thus LAMP can be a practical alternative to the PCR for the diagnosis of A. marginale infection in the cattle even in field condition.

Equine Granulocytic Anaplasmosis.

Equine granulocytic anaplasmosis is a clinically significant and common disease of equids that has a broader prevalence than was once thought. The most common clinical signs include high fever and edema, with mild to mderate thrombocytopenia and lymphopenia typically noted on complete blood count. Subclinical cases are reported and many are self-limiting. Rare clinical presentations include neurologic disease, vasculitis, dysphagia, rhabdomyolysis, or bicavitary effusion. Most cases resolve rapidly with appropriate antimicrobial intervention.

Spiroplasma ixodetis Infections in Immunocompetent and Immunosuppressed Patients after Tick Exposure, Sweden.

We report 2 cases of Spiroplasma ixodetis infection in an immunocompetent patient and an immunocompromised patient who had frequent tick exposure. Fever, thrombocytopenia, and increased liver aminotransferase levels raised the suspicion of anaplasmosis, but 16S rRNA PCR and Sanger sequencing yielded a diagnosis of spiroplasmosis. Both patients recovered after doxycycline treatment.

Novel Chronic Anaplasmosis in Splenectomized Patient, Amazon Rainforest.

We report a case of unusual human anaplasmosis in the Amazon rainforest of French Guiana. Molecular typing demonstrated that the pathogen is a novel Anaplasma species, distinct to all known species, and more genetically related to recently described Anaplasma spp. causing infections in rainforest wild fauna of Brazil.

Lyme Disease, Anaplasmosis, and Babesiosis, Atlantic Canada.

In July 2021, a PCR-confirmed case of locally acquired Babesia microti infection was reported in Atlantic Canada. Clinical features were consistent with babesiosis and resolved after treatment. In a region where Lyme disease and anaplasmosis are endemic, the occurrence of babesiosis emphasizes the need to enhance surveillance of tickborne infections.

Do Not Forget About the Ticks: An Unusual Cause of Fever, GI Distress, and Cytopenias in a Child With ALL.

We report the case of a 5-year-old male with B-cell acute lymphoblastic leukemia in remission, receiving maintenance chemotherapy, who presented with fever, emesis, diarrhea, headache, and lethargy. He developed rapidly progressive cytopenias and was found to have acute human granulocytic anaplasmosis as well as evidence of past infection with Babesia microti. The case highlights the need to maintain a broad differential for infection in children undergoing chemotherapy or other immunosuppressive therapies with possible or known tick exposure.

Using rumination and activity data for early detection of anaplasmosis disease in dairy heifer calves.

Bovine anaplasmosis causes considerable economic losses in dairy cattle production systems worldwide, ranging from $300 million to $900 million annually. It is commonly detected through rectal temperature, blood smear microscopy, and packed cell volume (PCV). Such methodologies are laborious, costly, and difficult to systematically implement in large-scale operations. The objectives of this study were to evaluate (1) rumination and activity data collected by Hr-Tag sensors (SCR Engineers Ltd.) in heifer calves exposed to anaplasmosis; and (2) the predictive ability of recurrent neural networks in early identification of anaplasmosis. Additionally, we aimed to investigate the effect of time series length before disease diagnosis (5, 7, 10, or 12 consecutive days) on the predictive performance of recurrent neural networks, and how early anaplasmosis disease can be detected in dairy calves (5, 3, and 1 d in advance). Twenty-three heifer calves aged 119 ± 15 (mean ± SD) d and weighing 148 ± 20 kg of body weight were challenged with 2 × 107 erythrocytes infected with UFMG1 strain (GenBank no. EU676176) isolated from Anaplasma marginale. After inoculation, animals were monitored daily by assessing PCV. The lowest PCV value (14 ± 1.8%) and the finding of rickettsia on blood smears were used as a criterion to classify an animal as sick (d 0). Rumination and activity data were collected continuously and automatically at 2-h intervals, using SCR Heatime Hr-Tag collars. Two time series were built including last sequence of -5, -7, -10, or -12 d preceding d 0 or a sequence of 5, 7, 10, or 12 d randomly selected in a window from -50 to -15 d before d 0 to ensure a sequence of days in which PCV was considered normal (32 ± 2.4%). Long short-term memory was used as a predictive approach, and a leave-one-animal-out cross-validation (LOAOCV) was used to assess prediction quality. Anaplasmosis disease reduced 34 and 11% of rumination and activity, respectively. The accuracy, sensitivity, and specificity of long short-term memory in detecting anaplasmosis ranged from 87 to 98%, 83 to 100%, and 83 to 100%, respectively, using rumination data. For activity data, the accuracy, sensitivity, and specificity varied from 70 to 98%, 61 to 100%, and 74 to 100%, respectively. Predictive performance did not improve when combining rumination and activity. The use of longer time-series did not improve the performance of models to predict anaplasmosis. The accuracy and sensitivity in predicting anaplasmosis up to 3 d before clinical diagnosis (d 0) were greater than 80%, confirming the possibility for early identification of anaplasmosis disease. These findings indicate the great potential of wearable sensors in early identification of anaplasmosis diseases. This could positively affect the profitability of dairy farmers and animal welfare.

Outbreak of follicular conjunctivitis associated with the diagnosis of anaplasmosis in a sheep herd.

OBJECTIVE: To report an outbreak of follicular conjunctivitis in a group of sheep diagnosed with Anaplasma spp., without any other co-infection. ANIMALS STUDIED: In all, 18 animals from a sheep head, males and females, from eight months to four years of age, were assessed for follicular conjunctivitis. PROCEDURES: The procedures performed included general physical and ophthalmological examinations; PCR evaluation for infectious agents; analysis of hematological parameters, microbiological tests of ocular swabs, coproparasitological examination, histopathological examination of conjunctival biopsy. RESULTS: All 18 animals had uni- or bilateral follicular conjunctivitis, and one animal also had unilateral uveitis. The results of microbiological analyzes were negative for Moraxella spp., Staphylococcus spp., and Pseudomonas spp., and PCR analysis results were negative for Chlamydia spp., Mycoplasma spp., and Toxoplasma gondii. Anemia, thrombocytopenia, lymphocytosis, and an inclusion body in some erythrocytes, compatible with Anaplasma and PCR analysis for Anaplasma spp. were positive. CONCLUSION: Anaplasmosis may be associated with follicular conjunctivitis in sheep and should be included in the differential diagnosis list and investigated in cases of conjunctivitis in herds.

Human granulocytic anaplasmosis combined with rhabdomyolysis: a case report.

BACKGROUND: Human granulocytic anaplasmosis (HGA) is a systemic inflammatory response caused by the rickettsial bacterium Anaplasma phagocytophilum. Rhabdomyolysis and acute kidney injury (AKI) are rare complications of HGA. Here, we report a case of HGA concurrent with rhabdomyolysis and AKI in an elderly patient. CASE PRESENTATION: An 84-year old woman with a medical history of hypertension was hospitalised after two days of fever, dizziness, whole body pain, and general weakness. Laboratory investigations showed severe thrombocytopenia, leukopenia, impaired renal function, and elevated cardiac enzyme and myoglobin levels. On the day after admission, peripheral blood smear revealed morula inclusions in neutrophils, a suggestive finding of HGA. Real-time polymerase chain reaction (PCR) results indicated the presence of A. phagocytophilum. Antibiotics were de-escalated to doxycycline monotherapy. After 10 days of antibiotic treatment, laboratory tests showed complete recovery from HGA complicated with rhabdomyolysis and AKI. CONCLUSIONS: HGA can lead to serious complications in patients with associated risk factors. Therefore, in patients with HGA accompanied by rhabdomyolysis, management with antibiotics and hydration should be initiated immediately, and not delayed until diagnostic confirmation.

Use of Routine Complete Blood Count Results to Rule Out Anaplasmosis Without the Need for Specific Diagnostic Testing.

BACKGROUND: Anaplasmosis presents with fever, headache, and laboratory abnormalities including leukopenia and thrombocytopenia. Polymerase chain reaction (PCR) is the preferred diagnostic but is overutilized. We determined if routine laboratory tests could exclude anaplasmosis, improving PCR utilization. METHODS: Anaplasma PCR results from a 3-year period, with associated complete blood count (CBC) and liver function test results, were retrospectively reviewed. PCR rejection criteria, based on white blood cell (WBC) and platelet (PLT) counts, were developed and prospectively applied in a mock stewardship program. If rejection criteria were met, a committee mock-refused PCR unless the patient was clinically unstable or immunocompromised. RESULTS: WBC and PLT counts were the most actionable routine tests for excluding anaplasmosis. Retrospective review demonstrated that rejection criteria of WBC ≥11 000 cells/µL or PLT ≥300 000 cells/µL would have led to PCR refusal in 428 of 1685 true-negative cases (25%) and 3 of 66 true-positive cases (5%) involving clinically unstable or immunocompromised patients. In the prospective phase, 155 of 663 PCR requests (23%) met rejection criteria and were reviewed by committee, which endorsed refusal in 110 of 155 cases (71%) and approval in 45 (29%), based on clinical criteria. PCR was negative in all 45 committee-approved cases. Only 1 of 110 mock-refused requests yielded a positive PCR result; this patient was already receiving doxycycline at the time of testing. CONCLUSIONS: A CBC-based stewardship algorithm would reduce unnecessary Anaplasma PCR testing, without missing active cases. Although the prospectively evaluated screening approach involved medical record review, this was unnecessary to prevent errors and could be replaced by a rejection comment specifying clinical situations that might warrant overriding the algorithm.

Tick-Borne Diseases in the United States.

BACKGROUND: Tick-borne diseases are an important cause of human morbidity and mortality in the United States. The past several decades have witnessed an increase in both the number of recognized tick-borne pathogens and the number of tick-borne disease cases, whereas tick surveys have revealed substantial geographic expansions of tick populations throughout the country. Multiple laboratory testing options exist for diagnosis of tick-borne diseases, including serology, microscopy, and molecular-based methods. The preferred approach varies by the specific disease, locally available test options, and the stage of illness at patient presentation. Accurate and timely detection of tick-borne illness is of utmost importance, as prompt treatment is strongly linked to better outcomes. CONTENT: This review covers the clinical manifestations and preferred diagnostic approaches for important bacterial, viral, and parasitic tick-borne diseases in the United States, including Lyme disease, tick-borne relapsing fever, anaplasmosis, ehrlichiosis, spotted fever rickettsioses, and babesiosis. Infection with emerging pathogens such as Borrelia miyamotoi, Powassan virus, Heartland virus, Colorado tick fever virus, and Bourbon virus are also covered. SUMMARY: Our understanding of tick-borne diseases in the United States continues to improve with the detection of novel pathogens and development of new diagnostic modalities. While conventional diagnostic methods, including serology and microscopy, will play an ongoing role in the diagnosis of tick-borne diseases, implementation of advanced molecular diagnostics will further broaden our understanding of these diseases by facilitating detection of emerging pathogens and providing more accurate and timely diagnosis.

Asymptomatic-anaplasmosis confirmation using genetic and serological tests and possible coinfection with spotted fever group Rickettsia: a case report.

BACKGROUND: Anaplasmosis is an emerging acute febrile disease that is caused by a bite of an Anaplasma phagocytophilum-infected hard tick. As for healthy patients, reports on asymptomatic anaplasmosis resulting from such tick bites are rare. CASE PRESENTATION: A 55-year-old female patient visited the hospital with a tick bite in the right infraclavicular region. The tick was suspected to have been on the patient for more than 10 days. PCR and an indirect immunofluorescence assay (IFA) were performed to identify tick-borne infectious diseases. The blood sample collected at admission yielded a positive result in nested PCR targeting Ehrlichia- or Anaplasma-specific genes groEL and ankA. Subsequent sequencing confirmed the presence of A. phagocytophilum, and seroconversion was confirmed by the IFA involving an A. phagocytophilum antigen slide. PCR detected no Rickettsia-specific genes [outer membrane protein A (ompA) or surface cell antigen 1 (sca1)], but seroconversion of spotted fever group (SFG) rickettsiosis was confirmed by an IFA. CONCLUSIONS: This study genetically and serologically confirmed an asymptomatic A. phagocytophilum infection. Although SFG rickettsiosis was not detected genetically, it was detected serologically. These findings indicate the possibility of an asymptomatic coinfection: anaplasmosis plus SFG rickettsiosis. It is, therefore, crucial for clinicians to be aware of potential asymptomatic anaplasmosis following a tick bite.

First identification of Anaplasma phagocytophilum in both a biting tick Ixodes nipponensis and a patient in Korea: a case report.

BACKGROUND: Human granulocytic anaplasmosis (HGA) is a tick-borne infectious disease caused by Anaplasma phagocytophilum. To date, there have been no reported cases of A. phagocytophilum infection found in both the biting tick and the patient following a tick bite. CASE PRESENTATION: An 81-year-old woman presented with fever following a tick bite, with the tick still intact on her body. The patient was diagnosed with HGA. The tick was identified as Ixodes nipponensis by morphological and molecular biological detection methods targeting the 16S rRNA gene. The patient's blood was cultured after inoculation into the human promyelocytic leukemia cell line HL-60. A. phagocytophilum growth was confirmed via culture and isolation. A. phagocytophilum was identified in both the tick and the patient's blood by Anaplasma-specific groEL- and ankA-based nested polymerase chain reaction followed by sequencing. Moreover, a four-fold elevation in antibodies was observed in the patient's blood. CONCLUSION: We report a case of a patient diagnosed with HGA following admission for fever due to a tick bite. A. phagocytophilum was identified in both the tick and the patient, and A. phagocytophilum was successfully cultured. The present study suggests the need to investigate the possible incrimination of I. nipponensis as a vector for HGA in Korea.