Prevalence of Anaplasma phagocytophilum in humans in Belgium for the period 2013-2016.

Ticks are vectors for a broad range of pathogens of medical and veterinary importance, such as Borrelia spp., Babesia spp., Anaplasma spp., Rickettsia spp., Bartonella spp. and the tick-borne encephalitis virus. The Gram-negative bacterium Anaplasma phagocytophilum is present worldwide, including Belgium where numerous patients were shown to harbour antibodies against this pathogen as recorded by the Belgian National Reference Center (NRC) for Anaplasma. The clinical presentation of human granulocytic anaplasmosis is an acute, febrile, nonspecific, flu-like illness. Leukopenia, thrombocytopenia and increased hepatic transaminase activities are commonly present early in the disease. Diagnosis early in the course of infection relies on the detection of antibodies or of the bacterium in the blood, as is performed at the NRC for Anaplasma, part of the Clinical Laboratory of the Queen Astrid Military Hospital in Brussels, Belgium. In this article, we discuss diagnostic test results as well as recent clinical and demographic characteristics of patients whose samples were analyzed by the NRC for Anaplasma in a four-year period (2013-2016).

Accuracy of Diagnosis of Human Granulocytic Anaplasmosis in China.

In 2008, human granulocytic anaplasmosis (HGA) was reported from China. However, the clinical and laboratory findings, including reports of nosocomial transmission, were inconsistent with those reported for HGA in the United States. In 2012, it was demonstrated that the patients described in the 2008 report had all been infected with a newly discovered bunyavirus, severe fever with thrombocytopenia syndrome virus, which causes an illness with the same clinical features described for the patients in the 2008 report. This finding raises the question of HGA misdiagnosis in China and establishes the need for further studies to determine whether HGA occurs there.

Epidemiology of ehrlichiosis and anaplasmosis among American Indians in the United States, 2000-2007.

Ehrlichiosis and anaplasmosis infections among American Indians (AIs) have never been specifically examined, despite high rates of other tick-borne rickettsial diseases among AIs. The epidemiology of ehrlichiosis and anaplasmosis among AIs was analyzed using the National Electronic Telecommunications System for Surveillance (NETSS), Case Report Forms (CRFs), and Indian Health Service (IHS) inpatient and outpatient visits. The 2000-2007 average annual ehrlichiosis and anaplasmosis incidence among AIs reported to NETSS was almost 4-fold lower (4.0/1,000,000) than that using IHS data (14.9). American Indian cases reported from CRFs had a higher proportion of hospitalization (44%) compared with IHS (10%). American Indian incidence of ehrlichiosis and anaplasmosis was higher and showed a different age and geographical distribution than other races. These results highlight the need to improve collaboration between the ehrlichiosis and anaplasmosis surveillance systems for AIs so as to develop interventions that target the unique epidemiology and mitigate the burden of disease among this high-risk population.

Correlations among Anaplasma marginale parasitemia and markers of oxidative stress in crossbred calves.

The present study was designed to determine the correlations among Anaplasma marginale parasitemia and markers of oxidative stress in crossbred calves. Blood was collected from 11 crossbred calves infected with A. marginale along with 11 healthy crossbred calves as controls for determination of hematology and oxidative stress indicators. Percentage of parasitemia in infected calves varied from 0.8% to 6.0%. The values of hematological indicators and antioxidant enzymes were decreased, whereas erythrocytic lipid peroxidation (LPO) and plasma nitrate (NO) level were significantly (p < 0.05) augmented in A. marginale-infected animals over healthy group. Parasitemia was positively correlated (p < 0.01) with erythrocytic LPO and plasma NO and negatively correlated (p < 0.01) with hematological indicators and antioxidant enzymes. In addition, erythrocytic LPO was negatively correlated (p < 0.01) with the hemoglobin, erythrocyte count, and packed cell volume. From the present study, it can be concluded that anaplasmosis in crossbred calves is associated with a parasitic load-dependent oxidative damage as indicated by poor antioxidant status and enhanced oxidative stress, which are contributed to severe anemia.

[Laboratory tests in the diagnosis of feral herd infections].

Immunological laboratory tests play an important role in establishing the depth of extent of this or that infectious disease. Scheduled immunological monitoring (serological screening) is made to find out whether there are antibodies (Abs) against the causative agents of individual feral herd infections. The immunological examination is aimed at detecting Abs against the pathogens of infectious diseases of bacterial (Ixodes tick-borne borrelioses, tularemia, leptospiroses, human granulocytic anaplasmosis), viral (hemorrhagic fever with renal syndrome, tick-borne viral encephalitis, West Nile fever), and rickettsial (Q-fever) etiologies. The performed serological screening could yield data on the practically widespread of hemorrhagic fever with renal syndrome in the Ulyanovsk Region and show high rates of Abs to Ixodes tick-borne borrelioses (5.75), coxiellosis (3.7%), and human granulocytic anaplasmosis (4.3%).

Clinical, serological, and molecular evidence of ehrlichiosis and anaplasmosis in dogs in Tunisia.

A seroepidemiological survey was conducted in five bioclimatic areas of Tunisia to determine the prevalence of antibodies to Ehrlichia canis and Anaplasma phagocytophilum antigens, surrogate markers of the agents of canine monocytic ehrlichiosis (CME) and canine granulocytic ehrlichiosis, respectively. Among 286 collected sera, 54.2% and 25.2% were seropositive for E. canis and A. phagocytophilum, respectively, by the indirect immunofluorescence antibody (IFA) test. Clinical and hematological tests were done only for 58 sick dogs from Tunis area. A reverse line blot (RLB) hybridization was then used to identify isolated Ehrlichia and Anaplasma species infecting dogs (n = 228). Among them, only two dogs were infected by A. phagocytophilum; ten sample dogs were demonstrated infected by E. canis and ten infected by Ehrlichia sp., from which one dog showed a mixed infection with A. phagocytophilum and E. canis and one with A. phagocytophilum and Ehrlichia sp. RLB findings were confirmed by sequencing; BLAST search against GenBank revealed high similarity of the sequence of Ehrlichia sp. PCR/RLB amplicons with Anaplasma platys 16S rRNA partial sequence.

Characterization of anaplasma infections in Sicily, Italy.

This study aimed to characterize infection with Anaplasma marginale, A. phagocytophilum, A. ovis, and A. platys in humans, animals, and ticks in Sicily, Italy, during 2003-2006. Serologic (competitive ELISA [cELISA]) and indirect immunofluorescence antibody [IFA]; N= 1990) and DNA (polymerase chain reaction [PCR]; N= 2788) tests were conducted on horse, donkey, cattle, sheep, goat, pig, dog, cat, roe deer, wild boar, human, and tick samples. The results reported herein suggested that in Sicily cattle are a major reservoir for A. marginale, dogs for A. platys, and sheep and goats for A. ovis. Domestic animals, such as cattle, horses, donkeys, sheep, dogs, and cats, may serve as reservoir for A. phagocytophilum, but different strains may infect ruminants and humans. All Anaplasma spp. characterized in Sicily had some distinctive genotypes for this region. Low genetic diversity was observed in A. ovis and A. platys, whereas A. marginale and A. phagocytophilum strains showed high genetic diversity. These results expanded our knowledge about the prevalence of Anaplasma spp. in Sicily and provided information to understand the epidemiology of these infections and implement measures to diagnose, treat, and control transmission to humans and animals in this region.

Possible differential host tropism in Anaplasma phagocytophilum strains in the Western United States.

Despite organization into a single species, Anaplasma phagocytophilum, of bacteria from diverse hosts, there is evidence that different hosts vary in susceptibility to local strains of this bacterial pathogen. In particular, there is evidence that clinical hosts (humans, horses, and dogs) in the western part of the United States may be infected with strains of bacteria that differ from those in the reported wildlife reservoir, the dusky-footed woodrat. There is a lack of spatial overlap between clinical cases with woodrat exposure, genetic studies show highly distinctive strains in woodrats compared with those from clinical hosts, and experimental studies failed to transfer infection from woodrats into horses. These data suggest that multiple distinct A. phagocytophilum strains could circulate in western U.S. ecosystems. Host barriers to different bacterial strains would suggest the need for careful discrimination of A. phagocytophilum strains and further research to understand the host-pathogen interactions that result in differential outcomes in infection.

The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America.

Evidence-based guidelines for the management of patients with Lyme disease, human granulocytic anaplasmosis (formerly known as human granulocytic ehrlichiosis), and babesiosis were prepared by an expert panel of the Infectious Diseases Society of America. These updated guidelines replace the previous treatment guidelines published in 2000 (Clin Infect Dis 2000; 31[Suppl 1]:1-14). The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them. For each of these Ixodes tickborne infections, information is provided about prevention, epidemiology, clinical manifestations, diagnosis, and treatment. Tables list the doses and durations of antimicrobial therapy recommended for treatment and prevention of Lyme disease and provide a partial list of therapies to be avoided. A definition of post-Lyme disease syndrome is proposed.

Anaplasma and Ehrlichia infection.

Human and animal infections by Anaplasmataceae are increasingly recognized as important and potentially fatal arthropod-transmitted diseases. Since the first recognition and implementation of diagnostic methods for human infection by Ehrlichia chaffeensis and Anaplasma phagocytophilum, the incidence of infections has linearly increased. Moreover, diagnostic and epidemiological testing indicates that "ehrlichia" infections are globally distributed and suggests that additional agents of human and veterinary "ehrlichiosis" will be identified. With increasing disease identification has come recognition that the infections can be severe, with approximately one-half of patients requiring hospitalization for complications including respiratory distress, myocarditis, neurological complications, hepatitis, a septic or toxic shock-like disease, opportunistic infections, and death in 0.5 to 3.0%. An understanding of the diseases, pathophysiology, pathogenesis, control, and management will best be developed through fundamental investigations. Advances in comprehension as to the separate contributions of bacteria and host are crucial since most data now suggest that alterations in host neutrophil function and protection from innate and adaptive immunity also contribute to disease manifestations. It is reasonable to operate from the hypothesis that these host cell functional changes ultimately benefit bacterial survival while inadvertently eliciting clinical disease in poorly adapted hosts. A firmer basis for the scientific understanding of Anaplasmataceae biology will allow logical and rational approaches toward infection control, prevention, and treatment.

Human anaplasmosis presenting as atypical pneumonitis in France.

Human anaplasmosis is a febrile illness caused by Anaplasma phagocytophilum, an intracellular bacterium transmitted by Ixodes ticks in the United States and Europe. Although cough is reported in 30% of the American cases, interstitial pneumonitis has been noted only once. Of the 9 confirmed cases reported in Europe, 3 presented with atypical pneumonitis. A. phagocytophilum should be added to the list of agents responsible for interstitial pneumonitis, especially in areas where human anaplasmosis is endemic.

Analysis of sequences and loci of p44 homologs expressed by Anaplasma phagocytophila in acutely infected patients.

Anaplasma phagocytophila is an obligatory intragranulocytic bacterium that causes human granulocytic ehrlichiosis. Immunodominant 44-kDa outer membrane proteins of A. phagocytophila are encoded by a p44 multigene family. In the present study, expression profiles of p44 genes in the blood of acutely infected patients in the year 2000 were characterized. A single p44 gene was predominantly expressed in peripheral blood leukocytes from one patient, while up to 17 different p44 genes were transcribed without a single majority in the other two patients. The cDNA sequences of the central hypervariable region of several p44 genes were identical among the isolates from the three patients and a 1995 A. phagocytophila isolate. A. phagocytophila was isolated by cell culture from all of the three 2000 patients. Genomic Southern blot analysis of the three 2000 and two 1995 A. phagocytophila isolates with probes specific to the most dominant p44 transcript in each patient showed that the p44 loci in the A. phagocytophila genome were conserved. Analysis of the predicted amino acid sequences of 43 different p44 genes including 19 new sequences found in the present study, revealed that five amino acids were absolutely conserved. The hypervariable region was subdivided into five domains, including three extremely hypervariable central domains. These results suggest that variations in the sequences of p44 are not random but are restricted. Furthermore, several p44 genes are not hypermutatable in nature, based on the conservation of gene sequences and loci among isolates obtained 5 years apart.

Reduced weight gain due to subclinical Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) infection.

Tick-borne fever (TBF) is caused by the rickettsia Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) and is a common disease in sheep in areas of Norway infested by Ixodes ricinus ticks. TBF can cause both direct and indirect losses to sheep kept on tick-infested pastures. In the present work we studied a sheep flock of 26 ewes and 50 lambs on pasture from May until September. No cases of TBF had earlier been observed on this pasture. Blood samples from lambs with a reduced weekly weight gain were collected and analysed for A. phagocytophilum infection by blood smear examination. In addition, at the end of the study, sera from all lambs were analysed by an indirect fluorescent antibody assay (IFA) to determine the antibody titre to E. equi. No clinical signs of tick-borne infections were observed, except in one lamb. However, 30 (60%) of the lambs grazing on this pasture became infected with A. phagocytophilum, and the infected lambs had a reduced weight gain (mean) of 3.8 kg compared with the uninfected lambs. The present study indicates that A. phagocytophilum infection may be widespread and contribute to considerable productivity losses even on pastures with no apparent tick infestation.

Anaplasma marginale: effect of challenge of cattle with varying doses of infected erythrocytes.

Three groups, each of 6 Hereford cattle, were infected by the i.v. inoculation of 10(10), 10(8) or 10(6) Anaplasma marginale-infected erythrocytes. The mean time taken to reach a 1% parasitaemia was 7.3, 13.9 and 19.9 days in the 10(10), 10(8)and 10(6) infection dose groups, respectively. The rates of increase in parasitaemias during the exponential phase of parasite multiplication were similar for the 3 groups (doubling time 0.9 days). The exponential increase of the parasitaemia in the 10(10) dose group extended to a higher level or 10(6) dose groups (to approximately 10% compared with 3%). The mean maximum parasitaemia attained in the 10(10), 10(8), and 10(6) infection dose groups was 23.7, 14.7 and 8.7%, respectively> The time taken to reach the treatment criterion (packed cell volume decrease to 15% or lower) from a 1% parasitaemia was similar for the 3 groups. These results showed that the pathological outcome (anaemia) of anaplasmosis were similar over the 10,000-fold infective dose range tested.

[Clinical and hematological changes in calves infected with Anaplasma marginale]. / Cambios clínicos y hematológicos en becerros infectados con Anaplasma marginale.

Clinical and hematological changes of six Anaplasma marginale (isolated Zulia) inoculated calves (experimental group) and four healthy calves (control group) were studied during twenty and eighty days before and after infection, respectively. The behavior of the four calves used as control group was stable and no significant changes in the parameters analyzed was observed. The experimental group developed the three typical phases of illness. During the prepatent phase, which lasted a mean of 21.2 +/- 2.56 days, the animals were asymptomatic and no significant changes in the hematological values occurred, but a remarkable transitory decrease in number of lymphocytes from 6.5 x 10(6) to 3.3 x 10(6) cells/ml. The infection during the acute phase produced a highly severe effect in two animals, a severe effect in three animals and a mild effect in one. The effects observed were the following: 1) a fast decrease in haematocrite, ranging from 6 to 10%; 2) values of parasitaemia varied from 15 to 48%; 3) a greater body temperature than the control animals (40.5 vs. 38.5 degrees C); 4) a elevated heart frequency, from 60 to 110 beats/min; 5) an increase in the concentration of neotrophiles from 10 x 10(6) to 13 x 10(6) cells/ml; 6) The number of monocytes also augmented from 3 x 10(6) to 6 x 10(6) cells/ml; and 7) an important decrease of weight gain. The natural course of infection was interrupted with oxytetracycline when the haematocrite of the animal lowered to values less or equal to 10%. Then, the animals showed a rapid recovery with an undetectable parasitaemia and concomitant return to basal line of the rest of the parameters.

Cambios clinicos y hematologicos en becerros infectados con Anaplasma marginale / Clinical and hematological change in calves infected with Anaplasma marginale

Clinical and hematological changes of six Anaplasma marginale(isolated Zulia) inoculated calves (experimental group) and four healthy calves (control group) were studied during twenty and eighty days before and after infection, respectively. The behavior of the four calves used as control group was stable and no significant changes in the parameters analyzed was observed. The experimental group developed the three typical phases of illness. During the prepatent phase, which lasted a mean of 21.2 + /- 2.56 days, the animals were asymptomatic and no significant changes in the hematological values occurred, but a remarkable transitory decrease in number of lymphocytes from 6.5 x 10(6) to 3.3 x 10(6) cells/ml. The infection during the acute phase produced a highly severe effect in two animals, a severe effect in three animals and a mild effect in one. The effects observed were the following: 1) a fast decrease in haematocrite, ranging from 6 to 10 percent; 2) values of parasitaemia varied from 15 to 48 percent 3) a greater body temperature than the control animals (40.5 vs. 38.5 degrees C); 4) a elevated heart frequency, from 60 to 110 beats/min; 5) an increase in the concentration of neotrophiles from 10 x 10(6) to 13 x 10(6) cells/ml; 6) The number of monocytes also augmented from 3 x 10(6) to 6 x 10(6) cells/ml; and 7) an important decrease of weight gain. The natural course of infection was interrupted with oxytetracycline when the haematocrite of the animal lowered to values less or equal to 10 percent. Then, the animals showed a rapid recovery with an undetectable parasitaemia and concomitant return to basal line of the rest of the parameters

Effect of chemotherapy on semen characteristics of Balami rams infected with Anaplasma ovis.

Six intact Balami rams were experimentally infected with Anaplasma ovis. Another six were infected one month after splenectomy and six others served as controls. Clinical manifestations of the disease, first observed between 5 to 7 days post-infection, were more severe and prolonged in the splenectomised-infected than in the intact-infected group. There was progressive deterioration in semen quality, which was also significantly more severe and prolonged in the splenectomised than in the intact-infected rams. Following treatment with long-acting terramycine, clinical recovery occurred earlier in the intact-infected (1-4 weeks) than in the splenectomised-infected group (5-7 weeks). A similar pattern was observed in post-treatment improvement in the sperimiogram. However, although the infected animals recovered clinically by 1-7 weeks post-treatment, restoration of the reproductive potential did not occur for 20 to 25 weeks. It appears that stress factors may aggravate the deliterious effects of anaplasmosis.