Current management of human granulocytic anaplasmosis, human monocytic ehrlichiosis andEhrlichia ewingiiehrlichiosis

Abstract

Anaplasma phagocytophilum, Ehrlichia chaffeensis and Ehrlichia ewingii are emerging tick-borne pathogens and are the causative agents of human granulocytic anaplasmosis, human monocytic ehrlichiosis and E. ewingii ehrlichiosis, respectively. Collectively, these are referred to as human ehrlichioses. These obligate intracellular bacterial pathogens of the family Anaplasmataceae are transmitted by Ixodes spp. or Amblyomma americanum ticks and infect peripherally circulating leukocytes to cause infections that range in clinical spectra from asymptomatic seroconversion to mild, severe or, in rare instances, fatal disease. This review describes: the ecology of each pathogen; the epidemiology, clinical signs and symptoms of the human diseases that each causes; the choice methods for diagnosing and treating human ehrlichioses; recommendations for patient management; and is concluded with suggestions for potential future research.

Anaplasma phagocytophilum Infection in Domestic Animals in Ten Provinces/Cities of China

“…2 The disease is often misdiagnosed in clinics, resulting in multi-organ involvement and even the death of patients. 3 Several seroepidemiologic surveys of HGA showed this disease was widely distributed in China. [4][5][6] Although domestic animals have been implicated as important hosts for transmission of HGA, little epidemiologic investigation of domestic animal infections in rural areas of China has been conducted.…”

Longitudinal field study on bovine Babesia spp. and Anaplasma phagocytophilum infections during a grazing season in Belgium

“…Anaplasma phagocytophilum is a polymorphic gramnegative bacterium that strictly parasitizes mammals; wild and domestic animals are the main reservoirs (Halos et al 2010), but infection is potentially zoonotic causing human granulocytic anaplasmosis (HGA). The symptoms of this disease vary from asymptomatic infection to severe disease by way of nonspecific flu-like clinical signs (Bakken and Dumler 2008;Thomas et al 2009). A. phagocytophilum causes hematologic changes characterized by bacteremia, leukopenia, and thrombocytopenia.…”

Comparison of a Real-Time PCR Method with Serology and Blood Smear Analysis for Diagnosis of Human Anaplasmosis: Importance of Infection Time Course for Optimal Test Utilization

“…Although some differences in clinical presentation have been reported for these diseases, they are largely indistinguishable. Symptoms may be mild to severe and frequently include fever, chills, headache, myalgia, nausea, and cough, as well as laboratory-detected features of leukopenia, thrombocytopenia, and elevated hepatic transaminase levels (2,3). Differences in the disease presentations include rashes frequently reported in ehrlichiosis, but rarely for anaplasmosis, patients (1,4).…”

“…Although most anaplasmosis and ehrlichiosis infections resolve, mortality occurs in 1 to 2% of cases (1). In addition, although anaplasmosis and ehrlichiosis are both effectively treated with doxycycline and tetracycline antibiotics, not all antibiotics are successful at treating both infections (3,5).…”

“…At present, serologic diagnostic methods are most frequently used, but these tests have been shown to have poor sensitivity during the acute phases of infection (Ͻ1 week since symptom onset), when tests are most likely to be performed (6). A single positive titer result also is unable to distinguish between current infection and evidence of previous exposure to these pathogens, as IgG antibodies may persist in patients for several years postinfection (3,7,8). Thus, evidence of seroconversion or a 4-fold increase in titers between acute and convalescent serologic testing is recommended for confirming the diagnosis (according to the CDC case definitions for anaplasmosis [see http: //www.cdc.gov/anaplasmosis/] and ehrlichiosis [see http://www .cdc.gov/ehrlichiosis/]); however, physicians rarely test a patient twice (1).…”