Human Monocytotropic Ehrlichiosis, Missouri

Abstract

To determine the incidence, clinical and laboratory characteristics, and utility of molecular diagnosis of human monocytotropic ehrlichiosis (HME) in the primary care setting, we conducted a prospective study in an outpatient primary care clinic in Cape Girardeau, Missouri. One hundred and two patients with a history of fever for 3 days (>37.7°C), tick bite or exposure, and no other infectious disease diagnosis were enrolled between March 1997 and December 1999. HME was diagnosed in 29 patients by indirect immunofluorescent antibody assay and polymerase chain reaction (PCR). Clinical and laboratory manifestations included fever (100%), headache (72%), myalgia or arthralgia (69%), chills (45%), weakness (38%), nausea (38%), leukopenia (60%), thrombocytopenia (56%), and elevated aspartate aminotransferase level (52%). Hospitalization occurred in 41% of case-patients. PCR sensitivity was 56%; specificity, 100%. HME is a prevalent, potentially severe disease in southeastern Missouri that often requires hospitalization. Because clinical presentation of HME is nonspecific, PCR is useful in the diagnosis of acute HME.

Detection of Medically Important Ehrlichia by Quantitative Multicolor TaqMan Real-Time Polymerase Chain Reaction of the dsb Gene

“…11,15,24 However, in another study, a substantial number of confirmed cases of HME had undetectable ehrlichial DNA by PCR. 25 Because of the limited data available and lack of a standard PCR protocol, current recommendations for the diagnosis of HME suggest that PCR is a valuable adjunct to IFA. 26 Nevertheless, more studies are needed to unequivocally determine the clinical sensitivity of PCR during initial presentation in the primary care setting.…”

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

“…Case-fatality rates are highest among children aged <10 years and adults aged ≥70 years, and an increased risk for death has been documented among persons who are immunosuppressed (5,13). In areas where ehrlichiosis is endemic, the actual disease incidence is likely underrepresented in estimates that are based on passive surveillance (51)(52)(53).…”

“…Although older age (≥60 years) and immunosuppression are risk factors for severe ehrlichiosis (5,10,13), many cases of severe or fatal ehrlichiosis have been described in previously healthy children and young adults (128). Pediatric patients frequently have an asymptomatic or a mild infection (51,128,132); however, children aged <10 years have the highest case-fatality rate among passively reported cases (5,13). Receiving a sulfonamide antimicrobial agent might also predispose to severe ehrlichial illness (150)(151)(152)(153).…”

“…The rash typically involves the extremities and trunk but can affect the palms, soles, or face (134). Cough or respiratory symptoms are reported in approximately 28% of patients and are more common among adults (10,51,129). Central nervous system involvement, such as meningitis or meningoencephalitis, is present in approximately 20% of patients (135).…”

“…chaffeensis ehrlichiosis can cause severe disease or death, although at lower rates than have been observed for RMSF. Approximately 3% of patients with symptoms severe enough to seek medical attention die from the infection (51,128). The severity of ehrlichiosis could be related, in part, to host factors such as age and the immune status of the patient.…”