Differences and Similarities between Culture-Confirmed Human Granulocytic Anaplasmosis and Early Lyme Disease

Abstract

Lyme disease is transmitted by the bite of certain Ixodes ticks, which can also transmit Anaplasma phagocytophilum, the cause of human granulocytic anaplasmosis (HGA). Although culture can be used to identify patients infected with A. phagocytophilum and is the microbiologic gold standard, few studies have evaluated culture-confirmed patients with HGA. We conducted a prospective study in which blood culture was used to detect HGA infection in patients with a compatible clinical illness. Early Lyme disease was defined by the presence of erythema migrans. The epidemiologic, clinical, and laboratory features of 44 patients with culture-confirmed HGA were compared with those of a convenience sample of 62 patients with early Lyme disease. Coinfected patients were excluded. Patients with HGA had more symptoms (P ‫؍‬ 0.003) and had a higher body temperature on presentation (P < 0.001) than patients with early Lyme disease. HGA patients were also more likely to have a headache, dizziness, myalgias, abdominal pain, anorexia, leukopenia, lymphopenia, thrombocytopenia, or elevated liver enzymes. A direct correlation between the number of symptoms and the duration of illness at time of presentation (rho ‫؍‬ 0.389, P ‫؍‬ 0.009) was observed for HGA patients but not for patients with Lyme disease. In conclusion, although there are overlapping features, culture-confirmed HGA is a more severe illness than early Lyme disease. Human granulocytic anaplasmosis (HGA) and Lyme disease typically occur in the same geographic areas since both are acquired by the bite of infected Ixodes ticks (1-5). The etiologic agents, however, are quite different. HGA is caused by Anaplasma phagocytophilum, an obligate intracellular bacterium, whereas Lyme disease is caused by an extracellular spirochetal bacterium, Borrelia burgdorferi (1, 2).The hallmark of early Lyme disease is a distinctive annular erythematous skin lesion, called erythema migrans, that occurs at the site of tick inoculation of B. burgdorferi. Erythema migrans usually can be diagnosed clinically without the need for laboratory confirmation (1). In contrast, HGA is not known to be associated with a distinctive clinical feature, and therefore, laboratory testing is required to establish the diagnosis (2-5).Although A. phagocytophilum can be cultured in vitro, few laboratories offer such testing. Consequently, most of the reported cases have been diagnosed serologically or through PCR detection of A. phagocytophilum DNA. These laboratory methods, while generally reliable, are not necessarily equivalent to the diagnostic gold standard in microbiology of a positive culture. No systematic comparison of culture-confirmed HGA with Lyme disease has been reported. In this study, we compare the epidemiologic, clinical, and laboratory features of culture-confirmed HGA with those of early Lyme disease. MATERIALS AND METHODSStudy design. This was a prospective, observational study that recorded the baseline epidemiologic, clinical, and laboratory features of patients with culture-confirmed HGA ...

Prevalence of Lyme Disease Among Forestry Workers

“…Dotychczasowe wyniki badań Wormsera i wsp. porównujących 2 grupy pacjentów z ustalonym zakaże-niem HGA i wczesną postacią boreliozy wskazały na statystycznie istotny wzrost takich objawów, jak podwyższona temperatura ciała, bóle mięśni, bóle głowy i brak łaknienia w grupie z ustaloną ludzką anaplazmozą granulocytarną, szczególnie na wczesnym etapie choroby (26).…”

Fatigue in patients with erythema migrans

“…Fatigue is a common complaint in many other infectious diseases, including other deer tick transmitted infections [12,19-21]. In certain other infections, emerging data suggest that a SNP in the IFN-gamma gene is significantly associated with experiencing severe fatigue per se [15], a topic that should be considered for potential investigation in Lyme disease patients as well.…”

“…Serologic testing was performed using the C6 Lyme ELISA kit (Immunetics, Inc., Boston, Massachusetts) according to the manufacturer's recommendations. In addition, patients were evaluated for co-infections with Anaplasma phagocytophilum and Babesia microti by serology (based on a 4-fold rise in titer between acute and convalescent serum samples on testing performed by Focus Diagnostics, Inc., Cypress, California) and in selected cases with highly suggestive clinical features, such as new onset fever while on antibiotic treatment for erythema migrans, by a blood smear or polymerase chain reaction, as described elsewhere [11,12]. …”

“Orange” You Glad You Checked the Buffy Coat?

“…Leukopenia, thrombocytopenia, and elevated alanine aminotransferase levels, are documented to be significantly more associated with patients suffering from HGA (11), while the rash of erythema migrans is very specific for patients infected with the Lyme disease spirochete and not suffering from HGA (11,12). Co-infection and even triple infections with tick-borne agents are also possible (13).…”

“…Clinical improvement generally occurs within 24 to 72 hours after initiation of therapy. For cases when doxycycline cannot be used (i.e., pregnant women), rifampin has been used successfully (12,14). Doxycycline is also the recommended treatment for Lyme disease; therefore, an antimicrobial treatment course of 10 to 14 days should be sufficient for patients suspected of having both HGA and Lyme disease (12,14).…”