Original scientific paper
Human granulocytic anaplasmosis in Croatia and new insights about anaplasma and ehrlichia species
Oktavija Đaković Rode
orcid.org/0000-0001-8023-4314
; Klinika za infektivne bolesti "Dr. Fran Mihaljević", Zagreb, Hrvatska
Abstract
Anaplasma phagocytophilum is an emergent tick-born pathogen in Europe transmitted by Ixodes ricinus ticks which may also transmit tick-borne encephalitis virus, Borrelia sensu lato, Babesia and some Rickettsia spp. A. phagocytophilum is an obligate intracellular Gram- negative bacteria that has tropism for granulocytes and causes human granulocytic anaplasmosis (HGA). The diagnosis of HGA relies on clinical suspicion and must be confirmed with seroconversion or 4-fold increase in antibody titre or by DNA determination. Antibodies are often negative in the initial phase of acute illness and paired sera taken 2–4 weeks later are obligatory. PCR on anticoagulated blood could be more efficient tool in this phase but it is of limited availability. Morulae in Giemsa-stained peripheral blood smears may provide early diagnosis but could be observed very rarely in HGA. From 2009 till 2012, we tested 496 sera from 425 patients for IgM and IgG anti-A. phagocytophilum antibodies at the University Hospital for Infectious Diseases in Zagreb. Paired sera were sent for only 68 patients. Positive antibodies against A. phagocytophilum were found in 160 (37.6%) patients. Three patients fulfilled the criteria for acute HGA. The presence of IgG in titres 256 or higher defined as probable HGA was found in 40 patients. Only IgM, and IgM and IgG anti-A. phagocytophilum antibodies were nadetected in 17 and 16 patients, respectively. Anti-A. phagocytophilum IgG in titres 64 or 128 was found in 84 patients. The data show that A. phagocytophilum infections are present in Croatia, although most of the acute infections remain unconfirmed as self-resolved diseases. HGA should be included in the differential diagnosis of patients with flu-like illness in regions with Ixodes ricinus, especially during tick-activity season. Different members of Anaplasmataceae family were found in animals and ticks in Croatia, which is why better awareness of HGAand diagnostics effort are needed.
Keywords
Human granulocytic anaplasmosis (HGA); Croatia; Anaplasma phagocytophilum; diagnostics
Hrčak ID:
149980
URI
Publication date:
31.1.2015.
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