Seroepidemiology of cytomegalovirus infections in Croatia.
BACKGROUND
Cytomegalovirus (CMV) is endemic worldwide, with marked differences in the seroprevalence rates between countries. The aim of this study was to analyze the seroprevalence of CMV infections in Croatia.


METHODS
During a 3-year period (2013-2015) 2438 consecutive serum samples collected from Croatian residents were tested for the presence of CMV IgM and IgG antibodies using enzyme-linked immunoassay. The IgM/IgG positive samples were further tested for IgG avidity.


RESULTS
The overall seroprevalence rates for CMV IgG and IgM antibodies were 74.4 % and 4.3 %, respectively. The IgG seroprevalence showed significant differences between population groups: children/adolescents 54.6 %, general adult population 77.2 %, hemodialysis patients 91.4 % (p < 0.001). Seropositivity of CMV was strongly age-dependent with prevalences ranging from 53.0 % in children less than 10 years old to 93.8 % in persons above 60 years (p < 0.001). There was no difference in the prevalence rate between women with normal pregnancy and women with poor obstetric history. Gender and place of residence were not associated with CMV seropositivity. Using IgG avidity, current/recent primary CMV infection was confirmed by a low/borderline avidity index (AI) in 46.7 % participants, while in 53.3 % a high AI indicated CMV reactivation or reinfection. Primary infections were detected mainly in children and adolescents (83.2 % and 70.5 %, respectively), while reactivation/reinfection was common in persons older than 40 (77.0-100 %). Reactivation/reinfection was most commonly detected in hemodialysis patients (92.3 %). Logistic regression showed that older age and being on hemodialysis were significant predictors of CMV seropositivity.


CONCLUSIONS
Infections with CMV are widespread in the Croatian population. Older age and being on hemodialysis appear to be the main risk factors for CMV infection.
Department of Virology, Croatian National Institute of Public Health, Rockefellerova 12, 10000, Zagreb, Croatia. tatjana.vilibic-cavlek@hzjz.hr.|School of Medicine University of Zagreb, Zagreb, Croatia. tatjana.vilibic-cavlek@hzjz.hr.
Tatjana
T
Vilibic-Cavlek
Department of Epidemiology, Andrija Stampar Teaching Institute of Public Health, Zagreb, Croatia.|School of Medicine University of Rijeka, Rijeka, Croatia.
Branko
B
Kolaric
School of Medicine University of Zagreb, Zagreb, Croatia.|Clinical Hospital Centre, Zagreb, Croatia.
Natasa
N
Beader
Department of Virology, Croatian National Institute of Public Health, Rockefellerova 12, 10000, Zagreb, Croatia.
Izabela
I
Vrtar
Department of Virology, Croatian National Institute of Public Health, Rockefellerova 12, 10000, Zagreb, Croatia.
Irena
I
Tabain
Department of Virology, Croatian National Institute of Public Health, Rockefellerova 12, 10000, Zagreb, Croatia.|School of Medicine University of Zagreb, Zagreb, Croatia.
Gordana
G
Mlinaric-Galinovic
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D017523:Croatia / Q000453:epidemiology; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D017678:Sex Distribution; D055815:Young Adult
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M
Croatia; Cytomegalovirus; Epidemiology; Seroprevalence