the prevalence of antibodies in adults varies in different geographic regions , from 40%-100% , with lower rates in europe , parts of north america and australia , and higher rates in africa and asia .
cmv has been detected in many body fluids , including saliva , urine , blood , cervicovaginal secretions , semen and breast milk . in children ,
however , the incidence and spectrum of disease in immunocompromised people establish this virus as an important human pathogen . moreover , there are number of reports of severe clinical manifestations of cmv infections in immunocompetent patients .
it has been well documented that hemodialysis patients have impaired immune response , which may result in higher prevalence rates of viral infections , including cmv .
infections in these patients may be due to primary infection or , more commonly , by reactivation of latent virus or re - infection with exogenous virus , which may be introduced by blood transfusion or kidney transplant .
the aim of this study was to analyze the prevalence and dynamics of cmv infection among patients in end - stage renal disease undergoing chronic hemodialysis .
during a 3-year period ( 20102012 ) , serum samples from 162 consecutive patients undergoing chronic hemodialysis were tested for the presence of cmv - specific igm and igg antibodies .
the control group consisted of 160 patients presenting for routine check - up with no symptoms of acute febrile disease ( antenatal screening , couples undergoing medically assisted reproduction , elective preoperative check - up ) .
the mean patient age was 53.7  12.4 ( range 21 - 78 ) years , whereas the mean age of control subjects was 52.5  12.4 ( range 26 - 79 ) years [ figure 1 ] .
a subset of 34 hemodialysis patients , enrolled in the transplant program , was evaluated during a period of 2 years on the request of the referring physician .
age distribution of study participants anti - cmv igm and igg antibodies were detected using a commercial enzyme - linked immunosorbent assay ( elisa ) ( eti - cytok m / eti - cytok g ; diasorin , saluggia , italy ) and expressed in arbitrary units ( au / ml ) .
samples with absorbance values greater than or equal to the cut - off value + 10% are considered positive .
all igm / igg - positive samples were further tested for igg avidity to confirm or to rule out acute cmv infection .
the determination of igg avidity was carried out with urea as the denaturing agent using a commercial assay ( avidity : anti - cmv elisa igg , euroimmun , lbeck , germany ) . the igg avidity index ( ai )
was calculated and expressed as percentage using the od values with and without urea treatment and interpreted as follows : ai < 40% = low avidity antibodies indicating recent primary cmv infection ; ai 4060% = borderline avidity ; ai > 60% = high avidity antibodies indicating past cmv infection .
groups of categorical variables were compared by fischer 's exact test . since distributions of numerical variables were not significantly different from normal distribution ( kolmogorov  smirnov test ) , t - test for two groups ' comparison was used .
the strength of association between dependent ( igg positivity ) and independent variables was assessed by univariate and multiple logistic regression .
the analysis was performed using software package stata / ic 11.2 for windows ( statacorp lp , usa ) .
groups of categorical variables were compared by fischer 's exact test . since distributions of numerical variables were not significantly different from normal distribution ( kolmogorov  smirnov test ) , t - test for two groups ' comparison was used .
the strength of association between dependent ( igg positivity ) and independent variables was assessed by univariate and multiple logistic regression .
the analysis was performed using software package stata / ic 11.2 for windows ( statacorp lp , usa ) .
cytomegalovirus igg antibodies were detected in 147/90.7% ( 95% ci = 84.494.2 ) hemodialysis patients and 131/81.9% ( 95% ci = 75.087.5 ) control subjects [ table 1 ] .
logistic regression showed that the overall cmv igg positivity in hemodialysis patients was significantly higher than in controls : crude or was 2.02 ( 95% ci = 1.24.35 ) , while or adjusted for age and gender amounted 2.18 ( 95% ci = 1.04.25 ) [ table 2 ] . according to age , a progressive increase in igg seroprevalence was observed in both hemodialysis patients ( 73.3%96.8% ) and control group ( 42.9%89.3% ) . comparing seropositivity between the same age groups , patients on hemodialysis younger than 34 years had almost two times higher prevalence than control subjects ( 73.3% vs. 42.9% ) [ table 1 ] .
older age group was a significant risk factor for cmv seropositivity [ table 2 ] .
cmv seroprevalence did not differ significantly between males and females ( or = 1.22 , 95% ci = 0.652.29 ) .
prevalence of cmv igg antibodies in hemodialysis patients ( n=162 ) and control group ( n=160 ) logistic regression analysis for the risk of cmv igg seropositivity levels of cmv igg titers in patients and controls are presented in figure 2 .
a nonsignificant higher proportion of hemodialysis patients ( 22.8% ) showed a very high igg titer exceeding the upper cut - off ( > 10 au / ml ) compared to 16.4% of controls .
the proportions of participants with lower cmv titers were similar in both groups ( p = 0.219 ) .
cytomegalovirus igg antibody titers in hemodialysis patients and controls cytomegalovirus igm antibodies were detected in three ( 1.9% ) hemodialysis patients and four ( 2.5% ) controls .
all three igm - positive hemodialysis patients showed evidence of recurrent cmv infection ( igg avidity 81% , 83% and 95% , respectively ) .
one initially seronegative hemodialysis patient ( 0.6% ) seroconverted during the second year of the follow - up period .
one of them demonstrated low igg avidity ( 29% ) and two demonstrated borderline igg avidity ( 42% and 58% , respectively ) .
cytomegalovirus is one of the most frequently encountered opportunistic viral pathogens in immunocompromised individuals , including hemodialysis patients .
there are several published articles on seroprevalence of cmv among hemodialysis patients in europe in 1990s .
the prevalence of cmv antibodies in this population is reported to be 67% in italy,80% in the czech republic , 83% in germany and 99.3% in serbia .
a study conducted in the netherlands in 2007 showed a seroprevalence rate of 68.7% among dutch patients . in croatia
, there are very few data on the prevalence of cmv infection . the only published study conducted from 2005 to 2009 among childbearing - aged women showed a seropositivity rate of 75.3% . in the croatian general population ,
overall cmv seroprevalence is reported to be 63% ( 78% in adults ; unpublished data of the laboratory for virologic serologic diagnostics , croatian national institute of public health ) .
results of this study showed a significantly higher cmv seropositivity among hemodialysis patients ( 90.7% ) compared to the healthy control group ( 81.9% ) .
studies conducted in germany and in turkey showed similar results , while in a dutch study , the percentage of cmv - seropositive hemodialysis patients was in the range of the reported prevalence in the general population .
a higher cmv prevalence in hemodialysis patients could be explained by the acquisition of cmv through repeated blood transfusions or exposure to cmv during hemodialysis procedures . in hyperendemic areas such as saudi arabia and sudan where high percentages of cmv in the population ( up to 100% ) were reported , the differences among hemodialysis patients and the general population were not observed . in this study ,
no significant difference in cmv igg antibody titers between hemodialysis patients and controls was documented .
in contrast , a study conducted in thailand showed higher mean antibody titer in patients on hemodialysis compared to healthy controls .
our results showed that age was a significant risk factor for cmv seropositivity . a progressive increase in seroprevalence with age
age - related increase in the seroprevalence of cmv antibodies has also been shown in some other studies .
females generally had higher cmv seroprevalences than males , although in most studies the differences were small .
this study showed similar results ( seroprevalence in women and men was 96.3% and 87.0% , respectively ) . among immunosuppressed individuals ,
reactivation of latent cmv infection seems to be more frequent than that experienced by the general population .
reactivation of cmv in hemodialysis patients may be caused by the uremia - associated immunodeficiency in these patients . in this study ,
the prevalence of active cmv infection ( detection of igm antibodies ) was similar among hemodialysis patients and control group ( 1.9% vs. 2.5% ) .
recurrent cmv infection was documented in all hemodialysis igm - positive patients ( two of them reported recurrent infection during the second year ) , compared to one control subject .
infection was not confirmed by nucleic acid testing since pcr is not routinely performed in asymptomatic patients . in three participants from the control group ,
in addition , primary infection was confirmed by seroconversion in one initially seronegative hemodialysis patient during the second year of follow - up period .
the results of this study indicate that being on hemodialysis and older age are significant risk factors affecting cmv seropositivity .
since primary cmv infection remains a concern due to its potential for severe disease in immunocompromised individuals , identification of seronegative individuals is important in preventing this disease .
 cytomegalovirus ( cmv ) is an important pathogen in immunocompromised individuals . 
 the aim of this study was to analyze prevalence and dynamics of cmv infection among patients undergoing chronic hemodialysis . from 2010 to 2012 , a total of 162 patients and 160 control subjects were tested for the presence of cmv igm and igg antibodies using enzyme - linked immunosorbent assay . 
 igm / igg reactive samples were further evaluated for igg avidity to confirm or rule out recent primary cmv infection . 
 the overall igg seropositivity was higher in hemodialysis patients compared to controls ( 90.7% vs. 81.9% ; crude odds ratio [ or ] = 2.02 , 95% confidence interval [ ci ] = 1.053.89 ; or adjusted for age and gender = 2.18 , 95% ci = 1.054.55 ) . 
 cmv igg antibody titers were similar in both groups . 
 there was no difference in cmv prevalence between males ( 87.9% ) and females ( 96.3% ) . according to age , a progressive increase in seropositivity 
 was observed in both hemodialysis patients and the control group . 
 three hemodialysis patients ( 1.9% ) developed recurrent cmv infection ( positive igm with high avidity igg antibodies ) . 
 in one patient ( 2.9% ) , seroconversion was documented during the second year of the follow - up period indicating primary infection . 
 in contrast , in the control group , recent primary cmv infection ( positive igm with low / borderline igg avidity ) was demonstrated in three subjects ( 1.9% ) , whereas one ( 0.6% ) developed recurrent infection . on multivariate logistic regression , hemodialysis and older age were significant predictors for cmv seropositivity . 
Introduction
Materials and Methods
Statistical analysis
Results
Discussion
Conclusion