Impact of socioeconomic risk factors on the seroprevalence of cytomegalovirus infections in a cohort of pregnant Polish women between 2010 and 2011

W. Wujcicka 0 2 Z. Gaj 0 2 J. Wilczyski 0 2 W. Sobala 0 2 E. piewak 0 2 D. Nowakowska 0 2 0 W. Sobala Department of Environmental Epidemiology, Institute of Occupational Medicine , Lodz, Poland 1 ) Department of Fetal-Maternal Medicine and Gynecology, Polish Mother's Memorial Hospital Research Institute , 281/289 Rzgowska Street, Lodz 93-338, Poland 2 E. piewak Department of Microbiology, Polish Mother's Memorial Hospital Research Institute , Lodz, Poland The purpose of this investigation was to perform an evaluation of the prevalence and socioeconomic risk factors for human cytomegalovirus (HCMV) infections in a cohort of Polish pregnant women between 2010 and 2011. HCMVspecific IgG and IgM antibody levels were assayed with enzyme-linked immunosorbent assay (ELISA) tests in serum samples collected from 1,250 pregnant women attending outpatient obstetric clinics and hospitalized at two hospitals in Lodz. The seroprevalence of anti-HCMV IgG and IgM antibodies was 62.4 and 2.2 %, respectively, and differed significantly between age-stratified groups (p0.05). The highest IgG prevalence was observed in women above 36 years of age (76.2 %) and IgM in adolescent women aged 16-20 years (6.0 %). Of the various socioeconomic factors, age above 36 years, basic and professional education, and offspring were significantly associated with HCMV IgG prevalence rates (PRs; 1.89, 1.80, and 1.56, respectively). Financial status, occupational risk related to contact with children, and transfusions were not related to the prevalence of IgG antibodies. - Human cytomegalovirus (HCMV) is the most common factor of intrauterine viral infections, transmitted in urine, blood, saliva, by breastfeeding, genitourinary tract secretions, feces, tears, and transplanted organs [17]. HCMV infections may be acquired prenatally, perinatally, or postnatally, and can cause permanent physical sequelae, with an increased risk of infant mortality. Congenital infections occur via vertical transmission of the virus by a hematogenous route from infected pregnant woman to the fetus via the placenta [6]. The incidence rates of viral transmissions from mothers with primary infections during pregnancy to their fetuses are estimated to be in the range 3040 %, while in those with recurrent infections, the range is 0.22.2 % [812]. The diagnosis of cytomegaly is based mostly on serological tests during pregnancy. The primary infection is defined as HCMV IgG seroconversion during pregnancy but, in most cases, the distinction between primary and non-primary maternal cytomegaly is very difficult, due to the lack of data on the preconception serologic status. The presence of specific HCMV IgM antibodies and the low IgG avidity do not always indicate recent primary infection [8, 13]. In most cases, systematic ultrasound is not sensitive enough to detect signs of fetal cytomegaly beside its most characteristic symptoms, such as microcephaly, ventriculomegaly, increased periventricular echogenicity, and calcifications [8, 14]. Congenital HCMV infections during the first trimester of pregnancy are more likely to cause a severe form of the disease, but symptomatic cases were also reported, when transmission occurred in the third trimester of pregnancy [15]. Approximately 10 to 15 % of in utero infected newborns demonstrate clinical symptoms observed in various organs and systems and 8590 % of these children will develop some degree of psychomotor and mental retardation, including visual impairment and sensorineural hearing loss [8, 16]. Children born with asymptomatic HCMV infections (85 90 %) may also acquire cytomegaly-related symptoms, such as hearing impairment and difficulties in learning during the first months or, more often, in the first few years of life [6, 8, 11]. The prevalence of HCMV IgG antibodies varies between continents and countries, ranging from 40 to 100 % [7, 17, 18]. The prevalence rate of 76.7 % was observed in Polish pregnant women between the years 1999 and 2009, being one of the highest in Europe, alongside such countries as Sweden or Italy (72 and 68 %, respectively) [3, 17, 19]. So far, studies in different countries have revealed elevated prevalence rates of congenital HCMV, related to non-white race, increased sexual activity with multiple partners, age below 25 years, an increased age of pregnant women, multiparity, preschool children in the household, and occupational exposure to children, as well as lower socioeconomic status (SES) [7, 2022]. The reported SES risk factors for increased HCMV prevalence included a lower level of education and lower incomes of pregnant women [2326]. In the reported study, we investigated the prevalence of specific anti-HCMV IgG and IgM antibodies and the socioeconomic risk factors of HCMV infections in a group of pregnant women from Poland attending outpatient obstetric clinics and hospitalized between 2010 and 2011 at the Polish Mothers Memorial Hospital Research Institute (PMMHRI) and at the Ludwig Rydygier Hospital in Lodz. Materials and methods The study included 1,250 randomly selected, newly registered pregnant women who attended the outpatient obstetric clinics and were treated at the PMMHRI and the Ludwig Rydygier Hospital between April, 2010 and March, 2011. The cohort, hospitalized at the PMMHRI, consisted of pregnant women from the Lodz Province and from other Polish regions, as the PMMHRI houses a reference perinatal care center. Blood samples were obtained from pregnant women twice during pregnancy (at the 12th15th and the 30th34th gestational weeks) and within a day from childbirth. Blood specimens of 2.6 ml were collected from participants, who signed an informed consent form. The blood was collected into sterile, nonanticoagulated tubes. The collected samples were centrifuged at 3,000 g for 10 min and serum fractions were stored at 20 C. Serum anti-HCMV IgG and IgM antibody levels were assayed by enzyme-linked immunosorbent assay (ELISA) tests (LIAISON, DiaSorin, Italy), and seropositivity was determined, using the manufacturers guidelines. The screening was performed using a LIAISON immunoassay analyzer. All samples were considered as IgG- or IgM-positive when the antibody levels were >0.4 IU/ml and >30 AU/ml, respectively. For IgG avidity assessment, the indexes <0.300 were interpreted as low avidity suggesting recent infection, whereas the indexes 0.300 were interpreted as high avidity. Pregnant women were considered as probably recently infected in cases where specific IgG were elevated, IgM were present, and IgG avidity was low. The kinetics of the specific antibodies was of great importance. In those women, the presence of HCMV DNA was checked using a real-time Q PCR assay for the viral UL55 gene in blood, urine, and amniotic fluid specimens [4]. DNA isolation and real-time Q PCR were carried out at the Laboratory of Molecular Virology and Biological Chemistry, Institute of Medical Biology, Polish Academy of Sciences in Lodz. All pa (...truncated)